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Sample records for submaximal insulin concentration

  1. How swimming affects plasma insulin and glucose concentration in Thoroughbreds: A pilot study.

    Science.gov (United States)

    Bonelli, F; Sgorbini, M; Meucci, V; Sighieri, C; Baragli, P

    2017-08-01

    Low intensity exercise increases insulin-stimulated glucose uptake in skeletal muscle and decreases its plasma concentration. In this study, plasma insulin and glucose concentrations were evaluated 5min before and 5, 15, 25, 35, 45 and 60min after an IV bolus of glucose in 12 Thoroughbreds before and after 1 month of submaximal aquatraining exercise, monitored using heart rate and blood lactate. Plasma glucose concentrations were evaluated using a colorimetric enzymatic method, and plasma insulin concentrations with a solid-phase radioimmunoassay method. Pre-training plasma glucose concentrations at 15, 25 and 35min, area under the glucose curve and peak glucose concentration were significantly higher than post-training values (Pinsulin concentrations were significantly lower than in the post-training period, and plasma insulin was significantly higher at 45 and 60min in the pre-training period than the post-training period. These results indicate that aquatraining could improve insulin-glucose metabolism in horses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Estimating Neural Control from Concentric vs. Eccentric Surface Electromyographic Representations during Fatiguing, Cyclic Submaximal Back Extension Exercises

    Directory of Open Access Journals (Sweden)

    Gerold R. Ebenbichler

    2017-05-01

    Full Text Available Purpose: To investigate the differences in neural control of back muscles activated during the eccentric vs. the concentric portions of a cyclic, submaximal, fatiguing trunk extension exercise via the analysis of amplitude and time-frequency parameters derived from surface electromyographic (SEMG data.Methods: Using back dynamometers, 87 healthy volunteers performed three maximum voluntary isometric trunk extensions (MVC's, an isometric trunk extension at 80% MVC, and 25 cyclic, dynamic trunk extensions at 50% MVC. Dynamic testing was performed with the trunk angular displacement ranging from 0° to 40° and the trunk angular velocity set at 20°/s. SEMG data was recorded bilaterally from the iliocostalis lumborum at L1, the longissimus dorsi at L2, and the multifidus muscles at L5. The initial value and slope of the root mean square (RMS-SEMG and the instantaneous median frequency (IMDF-SEMG estimates derived from the SEMG recorded during each exercise cycle were used to investigate the differences in MU control marking the eccentric vs. the concentric portions of the exercise.Results: During the concentric portions of the exercise, the initial RMS-SEMG values were almost twice those observed during the eccentric portions of the exercise. The RMS-SEMG values generally increased during the concentric portions of the exercise while they mostly remained unchanged during the eccentric portions of the exercise with significant differences between contraction types. Neither the initial IMDF-SEMG values nor the time-course of the IMDF-SEMG values significantly differed between the eccentric and the concentric portions of the exercise.Conclusions: The comparison of the investigated SEMG parameters revealed distinct neural control strategies during the eccentric vs. the concentric portions of the cyclic exercise. We explain these differences by relying upon the principles of orderly recruitment and common drive governing motor unit behavior.

  3. Blood Glucose and Insulin Concentrations after Octreotide Administration in Horses With Insulin Dysregulation.

    Science.gov (United States)

    Frank, N; Hermida, P; Sanchez-Londoño, A; Singh, R; Gradil, C M; Uricchio, C K

    2017-07-01

    Octreotide is a somatostatin analog that suppresses insulin secretion. We hypothesized that octreotide would suppress insulin concentrations in horses and that normal (N) horses and those with insulin dysregulation (ID) would differ significantly in their plasma glucose and insulin responses to administration of octreotide. Twelve horses, N = 5, ID = 7. Prospective study. An oral sugar test was performed to assign horses to N and ID groups. Octreotide (1.0 μg/kg IV) was then administered, and blood was collected at 0, 5, 10, 15, 20, 25, 30, 45, 60, 75, and 90 minute, and 2, 3, 4, 6, 8, 12, and 24 hour for measurement of glucose and insulin concentrations. Area under the curve (AUC) values were calculated. Mean AUC values for glucose and insulin did not differ between normal (n = 5) and ID (n = 7) groups after octreotide injection. Significant time (P insulin concentrations. A group × time interaction (P = .091) was detected for insulin concentrations after administration of octreotide, but the group (P = .33) effect was not significant. Octreotide suppresses insulin secretion, resulting in hyperglycemia, and then concentrations increase above baseline as glycemic control is restored. Our hypothesis that octreotide causes insulin concentrations to decrease in horses was supported, but differences between N and ID groups did not reach statistical significance when blood glucose and insulin responses were compared. The utility of an octreotide response test remains to be determined. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  4. Increased serum leptin and insulin concentrations in canine hypothyroidism.

    Science.gov (United States)

    Mazaki-Tovi, Michal; Feuermann, Yonatan; Segev, Gilad; Klement, Eyal; Yas-Natan, Einat; Farkas, Amnon; Kol, Amir; Shamay, Avi

    2010-01-01

    Serum concentrations of leptin and insulin were compared between gender-matched hypothyroid (n=25) and healthy (n=25) client-owned dogs within comparable age and body condition score (BCS) ranges. Fasted blood samples were collected from each dog and analysed for glucose, cholesterol, triglyceride, leptin and insulin concentrations. Leptin and insulin concentrations were significantly higher in the hypothyroid compared to normal dogs (P=0.006 and P=0.001, respectively) following adjustment for potential confounders. A nearly significant (P=0.051) interaction with BCS was found in the association between hypothyroidism and leptin. Leptin concentrations were significantly higher in hypothyroid dogs compared to normal dogs, in separate analyses for BCS 6 (P=0.036) and 7 (P=0.049). There was no significant difference in glucose concentration between the hypothyroid and normal groups (P=0.84) following adjustment for BCS. This study showed that canine hypothyroidism is associated with increased serum leptin and insulin concentrations, neither of which may be attributed to obesity alone. Copyright 2008 Elsevier Ltd. All rights reserved.

  5. Association of fasting glucagon and proinsulin concentrations with insulin resistance

    DEFF Research Database (Denmark)

    Ferrannini, E; Muscelli, E; Natali, A

    2007-01-01

    AIMS/HYPOTHESIS: Hyperproinsulinaemia and relative hyperglucagonaemia are features of type 2 diabetes. We hypothesised that raised fasting glucagon and proinsulin concentrations may be associated with insulin resistance (IR) in non-diabetic individuals. METHODS: We measured IR [by a euglycaemic......-hyperinsulinaemic (240 pmol min(-1) m(-2)) clamp technique] in 1,296 non-diabetic (on a 75 g OGTT) individuals [716 women and 579 men, mean age 44 years, BMI 26 kg/m(2) (range 18-44 kg/m(2))] recruited at 19 centres in 14 European countries. IR was related to fasting proinsulin or pancreatic glucagon concentrations......, controlling for known determinants of insulin sensitivity (i.e. sex, age, BMI and glucose tolerance) as well as factors potentially affecting glucagon and proinsulin (i.e. fasting plasma glucose and C-peptide concentrations), glucagon and proinsulin were still positively associated, and adiponectin...

  6. The effect of submaximal exercise on fibrinolysis.

    Science.gov (United States)

    Fras, Zlatko; Keber, Dusan; Chandler, Wayne L

    2004-04-01

    We studied the relationship between sustained submaximal exercise, increased tissue plasminogen activator (t-PA) levels and decreased hepatic clearance of t-PA. Six healthy male volunteers exercised for 35 min while receiving constant rate infusions of either saline or two different doses of recombinant t-PA for 90 min (40 min before, 35 min during and 15 min after exercise). Liver blood flow was estimated simultaneously by constant rate indocyanine green infusion. Since t-PA is cleared rapidly by the liver in direct proportion to liver blood flow, it was expected that a significant decrease in liver blood flow during sustained submaximal exercise would be associated with a proportional increase in plasma t-PA. During submaximal exercise with a saline (placebo) infusion, steady-state t-PA antigen increased from a resting baseline of 6.3 +/- 3.1 to 15.1 +/- 5.1 ng/ml; with a 20 microg/min t-PA infusion, t-PA antigen increased from 33 +/- 12 to 84 +/- 25 ng/ml during exercise; and with a 40 microg/min t-PA infusion, t-PA antigen increased from 77 +/- 38 to 166 +/- 42 ng/ml during exercise. During submaximal exercise, liver blood flow fell on average 71, 68 and 70%, respectively, during the three procedures, while calculated t-PA clearance decreased on average 59, 59 and 53%. t-PA concentration versus time curves, displayed in proportional units, were similar. The comparable relative increases in endogenous and exogenous t-PA with simultaneous proportional decreases in liver blood flow suggests that diminished hepatic t-PA clearance is the major cause of increased t-PA concentration and blood fibrinolytic activity enhancement during sustained submaximal exercise.

  7. Umbilical cord plasma and salivary insulin and leptin concentrations in AGA neonates: a preliminary report.

    Science.gov (United States)

    Seal, Nuananong; Siddiqui, Danish S; Seal, John; Bernhard, Kiley A; Williams, Sumpan

    2014-11-01

    Background and objective: Insulin and leptin hormones are important regulators of food intake and energy balance. There is limited information about insulin and leptin hormones in neonates. This preliminary study aimed to investigate the concentrations of insulin and leptin in umbilical cord plasma and neonate's saliva and their relationships. Umbilical cord plasma and salivary samples were obtained from 13 healthy, appropriate for gestational age (AGA) neonates. Insulin and leptin concentrations in umbilical cord plasma and saliva were measured using the MILLIPLEX MAP® Human Metabolic Hormone Magnetic Bead Panel. Insulin concentrations in umbilical cord plasma correlates positively and significantly with leptin concentrations in umbilical cord plasma (r = 0.55, p = 0.04). More research is needed to explore the relationships between insulin and leptin hormones in neonate's saliva.

  8. Body fat related to daily physical activity and insulin concentrations in non-diabetic children

    DEFF Research Database (Denmark)

    Dencker, Magnus; Thorsson, Ola; Karlsson, Magnus K

    2007-01-01

    This study explored the associations between body fat versus daily physical activity and insulin concentrations in non-diabetic young children in a cross-sectional study of 172 children (93 boys and 79 girls) aged 8-11 years. Blood samples were analysed for serum insulin and daily physical activity......%). Body fat distribution was calculated as AFM/TBF. Body fat distribution was independently linked to both insulin concentrations and physical activity. In contrast, TBF, AFM, and BF% were linked to physical activity only and not to insulin concentrations. In conclusion in this population of non-diabetic...

  9. Peripheral blood transcriptomic signatures of fasting glucose and insulin concentrations

    NARCIS (Netherlands)

    B.H. Chen (Brian); M.-F. Hivert (Marie-France); M.J. Peters (Marjolein); L.C. Pilling (Luke); Hogan, J.D. (John D.); Pham, L.M. (Lisa M.); L.W. Harries (Lorna); C.S. Fox (Caroline); S. Bandinelli (Stefania); A. Dehghan (Abbas); D.G. Hernandez (Dena); A. Hofman (Albert); J. Hong (Jaeyoung); R. Joehanes (Roby); A.D. Johnson (Andrew); P.J. Munson (Peter); D. Rybin (Denis); A. Singleton (Andrew); A.G. Uitterlinden (André); S.-X. Ying (Sai-Xia); D. Melzer (David); D. Levy (Daniel); J.B.J. van Meurs (Joyce); L. Ferrucci (Luigi); J.C. Florez (Jose); J. Dupuis (Josée); J.B. Meigs (James); Kolaczyk, E.D. (Eric D.)

    2016-01-01

    textabstractGenome-wide association studies (GWAS) have successfully identified genetic loci associated with glycemic traits. However, characterizing the functional significance of these loci has proven challenging. We sought to gain insights into the regulation of fasting insulin and fasting

  10. Peripheral Blood Transcriptomic Signatures of Fasting Glucose and Insulin Concentrations.

    Science.gov (United States)

    Chen, Brian H; Hivert, Marie-France; Peters, Marjolein J; Pilling, Luke C; Hogan, John D; Pham, Lisa M; Harries, Lorna W; Fox, Caroline S; Bandinelli, Stefania; Dehghan, Abbas; Hernandez, Dena G; Hofman, Albert; Hong, Jaeyoung; Joehanes, Roby; Johnson, Andrew D; Munson, Peter J; Rybin, Denis V; Singleton, Andrew B; Uitterlinden, André G; Ying, Saixia; Melzer, David; Levy, Daniel; van Meurs, Joyce B J; Ferrucci, Luigi; Florez, Jose C; Dupuis, Josée; Meigs, James B; Kolaczyk, Eric D

    2016-12-01

    Genome-wide association studies (GWAS) have successfully identified genetic loci associated with glycemic traits. However, characterizing the functional significance of these loci has proven challenging. We sought to gain insights into the regulation of fasting insulin and fasting glucose through the use of gene expression microarray data from peripheral blood samples of participants without diabetes in the Framingham Heart Study (FHS) (n = 5,056), the Rotterdam Study (RS) (n = 723), and the InCHIANTI Study (Invecchiare in Chianti) (n = 595). Using a false discovery rate q fasting glucose and 433 transcripts associated with fasting insulin levels after adjusting for age, sex, technical covariates, and complete blood cell counts. Among the findings, circulating IGF2BP2 transcript levels were positively associated with fasting insulin in both the FHS and RS. Using 1000 Genomes-imputed genotype data, we identified 47,587 cis-expression quantitative trait loci (eQTL) and 6,695 trans-eQTL associated with the 433 significant insulin-associated transcripts. Of note, we identified a trans-eQTL (rs592423), where the A allele was associated with higher IGF2BP2 levels and with fasting insulin in an independent genetic meta-analysis comprised of 50,823 individuals. We conclude that integration of genomic and transcriptomic data implicate circulating IGF2BP2 mRNA levels associated with glucose and insulin homeostasis. © 2016 by the American Diabetes Association.

  11. Factors affecting insulin-like growth factor-I concentration in bovine milk.

    Science.gov (United States)

    Collier, R J; Miller, M A; Hildebrandt, J R; Torkelson, A R; White, T C; Madsen, K S; Vicini, J L; Eppard, P J; Lanza, G M

    1991-09-01

    To establish the naturally occurring range of insulin-like growth factor-I concentrations in bovine milk, samples from individual cows (n = 409) managed on five Missouri dairy herds were assayed. Parity, stage of lactation, and farm affected milk insulin-like growth factor-I concentration. Milk insulin-like growth factor-I concentration was higher in early lactation than mid and late lactation with concentrations in multiparous cows exceeding those in primiparous cows. Insulin-like growth factor-I concentration was negatively correlated to milk production the day of sample collection (r = -.15) and not correlated to predicted 305-d milk yields. Unprocessed bulk tank milk samples (n = 100) from a commercial processing plant had a mean concentration of insulin-like growth factor-I in milk of 4.32 ng/ml with a range of 1.27 to 8.10 ng/ml. This distribution was similar to the range detected in samples from individual cows, but values were lower than those reported for human milk. Concentration of insulin-like growth factor-I in milk was not altered by pasteurization (at 79 degrees C for 45 s). However, insulin-like growth factor-I was undetectable in milk heated to temperatures (121 degrees C for 5 min) required for infant formula preparation or in commercially available infant formula. These data indicated that insulin-like growth factor-I is a normal but quantitatively variable component of bovine milk that is not destroyed by pasteurization but is undetectable in infant formula. Concentration of insulin-like growth factor-I in bovine milk is lower than concentrations reported for human milk yet similar to those reported for human saliva.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Insulin

    Science.gov (United States)

    ... Information by Audience For Women Women's Health Topics Insulin Share Tweet Linkedin Pin it More sharing options ... medicines. You can do it. Back to Top Insulin Safety Tips Never drink insulin. Do not share ...

  13. The Relationship between Serum 25-Hydroxyvitamin D Concentration, Cardiorespiratory Fitness, and Insulin Resistance in Japanese Men

    Directory of Open Access Journals (Sweden)

    Xiaomin Sun

    2014-12-01

    Full Text Available Here, we aim to investigate the independent and combined associations of serum 25-hydroxyvitamin D (25(OHD and cardiorespiratory fitness (CRF with glucose metabolism. Fasting blood samples of 107 men aged 40–79 years were analyzed for 25(OHD, glucose, insulin, glycated hemoglobin, and lipid profile. Homeostasis model assessment of insulin resistance index (HOMA-IR was calculated from the fasting concentrations of glucose and insulin. Visceral fat area (VFA was determined by magnetic resonance imaging and CRF by measuring maximal oxygen uptake. Median 25(OHD concentration was 36.3 nmol/L, while the prevalence of 25(OHD deficiency was 74.8%. Participants with high CRF had significantly lower HOMA-IR, glycated hemoglobin, and insulin values than participants with low CRF (p < 0.05. Higher 25(OHD concentration was strongly correlated with lower HOMA-IR and insulin values independent of VFA (p < 0.01 but significantly affected by CRF. In the high CRF group, participants with higher 25(OHD concentration had lower HOMA-IR values than participants with low 25(OHD concentration (p < 0.05. Higher 25(OHD and CRF are crucial for reducing insulin resistance regardless of abdominal fat. In addition, higher 25(OHD concentration may strengthen the effect of CRF on reducing insulin resistance in middle-aged and elderly Japanese men with high CRF.

  14. Moderate alcohol consumption is associated with improved insulin sensitivity, reduced basal insulin secretion rate and lower fasting glucagon concentration in healthy women

    DEFF Research Database (Denmark)

    Bonnet, F; Disse, E; Laville, M

    2012-01-01

    Moderate alcohol consumption is associated with a reduced risk of type 2 diabetes with a stronger effect in women. As the underlying mechanisms remain poorly characterised, we investigated its relationship with insulin resistance, insulin secretion, clearance of insulin and glucagon concentration....

  15. Intermediate acting insulin given at bedtime: effect on blood glucose concentrations before and after breakfast

    National Research Council Canada - National Science Library

    Francis, A J; Home, P D; Hanning; Alberti, K G; Tunbridge, W M

    1983-01-01

    Six C-peptide deficient diabetics receiving twice daily mixtures of short and intermediate acting insulins were selected for study because of persistently raised blood glucose concentrations before and after breakfast...

  16. Evaluation of risk for metabolic syndrome according to the fasting insulin concentration in Korean men.

    Science.gov (United States)

    Jung, Ju Young; Park, Sung Keun; Choi, Joong-Myung; Hong, Hyun Pyo; Choi, Young-Jun; Ryoo, Jae-Hong

    2017-01-01

    As a well-known risk factor for cardiovascular disease, metabolic syndrome (MetS) is an important global health problem due to its high worldwide prevalence. The objective of this study is to determine whether the fasting serum insulin concentration influences future incidence of MetS. A total of 14,621 Korean men without MetS participating in a medical health check-up program were followed up from 2005 until 2010. They were divided into 4 groups according to baseline fasting insulin concentrations. The incidence of MetS was compared among the groups, and Cox proportional hazards model was used to determine if MetS was associated with higher fasting insulin concentration. The incidence of MetS increased according to the baseline fasting insulin concentration (first quartile: 8.4%, second quartile: 12.3%, third quartile: 16.3%, fourth quartile: 26.5%, Pfasting insulin concentration. Additionally, increased fasting insulin concentration was an independent risk factor for the future development of MetS. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Serum HER-2 concentration is associated with insulin resistance and decreases after weight loss

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    Moreno-Navarrete José

    2010-02-01

    Full Text Available Abstract Background HER2/neu is a member of the epidermal growth factor receptor family easily detectable in the serum of cancer patients. We aimed to evaluate circulating HER-2 concentrations in association with insulin resistance in healthy and obese subjects. Methods Insulin sensitivity (minimal model and serum HER-2 concentrations were evaluated in a cross sectional study in men (cohort 1, n = 167 and longitudinally after weight loss in obese subjects (cohort 2, n = 30. Results Serum HER-2 concentrations were positively associated with BMI and waist circumference (both r = 0.18, p = 0.02, post-load glucose (r = 0.28, p = 0.001 and fasting triglycerides (r = 0.26, p = 0.001; and negatively associated with insulin sensitivity (r = -0.29, p = 0.002, n = 109. Subjects with type 2 diabetes showed significantly increased soluble serum HER-2 concentrations. In different multivariate regression models, fasting triglycerides emerged as the factor that independently contributed to 10-11% of serum HER-2 variance. Serum HER-2 concentrations correlated significantly with fasting triglycerides and insulin sensitivity index in subjects from cohort 2. Weight loss led to a significant decrease of serum HER-2 concentrations. The change in serum HER-2 concentrations were significantly associated with the change in percent body fat and fasting triglycerides in young (below the median age of the cohort subjects. Conclusions Serum HER-2 concentrations might be implicated in the pathophysiology of insulin resistance and associated comorbidities.

  18. Serum Magnesium Concentrations in the Canadian Population and Associations with Diabetes, Glycemic Regulation, and Insulin Resistance.

    Science.gov (United States)

    Bertinato, Jesse; Wang, Kuan Chiao; Hayward, Stephen

    2017-03-17

    Total serum magnesium (Mg) concentration (SMC) is commonly used to assess Mg status. This study reports current SMCs of Canadians and their associations with demographic factors, diabetes, and measures of glycemic control and insulin resistance using results from the Canadian Health Measures Survey cycle 3 (2012-2013). Associations were examined in adults aged 20-79 years using linear mixed models. Mean SMCs and percentile distributions for 11 sex-age groups between 3 and 79 years (n = 5561) are reported. SMCs were normally distributed and differences (p insulin concentrations, and homeostatic model assessment of insulin resistance were negatively associated with SMC. This is the first study to report SMCs in a nationally representative sample of the Canadian population. A substantial proportion of Canadians are hypomagnesaemic in relation to a population-based reference interval, and SMC was negatively associated with diabetes and indices of glycemic control and insulin resistance.

  19. Influence of menstrual phase on ventilatory response to submaximal ...

    African Journals Online (AJOL)

    Objectives. To determine whether an increase in respiratory drive, due to elevated progesterone and oestrogen concentration during various menstrual phases, persists throughout prolonged submaximal exercise and potentially contributes to fatigue. Furthermore, to determine whether the difference in the ventilatory ...

  20. Early Pregnancy-Associated Plasma Protein A Concentrations Are Associated With Third Trimester Insulin Sensitivity.

    Science.gov (United States)

    Petry, Clive J; Ong, Ken K; Hughes, Ieuan A; Acerini, Carlo L; Frystyk, Jan; Dunger, David B

    2017-06-01

    First or early second trimester pregnancy-associated plasma protein A (PAPP-A) concentrations have previously been shown to be lower in women who subsequently develop gestational diabetes mellitus (GDM) and gestational hypertension. We therefore sought to investigate why circulating PAPP-A concentrations are related to the subsequent risk of GDM and gestational hypertension. We measured serum PAPP-A concentrations around week 15 of pregnancy and related these to indices derived from week 28 oral glucose tolerance tests and blood pressures across pregnancy in the Cambridge Baby Growth Study cohort. Increased PAPP-A concentrations were associated with reduced GDM risk [odds ratio 0.623 (0.453, 0.856), P = 3.5 × 10-3, n = 777] and reduced mean arterial blood pressures (β = -0.202 to -0.177, P = 1.7 to 6.9 × 10-3, n = 347 to 355). They were also negatively associated with week 28 fasting (β = -0.149, P = 6.6 × 10-4, n = 777) and 60-minute (β = -0.188, P = 1.5 × 10-5, n = 777) oral glucose tolerance test glucose concentrations. These associations were underpinned by the strong associations between increased week 15 PAPP-A concentrations and decreased week 28 insulin resistance (homeostasis model assessment of insulin resistance: β = -0.319, P = 1.7 × 10-13, n = 768), as well as increased insulin secretion relative to insulin sensitivity (insulin disposition index: β = 0.202, P = 6.5 × 10-6, n = 731). These results suggest that links between PAPP-A concentrations in early pregnancy and subsequent glucose concentrations and blood pressures may be mediated by changes in insulin sensitivity (and secretion).

  1. Elevation of serum insulin concentration during euglycemic hyperinsulinemic clamp studies leads to similar activation of insulin receptor kinase in skeletal muscle of subjects with and without NIDDM

    DEFF Research Database (Denmark)

    Klein, H H; Vestergaard, H; Kotzke, G

    1995-01-01

    The role of skeletal muscle insulin receptor kinase in the pathogenesis of non-insulin-dependent diabetes mellitus (NIDDM) was investigated. Muscle biopsies from 13 patients with NIDDM and 10 control subjects at fasting serum insulin concentrations and approximately 1,000 pmol/l steady-state serum...... insulin during euglycemic hyperinsulinemic clamps were immediately frozen. The biopsies were then solubilized, and the receptors were immobilized to anti-insulin receptor antibody-coated microwells. Receptor kinase and binding activities were consecutively measured in these wells. The increase in serum...... insulin concentration (73 +/- 14 to 1,004 +/- 83 and 45 +/- 7 to 1,07 +/- 77 pmol/l in the NIDDM and control groups, respectively) had similar effects on receptor kinase activity in both study groups (12 +/- 1 to 42 +/- 5 and 12 +/- 2 to 47 +/- 5 amol P.fmol binding activity-1. min-1 in the NIDDM...

  2. [Adiponectin, insulin and glucose concentrations in overweight and obese subjects after a complex carbohydrates (fiber) diet].

    Science.gov (United States)

    González Rodríguez, Dora Cristina; Solano R, Liseti; González Martínez, Julio César

    2009-09-01

    Adiponectin one of the cytokines secreted by the adipose tissue that regulates the energetic metabolism through glucose and insulin interactions, stimulates the oxidation of fatty acids, reduces the plasmatic triglycerides and improves glucose metabolism by increasing insulin sensibility. Serum concentrations of adiponectin, insulin and glucose were assessed in order to establish association to weight loss after a dietary regime based on consumption of complex carbohydrates (fiber) during six weeks. Overweight and obese subjects (n=56) were studied by anthropometry. Adiponectin and insulin were measured by ELISA and glucose by Colorimetry. Data was analyzed by non parametric tests to compare independent or related samples. 12 men and 44 women, aged 20 to 55 years, 17 overweight and 39 obese were assessed. Adiponectin concentration was significantly low at basal determination in all the subjects (4,47 +/- 1,64); being higher in women (4,62 +/- 1,57 vs 3,93 +/- 1,86 microU/mL in men), while glucose and insulin values were at normal range (82,46 +/-26,51 mg/dL and 14,12 +/- 10,15 microU/mL) respectively with no significant differences for sex. Overweight subjects had significantly higher adiponectin concentrations than obese participants, at all measurements. Dietary regime promoted significant increase in adiponectin concentration at second and sixth week, with a negative correlation to body mass index and gender as they lost body weight.

  3. Cord plasma concentrations of visfatin, adiponectin and insulin in healthy term neonates: positive correlation with birthweight.

    Science.gov (United States)

    Cekmez, Ferhat; Pirgon, Ozgur; Tanju, Asya; Ipcioglu, Osman Metin

    2009-09-01

    The aims of this study were to examine the relationships between adiponectin, insulin, visfatin and weight at birth in healthy term infants. Anthropometric parameters including weight, length were measured and plasma lipid profiles, insulin, visfatin and adiponectin concentrations in cord blood samples from 50 LGA and 50 AGA singleton infants born at term after uncomplicated pregnancies were assayed. Mean visfatin and adiponectin levels were significantly higher in the LGA group than AGA group (11.8 ± 8 vs. 6.3 ± 5.5 ng/ml, pCord plasma adiponectin, visfatin and insulin levels correlated significantly and positively with birthweight (p=0.01, pCord plasma adiponectin concentration correlated positively with visfatin level (p=0.005), but not with insulin level (p=0.8), and cord plasma visfatin concentration correlated positively with insulin level (pcord blood in LGA group. Cord plasma adiponectin and visfatin levels are positively correlated with birthweight. This suggests that adiponectin and visfatin may be involved in regulating fetal growth.

  4. Iron and obesity status-associated insulin resistance influence circulating fibroblast-growth factor-23 concentrations.

    Science.gov (United States)

    Fernández-Real, José Manuel; Puig, Josep; Serrano, Marta; Sabater, Mónica; Rubió, Antoni; Moreno-Navarrete, José María; Fontan, Marina; Casamitjana, Roser; Xifra, Gemma; Ortega, Francisco José; Salvador, Javier; Frühbeck, Gema; Ricart, Wifredo

    2013-01-01

    Fibroblast growth factor 23 (FGF-23) is known to be produced by the bone and linked to metabolic risk. We aimed to explore circulating FGF-23 in association with fatness and insulin sensitivity, atherosclerosis and bone mineral density (BMD). Circulating intact FGF-23 (iFGF-23) and C-terminal (CtFGF-23) concentrations (ELISA) were measured in 133 middle aged men from the general population in association with insulin sensitivity (Cohort 1); and in association with fat mass and bone mineral density (DEXA) and atherosclerosis (intima media thickness, IMT) in 78 subjects (52 women) with a wide range of adiposity (Cohort 2). Circulating iFGF-23 was also measured before and after weight loss. In all subjects as a whole, serum intact and C-terminal concentrations were linearly and positively associated with BMI. In cohort 1, both serum iFGF-23 and CtFGF-23 concentrations increased with insulin resistance. Serum creatinine contributed to iFGF-23 variance, while serum ferritin and insulin sensitivity (but not BMI, age or serum creatinine) contributed to 17% of CtFGF-23 variance. In cohort 2, CtFGF-23 levels were higher in women vs. men, and increased with BMI, fat mass, fasting and post-load serum glucose, insulin, HOMA-IR and PTH, being negatively associated with circulating vitamin D and ferritin levels. The associations of CtFGF-23 with bone density in the radius, lumbar spine and carotid IMT were no longer significant after controlling for BMI. Weight loss led to decreased iFGF-23 concentrations. In summary, the associations of circulating FGF-23 concentration with parameters of glucose metabolism, bone density and atherosclerosis are dependent on iron and obesity status-associated insulin resistance.

  5. Iron and Obesity Status-Associated Insulin Resistance Influence Circulating Fibroblast-Growth Factor-23 Concentrations

    Science.gov (United States)

    Fernández-Real, José Manuel; Puig, Josep; Serrano, Marta; Sabater, Mónica; Rubió, Antoni; Moreno-Navarrete, José María; Fontan, Marina; Casamitjana, Roser; Xifra, Gemma; Ortega, Francisco José; Salvador, Javier; Frühbeck, Gema; Ricart, Wifredo

    2013-01-01

    Fibroblast growth factor 23 (FGF-23) is known to be produced by the bone and linked to metabolic risk. We aimed to explore circulating FGF-23 in association with fatness and insulin sensitivity, atherosclerosis and bone mineral density (BMD). Circulating intact FGF-23 (iFGF-23) and C-terminal (CtFGF-23) concentrations (ELISA) were measured in 133 middle aged men from the general population in association with insulin sensitivity (Cohort 1); and in association with fat mass and bone mineral density (DEXA) and atherosclerosis (intima media thickness, IMT) in 78 subjects (52 women) with a wide range of adiposity (Cohort 2). Circulating iFGF-23 was also measured before and after weight loss. In all subjects as a whole, serum intact and C-terminal concentrations were linearly and positively associated with BMI. In cohort 1, both serum iFGF-23 and CtFGF-23 concentrations increased with insulin resistance. Serum creatinine contributed to iFGF-23 variance, while serum ferritin and insulin sensitivity (but not BMI, age or serum creatinine) contributed to 17% of CtFGF-23 variance. In cohort 2, CtFGF-23 levels were higher in women vs. men, and increased with BMI, fat mass, fasting and post-load serum glucose, insulin, HOMA-IR and PTH, being negatively associated with circulating vitamin D and ferritin levels. The associations of CtFGF-23 with bone density in the radius, lumbar spine and carotid IMT were no longer significant after controlling for BMI. Weight loss led to decreased iFGF-23 concentrations. In summary, the associations of circulating FGF-23 concentration with parameters of glucose metabolism, bone density and atherosclerosis are dependent on iron and obesity status-associated insulin resistance. PMID:23555610

  6. Iron and obesity status-associated insulin resistance influence circulating fibroblast-growth factor-23 concentrations.

    Directory of Open Access Journals (Sweden)

    José Manuel Fernández-Real

    Full Text Available Fibroblast growth factor 23 (FGF-23 is known to be produced by the bone and linked to metabolic risk. We aimed to explore circulating FGF-23 in association with fatness and insulin sensitivity, atherosclerosis and bone mineral density (BMD. Circulating intact FGF-23 (iFGF-23 and C-terminal (CtFGF-23 concentrations (ELISA were measured in 133 middle aged men from the general population in association with insulin sensitivity (Cohort 1; and in association with fat mass and bone mineral density (DEXA and atherosclerosis (intima media thickness, IMT in 78 subjects (52 women with a wide range of adiposity (Cohort 2. Circulating iFGF-23 was also measured before and after weight loss. In all subjects as a whole, serum intact and C-terminal concentrations were linearly and positively associated with BMI. In cohort 1, both serum iFGF-23 and CtFGF-23 concentrations increased with insulin resistance. Serum creatinine contributed to iFGF-23 variance, while serum ferritin and insulin sensitivity (but not BMI, age or serum creatinine contributed to 17% of CtFGF-23 variance. In cohort 2, CtFGF-23 levels were higher in women vs. men, and increased with BMI, fat mass, fasting and post-load serum glucose, insulin, HOMA-IR and PTH, being negatively associated with circulating vitamin D and ferritin levels. The associations of CtFGF-23 with bone density in the radius, lumbar spine and carotid IMT were no longer significant after controlling for BMI. Weight loss led to decreased iFGF-23 concentrations. In summary, the associations of circulating FGF-23 concentration with parameters of glucose metabolism, bone density and atherosclerosis are dependent on iron and obesity status-associated insulin resistance.

  7. Associations of prenatal metabolic abnormalities with insulin and adiponectin concentrations in human milk.

    Science.gov (United States)

    Ley, Sylvia H; Hanley, Anthony J; Sermer, Mathew; Zinman, Bernard; O'Connor, Deborah L

    2012-04-01

    Emerging evidence indicates that metabolic hormones are present in human milk, but, to our knowledge, no studies have investigated the impact of maternal metabolic status assessed during pregnancy on insulin and adiponectin concentrations in milk. We aimed to investigate the associations of prenatal metabolic abnormalities with insulin and adiponectin in human milk and to compare the concentrations of these hormones in early and mature milk. Pregnant women aged ≥20 y with intention to breastfeed and without preexisting type 1 or 2 diabetes were recruited. Participants (n = 170) underwent a 3-h oral-glucose-tolerance test at 30 wk (95% CI: 25, 33 wk) gestation and donated early (the first week postpartum) and mature (3 mo postpartum) milk. Adiponectin and insulin concentrations in early milk were higher than those in mature milk (both P milk after covariate adjustment. Prenatal metabolic measures were not associated with milk adiponectin, but obstetrical measures that included nulliparity (0.171 ± 0.058; P = 0.004), longer duration of gestation (0.546 ± 0.146; P = 0.0002), and unscheduled cesarean delivery (0.387 ± 0.162; P = 0.02) were associated with higher adiponectin in early milk after covariate adjustment, including the time elapsed from delivery to milk collection. Maternal prenatal metabolic abnormalities are associated with high insulin concentrations in mature milk, whereas only obstetrical variables are associated with adiponectin concentrations in early milk.

  8. Influence of various carbohydrate sources on postprandial glucose, insulin and NEFA concentrations in obese cats.

    Science.gov (United States)

    Mori, A; Ueda, K; Lee, P; Oda, H; Ishioka, K; Sako, T

    2016-01-01

    Carbohydrate is an important source of energy, which can significantly affect postprandial blood glucose and insulin levels in cats. In healthy animals, this is not a big concern; however, in obese and diabetic animals, this is an important detail. In the present study, the impact of four different carbohydrate sources (glucose, maltose, corn starch, and trehalose) on short-term post-prandial serum glucose, insulin, and non-esterified fatty acid (NEFA) concentrations was investigated with four obese cats. Each of the carbohydrate sources was added to a commercial wet food diet for feeding the animals. A significant difference was observed in postprandial glucose, insulin, and NEFA area under the curve (AUC) values between each carbohydrate source in obese cats. Furthermore, glucose and maltose induced the highest postprandial glucose and insulin AUC values, whereas trehalose induced the lowest postprandial glucose and insulin AUC value amongst all carbohydrate sources, respectively, in obese cats. However, trehalose has a higher risk of inducing side effects, such as diarrhea, as compared to other carbohydrate sources. As such, different carbohydrate sources appear to have a very significant impact on post-prandial glycemia and subsequent insulin requirement levels in obese cats. These results might be useful when selecting a prescription diet for obese or diabetic cats. In addition, maltose appears to be capable of inducing experimentally evoked postprandial hyperglycemia in obese cats, which may serve as a good tool for use to check the impact and effectiveness of newly developed oral hypoglycemic drugs or supplements for cats in future experiments.

  9. Intranasal insulin decreases circulating cortisol concentrations during early sleep in elderly humans.

    Science.gov (United States)

    Thienel, Matthias; Wilhelm, Ines; Benedict, Christian; Born, Jan; Hallschmid, Manfred

    2017-06-01

    Aging is associated with increases in hypothalamic-pituitary-adrenal (HPA) axis activity that can predispose to metabolic and cognitive impairments. We investigated in elderly and young subjects whether intranasal insulin administration to the human brain reduces early-sleep nadir concentrations of adrenocorticotropin and cortisol, that is, indicators of baseline HPA axis activity. In within-subject comparisons, intranasal insulin (160 IU) or placebo was administered to 14 elderly (mean age 70.0 years) and 30 young (23.6 years) healthy subjects before bedtime. Sleep was polysomnographically assessed and blood samples were repeatedly collected. Elderly compared with young participants displayed increased early-sleep cortisol concentrations (p Insulin administration reduced cortisol levels between 2300 hours and 0020 hours in the elderly (p = 0.03) but not young participants (p = 0.56; p = 0.003 for interaction). Findings indicate that central nervous insulin acts as an inhibitory signal in basal HPA axis activity regulation and suggest that intranasal insulin may normalize sleep-associated stress axis activity in older age. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  10. Glucose-stimulated insulin response in pregnant sheep following acute suppression of plasma non-esterified fatty acid concentrations

    Directory of Open Access Journals (Sweden)

    Sriskandarajah Nadarajah

    2004-09-01

    Full Text Available Abstract Background Elevated non-esterified fatty acids (NEFA concentrations in non-pregnant animals have been reported to decrease pancreatic responsiveness. As ovine gestation advances, maternal insulin concentrations fall and NEFA concentrations increase. Experiments were designed to examine if the pregnancy-associated rise in NEFA concentration is associated with a reduced pancreatic sensitivity to glucose in vivo. We investigated the possible relationship of NEFA concentrations in regulating maternal insulin concentrations during ovine pregnancy at three physiological states, non-pregnant, non-lactating (NPNL, 105 and 135 days gestational age (dGA, term 147+/- 3 days. Methods The plasma concentrations of insulin, growth hormone (GH and ovine placental lactogen (oPL were determined by double antibody radioimmunoassay. Insulin responsiveness to glucose was measured using bolus injection and hyperglycaemic clamp techniques in 15 non-pregnant, non-lactating ewes and in nine pregnant ewes at 105 dGA and near term at 135 dGA. Plasma samples were also collected for hormone determination. In addition to bolus injection glucose and insulin Area Under Curve calculations, the Mean Plasma Glucose Increment, Glucose Infusion Rate and Mean Plasma Insulin Increment and Area Under Curve were determined for the hyperglycaemic clamp procedures. Statistical analysis of data was conducted with Students t-tests, repeated measures ANOVA and 2-way ANOVA. Results Maternal growth hormone, placental lactogen and NEFA concentrations increased, while basal glucose and insulin concentrations declined with advancing gestation. At 135 dGA following bolus glucose injections, peak insulin concentrations and insulin area under curve (AUC profiles were significantly reduced in pregnant ewes compared with NPNL control ewes (p Conclusions Results suggest that despite an acute suppression of circulating NEFA concentrations during pregnancy, the associated steroids and hormones

  11. Concentrations of insulin glargine and its metabolites during long-term insulin therapy in type 2 diabetic patients and comparison of effects of insulin glargine, its metabolites, IGF-I, and human insulin on insulin and IGF-I receptor signaling

    NARCIS (Netherlands)

    A.J. Varewijck (Aimee); H. Yki-Jarvinen (Hannele); R. Schmidt (Reinhold); N. Tennagels (Norbert); J.A.M.J.L. Janssen (Joseph)

    2013-01-01

    textabstractWe investigated 1) the ability of purified glargine (GLA), metabolites 1 (M1) and 2 (M2), IGF-I, and NPH insulin to activate the insulin receptor (IR)-A and IR-B and IGF-I receptor (IGF-IR) in vitro; 2) plasma concentrations of GLA, M1, and M2 during longterm insulin therapy in type 2

  12. Lower insulin-like growth factor-1 concentrations in women with premenstrual dysphoric disorder.

    Science.gov (United States)

    Thys-Jacobs, Susan; McMahon, Don; Bilezikian, John P

    2008-05-01

    Recent evidence suggests that abnormalities in calcium metabolism may be responsible for the luteal phase symptoms in women experiencing premenstrual syndrome. Our objective was to measure the cyclic variations in bone turnover across the menstrual cycle in women with and without luteal phase symptoms consistent with severe premenstrual syndrome or premenstrual dysphoric disorder. We measured the indices of bone metabolism, N-telopeptide, osteocalcin and insulin-like growth factor-1 in women with and without premenstrual dysphoric disorder using a cross-sectional and prospective design. Participating women underwent 2 months of self-assessment symptom screening and 1 month of hormonal evaluation. Overall serum insulin-like growth factor-1 (mean +/- standard deviation) was significantly lower in the premenstrual dysphoric disorder group compared with controls (205.7 +/- 56.8 vs 240.2 +/- 76.9 ng/ mL, P = .01) and was significantly lower throughout all 5 phases of the menstrual cycle in the premenstrual dysphoric disorder group compared with controls. In both groups of women, serum insulin-like growth factor-1 concentrations were highest and urinary N-telopeptide levels were lowest during the luteal phase. Bone remodeling indices of formation and resorption during the menstrual cycle were greater and appeared earlier in the control compared with the premenstrual dysphoric disorder group. Significantly lower insulin-like growth factor-1 concentrations in premenstrual dysphoric disorder subjects compared with controls may hold insights about how premenstrual dysphoric disorder subjects differ from asymptomatic controls.

  13. Alteration of postprandial glucose and insulin concentrations with meal frequency and composition.

    Science.gov (United States)

    Kanaley, Jill A; Heden, Timothy D; Liu, Ying; Fairchild, Timothy J

    2014-11-14

    A frequent eating pattern may alter glycaemic control and augment postprandial insulin concentrations in some individuals due to the truncation of the previous postprandial period by a subsequent meal. The present study examined glucose, insulin, C-peptide and glucose-dependent insulinotropic peptide (GIP) responses in obese individuals when meals were ingested in a high-frequency pattern (every 2 h, 6M) or in a low-frequency pattern (every 4 h, 3M) over 12 h. It also examined these postprandial responses to high-frequency, high-protein meals (6MHP). In total, thirteen obese subjects completed three 12 h study days during which they consumed 6276 kJ (1500 kcal): (1) 3M - 15 % protein and 65 % carbohydrate; (2) 6M - 15 % protein and 65 % carbohydrate; (3) 6MHP - 45 % protein and 35 % carbohydrate. Blood samples were collected every 10 min and analysed for glucose, insulin, C-peptide and GIP. Insulin total AUC (tAUC) and peak insulin concentrations (Pglucose tAUC between the conditions. The 6MHP regimen (glucose: 3569 (se 83) mmol/l × min (64·3 (se 1·5) g/dl × min), insulin: 1·577 (se 0·146) pmol/l (22·7 (se 2·1) μIU/dl) for 12 h) lowered glucose and insulin excursions more so over 12 h than either the 3M regimen (glucose: 3913 (se 78) mmol/l × min (70·5 (se 1·4) g/dl × min), insulin: 2·195 (se 0·146) pmol/l × min (31·6 (se 2·1) μIU/dl × min) for 12 h) or the 6M regimen (glucose: 3902 (se 83) mmol/l × min (70·3 (se 1·5) g/dl × min), insulin: 1·861 (se 0·174) pmol/l × min (26·8 (se 2·5) μIU/dl × min) for 12 h; Pglucose:insulin ratio were not altered by meal frequency or composition. In obese subjects, ingestion of meals in a low-frequency pattern does not alter glucose tAUC, but increases postprandial insulin responses. The substitution of carbohydrates with protein in a frequent meal pattern results in tighter glycaemic control and reduced postprandial insulin responses.

  14. Increased maternal nighttime cortisol concentrations in late gestation alter glucose and insulin in the neonatal lamb

    Science.gov (United States)

    Antolic, Andrew; Feng, Xiaodi; Wood, Charles E; Richards, Elaine M; Keller-Wood, Maureen

    2015-01-01

    Previous studies in our laboratory have shown that a modest chronic increase in maternal cortisol concentrations impairs maternal glucose metabolism and increases the incidence of perinatal stillbirth. The dramatic outcomes prevented our ability to study the effects of maternal hypercortisolemia on neonatal growth, glucose metabolism, and hypothalamo–pituitary–adrenal axis response. Therefore, we developed a model in which pregnant ewes are infused for 12 h/day at 0.5 mg·kg–1·day–1 from day 115 of gestation until delivery (˜145), elevating nighttime plasma cortisol concentrations. This pattern of elevation of cortisol mimics that in patients with elevated evening cortisol concentrations, as in Cushing’s syndrome or chronic depression. Plasma cortisol, glucose, insulin, and electrolytes were measured during pregnancy and postpartum in control and cortisol-infused ewes and their postnatal lambs for the first 14 days after delivery. Neonatal growth and plasma ACTH, aldosterone, renin activity, and electrolytes, and organ weights at 14 days of age were also measured. Infusion of cortisol increased maternal plasma cortisol during pregnancy but not postpartum, and did not alter neonatal ACTH or cortisol. Although maternal glucose and insulin concentrations were not changed by the maternal infusion of cortisol, neonatal plasma glucose was increased and plasma insulin was decreased compared to those in the control group. Neonatal ponderal index and kidney weight were reduced, left ventricular wall thickness was increased, and plasma sodium and creatinine were increased after maternal cortisol infusion. These results suggest that excess maternal cortisol concentrations in late gestation alter growth, glucose and insulin regulation, and organ maturation in the neonate. PMID:26371232

  15. Fasting plasma chenodeoxycholic acid and cholic acid concentrations are inversely correlated with insulin sensitivity in adults

    Directory of Open Access Journals (Sweden)

    Laville Martine

    2011-07-01

    Full Text Available Abstract Background Accumulating data suggest a novel role for bile acids (BAs in modulating metabolic homeostasis. BA treatment has been shown to improve glucose tolerance and to increase energy expenditure in mice. Here, we investigated the relationship between fasting plasma BAs concentrations and metabolic parameters in humans. Findings Fasting plasma glucose, insulin and lipid profile were measured in 14 healthy volunteers, 20 patients with type 2 diabetes (T2D, and 22 non-diabetic abdominally obese subjects. Insulin sensitivity was also assessed by the determination of the glucose infusion rate (GIR during a hyperinsulinemic-euglycemic clamp in a subgroup of patients (9 healthy and 16 T2D subjects. Energy expenditure was measured by indirect calorimetry. Plasma cholic acid (CA, chenodeoxycholic acid (CDCA and deoxycholic acid (DCA concentrations were analyzed by gas chromatograph-mass spectrometry. In univariable analysis, a positive association was found between HOMA-IR and plasma CDCA (β = 0.09, p = 0.001, CA (β = 0.03, p = 0.09 and DCA concentrations (β = 0.07, p Conclusions Both plasma CDCA, CA and DCA concentrations were negatively associated with insulin sensitivity in a wide range of subjects.

  16. Effects of pasteurization on adiponectin and insulin concentrations in donor human milk.

    Science.gov (United States)

    Ley, Sylvia H; Hanley, Anthony J; Stone, Debbie; O'Connor, Deborah L

    2011-09-01

    Although pasteurization is recommended before distributing donor human milk in North America, limited data are available on its impact on metabolic hormones in milk. We aimed to investigate the effects of pasteurization on adiponectin and insulin concentrations in donor human milk. The study investigates concentrations of components in donor human milk before and after Holder pasteurization. After the guidelines of the Human Milk Bank Association of North America, human milk samples were pooled to produce 17 distinct batches (4 individuals per batch) and pasteurized at 62.5°C for 30 min. Adiponectin, insulin, energy, fat, total protein, and glucose concentrations were measured pre- and postpasteurization. Pasteurization reduced milk adiponectin and insulin by 32.8 and 46.1%, respectively (both p milk composition (r = 0.36-0.47; all p milk hormone concentrations remained significant after adjusting for fat and energy (beta ± SEE: -4.11 ± 1.27, p = 0.003 for adiponectin; -70.0 ± 15.0, p milk. In view of emerging knowledge on the importance of milk components, continued work to find the optimal pasteurization process that mitigates risks but promotes retention of bioactive components is needed.

  17. Increased chemerin concentrations in fetuses of obese mothers and correlation with maternal insulin sensitivity.

    Science.gov (United States)

    Barker, Gillian; Lim, Ratana; Rice, Gregory E; Lappas, Martha

    2012-11-01

    The aim of this study was to determine the effect of maternal obesity and gestational diabetes mellitus (GDM) on (i) the circulating concentrations of chemerin in cord and maternal plasma, and (ii) gene expression and release of chemerin from human placenta and adipose tissue. Chemerin concentrations were measured in maternal and cord plasma from 62 normal glucose tolerant women (NGT) and 69 women with GDM at the time of term elective Caesarean section. Placenta and adipose tissue expression and release of chemerin was measured from 22 NGT and 22 GDM women. There was no effect of maternal obesity or GDM on maternal chemerin concentrations. Chemerin concentrations were significantly higher in cord plasma from women with maternal obesity. Cord chemerin concentrations in NGT women negatively correlated with the concentrations of maternal insulin sensitivity. There was no effect of GDM on maternal and cord chemerin concentrations, and on the release of chemerin from placenta and adipose tissue. At the time of term Caesarean section, preexisting maternal obesity, and its associated insulin resistance, is associated with higher cord plasma chemerin concentrations.

  18. Eccentric exercise decreases maximal insulin action in humans

    DEFF Research Database (Denmark)

    Asp, Svend; Daugaard, J R; Kristiansen, S

    1996-01-01

    ) necessary to maintain euglycaemia during maximal insulin stimulation was lower during PEC compared with CC (15.7%, 81.3 +/- 3.2 vs. 96.4 +/- 8.8 mumol kg-1 min-1, P 2 days after unaccustomed eccentric exercise, muscle and whole-body insulin action is impaired at maximal...... subjects participated in two euglycaemic clamps, performed in random order. One clamp was preceded 2 days earlier by one-legged eccentric exercise (post-eccentric exercise clamp (PEC)) and one was without the prior exercise (control clamp (CC)). 2. During PEC the maximal insulin-stimulated glucose uptake...... over the eccentric thigh was marginally lower when compared with the control thigh, (11.9%, 64.6 +/- 10.3 vs. 73.3 +/- 10.2 mumol kg-1 min-1, P = 0.08), whereas no inter-thigh difference was observed at a submaximal insulin concentration. The glycogen concentration was lower in the eccentric thigh...

  19. Insulin Secretion and Incretin Hormone Concentration in Women with Previous Gestational Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Sung Hoon Yu

    2011-02-01

    Full Text Available BackgroundWe examined the change in the levels of incretin hormone and effects of glucose-dependent insulinotropic polypeptide (GIP and glucagon-like peptide 1 (GLP-1 on insulin secretion in women with previous gestational diabetes (pGDM.MethodsA 75-g oral glucose tolerance test (OGTT was conducted on 34 women with pGDM. In addition, 11 women with normal glucose tolerance, matched for age, height and weight, were also tested. The insulin, GIP, GLP-1, and glucagon concentrations were measured, and their anthropometric and biochemical markers were also measured.ResultsAmong 34 women with pGDM, 18 had normal glucose tolerance, 13 had impaired glucose tolerance (IGT and 1 had diabetes. No significant differences were found in GLP-1 concentration between the pGDM and control group. However, a significantly high level of glucagon was present in the pGDM group at 30 minutes into the OGTT. The GIP concentration was elevated at 30 minutes and 60 minutes in the pGDM group. With the exception of the 30-minute timepoint, women with IGT had significantly high blood glucose from 0 to 120 minutes. However, there was no significant difference in insulin or GLP-1 concentration. The GIP level was significantly high from 0 to 90 minutes in patients diagnosed with IGT.ConclusionGLP-1 secretion does not differ between pGDM patients and normal women. GIP was elevated, but that does not seem to induce in increase in insulin secretion. Therefore, we conclude that other factors such as heredity and environment play important roles in the development of type 2 diabetes.

  20. Relationship between serum adiponectin concentration, body condition score, and peripheral tissue insulin response of dairy cows during the dry period.

    Science.gov (United States)

    De Koster, J; Urh, C; Hostens, M; Van den Broeck, W; Sauerwein, H; Opsomer, G

    2017-04-01

    The aim of the present study was to describe the relationship between serum adiponectin concentration and peripheral tissue insulin response in dairy cows with a variable body condition score (BCS) during the dry period. Cows were selected at the beginning of the dry period based on BCS (BCS 3.75, n = 5). Animals were followed from the beginning of the dry period by weekly blood sampling and assessment of BCS and backfat thickness. Weekly blood samples were analyzed for adiponectin concentration using a bovine specific ELISA. Hyperinsulinemic euglycemic clamp tests were performed at the end of the dry period to measure peripheral tissue insulin response. Insulin dose response curves were established for both glucose and fatty acid metabolism. Regression analysis revealed that the serum concentrations of adiponectin dropped at the end of the dry period (P < 0.05) and were negatively associated with BCS (P < 0.05). At the level of the glucose metabolism, serum concentrations of adiponectin were positively correlated with insulin responsiveness (reflecting the maximal effect of insulin; r = 0.76, P < 0.05), but not with insulin sensitivity (reflecting the insulin concentration needed to achieve halfmaximal effect; r = -0.54, P = 0.13). At the level of the fatty acid metabolism, greater adiponectin concentrations were negatively correlated with lower NEFA levels during the HEC test reflecting the insulin responsiveness of the NEFA metabolism (r = -0.61, P = 0.08), whereas there was no association with the insulin sensitivity of the NEFA metabolism (r = -0.16, P = 0.67). In conclusion, serum concentrations of adiponectin were negatively associated with the BCS of dairy cows during the dry period and positively associated with insulin responsiveness of the glucose and fatty acid metabolism. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Testosterone Plasma Concentration is Associated with Insulin Resistance in Male Hypertensive Patients.

    Science.gov (United States)

    Schianca, Gian Piero Carnevale; Fra, Gian Paolo; Brustia, Fabio; Bellan, Mattia; Pirovano, Alice; Gualerzi, Alessandro; Gentile, Michela; Gibbin, Antonello; Menegatti, Mirta; Bartoli, Ettore; Pirisi, Mario

    2017-03-01

    Background: Low testosterone levels are a common finding among men with Type 2 Diabetes Mellitus (T2DM) and are inversely related to insulin resistance. Whether this relationship holds true in patients with hypertension, but normal glucose tolerance or prediabetes, is unclear. Methods: We recruited 87 male outpatients with essential arterial hypertension, aged 35-70 years. Anthropometric data were collected, an Oral Glucose Tolerance Test (OGTT) performed, and the homeostasis model assessment of insulin resistance (HOMA-IR) score calculated. Follicle-Stimulating Hormone, Luteinizing Hormone, testosterone, Sex Hormone-Binding-Globulin and free-testosterone were measured. The concentrations of sex hormones were compared between normoglucotolerant, prediabetic and diabetic patients. Non-parametric tests were applied as appropriate to verify differences among groups, while multiple linear regression was used to predict the variability of testosterone and free-testosterone. Results: Total serum testosterone concentration was significantly lower in T2DM in comparison to normoglucotolerant subjects (pfree testosterone; HOMA-IR was related to testosterone and free-testosterone even in patients with normal glucose tolerance (r=- 0.47, ptestosterone (pfree-testosterone (p<0.05) plasma concentration. Conclusions: In males with hypertension, the link between insulin sensitivity and hypothalamic-pituitary-gonadal axis is maintained along the entire spectrum of glucose tolerance. © Georg Thieme Verlag KG Stuttgart · New York.

  2. Plasma adiponectin concentration is associated with skeletal muscle insulin receptor tyrosine phosphorylation, and low plasma concentration precedes a decrease in whole-body insulin sensitivity in humans

    DEFF Research Database (Denmark)

    Stefan, Norbert; Vozarova, Barbora; Funahashi, Tohru

    2002-01-01

    with diabetes). Group 1 (19 subjects) underwent skeletal muscle biopsies for the measurement of basal and insulin-stimulated tyrosine phosphorylation of the IR (stimulated by 100 nmol/l insulin). The fold increase after insulin stimulation was calculated as the ratio between maximal and basal phosphorylation...

  3. Low serum uric acid concentration augments insulin effects on the prevalence of metabolic syndrome.

    Science.gov (United States)

    Porchia, Leonardo M; Gonzalez-Mejia, M Elba; Torres-Rasgado, Enrique; Ruiz-Vivanco, Guadalupe; Pérez-Fuentes, Ricardo

    2017-12-22

    Insulin and uric acid were shown affect the prevalence of Metabolic Syndrome (MetS), but no studies examine their interaction. Therefore, we conducted this study to determine their biological interaction in subjects from central Mexico. 433 subjects were enrolled for a cross-sectional study. MetS was defined according to the Harmonizing Definition. Hyperuricemia was defined as ≥7.0 mg/dL in males and ≥5.8 mg/dL in females. Hyperinsulinemia was defined as ≥11.0 μU/mL. Pearson correlation coefficient (r) was calculated to determine the association between uric acid or insulin and MetS. Logistic regression was used to determine the risk (odds ratio) of developing MetS. Biological interactions were determined by the PROCESS Macro and Anderson's method. Insulin and uric acid levels were elevated in MetS positive group (p uric acid and insulin was associated with the number of MetS components (PROCESS Model 1, interaction coefficient = -0.009, 95%CI: -0.017 to -0.001, p = .036). Johnson-Neyman analysis suggests the interaction is lost when uric acid concentration increased >7.0 mg/dL. When the cohort was separated by hyperinsulinemia and hyperuricemia, there was a significant risk of developing MetS for subjects with hyperuricemia (odds ratio = 2.3; 95%CI: 1.1-4.8, p uric acid and insulin augments the prevalence of MetS; however, no biological interaction was determined for hyperuricemia and hyperinsulinemia. Copyright © 2017 Diabetes India. Published by Elsevier Ltd. All rights reserved.

  4. Chronic exposure of HIT cells to high glucose concentrations paradoxically decreases insulin gene transcription and alters binding of insulin gene regulatory protein.

    Science.gov (United States)

    Olson, L K; Redmon, J B; Towle, H C; Robertson, R P

    1993-07-01

    Chronically culturing HIT-T15 cells in media containing high glucose concentrations leads to decreased insulin mRNA levels, insulin content, and insulin secretion. These changes can be prevented by culturing the cells in media containing lower glucose levels (Robertson, R. P., H.-J. Zhang, K. L. Pyzdrowski, and T. F. Walseth. 1992. J. Clin. Invest. 90:320-325). The mechanism of this seemingly paradoxical phenomenon was examined by transiently transfecting HIT cells with a chloramphenicol acetyl transferase (CAT) reporter gene controlled by the 5'-regulatory domain of the human insulin gene (INSCAT). Early passages of HIT cells readily expressed INSCAT, whereas late passages of cells chronically cultured in 11.1 mM glucose expressed only 28.7 +/- 2.3% (mean +/- SEM) of the CAT activity expressed in early passages. In contrast, late passages of HIT cells chronically cultured in 0.8 mM glucose retained the ability to express the INSCAT reporter gene to 69.6 +/- 10.0% of the CAT activity observed in early passages. The decrease in INSCAT expression in late passages of cells serially cultured in 11.1 mM glucose was associated with the inability to form a specific nuclear protein-DNA complex with the CT motifs of the human insulin promoter. Formation of this specific protein-DNA complex was preserved in late passages of HIT cells when serially cultured in 0.8 mM glucose. Mutations of the CT motifs caused markedly diminished CAT activity in all passages examined. These data indicate that chronic exposure of the beta cell to high glucose concentrations can paradoxically decrease insulin gene transcription, in part, by altering the ability of a regulatory protein (GSTF) to interact with the insulin gene promoter. This provides a potential mechanism for glucotoxic effects on the beta cell at the level of the insulin gene.

  5. Dynamics of glucose and insulin concentration connected to the β‐cell cycle: model development and analysis

    OpenAIRE

    Gallenberger Martina; Castell Wolfgang zu; Hense Burkhard A; Kuttler Christina

    2012-01-01

    Abstract Background Diabetes mellitus is a group of metabolic diseases with increased blood glucose concentration as the main symptom. This can be caused by a relative or a total lack of insulin which is produced by the β‐cells in the pancreatic islets of Langerhans. Recent experimental results indicate the relevance of the β‐cell cycle for the development of diabetes mellitus. Methods This paper introduces a mathematical model that connects the dynamics of glucose and insulin concentration w...

  6. Growth hormone and sex steroid effects on serum glucose, insulin, and lipid concentrations in healthy older women and men.

    Science.gov (United States)

    Münzer, Thomas; Harman, S Mitchell; Sorkin, John D; Blackman, Marc R

    2009-10-01

    With aging, GH, IGF-I, and sex steroid concentrations and glucose tolerance decrease, and body fat and serum lipids increase. The aim of the study was to assess GH and/or sex steroid administration effects on serum glucose, insulin, insulin sensitivity, and lipids in older individuals. A double-masked, 2 x 2 factorial, placebo-controlled, double-dummy design was used for the study. GH and/or sex steroid [transdermal estradiol plus oral medroxyprogesterone acetate in women (HRT); testosterone enanthate (T) in men] were administered for 6 months. Healthy, community-dwelling women (n = 57) and men (n = 74) ages 65-88 yr (mean, 72 yr) participated in the study. We measured serum glucose, insulin, and insulin sensitivity [quantitative insulin sensitivity check index (QUICKI) and insulin sensitivity index (ISI)] before and during an oral glucose tolerance test and lipid profiles. In women, GH did not alter oral glucose tolerance test 120 min or 2-h area under the curve (AUC) glucose values, but it increased 120 min insulin and AUC insulin. There were no significant effects of HRT or GH+HRT. ISI and QUICKI decreased after GH. In men, GH increased 120 min and AUC glucose and insulin AUC. GH+T increased 120 min glucose and glucose and insulin AUCs. T alone did not affect glucose or insulin. ISI decreased after GH and GH+T, whereas QUICKI decreased after GH. GH in women and men and GH+T in men decreased QUICKI by 4 wk. In women, HRT decreased total cholesterol and low-density lipoprotein (LDL)-cholesterol, and GH decreased LDL-cholesterol. In men, total cholesterol decreased after T and GH+T. LDL-cholesterol decreased after GH and GH+T. GH increased serum triglycerides. GH administration to healthy older individuals for 6 months increased insulin resistance with moderately beneficial effects on lipids.

  7. Analysis of serum insulin growth factor-1 concentrations in localized osteosarcoma: a children's oncology group study.

    Science.gov (United States)

    Borinstein, Scott C; Barkauskas, Donald A; Bernstein, Mark; Goorin, Allen; Gorlick, Richard; Krailo, Mark; Schwartz, Cindy L; Wexler, Leonard H; Toretsky, Jeffrey A

    2014-04-01

    To investigate the role of insulin-like growth factor-1 (IGF-1), in localized osteosarcoma, serum levels of IGF-1, IGFBP-2, and IGFBP-3 were measured in 224 similarly treated, newly diagnosed patients. We demonstrated that younger patients had lower concentrations of IGF-1 and IGFBP-3 compared to older (P < 0.001) along with lower IGFBP-3:IGF-1 and IGFBP-2:IGF-1 ratios (P < 0.001). IGFBP-2 did not correlate with age (P = 0.16), yet IGFBP-2:IGF-1 ratios were higher in the younger population (P < 0.001). These findings show that older patients have higher concentrations of free IGF-1. None of IGF-1, IGFBP-2, nor IGFBP-3 concentrations were associated with event-free nor overall survival. © 2013 Wiley Periodicals, Inc.

  8. Lower waist circumference in mildly-stunted adolescents is associated with elevated insulin concentration.

    Science.gov (United States)

    Clemente, Ana Paula Grotti; Santos, Carla Danusa da Luz; Martins, Vinicius J B; Albuquerque, Maria Paula; Fachim, Mariana B; Sawaya, Ana Lydia

    2014-01-01

    Augmented waist circumference (WC) is associated with non-communicable diseases and could represent a valuable marker in screening for metabolic dysfunctions in subjects with insufficient linear growth. The objective of the present study was to determine whether biochemical and hemodynamic parameters and waist circumference vary between mildly-stunted and non-stunted adolescents from impoverished communities of São Paulo, Brazil. The cross-sectional study involved 206 subjects, aged between 9 and 19 years and living in impoverished areas of São Paulo, Brazil. The sample population was divided according to height-for-age Z-score (HAZ) into stunted (-1 > HAZ ≥ -2) and non-stunted (HAZ ≥ -1) groups, and was sub-divided according to gender. Logistic regression analysis was employed to compare individuals with elevated (> 75th percentile) insulin concentrations. The receiver operating characteristic curves were constructed to determine WC cut-off points that could be used to identify stunted and non-stunted individuals with elevated insulin concentrations. WC cut-off points of 58.25cm and 67.2cm allowed for correct classification of 90.7% of stunted and 88.7% of non-stunted individuals in the studied population. While the sensitivity of the model was high for stunted and non-stunted subjects (98.8% and 97.2%, respectively), the specificity was modest (57.1% and 41.2%, respectively). The results presented herein suggest that an increase in plasma insulin is one of the primary metabolic modifications in stunted individuals, and that this alteration could be identified at a lower WC cut-off point than in non-stunted counterparts. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  9. Lower waist circumference in mildly-stunted adolescents is associated with elevated insulin concentration

    Directory of Open Access Journals (Sweden)

    Ana Paula Grotti Clemente

    2014-09-01

    Full Text Available Objective: Augmented waist circumference (WC is associated with non-communicable diseases and could represent a valuable marker in screening for metabolic dysfunctions in subjects with insufficient linear growth. The objective of the present study was to determine whether bio-chemical and hemodynamic parameters and waist circumference vary between mildly-stunted and non-stunted adolescents from impoverished communities of São Paulo, Brazil. Methods: The cross-sectional study involved 206 subjects, aged between 9 and 19 years and living in impoverished areas of São Paulo, Brazil. The sample population was divided according to height-for-age Z-score (HAZ into stunted (−1 > HAZ ≥ −2 and non-stunted (HAZ ≥ −1 groups, and was sub-divided according to gender. Logistic regression analysis was employed to compare individuals with elevated (> 75th percentile insulin concentrations. The receiver operating characteristic curves were constructed to determine WC cut-off points that could be used to identify stunted and non-stunted individuals with elevated insulin concentrations. Results: WC cut-off points of 58.25 cm and 67.2 cm allowed for correct classification of 90.7% of stunted and 88.7% of non-stunted individuals in the studied population. While the sensitivity of the model was high for stunted and non-stunted subjects (98.8% and 97.2%, respectively, the specificity was modest (57.1% and 41.2%, respectively. Conclusion: The results presented herein suggest that an increase in plasma insulin is one of the primary metabolic modifications in stunted individuals, and that this alteration could be identified at a lower WC cut-off point than in non-stunted counterparts.

  10. Reduced plasma aldosterone concentrations in randomly selected patients with insulin-dependent diabetes mellitus.

    LENUS (Irish Health Repository)

    Cronin, C C

    2012-02-03

    Abnormalities of the renin-angiotensin system have been reported in patients with diabetes mellitus and with diabetic complications. In this study, plasma concentrations of prorenin, renin, and aldosterone were measured in a stratified random sample of 110 insulin-dependent (Type 1) diabetic patients attending our outpatient clinic. Fifty-four age- and sex-matched control subjects were also examined. Plasma prorenin concentration was higher in patients without complications than in control subjects when upright (geometric mean (95% confidence intervals (CI): 75.9 (55.0-105.6) vs 45.1 (31.6-64.3) mU I-1, p < 0.05). There was no difference in plasma prorenin concentration between patients without and with microalbuminuria and between patients without and with background retinopathy. Plasma renin concentration, both when supine and upright, was similar in control subjects, in patients without complications, and in patients with varying degrees of diabetic microangiopathy. Plasma aldosterone was suppressed in patients without complications in comparison to control subjects (74 (58-95) vs 167 (140-199) ng I-1, p < 0.001) and was also suppressed in patients with microvascular disease. Plasma potassium was significantly higher in patients than in control subjects (mean +\\/- standard deviation: 4.10 +\\/- 0.36 vs 3.89 +\\/- 0.26 mmol I-1; p < 0.001) and plasma sodium was significantly lower (138 +\\/- 4 vs 140 +\\/- 2 mmol I-1; p < 0.001). We conclude that plasma prorenin is not a useful early marker for diabetic microvascular disease. Despite apparently normal plasma renin concentrations, plasma aldosterone is suppressed in insulin-dependent diabetic patients.

  11. Cheddar Cheese Ripening Affects Plasma Nonesterified Fatty Acid and Serum Insulin Concentrations in Growing Pigs.

    Science.gov (United States)

    Thorning, Tanja K; Bendsen, Nathalie T; Jensen, Søren K; Ardö, Ylva; Tholstrup, Tine; Astrup, Arne; Raben, Anne

    2015-07-01

    Meta-analyses of observational studies found cheese consumption to be inversely associated with risk of type 2 diabetes and metabolic syndrome. This may be attributed to the bioactive compounds produced during cheese ripening. The objective of this study was to investigate by means of a porcine model how cheeses with different ripening times affect blood glucose, insulin, and lipid concentrations and fecal-fat excretion. A parallel-arm randomized intervention study with 36 Landrace × Yorkshire × Duroc crossbred 3-mo-old female pigs was conducted. The pigs were fed a 21-d butter-rich run-in diet (143 g of butter/kg diet), followed by a 14-d intervention with 1 of 3 isocaloric diets: 4-mo ripened cheddar (4-MRC) diet, 14-mo ripened cheddar (14-MRC) diet, or 24-mo ripened cheddar (24-MRC) diet (350 g of cheese/kg diet). Serum cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, and insulin; plasma nonesterified fatty acids (NEFAs) and glucose; fecal-fat excretion; and body weight were measured. Plasma NEFAs were lower in the 24-MRC (201 ± 26 μEq/L) and in the 14-MRC (171 ± 19 μEq/L) diet groups than in the 4-MRC diet group (260 ± 27 μEq/L; P = 0.044 and P = 0.001). Serum insulin was lower in the 24-MRC diet group (1.04 ± 0.09 mmol/L) than in the 4-MRC diet group (1.44 ± 0.14 mmol/L; P = 0.002), but intermediate and not different from either in the 14-MRC diet group (1.25 ± 0.11 mmol/L). Likewise, homeostasis model assessment of insulin resistance was lower in the 24-MRC diet group (0.030 ± 0.003) than in the 4-MRC diet group (0.041 ± 0.005; P < 0.01), but intermediate and not different from either in the 14-MRC group (0.036 ± 0.004). Intake of long-term ripened cheddar improved indicators of insulin sensitivity in growing pigs compared with short-term ripened cheddar. This may also be important for human health. © 2015 American Society for Nutrition.

  12. Effects of intraperitoneal insulin versus subcutaneous insulin administration on sex hormone-binding globulin concentrations in patients with type 1 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    M Boering

    2016-06-01

    Full Text Available Aims Elevated sex hormone-binding globulin (SHBG concentrations have been described in patients with type 1 diabetes mellitus (T1DM, probably due to low portal insulin concentrations. We aimed to investigate whether the route of insulin administration, continuous intraperitoneal insulin infusion (CIPII, or subcutaneous (SC, influences SHBG concentrations among T1DM patients. Methods Post hoc analysis of SHBG in samples derived from a randomized, open-labeled crossover trial was carried out in 20 T1DM patients: 50% males, mean age 43 (±13 years, diabetes duration 23 (±11 years, and hemoglobin A1c (HbA1c 8.7 (±1.1 (72 (±12 mmol/mol. As secondary outcomes, testosterone, 17-β-estradiol, luteinizing hormone (LH, and follicle-stimulating hormone (FSH were analyzed. Results Estimated mean change in SHBG was −10.3nmol/L (95% CI: −17.4, −3.2 during CIPII and 3.7nmol/L (95% CI: −12.0, 4.6 during SC insulin treatment. Taking the effect of treatment order into account, the difference in SHBG between therapies was −6.6nmol/L (95% CI: −17.5, 4.3; −12.7nmol/L (95% CI: −25.1, −0.4 for males and −1.7nmol/L (95% CI: −24.6, 21.1 for females, respectively. Among males, SHBG and testosterone concentrations changed significantly during CIPII; −15.8nmol/L (95% CI: −24.2, −7.5 and −8.3nmol/L (95% CI: −14.4, −2.2, respectively. The difference between CIPII and SC insulin treatment was also significant for change in FSH 1.2U/L (95% CI: 0.1, 2.2 among males. Conclusions SHBG concentrations decreased significantly during CIPII treatment. Moreover, the difference in change between CIPII and SC insulin therapy was significant for SHBG and FSH among males. These findings support the hypothesis that portal insulin administration influences circulating SHBG and sex steroids.

  13. Effect of apple polyphenol concentrate on lipid metabolism in rats under experimental insulin resistance.

    Science.gov (United States)

    Zagayko, Andriy L; Kravchenko, Ganna B; Fylymonenko, Viktoriia P; Krasilnikova, Oksana A

    Obesity is strongly associated with an increased risk of developing insulin resistance as the metabolic indicator of prediabetes and a major risk factor in diabetes mellitus type 2 pathogenesis. Medicinal products obtained from apples can be used as potent prophylactic and therapeutic remedies in treatment of diabetes mellitus. Experiment was designed to study the effect of total apple polyphenol food concentrate on lipid metabolism under experimental IR. Male Wistar rats weighting 180-210 g were used in the experiment. IR was induced by high-calorie diet enriched with fructose. The effect of total apple polyphenol food concentrate was compared with the action of epigallocatechin gallate and quercetin. To estimate the alterations in lipid metabolism in liver homogenate were measured triacylglycerols, free fatty acids, total phospholipids, TBA-reactive substance and conjugated dienes contents. In blood serum were measured total lipids, triacylglycerols, cholesterol, total phospholipids and reduced glutathione levels. The obtained results indicated that feeding rats with high-calorie diet enriched with fructose caused the dyslipidemia and oxidative stress development. The administration of quercetin, epigallocatechin gallate and total apple polyphenol food concentrate improved disorders of lipid metabolism and pro-oxidant-antioxidant homeostasis. Total apple polyphenol food concentrate had a more pronounced effect on studied indices that is probably due to synergism and additive effect of extract numerous components.

  14. Cheddar cheese ripening affects plasma nonesterified fatty acids and serum insulin concentrations in growing pigs

    DEFF Research Database (Denmark)

    Thorning, Tanja Kongerslev; Bendsen, Nathalie Tommerup; Jensen, Søren Krogh

    2015-01-01

    a 21-d butter-rich run-in diet (143 g of butter/kg diet), followed by a 14-d intervention with 1 of 3 isocaloric diets: 4-mo ripened cheddar (4-MRC) diet, 14-mo ripened cheddar (14-MRC) diet, or 24-mo ripened cheddar (24-MRC) diet (350 g of cheese/kg diet). Serum cholesterol, triglyceride, HDL......BACKGROUND: Meta-analyses of observational studies found cheese consumption to be inversely associated with risk of type 2 diabetes and metabolic syndrome. This may be attributed to the bioactive compounds produced during cheese ripening. OBJECTIVE: The objective of this study was to investigate...... by means of a porcine model how cheeses with different ripening times affect blood glucose, insulin, and lipid concentrations and fecal-fat excretion. METHODS: A parallel-arm randomized intervention study with 36 Landrace × Yorkshire × Duroc crossbred 3-mo-old female pigs was conducted. The pigs were fed...

  15. Attenuated Suppression of Lipolysis Explains Increases in Triglyceride Secretion and Concentration with Basal Insulin Peglispro (BIL) Relative to Insulin Glargine Treatment in Patients with Type 1 Diabetes

    DEFF Research Database (Denmark)

    Johansen, Rakel Fuglsang; Søndergaard, Esben; Linnebjerg, Helle

    2017-01-01

    AIMS: In patients with type 1 diabetes, basal insulin peglispro (BIL) lowers weight and increases plasma triglycerides (TG) and hepatic fat relative to insulin glargine (GL). To explain this, we hypothesised that BIL's attenuated peripheral effects may include increased free fatty acid flux...... to the liver, causing increased VLDL-TG secretion and lipid oxidation, and decreased TG adipose tissue deposition. MATERIALS AND METHODS: In this open-label, randomised, 2-period crossover study, 14 patients with type 1 diabetes received once-daily, individualised, stable BIL or GL doses for 3 weeks. Palmitate.......90), respectively. The difference in LS means (95% CI) for VLDL-TG storage rate was -0.36 (-0.83, 0.12). CONCLUSIONS: BIL-treated patients had higher effective lipolysis, VLDL-TG secretion and VLDL-TG concentration versus GL, explaining the increased plasma TG concentrations reported previously. Data support...

  16. Adrenal Demedullation and Oxygen Supplementation Independently Increase Glucose-Stimulated Insulin Concentrations in Fetal Sheep With Intrauterine Growth Restriction

    Science.gov (United States)

    Macko, Antoni R.; Yates, Dustin T.; Chen, Xiaochuan; Shelton, Leslie A.; Kelly, Amy C.; Davis, Melissa A.; Camacho, Leticia E.; Anderson, Miranda J.

    2016-01-01

    In pregnancies complicated by placental insufficiency and intrauterine growth restriction (IUGR), fetal glucose and oxygen concentrations are reduced, whereas plasma norepinephrine and epinephrine concentrations are elevated throughout the final third of gestation. Here we study the effects of chronic hypoxemia and hypercatecholaminemia on β-cell function in fetal sheep with placental insufficiency-induced IUGR that is produced by maternal hyperthermia. IUGR and control fetuses underwent a sham (intact) or bilateral adrenal demedullation (AD) surgical procedure at 0.65 gestation. As expected, AD-IUGR fetuses had lower norepinephrine concentrations than intact-IUGR fetuses despite being hypoxemic and hypoglycemic. Placental insufficiency reduced fetal weights, but the severity of IUGR was less with AD. Although basal plasma insulin concentrations were lower in intact-IUGR and AD-IUGR fetuses compared with intact-controls, glucose-stimulated insulin concentrations were greater in AD-IUGR fetuses compared with intact-IUGR fetuses. Interestingly, AD-controls had lower glucose- and arginine-stimulated insulin concentrations than intact-controls, but AD-IUGR and AD-control insulin responses were not different. To investigate chronic hypoxemia in the IUGR fetus, arterial oxygen tension was increased to normal levels by increasing the maternal inspired oxygen fraction. Oxygenation of IUGR fetuses enhanced glucose-stimulated insulin concentrations 3.3-fold in intact-IUGR and 1.7-fold in AD-IUGR fetuses but did not lower norepinephrine and epinephrine concentrations. Together these findings show that chronic hypoxemia and hypercatecholaminemia have distinct but complementary roles in the suppression of β-cell responsiveness in IUGR fetuses. PMID:26937714

  17. pH-dependent self-association of zinc-free Insulin characterized by concentration-gradient static light scattering

    OpenAIRE

    Attri, Arun K.; Fernández, Cristina; Minton, Allen P.

    2010-01-01

    Insulin self-association at pH 1.85, 1.95, 3.0, 7.2, 8.0 and 10 was studied via composition gradient light scattering (CG-SLS). At pH 1.95 in acetic acid, insulin was found to exist as a monomer, and in pH 1.85 HCl as a dimer. At pH values of 3.0 – 8.0, the dependence of scattering intensity upon total insulin concentration at concentrations of up to 1.5 mg/mL may be quantitatively accounted for by a simple isodesmic association equilibrium scheme requiring only a single association constant ...

  18. Potential life-threatening variations of drug concentrations in intravenous infusion systems: potassium chloride, insulin, and heparin

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, N.; Vellar, I.D.

    1982-09-18

    The investigation of concentrations of active agents in common carrier media for intravenous infusion revealed that potassium chloride tends to form a pool when it is added without mixing to carrier media in glass or polyvinyl chloride (PVC) containers which are already suspended in their functional position with ports pointing downwards. Heparin behaves in a similar fashion when added without mixing to carrier media in PVC containers. Such uneven distribution may expose a patient to potentially dangerous, possibly lethal, concentrations of a drug even when a relatively small amount of it is used. Insulin floats to the top of a Haemaccel container if its contents are not adequately mixed after addition of insulin. The resultant irregularity of insulin dosage may make the management of diabetic ketoacidosis more difficult. It is recommended that the instructions for the adequate mixing of contents should appear on all containers of carrier media for intravenous infusions.

  19. Changes in serum concentrations of growth hormone, insulin, insulin-like growth factor and insulin-like growth factor-binding proteins 1 and 3 and urinary growth hormone excretion during the menstrual cycle

    DEFF Research Database (Denmark)

    Juul, A; Scheike, Thomas Harder; Pedersen, A T

    1997-01-01

    Few studies exist on the physiological changes in the concentrations of growth hormone (GH), insulin-like growth factors (IGF) and IGF-binding proteins (IGFBP) within the menstrual cycle, and some controversy remains. We therefore decided to study the impact of endogenous sex steroids on the GH......, with significantly higher values in the luteal phase compared to the proliferative phase (P changes in IGFBP-3 serum concentrations and no differences in IGFBP-3...... that returned to baseline at the day of the LH surge. Fasting insulin concentrations showed large fluctuations throughout the menstrual cycle without any distinct cyclic pattern. No cyclic changes in urinary GH excretion during menstrual cycle were detected. We conclude that, although IGF-I concentrations...

  20. Salsalate-induced Changes in Lipid/Lipoprotein/Apoprotein Concentrations in Obese/Overweight, Insulin Resistant, Nondiabetic Individuals

    Science.gov (United States)

    Ariel, Danit; Kim, Sun H.; Liu, Alice; Abbasi, Fahim; Lamendola, Cindy A.; Grove, Kaylene; Tomasso, Vanessa; Reaven, Gerald M

    2015-01-01

    Background and Objective Although salsalate administration consistently lowers plasma triglyceride (TG) concentrations in patients with type 2 diabetes, prediabetes, and/or insulin resistance, changes in low-density lipoprotein cholesterol (LDL-C) concentrations have been inconsistent; varying from no change to a significant increase. To evaluate the clinical relevance of this discordance in more detail we directly measured LDL-C, as well as obtained a comprehensive assessment of changes in lipid/lipoprotein/apoprotein concentrations associated with salsalate use in insulin resistant individuals, overweight or obese, but without diabetes, using Vertical Auto Profile (VAP) method. Methods A single-blind, randomized, placebo-controlled study was performed in volunteers who were overweight or obese, without diabetes, and insulin resistant on the basis of their steady-state plasma glucose concentration during an insulin suppression test. Participants were randomized 2:1 to receive salsalate 3.5 grams/day (n=27) or placebo (n=14) for 4 weeks. Comprehensive lipid/lipoprotein/apoprotein analysis by VAP was obtained after an overnight fast, before and after study intervention. Results There was no change in directly measured LDL-C concentration in salsalate-treated individuals. However, salsalate administration was associated with various changes considered to decrease atherogenicity; including decreases in TG and total very-low-density lipoprotein cholesterol (VLDL-C) concentrations, a shift from small denser LDL lipoproteins towards larger, more buoyant LDL particles, decreases in VLDL1+2-C and LDL4-C, and non-significant decreases in non-high-density lipoprotein cholesterol and apolipoprotein B. No significant changes occurred in the placebo-treated group. Conclusion Atherogenicity of the lipid/lipoprotein/apoprotein profile of insulin resistant individuals who were overweight or obese improved significantly in association with salsalate treatment. The clinical

  1. Dynamics of glucose and insulin concentration connected to the β‐cell cycle: model development and analysis

    Directory of Open Access Journals (Sweden)

    Gallenberger Martina

    2012-11-01

    Full Text Available Abstract Background Diabetes mellitus is a group of metabolic diseases with increased blood glucose concentration as the main symptom. This can be caused by a relative or a total lack of insulin which is produced by the β‐cells in the pancreatic islets of Langerhans. Recent experimental results indicate the relevance of the β‐cell cycle for the development of diabetes mellitus. Methods This paper introduces a mathematical model that connects the dynamics of glucose and insulin concentration with the β‐cell cycle. The interplay of glucose, insulin, and β‐cell cycle is described with a system of ordinary differential equations. The model and its development will be presented as well as its mathematical analysis. The latter investigates the steady states of the model and their stability. Results Our model shows the connection of glucose and insulin concentrations to the β‐cell cycle. In this way the important role of glucose as regulator of the cell cycle and the capability of the β‐cell mass to adapt to metabolic demands can be presented. Simulations of the model correspond to the qualitative behavior of the glucose‐insulin regulatory system showed in biological experiments. Conclusions This work focusses on modeling the physiological situation of the glucose‐insulin regulatory system with a detailed consideration of the β‐cell cycle. Furthermore, the presented model allows the simulation of pathological scenarios. Modification of different parameters results in simulation of either type 1 or type 2 diabetes.

  2. Effects of prior exercise on the action of insulin-like growth factor I in skeletal muscle

    Science.gov (United States)

    Henriksen, E. J.; Louters, L. L.; Stump, C. S.; Tipton, C. M.

    1992-01-01

    Prior exercise increases insulin sensitivity for glucose and system A neutral amino acid transport activities in skeletal muscle. Insulin-like growth factor I (IGF-I) also activates these transport processes in resting muscle. It is not known, however, whether prior exercise increases IGF-I action in muscle. Therefore we determined the effect of a single exhausting bout of swim exercise on IGF-I-stimulated glucose transport activity [assessed by 2-deoxy-D-glucose (2-DG) uptake] and system A activity [assessed by alpha-(methylamino)isobutyric acid (MeAIB) uptake] in the isolated rat epitrochlearis muscle. When measured 3.5 h after exercise, the responses to a submaximal concentration (0.2 nM), but not a maximal concentration (13.3 nM), of insulin for activation of 2-DG uptake and MeAIB uptake were enhanced. In contrast, prior exercise increased markedly both the submaximal (5 nM) and maximal (20 nM) responses to IGF-I for activation of 2-DG uptake, whereas only the submaximal response to IGF-I (3 nM) for MeAIB uptake was enhanced after exercise. We conclude that 1) prior exercise significantly enhances the response to a submaximal concentration of IGF-I for activation of the glucose transport and system A neutral amino acid transport systems in skeletal muscle and 2) the enhanced maximal response for IGF-I action after exercise is restricted to the signaling pathway for activation of the glucose transport system.

  3. Jatropha curcas Protein Concentrate Stimulates Insulin Signaling, Lipogenesis, Protein Synthesis and the PKCα Pathway in Rat Liver.

    Science.gov (United States)

    León-López, Liliana; Márquez-Mota, Claudia C; Velázquez-Villegas, Laura A; Gálvez-Mariscal, Amanda; Arrieta-Báez, Daniel; Dávila-Ortiz, Gloria; Tovar, Armando R; Torres, Nimbe

    2015-09-01

    Jatropha curcas is an oil seed plant that belongs to the Euphorbiaceae family. Nontoxic genotypes have been reported in Mexico. The purpose of the present work was to evaluate the effect of a Mexican variety of J. curcas protein concentrate (JCP) on weight gain, biochemical parameters, and the expression of genes and proteins involved in insulin signaling, lipogenesis, cholesterol and protein synthesis in rats. The results demonstrated that short-term consumption of JCP increased serum glucose, insulin, triglycerides and cholesterol levels as well as the expression of transcription factors involved in lipogenesis and cholesterol synthesis (SREBP-1 and LXRα). Moreover, there was an increase in insulin signaling mediated by Akt phosphorylation and mTOR. JCP also increased PKCα protein abundance and the activation of downstream signaling pathway targets such as the AP1 and NF-κB transcription factors typically activated by phorbol esters. These results suggested that phorbol esters are present in JCP, and that they could be involved in the activation of PKC which may be responsible for the high insulin secretion and consequently the activation of insulin-dependent pathways. Our data suggest that this Mexican Jatropha variety contains toxic compounds that produce negative metabolic effects which require caution when using in the applications of Jatropha-based products in medicine and nutrition.

  4. Circulating branched-chain amino acid concentrations are associated with obesity and future insulin resistance in children and adolescents.

    Science.gov (United States)

    McCormack, S E; Shaham, O; McCarthy, M A; Deik, A A; Wang, T J; Gerszten, R E; Clish, C B; Mootha, V K; Grinspoon, S K; Fleischman, A

    2013-02-01

    What is already known about this subject Circulating concentrations of branched-chain amino acids (BCAAs) can affect carbohydrate metabolism in skeletal muscle, and therefore may alter insulin sensitivity. BCAAs are elevated in adults with diet-induced obesity, and are associated with their future risk of type 2 diabetes even after accounting for baseline clinical risk factors. What this study adds Increased concentrations of BCAAs are already present in young obese children and their metabolomic profiles are consistent with increased BCAA catabolism. Elevations in BCAAs in children are positively associated with insulin resistance measured 18 months later, independent of their initial body mass index. Branched-chain amino acid (BCAA) concentrations are elevated in response to overnutrition, and can affect both insulin sensitivity and secretion. Alterations in their metabolism may therefore play a role in the early pathogenesis of type 2 diabetes in overweight children. To determine whether paediatric obesity is associated with elevations in fasting circulating concentrations of BCAAs (isoleucine, leucine and valine), and whether these elevations predict future insulin resistance. Sixty-nine healthy subjects, ages 8-18 years, were enrolled as a cross-sectional cohort. A subset of subjects who were pre- or early-pubertal, ages 8-13 years, were enrolled in a prospective longitudinal cohort for 18 months (n = 17 with complete data). Elevations in the concentrations of BCAAs were significantly associated with body mass index (BMI) Z-score (Spearman's Rho 0.27, P = 0.03) in the cross-sectional cohort. In the subset of subjects that followed longitudinally, baseline BCAA concentrations were positively associated with homeostasis model assessment for insulin resistance measured 18 months later after controlling for baseline clinical factors including BMI Z-score, sex and pubertal stage (P = 0.046). Elevations in the concentrations of circulating BCAAs are significantly

  5. Relationship between Serum Concentration of Uric Acid and Insulin Secretion among Adults with Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    J. A. Robles-Cervantes

    2011-01-01

    Full Text Available To determine the relationship between serum concentrations of uric acid and insulin secretion with hyperglycaemic clamp technique among adults with type 2 diabetes mellitus (DM2 without hyperuricemia, we carried out a cross-sectional study on 45 patients of both gender. We observed correlation between uric acid with male gender r=0.710 (P=0.001. Also correlation between uric acid and total insulin secretion was positive r=0.295 (P=0.049. As well as a positive correlation adjusted for body mass index was demonstrated for the first, second, and total phases of insulin secretion, respectively, r=0.438 (P=0.022, r=0.433 (P=0.022, and r=0.439 (P=0.024. Serum concentration of uric acid showed a positive relationship with the total phase of insulin secretion; even in states prior to hyperuricemia, uric acid can play an important role in the function of the beta cell in patients with DM2.

  6. Common variants related to serum uric acid concentrations are associated with glucose metabolism and insulin secretion in a Chinese population.

    Directory of Open Access Journals (Sweden)

    Xue Sun

    Full Text Available Elevated serum uric acid concentration is an independent risk factor and predictor of type 2 diabetes (T2D. Whether the uric acid-associated genes have an impact on T2D remains unclear. We aimed to investigate the effects of the uric acid-associated genes on the risk of T2D as well as glucose metabolism and insulin secretion.We recruited 2,199 normal glucose tolerance subjects from the Shanghai Diabetes Study I and II and 2,999 T2D patients from the inpatient database of Shanghai Diabetes Institute. Fifteen single nucleotide polymorphisms (SNPs mapped in or near 11 loci (PDZK1, GCKR, LRP2, SLC2A9, ABCG2, LRRC16A, SLC17A1, SLC17A3, SLC22A11, SLC22A12 and SF1 were genotyped and serum biochemical parameters related to uric acid and T2D were determined.SF1 rs606458 showed strong association to T2D in both males and females (p = 0.034 and 0.0008. In the males, LRRC16A was associated with 2-h insulin and insulin secretion (p = 0.009 and 0.009. SLC22A11 was correlated with HOMA-B and insulin secretion (p = 0.048 and 0.029. SLC2A9 rs3775948 was associated with 2-h glucose (p = 0.043. In the females, LRP2 rs2544390 and rs1333049 showed correlations with fasting insulin, HOMA-IR and insulin secretion (p = 0.028, 0.033 and 0.052 and p = 0.034, 0.047 and 0.038, respectively. SLC2A9 rs11722228 was correlated with 2-h glucose, 2-h insulin and insulin secretion (p = 0.024, 0.049 and 0.049, respectively.Our results indicated that the uric acid-associated genes have an impact on the risk of T2D, glucose metabolism and insulin secretion in a Chinese population.

  7. Inflammation but not obesity or insulin resistance is associated with increased plasma fibroblast growth factor 23 concentration in the elderly.

    Science.gov (United States)

    Holecki, Michał; Chudek, Jerzy; Owczarek, Aleksander; Olszanecka-Glinianowicz, Magdalena; Bożentowicz-Wikarek, Maria; Duława, Jan; Mossakowska, Małgorzata; Zdrojewski, Tomasz; Skalska, Anna; Więcek, Andrzej

    2015-06-01

    Fibroblast growth factor 23 (FGF23) is a hormone involved in calcium-phosphate homoeostasis. The data of recently published studies suggest that FGF-23 may also play a role in some metabolic processes beyond mineral metabolism, such as insulin resistance or energy homoeostasis. The aim of the study was to attempt the relationships between plasma cFGF-23 (C-terminal) and iFGF-23 (intact) concentrations and the occurrence of obesity, insulin resistance and inflammation in elderly population. The analysis included 3115 elderly subjects (1485 women). During three visits, a questionnaire survey, comprehensive geriatric assessment and anthropometric measurements were performed as well as blood and urine samples were collected by trained nurses. Serum phosphorus, calcium, intact parathormone (iPTH), 25(OH)D3 , iFGF-23 and cFGF-23, insulin, glucose, albumin (also in urine), creatinine, hs-CRP, interleukin-6 and NT-proBNP concentrations were assessed. HOMA-IR was calculated according to the standard formula. Both forms of FGF23, iPTH and 25-OH-D3 levels were not related to the occurrence of obesity and insulin resistance. Increase in phosphorus, iPTH and NT-proBNP concentrations is associated with rise in plasma iFGF23 and cFGF23 levels. Additionally, increase in hs-CRP explained the elevated plasma iFGF23 levels. In multiple regression models, circulating iFGF23 and cFGF23 level's variability in elderly population were explained by changes in serum phosphorus, iPTH, eGFR, hs-CRP and NT-proBNP levels but not by BMI and HOMA-IR values. In conclusion, our study shows that increased levels of both circulating Fibroblast growth factor 23 forms in elderly subjects are associated with inflammation but not obesity or insulin resistance per se. © 2015 John Wiley & Sons Ltd.

  8. The influence of sodium propionate on blood glucose, insulin and cortisol concentrations in calves of different ages

    Directory of Open Access Journals (Sweden)

    Biljana Radojičić

    2016-01-01

    Full Text Available The process of gluconeogenesis in ruminants is under the direct influence of insulin and glucocorticoid hormones. The goal of this study was to determine the effects of added Na-propionate on the neuroendocrine regulation of blood glucose in calves at three specific physiological periods: on exclusive milk nutrition; on mixed milk and forage nutrition; and with established ruminant digestion. The influence of Na-propionate on blood glucose, insulin and cortisol concentrations was examined in the same 20 female Holstein calves at different stages of forestomach development (15 days, 2 months, and 4 months of age of calves. Group 1 of calves (n = 10 received Na-propionate intravenously; group 2 (n = 10 received Na-propionate mixed in milk. Blood sampling was performed 1 and 3 h after Na-propionate administration. After i.v. administration of Na-propionate, a significant increase (P < 0.05 in blood glucose concentration was observed 1 h after administration only in calves aged 2 and 4 months; blood insulin concentration was significantly higher (P < 0.01 1 and 3 h after i.v. administration in 2-month-old calves; and cortisol concentration increased (P < 0.01 1 h after administration in each selected calf in all testing periods. Orally administered Na-propionate led to a significant increase (P < 0.01 of insulin concentration 1 and 3 h after administration in 15-day-old calves, and 3 h after administration in 2-month-old calves. Based on these results it could be assumed that i.v. and p.o. administration of Na-propionate affects the neuroendocrine regulation of glycaemia in calves of different age.

  9. Effect of post-exercise caffeine and green coffee bean extract consumption on blood glucose and insulin concentrations.

    Science.gov (United States)

    Beam, Jason R; Gibson, Ann L; Kerksick, Chad M; Conn, Carole A; White, Ailish C; Mermier, Christine M

    2015-02-01

    The aim of this study was to investigate the effects of ingesting caffeine and green coffee bean extract on blood glucose and insulin concentrations during a post-exercise oral glucose tolerance test. Ten male cyclists (age: 26 ± 5 y; height: 179.9 ± 5.4 cm; weight: 77.6 ± 13.3 kg; body mass index: 24 ± 4.3 kg/m(2); VO2 peak: 55.9 ± 8.4 mL·kg·min(-1)) participated in this study. In a randomized order, each participant completed three 30-min bouts of cycling at 60% of peak power output. Immediately after exercise, each participant consumed 75 g of dextrose with either 5 mg/kg body weight of caffeine, 10 mg/kg of green coffee bean extract (5 mg/kg chlorogenic acid), or placebo. Venous blood samples were collected immediately before and after exercise during completion of the oral glucose tolerance test. No significant time × treatment effects for blood glucose and insulin were found. Two-h glucose and insulin area under the curve values, respectively, for the caffeine (658 ± 74 mmol/L and 30,005 ± 13,304 pmol/L), green coffee bean extract (637 ± 100 mmol/L and 31,965 ± 23,586 pmol/L), and placebo (661 ± 77 mmol/L and 27,020 ± 12,339 pmol/L) trials were not significantly different (P > 0.05). Caffeine and green coffee bean extract did not significantly alter postexercise blood glucose and insulin concentrations when compared with a placebo. More human research is needed to determine the impact of these combined nutritional treatments and exercise on changes in blood glucose and insulin. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. No effect of modest selenium supplementation on insulin resistance in UK pregnant women, as assessed by plasma adiponectin concentration.

    Science.gov (United States)

    Mao, Jinyuan; Bath, Sarah C; Vanderlelie, Jessica J; Perkins, Anthony V; Redman, Christopher W G; Rayman, Margaret P

    2016-01-14

    Concern has been expressed recently that Se may increase the risk of type 2 diabetes, but this has not been tested in a randomised-controlled trial (RCT) in pregnant women. We took advantage of having stored plasma samples from the Se in Pregnancy Intervention (SPRINT) RCT of Se supplementation in pregnancy to test the effect of Se supplementation on a marker of insulin resistance in UK pregnant women. Because our blood samples were not fasted, we measured plasma adiponectin concentration, a recognised marker of insulin resistance that gives valid measurements in non-fasted samples, as diurnal variability is minor and there is no noticeable effect of food intake. In SPRINT, 230 primiparous UK women were randomised to treatment with Se (60 μg/d) or placebo from 12 weeks of gestation until delivery. We hypothesised that supplementation with Se at a nutritional level would not exacerbate the fall in adiponectin concentration that occurs in normal pregnancy, indicating the lack of an adverse effect on insulin resistance. Indeed, there was no significant difference between the two groups in the change in adiponectin from 12 to 35 weeks (P=0·938), nor when the analysis was restricted to the bottom or top quartiles of baseline whole-blood Se (P=0·515 and 0·858, respectively). Cross-sectionally, adiponectin concentration was not associated with any parameter of Se status, either at 12 or 35 weeks. It is reassuring that a nutritional dose of Se had no adverse effect on the concentration of adiponectin, a biomarker of insulin resistance, in pregnant women of modest Se status.

  11. pH-dependent self-association of zinc-free insulin characterized by concentration-gradient static light scattering.

    Science.gov (United States)

    Attri, Arun K; Fernández, Cristina; Minton, Allen P

    2010-05-01

    Insulin self-association at pH 1.85, 1.95, 3.0, 7.2, 8.0 and 10 was studied via composition gradient light scattering (CG-SLS). At pH 1.95 in acetic acid, insulin was found to exist as a monomer, and in pH 1.85 HCl as a dimer. At pH values of 3.0-8.0, the dependence of scattering intensity upon total insulin concentration at concentrations of up to 1.5mg/mL may be quantitatively accounted for by a simple isodesmic association equilibrium scheme requiring only a single association constant for addition of monomer to monomer or any oligomer. At pH 10, the association constant for addition of monomer to monomer was found to be smaller than the association constant for addition of monomer to all higher oligomers by a factor of approximately five. The isodesmic association scheme was also found to quantitatively account for the concentration dependence of the weight-average molecular weight derived from previously published sedimentation equilibrium measurements made at pH 7.0, and the best-fit value of the stepwise equilibrium constant obtained therefrom was in excellent agreement with that obtained from analysis of the light scattering data obtained at pH 7.2.

  12. The Effect of Acute Exercise on Serum Vaspin Level and Its Relation to Insulin Sensitivity in Overweight Elderly Men

    Directory of Open Access Journals (Sweden)

    Jabbar Bashiri

    2014-08-01

    Full Text Available Background: Vaspin is a new discovered adipocytokine which is a member of serine protease inhibitor family secreted from adipose tissue and might play a role in insulin sensitivity. The purpose of this study was to investigate the effect of acute exercise on serum vaspin levels and its relation to insulin sensitivity in overweight elderly men. Materials and Methods: In this semi-experimental study, 12 healthy elderly men volunteers randomly selected and performed one session aerobic exercise including 30 minutes of cycling at 70-75% of HRmax, which was followed by 30 minutes of recovery. Three blood samples were taken before exercise, immediately after exercise and after 30 minutes of recovery. Data were analyzed by repeated measure ANOVA and Bonferroni test and Pearson’s correlations were performed to identify possible relationship among the assessed variables. Statistical significance was set at p≤0.05. Results: There were no significant differences for vaspin across time. Insulin and glucose concentration and insulin resistance decreased immediately after exercise. However insulin concentration and insulin resistance returned to pre-exercise level at the end of recovery. Furthermore, no significant correlations were observed among the variables assessed except for the expected between insulin level and insulin resistance. Conclusion: These results indicate that a sub-maximal aerobic workout does not result in significant changes in vaspin levels in elderly men. Furthermore, we observed that vaspin is not associated with insulin sensitivity in this study.

  13. Consumption of meat is associated with higher fasting glucose and insulin concentrations regardless of glucose and insulin genetic risk scores: a meta-analysis of 50,345 Caucasians12

    Science.gov (United States)

    Fretts, Amanda M; Follis, Jack L; Nettleton, Jennifer A; Lemaitre, Rozenn N; Ngwa, Julius S; Wojczynski, Mary K; Kalafati, Ioanna Panagiota; Varga, Tibor V; Frazier-Wood, Alexis C; Houston, Denise K; Lahti, Jari; Ericson, Ulrika; van den Hooven, Edith H; Mikkilä, Vera; Kiefte-de Jong, Jessica C; Mozaffarian, Dariush; Rice, Kenneth; Renström, Frida; North, Kari E; McKeown, Nicola M; Feitosa, Mary F; Kanoni, Stavroula; Smith, Caren E; Garcia, Melissa E; Tiainen, Anna-Maija; Sonestedt, Emily; Manichaikul, Ani; van Rooij, Frank JA; Dimitriou, Maria; Raitakari, Olli; Pankow, James S; Djoussé, Luc; Province, Michael A; Hu, Frank B; Lai, Chao-Qiang; Keller, Margaux F; Perälä, Mia-Maria; Rotter, Jerome I; Hofman, Albert; Graff, Misa; Kähönen, Mika; Mukamal, Kenneth; Johansson, Ingegerd; Ordovas, Jose M; Liu, Yongmei; Männistö, Satu; Uitterlinden, André G; Deloukas, Panos; Seppälä, Ilkka; Psaty, Bruce M; Cupples, L Adrienne; Borecki, Ingrid B; Franks, Paul W; Arnett, Donna K; Nalls, Mike A; Eriksson, Johan G; Orho-Melander, Marju; Franco, Oscar H; Lehtimäki, Terho; Dedoussis, George V; Meigs, James B; Siscovick, David S

    2015-01-01

    Background: Recent studies suggest that meat intake is associated with diabetes-related phenotypes. However, whether the associations of meat intake and glucose and insulin homeostasis are modified by genes related to glucose and insulin is unknown. Objective: We investigated the associations of meat intake and the interaction of meat with genotype on fasting glucose and insulin concentrations in Caucasians free of diabetes mellitus. Design: Fourteen studies that are part of the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium participated in the analysis. Data were provided for up to 50,345 participants. Using linear regression within studies and a fixed-effects meta-analysis across studies, we examined 1) the associations of processed meat and unprocessed red meat intake with fasting glucose and insulin concentrations; and 2) the interactions of processed meat and unprocessed red meat with genetic risk score related to fasting glucose or insulin resistance on fasting glucose and insulin concentrations. Results: Processed meat was associated with higher fasting glucose, and unprocessed red meat was associated with both higher fasting glucose and fasting insulin concentrations after adjustment for potential confounders [not including body mass index (BMI)]. For every additional 50-g serving of processed meat per day, fasting glucose was 0.021 mmol/L (95% CI: 0.011, 0.030 mmol/L) higher. Every additional 100-g serving of unprocessed red meat per day was associated with a 0.037-mmol/L (95% CI: 0.023, 0.051-mmol/L) higher fasting glucose concentration and a 0.049–ln-pmol/L (95% CI: 0.035, 0.063–ln-pmol/L) higher fasting insulin concentration. After additional adjustment for BMI, observed associations were attenuated and no longer statistically significant. The association of processed meat and fasting insulin did not reach statistical significance after correction for multiple comparisons. Observed associations were not modified by genetic

  14. Reduced plasma adiponectin concentrations may contribute to impaired insulin activation of glycogen synthase in skeletal muscle of patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Højlund, K.; Frystyk, J.; Levin, K.

    2006-01-01

    AIMS/HYPOTHESIS: Circulating levels of adiponectin are negatively associated with multiple indices of insulin resistance, and the concentration is reduced in humans with insulin resistance and type 2 diabetes. However, the mechanisms by which adiponectin improves insulin sensitivity remain unclear...... (ten lean, 21 obese and 20 with type 2 diabetes). RESULTS: Plasma adiponectin was significantly reduced in type 2 diabetic compared with obese and lean subjects. In lean and obese subjects, insulin significantly reduced plasma adiponectin, but this response was blunted in patients with type 2 diabetes...... by improving the capacity to switch from lipid to glucose oxidation and to store glucose as glycogen in response to insulin, and that low adiponectin may contribute to impaired insulin activation of GS in skeletal muscle of patients with type 2 diabetes....

  15. Antepartal insulin-like growth factor concentrations indicating differences in the metabolic adaptive capacity of dairy cows

    Science.gov (United States)

    Holzhausen, Lars; Araujo, Marcelo Gil; Heppelmann, Maike; Sipka, Anja; Pfarrer, Chistiane; Schuberth, Hans-Joachim; Bollwein, Heinrich

    2014-01-01

    Cows with different Insulin-like Growth Factor-I (IGF-I) concentrations showed comparable expression levels of hepatic growth hormone receptor (GHR). Suppressor of cytokine signaling 2 (SOCS2), could be responsible for additional inhibition of the GHR signal cascade. The aims were to monitor cows with high or low antepartal IGF-I concentrations (IGF-Ihigh or IGF-Ilow), evaluate the interrelationships of endocrine endpoints, and measure hepatic SOCS2 expression. Dairy cows (n = 20) were selected (240 to 254 days after artificial insemination (AI)). Blood samples were drawn daily (day -17 until calving) and IGF-I, GH, insulin, thyroid hormones, estradiol, and progesterone concentrations were measured. Liver biopsies were taken (day 264 ± 1 after AI and postpartum) to measure mRNA expression (IGF-I, IGFBP-2, IGFBP-3, IGFBP-4, acid labile subunit (ALS), SOCS2, deiodinase1, GHR1A). IGF-I concentrations in the two groups were different (p 0.05). Thyroxine levels and ALS expression were higher in the IGF-Ihigh cows compared to IGF-Ilow cows. Estradiol concentration tended to be greater in the IGF-Ilow group (p = 0.06). It was hypothesized that low IGF-I levels are associated with enhanced SOCS2 expression although this could not be decisively confirmed by the present study. PMID:24962413

  16. Diminished concentrations of insulin-like growth factor I in cystic fibrosis

    DEFF Research Database (Denmark)

    Laursen, Erik; Juul, A; Lanng, S

    1995-01-01

    Cystic fibrosis is frequently accompanied by a catabolic condition with low body mass index caused by a number of disease complications. Insulin-like growth factor-I (IGF-I) is an anabolic hormone and an important marker of nutritional status, liver function, and linear growth. Available data...

  17. Circulating concentrations of insulin-like growth factor-1 in dogs with naturally occurring mitral regurgitation

    DEFF Research Database (Denmark)

    Pedersen, Henrik Duelund; Falk, Bo Torkel; Häggström, Jens

    2005-01-01

    Insulin-like growth factor-1 (IGF-1), which mediates most effects of growth hormone, has effects on cardiac mass and function, and plays an important role in the regulation of vascular tone. In humans, an inverse relationship between degree of heart failure (HF) and circulating IGF-1 concentratio...

  18. Antepartal insulin-like growth factor 1 and insulin-like growth factor binding protein 2 concentrations are indicative of ketosis in dairy cows.

    Science.gov (United States)

    Piechotta, M; Mysegades, W; Ligges, U; Lilienthal, J; Hoeflich, A; Miyamoto, A; Bollwein, H

    2015-05-01

    A study involving a small number of cows found that the concentrations of insulin-like growth hormone 1 (IGF1) may be a useful predictor of metabolic disease. Further, IGF1 may provide also a pathophysiological link to metabolic diseases such as ketosis. The objective of the current study was to test whether the low antepartal total IGF1 or IGF1 binding protein (IGFBP) concentrations might predict ketosis under field conditions. Clinical examinations and blood sampling were performed antepartum (262-270 d after artificial insemination) on 377 pluriparous pregnant Holstein Friesian cows. The presence of postpartum diseases were recorded (ketosis, fatty liver, displacement of the abomasum, hypocalcemia, mastitis, retention of fetal membranes, and clinical metritis or endometritis), and the concentrations of IGF1, IGFBP2, IGFBP3, and nonesterified fatty acids were measured. Cows with postpartum clinical ketosis had lower IGF1 concentrations antepartum than healthy cows. The sensitivity of antepartal IGF1 as a marker for postpartum ketosis was 0.87, and the specificity was 0.43; a positive predictive value of 0.91 and a negative predictive value of 0.35 were calculated. The cows with ketosis and retained fetal membranes had lower IGFBP2 concentrations compared with the healthy cows. It can be speculated that lower IGF1 production in the liver during late pregnancy may increase growth hormone secretions and lipolysis, thereby increasing the risk of ketosis. Lower IGFBP2 concentrations may reflect the suppression of IGFBP2 levels through higher growth hormone secretion. In conclusion, compared with nonesterified fatty acids as a predictive parameter, IGF1 and IGFBP2 may represent earlier biomarkers of inadequate metabolic adaptation to the high energy demand required postpartum. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  19. Concentrated Arabinoxylan but Not Concentrated Beta-Glucan in Wheat Bread Has Similar Effects on Postprandial Insulin as Whole-Grain Rye in Porto-arterial Catheterized Pigs

    DEFF Research Database (Denmark)

    Christensen, Kirstine Lykke; Hedemann, Mette Skou; Lærke, Helle Nygaard

    2013-01-01

    The acute glycemic effects of concentrated dietary fibers (DF) versus whole-grain rye were studied in portoarterial catheterized pigs. Two white wheat breads with wheat arabinoxylan (AX) or oat beta-glucan (BG), two rye breads with intact rye kernels (RK) or milled rye (GR), and a low DF white...... min postprandial for AX and GR (74.4 and 129 pmol/min for AX and GR, respectively, compared to 738 pmol/min for WF, P effective in improving insulin economy, suggesting that arabinoxylan from wheat and rye induces similar outcomes in the metabolic...

  20. Postprandial insulin and glucose levels are reduced in healthy subjects when a standardised breakfast meal is supplemented with a filtered sugarcane molasses concentrate.

    Science.gov (United States)

    Ellis, Timothy P; Wright, Alison G; Clifton, Peter M; Ilag, Leodevico L

    2016-12-01

    A phytochemical- and mineral-rich filtered sugarcane molasses concentrate (FMC), when added to carbohydrate-containing foods as a functional ingredient, lowers postprandial blood glucose and insulin responses. We hypothesised that this beneficial effect would also occur if FMC was administered as an oral supplement taken before a meal. This study measured the postprandial glucose and insulin responses elicited by different doses of FMC administered immediately prior to a standard breakfast to healthy subjects. Each subject was given three or five breakfast meals once, on different days. The composition of the meals was identical, except for the addition of either placebo syrup (test meal 1) or increasing doses of FMC (test meals 2-5). The plasma glucose concentration curves were similar for the five test meals. Plasma insulin curves were lowered in a dose-dependent manner. Stratifying subjects based on age, BMI and insulin resistance showed greater effects of low doses of FMC on lowering insulin responses in those subjects with potentially greater insulin resistance. When insulin response is standardised to amount of carbohydrate in the meal/dose combination, the reduction in response is linear and inversely proportional to the FMC dose. FMC shows promise as an agent that can reduce insulin responses and lessen the load on the pancreatic beta cells.

  1. Effects of acute exposure to increased plasma branched-chain amino acid concentrations on insulin-mediated plasma glucose turnover in healthy young subjects.

    Directory of Open Access Journals (Sweden)

    Sarah Everman

    Full Text Available Plasma branched-chain amino acids (BCAA are inversely related to insulin sensitivity of glucose metabolism in humans. However, currently, it is not known whether there is a cause-and-effect relationship between increased plasma BCAA concentrations and decreased insulin sensitivity.To determine the effects of acute exposure to increased plasma BCAA concentrations on insulin-mediated plasma glucose turnover in humans.Ten healthy subjects were randomly assigned to an experiment where insulin was infused at 40 mU/m2/min (40U during the second half of a 6-hour intravenous infusion of a BCAA mixture (i.e., BCAA; N = 5 to stimulate plasma glucose turnover or under the same conditions without BCAA infusion (Control; N = 5. In a separate experiment, seven healthy subjects were randomly assigned to receive insulin infusion at 80 mU/m2/min (80U in association with the above BCAA infusion (N = 4 or under the same conditions without BCAA infusion (N = 3. Plasma glucose turnover was measured prior to and during insulin infusion.Insulin infusion completely suppressed the endogenous glucose production (EGP across all groups. The percent suppression of EGP was not different between Control and BCAA in either the 40U or 80U experiments (P > 0.05. Insulin infusion stimulated whole-body glucose disposal rate (GDR across all groups. However, the increase (% in GDR was not different [median (1st quartile - 3rd quartile] between Control and BCAA in either the 40U ([199 (167-278 vs. 186 (94-308] or 80 U ([491 (414-548 vs. 478 (409-857] experiments (P > 0.05. Likewise, insulin stimulated the glucose metabolic clearance in all experiments (P 0.05.Short-term exposure of young healthy subjects to increased plasma BCAA concentrations does not alter the insulin sensitivity of glucose metabolism.

  2. Effects of acute exposure to increased plasma branched-chain amino acid concentrations on insulin-mediated plasma glucose turnover in healthy young subjects.

    Science.gov (United States)

    Everman, Sarah; Mandarino, Lawrence J; Carroll, Chad C; Katsanos, Christos S

    2015-01-01

    Plasma branched-chain amino acids (BCAA) are inversely related to insulin sensitivity of glucose metabolism in humans. However, currently, it is not known whether there is a cause-and-effect relationship between increased plasma BCAA concentrations and decreased insulin sensitivity. To determine the effects of acute exposure to increased plasma BCAA concentrations on insulin-mediated plasma glucose turnover in humans. Ten healthy subjects were randomly assigned to an experiment where insulin was infused at 40 mU/m2/min (40U) during the second half of a 6-hour intravenous infusion of a BCAA mixture (i.e., BCAA; N = 5) to stimulate plasma glucose turnover or under the same conditions without BCAA infusion (Control; N = 5). In a separate experiment, seven healthy subjects were randomly assigned to receive insulin infusion at 80 mU/m2/min (80U) in association with the above BCAA infusion (N = 4) or under the same conditions without BCAA infusion (N = 3). Plasma glucose turnover was measured prior to and during insulin infusion. Insulin infusion completely suppressed the endogenous glucose production (EGP) across all groups. The percent suppression of EGP was not different between Control and BCAA in either the 40U or 80U experiments (P > 0.05). Insulin infusion stimulated whole-body glucose disposal rate (GDR) across all groups. However, the increase (%) in GDR was not different [median (1st quartile - 3rd quartile)] between Control and BCAA in either the 40U ([199 (167-278) vs. 186 (94-308)] or 80 U ([491 (414-548) vs. 478 (409-857)] experiments (P > 0.05). Likewise, insulin stimulated the glucose metabolic clearance in all experiments (P BCAA in either of the experiments (P > 0.05). Short-term exposure of young healthy subjects to increased plasma BCAA concentrations does not alter the insulin sensitivity of glucose metabolism.

  3. Serum paraoxonase-3 concentration is associated with insulin sensitivity in peripheral artery disease and with inflammation in coronary artery disease.

    Science.gov (United States)

    Rull, Anna; García, Raúl; Fernández-Sender, Laura; García-Heredia, Anabel; Aragonès, Gerard; Beltrán-Debón, Raúl; Marsillach, Judit; Alegret, Josep M; Martín-Paredero, Vicente; Mackness, Bharti; Mackness, Michael; Joven, Jorge; Camps, Jordi

    2012-02-01

    There are no data on the relationship between serum paraoxonase-3 (PON3) concentration and atherosclerosis in humans. Our aim was to investigate possible associations, using recently developed methods, in patients with peripheral artery disease (PAD) or coronary artery disease (CAD). We studied 118 PAD and 72 CAD patients and 175 healthy volunteers. Serum PON3 was determined by in-house ELISA using polyclonal antibodies generated against a synthetic peptide with a sequence specific to PON3. Polymorphisms of the PON3 promoter were analysed by the Iplex Gold MassArray™ method. There was a significant increase in serum PON3 concentration in both groups of patients with respect to the control group. In PAD patients, we observed significant positive correlations between PON3, insulin levels and HOMA index. These associations were not observed in CAD. There were significant positive associations between serum PON3 and β-2-microglobulin, CCL2 and high-sensitivity C-reactive protein in CAD patients, but not in PAD. We did not find any significant differences in PON3 gene promoter polymorphisms and their haplotypes between patients and controls, indicating that associations were not genetically determined. In both atherosclerotic phenotypes, serum PON3 concentration was increased, but this was associated with decreased insulin sensitivity in PAD and with inflammation in CAD. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Effects of immune challenge on concentrations of serum insulin-like growth factor-I and growth performance in pigs.

    OpenAIRE

    Hevener, W; Routh, P A; Almond, G W

    1999-01-01

    This study was designed to determine the long-term effects of repeated endotoxin treatment or immunization against human serum albumin on concentrations of serum insulin-like growth factor-I (IGF-I) and other indicators of growth performance in growing pigs. Thirty gilts (38.5 +/- 0.9 kg) were randomly assigned to 5 treatment groups (n = 6 animals/group): 1) lipopolysaccharide injections, 2) lipopolysaccharide pair-fed, 3) human serum albumin immunization, 4) human serum albumin pair-fed, and...

  5. Serum concentrations of insulin-like growth factor-I and insulin-like growth factor binding protein-2 and -3 in eight hoofstock species.

    Science.gov (United States)

    Govoni, Kristen E; Goodman, Danielle; Maclure, Rebecca M; Penfold, Linda M; Zinn, Steven A

    2011-01-01

    The somatotropic axis, which includes growth hormone, insulin-like growth factor (IGF)-I, and IGF binding proteins (IGFBP), is involved in the regulation of growth and metabolism. Measures of the somatotropic axis can be predictive of nutritional status and growth rate that can be utilized to identify nutritional status of individual animals. Before the somatotropic axis can be a predictive tool, concentrations of hormones of the somatotropic axis need to be established in healthy individuals. To begin to establish these data, we quantified IGF-I, IGFBP-2, and IGFBP-3 in males and females of eight threatened hoofstock species at various ages. Opportunistic blood samples were collected from Bos javanicus (Java banteng), Tragelaphus eurycerus isaaci (bongo), Gazella dama ruficollis (addra gazelle), Taurotragus derbianus gigas (giant eland), Kobus megaceros (Nile lechwe), Hippotragus equines cottoni (roan antelope), Ceratotherium simum simum (white rhinoceros), and Elephas maximus (Asian elephant). Serum IGF-I and IGFBPs were determined by radioimmunoassay and ligand blot, respectively. Generally, IGF-I and IGFBP-3 were greater in males, and IGFBP-2 was greater in females. In banteng (P = 0.08) and male Nile lechwe (P age, but decreased in rhinoceros (P = 0.07) and female Nile lechwe (P banteng, IGFBP-3 was greater (P Determination of concentrations of hormones in the somatotropic axis in healthy animals makes it possible to develop models that can identify the nutritional status of these threatened hoofstock species. © 2010 Wiley-Liss, Inc.

  6. Changes in serum concentrations of growth hormone, insulin, insulin-like growth factor and insulin-like growth factor-binding proteins 1 and 3 and urinary growth hormone excretion during the menstrual cycle

    DEFF Research Database (Denmark)

    Juul, A; Scheike, Thomas Harder; Pedersen, A T

    1997-01-01

    hormone (LH), oestradiol, progesterone, IGF-I, IGFBP-3, sex hormone-binding globulin, dihydroepiandrosterone sulphate and GH were determined in all samples, whereas insulin and IGFBP-1 were determined in fasted samples only. Serum IGF-I concentrations showed some fluctuation during the menstrual cycle......-IGF-IGFBP axis during the ovulatory menstrual cycle in 10 healthy women (aged 18-40 years). Blood sampling and urinary collection was performed every morning at 0800 h for 32 consecutive days. Every second day the subjects were fasted overnight before blood sampling. Follicle stimulating hormone, luteinizing......, with significantly higher values in the luteal phase compared to the proliferative phase (P serum concentrations and no differences in IGFBP-3...

  7. Plasma Progranulin Concentrations Are Increased in Patients with Type 2 Diabetes and Obesity and Correlated with Insulin Resistance

    Directory of Open Access Journals (Sweden)

    Hua Qu

    2013-01-01

    Full Text Available Insulin resistance (IR is considered to be one of the most important pathogenesis of glycolipid metabolism disorders. However, the molecular mechanism responsible for IR is not fully understood. Recently, the chronic inflammation has been proposed to be involved in the pathogenesis of IR. In this study, we aim to investigate the concentrations of plasma progranulin in Chinese patients with obesity (OB and type 2 diabetes mellitus (T2DM, and its relationship to IR. Plasma progranulin concentrations were significantly higher in the T2DM patients than in the normal glucose tolerant (NGT subjects (. Within the T2DM and the NGT patients, the concentrations of progranulin were significantly higher in obese subjects than that in the normal weight subjects (225.22 ± 34.39 ng/mL versus 195.59 ± 50.47 ng/mL and 183.79 ± 61.63 ng/mL versus 148.69 ± 55.27 ng/mL, . Plasma progranulin concentrations correlated positively with weight, waist circumferences, BMI, HbA1c, TG, IL-6, FINS and HOMA-IR (, while correlated negatively with HOMA-β (. Multiple linear regression analysis showed that BMI, HbA1c, IL-6 and TG correlated independently with circulating progranulin concentrations (. These results suggested that Plasma progranulin concentrations were higher in Chinese patients with type 2 diabetes and obesity and correlated closely with glycolipid metabolism, chronic inflammation and IR.

  8. Concentrated arabinoxylan but not concentrated β-glucan in wheat bread has similar effects on postprandial insulin as whole-grain rye in porto-arterial catheterized pigs.

    Science.gov (United States)

    Christensen, Kirstine L; Hedemann, Mette S; Lærke, Helle N; Jørgensen, Henry; Mutt, Shivaprakash J; Herzig, Karl-Heinz; Bach Knudsen, Knud E

    2013-08-14

    The acute glycemic effects of concentrated dietary fibers (DF) versus whole-grain rye were studied in porto-arterial catheterized pigs. Two white wheat breads with wheat arabinoxylan (AX) or oat β-glucan (BG), two rye breads with intact rye kernels (RK) or milled rye (GR), and a low DF white wheat bread were fed to six pigs in a randomized crossover design. Blood profiles were collected for 4 h after feeding. Glucose absorption was reduced in pigs fed the AX bread at 60 min postprandial (3.1 mmol/min for AX compared to 9.4 mmol/min for WF, P = 0.02) and insulin secretion was lowered at 30 min postprandial for AX and GR (74.4 and 129 pmol/min for AX and GR, respectively, compared to 738 pmol/min for WF, P breads were most effective in improving insulin economy, suggesting that arabinoxylan from wheat and rye induces similar outcomes in the metabolic response.

  9. Simultaneous observation of the GnRH pulse generator activity and plasma concentrations of metabolites and insulin during fasting and subsequent refeeding periods in Shiba goats.

    Science.gov (United States)

    Matsuyama, Shuichi; Ohkura, Satoshi; Ichimaru, Toru; Sakurai, Katsuyasu; Tsukamura, Hiroko; Maeda, Kei-ichiro; Okamura, Hiroaki

    2004-12-01

    The time course of GnRH pulse generator activity and plasma concentrations of energy substrates and insulin were simultaneously observed in female goats during 4-day fasting and subsequent refeeding in the presence or absence of estrogen for a better understanding of the mechanism of energetic control of gonadotropin secretion in ruminants. The GnRH pulse generator activity was electrophysiologically assessed with the intervals of characteristic increases in multiple-unit activity (MUA volleys) in the mediobasal hypothalamus. In estradiol-treated ovariectomized (OVX+E2) goats, the MUA volley intervals increased as fasting progressed. Plasma concentrations of non-esterified fatty acid and ketone body increased, while those of acetic acid and insulin decreased during fasting. The MUA volley intervals and plasma concentrations of those metabolites and insulin were restored to pre-fasting levels after subsequent refeeding. In ovariectomized (OVX) goats, changes in plasma metabolites and insulin concentrations were similar to those in OVX+E2 goats, but the MUA volley intervals were not altered. The present results demonstrated that fasting suppressed GnRH pulse generator activity in an estrogen-dependent manner. Changes in plasma concentrations of energy substrates and insulin during fasting were associated with the GnRH pulse generator activity in the presence of estrogen, but not in the absence of the steroid in female goats.

  10. Effect of inspiratory muscle warm-up on submaximal rowing performance.

    Science.gov (United States)

    Arend, Mati; Mäestu, Jarek; Kivastik, Jana; Rämson, Raul; Jürimäe, Jaak

    2015-01-01

    Performing inspiratory muscle warm-up might increase exercise performance. The aim of this study was to investigate the impact of inspiratory muscle warm-up to submaximal rowing performance and to find if there is an effect on lactic acid accumulation and breathing parameters. Ten competitive male rowers aged between 19 and 27 years (age, 23.1 ± 3.8 years; height, 188.1 ± 6.3 cm; body mass, 85.6 ± 6.6 kg) were tested 3 times. During the first visit, maximal inspiratory pressure (MIP) assessment and the incremental rowing test were performed to measure maximal oxygen consumption and maximal aerobic power (Pamax). A submaximal intensity (90% Pamax) rowing test was performed twice with the standard rowing warm-up as test 1 and with the standard rowing warm-up and specific inspiratory muscle warm-up as test 2. During the 2 experimental tests, distance, duration, heart rate, breathing frequency, ventilation, peak oxygen consumption, and blood lactate concentration were measured. The only value that showed a significant difference between the test 1 and test 2 was breathing frequency (52.2 ± 6.8 vs. 53.1 ± 6.8, respectively). Heart rate and ventilation showed a tendency to decrease and increase, respectively, after the inspiratory muscle warm-up (p < 0.1). Despite some changes in respiratory parameters, the use of 40% MIP intensity warm-up is not suggested if the mean intensity of the competition is at submaximal level (at approximately 90% maximal oxygen consumption). In conclusion, the warm-up protocol of the respiratory muscles used in this study does not have a significant influence on submaximal endurance performance in highly trained male rowers.

  11. Prediagnostic circulating concentrations of plasma insulin-like growth factor-I and risk of lymphoma in the European Prospective Investigation into Cancer and Nutrition

    NARCIS (Netherlands)

    Perez-Cornago, Aurora; Appleby, Paul N.; Tipper, Sarah; Key, Timothy J.; Allen, Naomi E.; Nieters, Alexandra; Vermeulen, Roel; Roulland, Sandrine; Casabonne, Delphine; Kaaks, Rudolf; Fortner, Renee T.; Boeing, Heiner; Trichopoulou, Antonia; La Vecchia, Carlo; Klinaki, Eleni; Hansen, Louise; Tjønneland, Anne; Bonnet, Fabrice; Fagherazzi, Guy; Boutron-Ruault, Marie Christine; Pala, Valeria; Masala, Giovanna; Sacerdote, Carlotta; Peeters, Petra H.; Bueno-de-Mesquita, H. Bas; Weiderpass, Elisabete; Dorronsoro, Miren; Quirós, J. Ramón; Barricarte, Aurelio; Gavrila, Diana; Agudo, Antonio; Borgquist, Signe; Rosendahl, Ann H.; Melin, Beatrice; Wareham, Nick; Khaw, Kay Tee; Gunter, Marc; Riboli, Elio; Vineis, Paolo; Travis, Ruth C.

    2017-01-01

    Insulin-like growth factor (IGF)-I has cancer promoting activities. However, the hypothesis that circulating IGF-I concentration is related to risk of lymphoma overall or its subtypes has not been examined prospectively. IGF-I concentration was measured in pre-diagnostic plasma samples from a nested

  12. [Insulin resistance and serum concentrations of ovarian and adrenal androgen in obese women without additional disease and with policystic ovary syndrome].

    Science.gov (United States)

    Olszanecka-Glinianowicz, Magdalena; Banaś, Michał; Zahorska-Markiewicz, Barbara; Kuglin, Dorota; Mokrzycka, Joanna; Mentel, Alicja

    2005-01-01

    of the present study was to evaluate serum concentrations of adrenal and ovarian androgens and sex hormone-binding globulin in obese women without additional diseases and in obese women with polycystic ovary syndrome with and without insulin resistance. The study group involved 73 obese women (39 with PCOS--A and 34 obese without additional diseases--B). The serum concentration of glucose and insulin were measured and the study group was divided on the basis of HOMA index into two subgroups: A I-PCO without insulin resistance (n=18, mean age 27.2+/-5.9 yr; BMI 33.2+/-3.5 kg/m2); AII-PCO with insulin resistance (n=21, mean age 27.5+/-7.1 yr; BMI 37.6+/-6.5 kg/m2); B I-obese without insulin resistance (n=8, age 33.5+/-7.5 yr; BMI 35.2+/-4.8 kg/m2); B II-obese with insulin resistance (n=24, age 30.3+/-5.2 yr; BMI 36.4+/-5.8 kg/m2). Body mass and height were measured and body mass index was calculated with formula. Body composition was measured using bioimpedance method. The serum concentrations of FSH, LH, total and free testosterone, androstendione, DHEAS, SHBG and insulin were determined by RIA method and glucose was determined by enzymatic procedure. We observed significantly higher body mass, fat mass and BMI in AII subgroup when compared to AI, BI and BII subgroups. Only serum concentration of free testosterone was significantly higher in AII subgroup when compared to AI subgroup. We observed a positive correlation between serum concentrations of insulin and free testosterone in both groups A and B, moreover we observed positive correlations between serum concentrations of insulin and both DHEAS and LH in group B. It seems that insulin resistance plays a key role in the development of hyperandrogenism in obese women. However mechanisms leading to hyperandrogenism in PCOS are still unrevealed and seem to be more complex.

  13. Drinks containing anthocyanin-rich blackcurrant extract decrease postprandial blood glucose, insulin and incretin concentrations.

    Science.gov (United States)

    Castro-Acosta, Monica L; Smith, Leanne; Miller, Rosalind J; McCarthy, Danielle I; Farrimond, Jonathan A; Hall, Wendy L

    2016-12-01

    Blackcurrants are rich in polyphenolic glycosides called anthocyanins, which may inhibit postprandial glycemia. The aim was to determine the dose-dependent effects of blackcurrant extract on postprandial glycemia. Men and postmenopausal women (14M, 9W, mean age 46 years, S.D.=14) were enrolled into a randomized, double-blind, crossover trial. Low sugar fruit drinks containing blackcurrant extract providing 150-mg (L-BE), 300-mg (M-BE) and 600-mg (H-BE) total anthocyanins or no blackcurrant extract (CON) were administered immediately before a high-carbohydrate meal. Plasma glucose, insulin and incretins (GIP and GLP-1) were measured 0-120min, and plasma 8-isoprostane F 2α , together with arterial stiffness by digital volume pulse (DVP) was measured at 0 and 120min. Early plasma glucose response was significantly reduced following H-BE (n=22), relative to CON, with a mean difference (95% CI) in area over baseline (AOB) 0-30min of -0.34mmol/l.h (-0.56, -0.11, Ppostprandial glycemia, insulinemia and incretin secretion, which suggests that inclusion of blackcurrant polyphenols in foods may provide cardio-metabolic health benefits. This trial was registered at clinicaltrials.gov as NCT01706653. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  14. Stimulation of proliferation of HL60 cells by low concentrations of 12-O-tetradecanoylphorbol-13-acetate and its relationship to the mitogenic effects of insulin

    Energy Technology Data Exchange (ETDEWEB)

    Trayner, I.D.; Clemens, M.J. (St. George' s Hospital Medical School, London (United Kingdom))

    1992-03-01

    The effects of the phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA) on the growth and differentiation of cultured human acute promyelocytic leukemia (HL60) cells have been studied using cells growing in a fully defined medium consisting of RPMI 1640 supplemented with selenium dioxide, insulin, and either transferrin or ferric citrate. High concentrations of TPA cause the expected inhibition of proliferation and induction of macrophage-like differentiation. In contrast, in cells deprived in insulin, which continue to grow at a slow rate, lower concentrations of TPA stimulate proliferation without inducing differentiation. The ability of higher concentrations of TPA to induce differentiation is independent of the presence of insulin. Low-TPA also stimulates the short-term incorporation of thymidine by three- to fourfold, as compared to a seven fold stimulation by insulin. The proliferative response to low TPA concentrations provides a useful model for dissecting the signaling pathways that control cell proliferation following stimulation by insulin and activators of protein kinase C.

  15. Diets high in protein or saturated fat do not affect insulin sensitivity or plasma concentrations of lipids and lipoproteins in overweight and obese adults.

    Science.gov (United States)

    Chiu, Sally; Williams, Paul T; Dawson, Taylor; Bergman, Richard N; Stefanovski, Darko; Watkins, Steven M; Krauss, Ronald M

    2014-11-01

    Previous human studies reported inconsistent effects of dietary protein and branched-chain amino acids (BCAAs) on insulin action and glucose metabolism. Similarly, it is unclear whether saturated fat (SF) intake influences these metabolic variables. The objective of this study was to test the effects of high [30% of energy (%E)] vs. moderate (20%E) intakes of protein (primarily whey) on insulin action and lipid and lipoprotein concentrations in the context of both high (15%E) and low (7%E) SF diets. The study was conducted as a randomized controlled trial in 158 overweight and obese men and women. After a 4-wk baseline diet [55%E carbohydrate, 15%E protein, 30%E fat (7%E SF)], participants were randomly assigned to 4 wk of either the baseline diet or 1 of 4 test diets containing 35%E carbohydrate and either 20%E or 30%E protein and either 7%E or 15%E SF. Frequently sampled i.v. glucose tolerance tests were administered after each dietary period. Other than significantly higher fasting glucose concentrations for high vs. moderate protein intakes with a low-fat diet (difference ± SE: 0.47 ± 0.14 mmol/L; P = 0.001), there were no significant effects of dietary protein or SF on glucose metabolism, plasma insulin, or concentrations of lipids and lipoproteins. Changes in plasma BCAAs across all diets were negatively correlated with changes in the metabolic clearance rate of insulin (ρ = -0.18, P = 0.03) and positively correlated with changes in the acute insulin response to glucose (ρ = 0.15, P = 0.05). These findings suggest that short-term intake of BCAAs can influence insulin dynamics. However, in this group of overweight and obese individuals, neither high protein nor SF intake affected insulin sensitivity or plasma concentrations of lipids and lipoproteins. This trial was registered at clinicaltrials.gov as NCT00508937. © 2014 American Society for Nutrition.

  16. Effects of 12-week high-intensity interval training on plasma visfatin concentration and insulin resistance in overweight men

    Directory of Open Access Journals (Sweden)

    Hasan Matinhomaee

    2014-06-01

    Full Text Available The purpose of this study was to determine the effects of 12 weeks of high-intensity interval training (HIIT on visfatin and insulin resistance (IR in overweight adult men during a weight-loss program. Eighteen overweight men (age = 31.8 ± 9.2 years; body mass index = 28.6 ± 1.4 kg/m2 were randomly recruited into one of the two groups, namely, HIIT (3 days/week, 20 minutes/day; 85–95% peak oxygen uptake and diet-induced weight-loss combined (DHIIT; n = 10 and diet-induced weight loss only (DIO; n = 8. The DHIIT and DIO groups undertook a 12-week weight-loss intervention using a moderate isocaloric energy-deficit diet. Both DHIIT and DIO groups demonstrated a significant reduction in body weight (p < 0.01. Total fat mass (p < 0.05 and lean body mass (p < 0.05 were decreased in the DIO group with no significant changes in abdominal fat mass, plasma insulin concentration, homeostasis model assessment-estimated IR (HOMA-IR, blood glucose level, and plasma visfatin. In the DHIIT group, total fat mass (p < 0.01, abdominal fat mass (p < 0.05, plasma insulin concentration (p < 0.05, plasma visfatin (p < 0.01, and HOMA-IR (p < 0.05 were reduced and lean body mass remained unchanged. In conclusion, adding a low-volume 20-minute HIIT (three times/week to an energy-deficit diet not only can improve the efficiency of weight-loss program in the reduction of body fat, plasma visfatin levels, and HOMA-IR, but also has a reservation effect on lean body mass.

  17. F-door spaces and F-submaximal spaces

    Directory of Open Access Journals (Sweden)

    Lobna Dridi

    2013-04-01

    Full Text Available Submaximal spaces and door spaces play an enigmatic role in topology. In this paper, reinforcing this role, we are concerned with reaching two main goals: The first one is to characterize topological spaces X such that F(X is a submaximal space (resp., door space for some covariant functor Ff rom the category Top to itself. T0, and FH functors are completely studied. Secondly, our interest is directed towards the characterization of maps f given by a flow (X, f in the category Set, such that (X,P(f is submaximal (resp., door where P(f is a topology on X whose closed sets are exactly the f-invariant sets.

  18. Oral glutamine increases circulating glucagon-like peptide 1, glucagon, and insulin concentrations in lean, obese, and type 2 diabetic subjects

    DEFF Research Database (Denmark)

    Greenfield, Jerry R; Farooqi, I Sadaf; Keogh, Julia M

    2008-01-01

    BACKGROUND: Incretin hormones, such as glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), play an important role in meal-related insulin secretion. We previously demonstrated that glutamine is a potent stimulus of GLP-1 secretion in vitro. OBJECTIVE: Our...... objective was to determine whether glutamine increases circulating GLP-1 and GIP concentrations in vivo and, if so, whether this is associated with an increase in plasma insulin. DESIGN: We recruited 8 healthy normal-weight volunteers (LEAN), 8 obese individuals with type 2 diabetes or impaired glucose...... tolerance (OB-DIAB) and 8 obese nondiabetic control subjects (OB-CON). Oral glucose (75 g), glutamine (30 g), and water were administered on 3 separate days in random order, and plasma concentrations of GLP-1, GIP, insulin, glucagon, and glucose were measured over 120 min. RESULTS: Oral glucose led...

  19. Effects of cord serum insulin, IGF-II, IGFBP-2, IL-6 and cortisol concentrations on human birth weight and length: pilot study.

    Directory of Open Access Journals (Sweden)

    Arianna Smerieri

    Full Text Available BACKGROUND: The IGF system is recognised to be important for fetal growth. We previously described increased Insulin-like growth factor binding protein (IGFBP-2 cord serum concentrations in intra-uterine growth retardation (IUGR compared with appropriate for gestational age (AGA newborns, and a positive relationship of IGFBP-2 with Interleukin (IL-6. The role of cortisol in the fetus at birth is largely unknown, and interactions among peptides are their real effect on birth size is unknown. Furthermore, almost all studies have previously assayed peptides in serum several years after birth, and follow-up data from pregnancy are always lacking. This study aimed at establishing and clarifying the effect of cord serum insulin, IGF-II, IGFBP-2, cortisol and IL-6 concentrations on birth length and weight. METHODS: 23 IUGR and 37 AGA subjects were followed up from the beginning of pregnancy, and were of comparable gestational age. Insulin, IGF-II, IGFBP-2, cortisol and IL-6 concentrations were assayed in cord serum at birth, and a multiple regression model was designed and applied to assess which were the significant biochemical determinants of birth size. RESULTS: Insulin, cortisol, and IL-6, showed similar concentrations in IUGR and AGA as previously described, whereas IGF-II was lower, and IGFBP-2 increased in IUGR compared with AGA. IGF-II serum concentration was found to have a significant positive effect on both birth length (r:(:0.546; p: 0.001 and weight (r:0.679; p: 0.0001. IGFBP-2 had a near significant negative effect on both birth weight (r:-0.342; p: 0.05 and length (r:-0.372; p:0.03. CONCLUSION: IGF-II cord serum concentration was shown to have a significant positive effect on both birth length and weight, whereas IGFBP-2 had a significant negative effect. Insulin, cortisol, and IL-6 cord serum concentrations had no significant effect on birth size.

  20. Associations between self-reported sleep duration and sleeping disorder with concentrations of fasting and 2-h glucose, insulin, and glycosylated hemoglobin among adults without diagnosed diabetes.

    Science.gov (United States)

    Ford, Earl S; Wheaton, Anne G; Chapman, Daniel P; Li, Chaoyang; Perry, Geraldine S; Croft, Janet B

    2014-07-01

    There is limited information from population-based investigations of the associations between sleep duration and sleep disorders and parameters of glucose homeostasis. The objective of the present study was to examine cross-sectional associations between sleep duration and sleep disordered breathing with concentrations of insulin, fasting and 2-h glucose, and HbA1c. Data from 11 815 adults aged ≥20 years without diagnosed diabetes (5002 with an oral glucose tolerance test) from the National Health and Nutrition Examination Survey 2005-2010 were used. Information about sleep duration (2005-2010) and sleep apnea and sleep-disordered breathing (2005-2008) was obtained via questionnaire. An estimated 36.0% of participants reported sleeping ≤6 h/night, 62.0% reported sleeping 7-9 h/night, and 2.0% reported sleeping ≥10 h/night. In 2005-2008, 33.0% reported snoring ≥5 nights per week, 5.9% reported they snorted, gasped, or stopped breathing ≥5 nights/week, and 4.2% reported sleep apnea. Sleep duration was significantly associated with fasting concentrations of insulin and concentrations of HbA1c only in models that did not adjust for body mass index (BMI). Concentrations of fasting and 2-h glucose were significantly associated with sleep duration in models that adjusted only for age. Snoring frequency was positively associated with concentrations of insulin and HbA1c. Frequency of snorting or stopping breathing and sleep apnea status were associated with concentrations of insulin and of HbA1c only when BMI was not accounted for. In a representative sample of US adults, concentrations of insulin and HbA1c were significantly associated with short sleep duration, possibly mediated by BMI. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  1. Insulin Resistance: Causes And Metabolic Implications | Igharo ...

    African Journals Online (AJOL)

    Insulin is an anabolic hormone that plays key roles in glucose metabolism. Insulin resistance is a decreased biological response to normal concentration of circulating insulin. In insulin resistance, normal amounts of insulin are inadequate to produce a normal insulin response from fat, muscle and liver cells. Insulin ...

  2. Effect of Age, Season, Body Condition, and Endocrine Status on Serum Free Cortisol Fraction and Insulin Concentration in Horses.

    Science.gov (United States)

    Hart, K A; Wochele, D M; Norton, N A; McFarlane, D; Wooldridge, A A; Frank, N

    2016-01-01

    Increased free cortisol fraction is associated with insulin dysregulation (ID) in people with Metabolic Syndrome and Cushing's Disease. Free cortisol has not been investigated in equine endocrine disorders. (1) In healthy horses, sex, age, body condition score (BCS), and season impact free cortisol; (2) free cortisol is increased in horses with Pituitary Pars Intermedia Dysfunction (PPID) or Equine Metabolic Syndrome (EMS). Fifty-seven healthy horses; 40 horses and ponies with PPID (n = 20) or EMS (n = 20). Prospective study. Serum collected seasonally from healthy animals and archived serum from PPID and EMS animals was analyzed for insulin, total and free cortisol concentrations, and free cortisol fraction (FCF). Linear mixed models were used to determine effects of age, sex, season, and BCS on hormones in controls. Hormone measurements were compared between disease groups and age- and season-matched controls with t-tests. EMS and hyperinsulinemic PPID animals were combined in an ID (hyperinsulinemia) group. Free cortisol concentrations were increased in overweight/obese controls (0.3 ± 0.1 μg/dL) compared to lean controls (0.2 ± 0.1 μg/dL; P = .017). Mean FCF was significantly higher in animals with PPID (8.8 ± 5.8 μg/dL, P = .005) or ID (8.8 ± 10.2 μg/dL, P = .039) than controls (5.0 ± 0.9 μg/dL), but total cortisol concentrations were similar (P ≥ .350) (PPID: 4.2 ± 4.3 μg/dL; ID: 5.0 ± 4.5 μg/dL; controls: 4.6 ± 1.7 and 5.1 ± 2.1 μg/dL). Increased FCF is associated with obesity in healthy horses and with ID (hyperinsulinemia) in horses and ponies with endocrine disease. Decreased plasma cortisol-binding capacity could be a component of these endocrine disorders in horses. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  3. Lycopene supplementation elevates circulating insulin-like growth factor-binding protein-1 and-2 concentrations in persons at greater risk of colorectal cancer

    NARCIS (Netherlands)

    Vrieling, A.; Voskuil, D.W.; Bonfrer, J.M.; Korse, C.M.; Doorn, J.; Cats, A.; Depla, A.C.; Timmer, R.; Witteman, B.J.M.; Leeuwen, van F.E.; van't Veer, L.J.; Rookus, M.A.; Kampman, E.

    2007-01-01

    Background: Higher circulating insulin-like growth factor I (IGF-I) concentrations have been related to a greater risk of cancer. Lycopene intake is inversely associated with cancer risk, and experimental studies have shown that it may affect the IGF system, possibly through an effect on IGF-binding

  4. Lycopene supplementation elevates circulating insulin-like growth factor binding protein-1 and -2 concentrations in persons at greater risk of colorectal cancer.

    NARCIS (Netherlands)

    Vrieling, A.; Voskuil, D.W.; Bonfrer, J.M.G.; Korse, C.M.; Doorn, J. van; Cats, A.; Depla, A.C.; Timmer, R.; Witteman, B.J.M.; Leeuwen, F.E. van; Veer, L.J. van 't; Rookus, M.A.; Kampman, E.

    2007-01-01

    BACKGROUND: Higher circulating insulin-like growth factor I (IGF-I) concentrations have been related to a greater risk of cancer. Lycopene intake is inversely associated with cancer risk, and experimental studies have shown that it may affect the IGF system, possibly through an effect on IGF-binding

  5. In vitro growth and maturation of isolated caprine preantral follicles: Influence of insulin and FSH concentration, culture dish, coculture, and oocyte size on meiotic resumption.

    Science.gov (United States)

    Silva, G M; Brito, I R; Sales, A D; Aguiar, F L N; Duarte, A B G; Araújo, V R; Vieira, L A; Magalhães-Padilha, D M; Lima, L F; Alves, B G; Silveira, L B R; Lo Turco, E G; Rodrigues, A P; Campello, C C; Wheeler, M B; Figueiredo, J R

    2017-03-01

    The aims of this study were: (1) to evaluate the effect of different insulin concentrations, alone or in combination with either a fixed FSH concentration or increasing FSH concentrations on the in vitro culture of isolated caprine preantral follicles and (2) to analyze the efficiency of two IVM media and maturation culture systems (with or without coculture with in vivo grown oocytes) on the meiosis resumption. Secondary follicles were cultured for 18 days in a basic medium supplemented with low- or high-insulin concentration alone or with a fixed FSH concentration or with increasing FSH concentrations. Oocytes grown in vivo or in vitro were matured alone or cocultured. The high-insulin concentration associated with fixed FSH treatment had higher meiotic resumption rate (P culture period improved meiotic resumption rate and produced MII oocytes from caprine preantral follicles cultured in vitro. The MII rate was similar between in vivo and in vitro grown oocytes ≥110 μm. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Recruitment of single muscle fibers during submaximal cycling exercise

    NARCIS (Netherlands)

    Altenburg, T.M.; Degens, H.; van Mechelen, W.; Sargeant, A.J.; de Haan, A.

    2007-01-01

    In literature, an inconsistency exists in the submaximal exercise intensity at which type II fibers are activated. In the present study, the recruitment of type I and II fibers was investigated from the very beginning and throughout a 45-min cycle exercise at 75% of the maximal oxygen uptake, which

  7. Differential contributions of ankle plantarflexors during submaximal isometric muscle action

    DEFF Research Database (Denmark)

    Masood, Tahir; Bojsen-Møller, Jens; Kalliokoski, Kari K

    2014-01-01

    The objective of this study was to investigate the relative contributions of superficial and deep ankle plantarflexors during repetitive submaximal isometric contractions using surface electromyography (SEMG) and positron emission tomography (PET). Myoelectric signals were obtained from twelve....... The findings of this study provide valuable reference for studies where individual muscle contributions are estimated using models and simulations....

  8. Myocardial oxygen consumption at rest and during submaximal ...

    African Journals Online (AJOL)

    olayemitoyin

    2008-11-26

    Nov 26, 2008 ... Department of Physiology, JSS Medical College, Constituent College of JSS University, Mysore – 570015, ... determine the effect of increased adiposity on myocardial oxygen consumption at rest and during submaximal exercise in ... during exercise suggesting higher hemodynamic stress to the heart.

  9. An Investigation into Submaximal Endurance in Children with Motor ...

    African Journals Online (AJOL)

    This study investigated the submaximal endurance levels of children with motor difficulties, using the six-minute walk test (6MWT). A prospective, cross-sectional study was conducted. Forty-eight children between ages seven and ten years were enrolled. They came from similar socio-economic backgrounds and attended ...

  10. Myocardial oxygen consumption at rest and during submaximal ...

    African Journals Online (AJOL)

    Overweight and obesity are major risk factors for cardiovascular diseases. The objective of this study was to determine the effect of increased adiposity on myocardial oxygen consumption at rest and during submaximal exercise in young adults. The study consisted of 85 young adults (18-22years) grouped into 3 based on ...

  11. Myocardial oxygen consumption at rest and during submaximal ...

    African Journals Online (AJOL)

    olayemitoyin

    2008-11-26

    Nov 26, 2008 ... and myocardial fatty acid utilization has been showed to decrease after weight loss from gastric bypass surgery or diet in obese persons (Fei ho et al., 1995,). During submaximal exercise and immediately after exercise, all three groups showed an increase in. RPP. The percentage increase in RPP was.

  12. Green Tea Extract and Catechol-O-Methyltransferase Genotype Modify Fasting Serum Insulin and Plasma Adiponectin Concentrations in a Randomized Controlled Trial of Overweight and Obese Postmenopausal Women.

    Science.gov (United States)

    Dostal, Allison M; Samavat, Hamed; Espejo, Luis; Arikawa, Andrea Y; Stendell-Hollis, Nicole R; Kurzer, Mindy S

    2016-01-01

    Green tea consumption has been associated with favorable changes in body weight and obesity-related hormones, although it is not known whether these changes result from green tea polyphenols or caffeine. We examined the impact of decaffeinated green tea extract (GTE) containing 843 mg of (-)-epigallocatechin-3-gallate on anthropometric variables, obesity-associated hormones, and glucose homeostasis. The Minnesota Green Tea Trial was a 12-mo randomized, double-blind, placebo-controlled clinical trial of 937 healthy postmenopausal women assigned to either decaffeinated GTE (1315 mg total catechins/d) or a placebo, stratified by catechol-O-methyltransferase (COMT) genotype. This study was conducted in a subset of 237 overweight and obese participants [body mass index (BMI) ≥25 kg/m(2)]. No changes in energy intake, body weight, BMI, or waist circumference (WC) were observed over 12 mo in women taking GTE (n = 117) or placebo (n = 120). No differences were seen in circulating leptin, ghrelin, adiponectin, or glucose concentrations at month 12. Participants randomly assigned to GTE with baseline insulin ≥10 μIU/mL (n = 23) had a decrease in fasting serum insulin from baseline to month 12 (-1.43 ± 0.59 μIU/mL), whereas those randomly assigned to placebo with baseline insulin ≥10 μIU/mL (n = 19) had an increase in insulin over 12 mo (0.55 ± 0.64 μIU/mL, P < 0.01). Participants with the homozygous high-activity (G/G) form of COMT had significantly lower adiponectin (5.97 ± 0.50 compared with 7.58 ± 0.53 μg/mL, P = 0.03) and greater insulin concentrations (7.63 ± 0.53 compared with 6.18 ± 0.36 μIU/mL, P = 0.02) at month 12 compared with those with the low-activity (A/A) genotype, regardless of treatment group. Decaffeinated GTE was not associated with reductions in body weight, BMI, or WC and did not alter energy intake or mean hormone concentrations in healthy postmenopausal women over 12 mo. GTE decreased fasting insulin concentrations in those with

  13. Low fat diet with omega-3 fatty acids increases plasma insulin-like growth factor concentration in healthy postmenopausal women

    Science.gov (United States)

    The insulin-like growth factor pathway plays a central role in the normal and abnormal growth of tissues; however, the nutritional determinants of insulin-like growth factor I (IGF-I) and its binding proteins in normal individuals are not well-defined. The purpose of this study was to determine the ...

  14. Effect of 6 Weeks of High-Intensity Interval Training with Cinnamon Supplementation on Serum Apelin Concentration and Insulin Resistance in Overweight Boys

    Directory of Open Access Journals (Sweden)

    A. Kazemi

    2016-09-01

    Full Text Available Aims: Playing an important role in regulating glucose hemostasis, apelin might empower the correlation between any increase in the adipose tissue mass and obesity and the correlated metabolic diseases. The aim of this study was to investigate the effects of 6-week intensive periodic massive exercises with cinnamon supplementation on the apelin serum concentration and insulin resistance in the overweight boys. Materials & Methods: In the semi-experimental study, 40 male overweight students were studied in Zahedan in 2014. The samples, randomly selected, were divided into four groups including exercise, exercise and supplementation, supplementation, and control. 6-week intensive periodic massive exercises were done in the exercise groups. In addition, three 380mg-cinnamon capsules were administrated in the supplementation groups. Blood sampling was done from the subjects 48 hours before and after the exercise program. Apelin, glucose, and insulin levels were measured. Data was analyzed by SPSS 19 software using one-way and two-way ANOVA tests and covariance analysis. Findings: There were significant differences between “exercise” and “exercise and supplementation” groups and “control” group in apelin and insulin resistance levels after the exercise program (p=0.0001. In addition, there was a significant difference between “cinnamon supplementation” and “control” groups in insulin resistance (p=0.001.There were significant differences between the exercise groups and supplementation group in apelin (p=0.0001 and insulin resistance (p=0.003 levels. Conclusion: The serum apelin level and the insulin resistance index in the overweight boys are reduced by 6-week intense periodic massive exercises. In addition, the cinnamon supplementation only reduces the insulin resistance index.

  15. The Dynamic Roles of Visfatin and Obestatin Serum Concentration in Pancreatic Beta Cells Dysfunction (HOMA-beta and Insulin Resistance (HOMA-IR in Centrally Obese Men

    Directory of Open Access Journals (Sweden)

    Bayu Winata Putera

    2012-04-01

    Full Text Available BACKGROUND: Obesity is a major health problem in the world today. Obesity is closely associated with insulin resistance and type 2 diabetes. Epidemiological studies have shown that obese persons are in a state of insulin resistance, however, most of them do not progress to type 2 diabetes. This occurs because the beta cell function is still good enough for maintaining normal glucose level. Obestatin and visfatin are cytokines that are known to have a role in beta cell function. The aim of this study was to assess the relationship between visfatin and obestatin and Homeostasis Model Assessment of beta cell function (HOMA-β and Homeostasis Model Assessment of insulin resistance (HOMA-IR. METHODS: This was a cross-sectional study involving 80 central obesity men with waist circumference >90 cm, age 30-65 years old. Visfatin and obestatin were measured by ELISA method. Beta pancreas cell dysfunction and insulin resistance were calculated by HOMA model. RESULTS: Our study showed a correlation between visfatin and HOMA-β (r=0.244 and p=0.029 and visfatin with HOMA-IR (r=0.287 and p=0.001 and no correlation was found between obestatin with HOMA-β (r=0.010 and p=0.990 and obestatin with HOMA-IR (r=0.080 and p=0.480. We also found visfatin and obestatin concentrations were fluctuative depending on the measurements of the waist circumferences. CONCLUSIONS: High visfatin and low obestatin concentration were independently associated with increased beta pancreas cell dysfunction and insulin resistance. KEYWORDS: obesity. visfatin, obestatin, beta cell dysfunction (HOMA-β, insulin resistance (HOMA-IR.

  16. Branched-chain amino acid catabolism rather than amino acids plasma concentrations is associated with diet-induced changes in insulin resistance in overweight to obese individuals.

    Science.gov (United States)

    Haufe, S; Engeli, S; Kaminski, J; Witt, H; Rein, D; Kamlage, B; Utz, W; Fuhrmann, J C; Haas, V; Mähler, A; Schulz-Menger, J; Luft, F C; Boschmann, M; Jordan, J

    2017-10-01

    3-Hydroxyisobutyrate (3-HIB), a catabolic intermediate of the BCAA valine, which stimulates muscle fatty acid uptake, has been implicated in the pathogenesis of insulin resistance. We tested the hypothesis that circulating 3-HIB herald insulin resistance and that metabolic improvement with weight loss are related to changes in BCAAs and 3-HIB. We analyzed plasma and urine in 109 overweight to obese individuals before and after six months on hypocaloric diets reduced in either carbohydrates or fat. We calculated the homeostasis model assessment index (HOMA-IR) and whole body insulin sensitivity from oral glucose tolerance tests and measured intramyocellular fat by magnetic resonance spectroscopy. BCAAs and 3-HIB plasma concentrations were inversely related to insulin sensitivity but not to intramyocellular fat content at baseline. With 7.4 ± 4.5% weight loss mean BCAA and 3-HIB plasma concentrations did not change, irrespective of dietary macronutrient content. Individual changes in 3-HIB with 6-month diet but not BCAAs were correlated to the change in whole body insulin sensitivity and HOMA-IR independently of BMI changes. 3-HIB relates to insulin sensitivity but is not associated with intramyocellular fat content in overweight to obese individuals. Moreover, changes in 3-HIB rather than changes in BCAAs are associated with metabolic improvements with weight loss. Registration number for clinical trials: ClinicalTrials.gov Identifier: NCT00956566. Copyright © 2017 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

  17. Correlation of maternal serum fetuin/alpha2-HS-glycoprotein concentration with maternal insulin resistance and anthropometric parameters of neonates in normal pregnancy and gestational diabetes.

    Science.gov (United States)

    Kalabay, László; Cseh, Károly; Pajor, Attila; Baranyi, Eva; Csákány, György M; Melczer, Zsolt; Speer, Gábor; Kovács, Margit; Siller, György; Karádi, István; Winkler, Gábor

    2002-08-01

    Human fetuin/alpha(2)-HS-glycoprotein (AHSG) is a 49 kDa serum and tissue protein which is a natural inhibitor of insulin receptor signaling. We investigated serum AHSG levels during pregnancy and whether the protein is involved in insulin resistance observed in healthy pregnant women and patients with gestational diabetes. One hundred and four healthy pregnant women and 23 of their neonates, 30 patients with gestational diabetes and their neonates and 30 healthy age-matched non-pregnant females as a control group were investigated in a case-control cross-sectional study. Serum AHSG was determined by radial immunodiffusion. We observed an increase of serum AHSG concentration in the second and third trimesters. Gestational diabetes patients had significantly higher AHSG levels than healthy pregnant women and non-pregnant controls. There was a highly significant positive correlation between serum AHSG concentration and indirect parameters of insulin resistance, i.e. tumor necrosis factor-alpha (TNF-alpha), leptin, C-peptide and C-peptide/blood glucose ratio. There was also a negative correlation between maternal AHSG, TNF-alpha, leptin levels and head circumference, body length and body weight of newborns. AHSG, TNF-alpha and leptin may contribute to insulin resistance during normal pregnancy and gestational diabetes. AHSG along with these cytokines may also negatively regulate neonatal skeletal development.

  18. Insulin Secretagogues

    Science.gov (United States)

    ... the Spikes Is mealtime insulin right for you? Insulin Secretagogues September 2017 Download PDFs English Espanol Editors ... Additional Resources Affordable Insulin Project FDA What are insulin secretagogues? Insulin secretagogues are one type of medicine ...

  19. Genetic variants associated with fasting glucose and insulin concentrations in an ethnically diverse population: results from the Population Architecture using Genomics and Epidemiology (PAGE) study.

    Science.gov (United States)

    Fesinmeyer, Megan D; Meigs, James B; North, Kari E; Schumacher, Fredrick R; Bůžková, Petra; Franceschini, Nora; Haessler, Jeffrey; Goodloe, Robert; Spencer, Kylee L; Voruganti, Venkata Saroja; Howard, Barbara V; Jackson, Rebecca; Kolonel, Laurence N; Liu, Simin; Manson, JoAnn E; Monroe, Kristine R; Mukamal, Kenneth; Dilks, Holli H; Pendergrass, Sarah A; Nato, Andrew; Wan, Peggy; Wilkens, Lynne R; Le Marchand, Loic; Ambite, José Luis; Buyske, Steven; Florez, Jose C; Crawford, Dana C; Hindorff, Lucia A; Haiman, Christopher A; Peters, Ulrike; Pankow, James S

    2013-09-25

    Multiple genome-wide association studies (GWAS) within European populations have implicated common genetic variants associated with insulin and glucose concentrations. In contrast, few studies have been conducted within minority groups, which carry the highest burden of impaired glucose homeostasis and type 2 diabetes in the U.S. As part of the 'Population Architecture using Genomics and Epidemiology (PAGE) Consortium, we investigated the association of up to 10 GWAS-identified single nucleotide polymorphisms (SNPs) in 8 genetic regions with glucose or insulin concentrations in up to 36,579 non-diabetic subjects including 23,323 European Americans (EA) and 7,526 African Americans (AA), 3,140 Hispanics, 1,779 American Indians (AI), and 811 Asians. We estimated the association between each SNP and fasting glucose or log-transformed fasting insulin, followed by meta-analysis to combine results across PAGE sites. Overall, our results show that 9/9 GWAS SNPs are associated with glucose in EA (p = 0.04 to 9 × 10-15), versus 3/9 in AA (p= 0.03 to 6 × 10-5), 3/4 SNPs in Hispanics, 2/4 SNPs in AI, and 1/2 SNPs in Asians. For insulin we observed a significant association with rs780094/GCKR in EA, Hispanics and AI only. Generalization of results across multiple racial/ethnic groups helps confirm the relevance of some of these loci for glucose and insulin metabolism. Lack of association in non-EA groups may be due to insufficient power, or to unique patterns of linkage disequilibrium.

  20. Higher habitual intake of dietary fat and carbohydrates are associated with lower leptin and higher ghrelin concentrations in overweight and obese postmenopausal women with elevated insulin levels.

    Science.gov (United States)

    Kong, Angela; Neuhouser, Marian L; Xiao, Liren; Ulrich, Cornelia M; McTiernan, Anne; Foster-Schubert, Karen E

    2009-11-01

    A highly regulated homeostatic system governs body weight; however, it is possible that this system might be impaired by the sustained intake of highly palatable foods. Short-term feeding studies suggest that the appetite-stimulating hormone ghrelin is suppressed less effectively by dietary fat intake, and diets high in sucrose decrease levels of the adipose hormone leptin. We hypothesized that higher habitual intake of dietary fat and carbohydrate (CHO) would be associated with elevated concentrations of circulating plasma ghrelin and lower circulating leptin in humans, a hormonal profile that could promote weight gain. To test our hypothesis, we examined the cross-sectional associations of ghrelin and leptin with the habitual macronutrient intake of 165 healthy overweight and obese sedentary women and tested the modifying role of insulin in these associations. We observed a significant inverse association between leptin concentrations and percentage energy from CHO independent of body mass index, percentage body fat, age, and intraabdominal fat (beta = -0.11 P = .04). No significant associations were observed between ghrelin and macronutrients or their subtypes among the total cohort. Among women with insulin concentrations at or greater than the median, we found a statistically significant positive association between intake of saturated fat and ghrelin concentrations, as well as additional statistically significant associations between leptin concentrations and macronutrients not observed among the total cohort. Our results provide some evidence that diets higher in fat and CHO are associated with a hormonal profile (ie, lower leptin and higher ghrelin concentrations), which could enhance weight gain, particularly among individuals with higher circulating insulin concentrations.

  1. The effect of intravenous injection of Ghrelin on the mean plasma concentrations of insulin in immature camels fed different levels of their energy requirements

    Directory of Open Access Journals (Sweden)

    2009-11-01

    Ghrelin is a peptide hormone secreted into the circulation from the stomach, but this peptide is also synthetized in a number of different body tissues including the brain and pancreas, suggesting both endocrine and paracrine effects. These include: stimulation of GH and ACTH secretion, an increase in appetite and diabetogenic effect on carbohydrate metabolism. Furthermore, ghrelin is the natural ligand of the growth hormone secretagogue receptor (GHS-R. Ghrelin and its mRNAas well as GH secretagogue receptor mRNAs are expressed in the pancreas and islet cells and regulates insulin release and glucose metabolism, but because the effect of ghrelin on insulin secretion before puberty in semiruminant animals has never been examined,   therefore the purpose of the present research was to determine the effect of ghrelin on insulin secretion before puberty in camels. In this investigation 12 camels were randomly divided into two groups. Animals in each group were fed either 50% and 100% energy content in diet for 2 weeks. After 2 weeks camels received 8 μg ghrelin/kg body weight via their jugular vein for 4 days. Blood samples were collected from the jugular vein of all animals before, during (30 minutes after injection of ghrelin and after the intervention for 4 continuous days and plasma insulin concentrations determined by RIA. Data obtained were analyzed by repeated measures –ANOVA and paired t-Test. p

  2. Effect of matrix composition, sphere size and hormone concentration on diffusion coefficient of insulin for controlled gastrointestinal delivery for diabetes treatment.

    Science.gov (United States)

    Villaverde Cendon, Fernando; Matos Jorge, Regina Maria; Weinschutz, Regina; Mathias, Alvaro Luiz

    2017-12-12

    Oral insulin administration is limited due to its degradation by proteases. The hormone was encapsulated in spheres made of either pure calcium alginate (ALG) or its association with whey protein isolate (WPI-ALG) in order to minimise loss in the stomach region while allowing liberation in the maximum absorption area, located in the intestine. Diffusion coefficients for both matrix compositions were determined in vitro for gastric pH (5.88 and 10.26 × 10-12 m2 s-1) and intestinal pH (21.11 and 79.29 × 10-12 m2 s-1). Higher initial insulin concentrations and lower diameters accelerated its release, confirming Fickian behaviour. The analytic model exhibited a good fit in most cases. Computer simulations revealed that ALG spheres are more convenient for oral administration because they release more insulin in the intestine than the WPI-ALG ones, thus supporting its therapeutic viability for the purpose of reducing stress in those who depend on insulin.

  3. Effects of prepartum fat supplementation on plasma concentrations of glucagon-like peptide-1, peptide YY, adropin, insulin, and leptin in periparturient dairy cows.

    Science.gov (United States)

    Zapata, Rizaldy C; Salehi, Reza; Ambrose, Divakar J; Chelikani, Prasanth K

    2015-10-01

    Dietary fat supplementation during the periparturient period is one strategy to increase energy intake and attenuate the degree of negative energy balance during early lactation; however, little is known of the underlying hormonal and metabolic adaptations. We evaluated the effects of prepartum fat supplementation on energy-balance parameters and plasma concentrations of glucagon-like peptide-1, peptide tyrosine-tyrosine (PYY), adropin, insulin, leptin, glucose, nonesterified fatty acid, and β-hydroxybutyric acid in dairy cows. Twenty-four pregnant dairy cows were randomized to diets containing either rolled canola or sunflower seed at 8% of dry matter, or no oilseed supplementation, during the last 5 wk of gestation and then assigned to a common lactation diet postpartum. Blood samples were collected at -2, +2, and +14 h relative to feeding, at 2 wk after the initiation of the diets, and at 2 wk postpartum. Dietary canola and sunflower supplementation alone did not affect energy balance, body weight, and plasma concentrations of glucagon-like peptide-1, PYY, adropin, insulin, leptin, nonesterified fatty acid, and β-hydroxybutyric acid; however, canola decreased and sunflower tended to decrease dry matter intake. We also observed that the physiological stage had a significant, but divergent, effect on circulating hormones and metabolite concentrations. Plasma glucagon-like peptide-1, PYY, adropin, nonesterified fatty acid, and β-hydroxybutyric acid concentrations were greater postpartum than prepartum, whereas glucose, insulin, leptin, body weight, and energy balance were greater prepartum than postpartum. Furthermore, the interaction of treatment and stage was significant for leptin and adropin, and tended toward significance for PYY and insulin; only insulin exhibited an apparent postprandial increase. Postpartum PYY concentrations exhibited a strong negative correlation with body weight, suggesting that PYY may be associated with body weight regulation during

  4. Insulin and Insulin Resistance

    Science.gov (United States)

    2005-01-01

    As obesity and diabetes reach epidemic proportions in the developed world, the role of insulin resistance and its consequences are gaining prominence. Understanding the role of insulin in wide-ranging physiological processes and the influences on its synthesis and secretion, alongside its actions from the molecular to the whole body level, has significant implications for much chronic disease seen in Westernised populations today. This review provides an overview of insulin, its history, structure, synthesis, secretion, actions and interactions followed by a discussion of insulin resistance and its associated clinical manifestations. Specific areas of focus include the actions of insulin and manifestations of insulin resistance in specific organs and tissues, physiological, environmental and pharmacological influences on insulin action and insulin resistance as well as clinical syndromes associated with insulin resistance. Clinical and functional measures of insulin resistance are also covered. Despite our incomplete understanding of the complex biological mechanisms of insulin action and insulin resistance, we need to consider the dramatic social changes of the past century with respect to physical activity, diet, work, socialisation and sleep patterns. Rapid globalisation, urbanisation and industrialisation have spawned epidemics of obesity, diabetes and their attendant co-morbidities, as physical inactivity and dietary imbalance unmask latent predisposing genetic traits. PMID:16278749

  5. Diurnal pattern of plasma metformin concentrations and its relation to metabolic effects in type 2 (non-insulin-dependent) diabetic patients.

    Science.gov (United States)

    Marchetti, P; Gregorio, F; Benzi, L; Giannarelli, R; Cecchetti, P; Villani, G; Di Cianni, G; Di Carlo, A; Brunetti, P; Navalesi, R

    1990-12-01

    The authors describe the diurnal profile of plasma metformin concentrations in a group of 6 Type 2 (noninsulin-dependent) diabetic patients studied at two different daily metformin doses (500 mg and 850 mg b.d.) and report data on the relationships between plasma metformin and metabolic effects over a 14 h period. In addition, the effect of circulating metformin on insulin binding to isolated monocytes has been evaluated. At the two different daily doses fasting plasma metformin concentrations were similar (3.23 +/- 0.35 mumol/l and 3.86 +/- 0.72 mumol/l, mean values +/- SEM, at low and high dose respectively). Drug peak values and averaged concentrations (4.66 +/- 0.39 mumol/l vs 6.35 +/- 0.69 mumol/l) were significantly higher when more drug was administered. Mean plasma glucose was lower when 1,700 mg/day instead of 1,000 mg/day of metformin was given (7.3 +/- 0.4 mmol/l vs 9.1 +/- 0.9 mmol/l, p less than 0.05). After dosing, at higher plasma metformin concentrations corresponded lower plasma glucose values. The averaged blood lactate levels resulted 1.46 +/- 0.4 mmol/l (p less than 0.05 vs matched diet treated diabetic patients) at the higher drug dose. A significant positive correlation emerged between mean plasma metformin concentrations and mean blood lactate levels (r: 0.76, p less than 0.02). Alanine, glycerol and B-OH-butyrate levels were similar at the two metformin daily doses, and were not correlated to plasma metformin. The binding of insulin to isolated human monocytes was similar in metformin-treated diabetic patients (4.48 +/- 0.45) as in healthy volunteers (4.62 +/- 0.34); insulin binding was correlated (p less than 0.05) with plasma metformin levels.

  6. Effect of growth in infancy on body composition, insulin resistance, and concentration of appetite hormones in adolescence

    DEFF Research Database (Denmark)

    Larnkjaer, Anni; Schack-Nielsen, Lene; Mølgaard, Christian

    2010-01-01

    High infancy weight gain is associated with increased body mass index (BMI) and insulin resistance (IR) in later life, but the association with later body composition has not been well explored. Appetite regulatory hormones may be programmed in early life, but data to support this are lacking....

  7. Superior Effects of Eccentric to Concentric Knee Extensor Resistance Training on Physical Fitness, Insulin Sensitivity and Lipid Profiles of Elderly Men

    Science.gov (United States)

    Chen, Trevor Chung-Ching; Tseng, Wei-Chin; Huang, Guan-Ling; Chen, Hsin-Lian; Tseng, Kuo-Wei; Nosaka, Kazunori

    2017-01-01

    It has been reported that eccentric training of knee extensors is effective for improving blood insulin sensitivity and lipid profiles to a greater extent than concentric training in young women. However, it is not known whether this is also the case for elderly individuals. Thus, the present study tested the hypothesis that eccentric training of the knee extensors would improve physical function and health parameters (e.g., blood lipid profiles) of older adults better than concentric training. Healthy elderly men (60–76 years) were assigned to either eccentric training or concentric training group (n = 13/group), and performed 30–60 eccentric or concentric contractions of knee extensors once a week. The intensity was progressively increased over 12 weeks from 10 to 100% of maximal concentric strength for eccentric training and from 50 to 100% for concentric training. Outcome measures were taken before and 4 days after the training period. The results showed that no sings of muscle damage were observed after any sessions. Functional physical fitness (e.g., 30-s chair stand) and maximal concentric contraction strength of the knee extensors increased greater (P ≤ 0.05) after eccentric training than concentric training. Homeostasis model assessment, oral glucose tolerance test and whole blood glycosylated hemoglobin showed improvement of insulin sensitivity only after eccentric training (P ≤ 0.05). Greater (P ≤ 0.05) decreases in fasting triacylglycerols, total, and low-density lipoprotein cholesterols were evident after eccentric training than concentric training, and high-density lipoprotein cholesterols increased only after eccentric training. These results support the hypothesis and suggest that it is better to focus on eccentric contractions in exercise medicine. PMID:28443029

  8. Insulin Basics

    Science.gov (United States)

    ... Text Size: A A A Listen En Español Insulin Basics There are different types of insulin depending ... you may be experiencing a reaction. Types of Insulin Rapid-acting insulin , begins to work about 15 ...

  9. Modest dietary K+ restriction provokes insulin resistance of cellular K+ uptake and phosphorylation of renal outer medulla K+ channel without fall in plasma K+ concentration.

    Science.gov (United States)

    Chen, Pei; Guzman, John P; Leong, Patrick K K; Yang, Li E; Perianayagam, Anjana; Babilonia, Elisa; Ho, Jennifer S; Youn, Jang H; Wang, Wen Hui; McDonough, Alicia A

    2006-05-01

    Extracellular K(+) concentration ([K(+)]) is closely regulated by the concerted regulatory responses of kidney and muscle. In this study, we aimed to define the responses activated when dietary K(+) was moderately reduced from a control diet (1.0% K(+)) to a 0.33% K(+) diet for 15 days. Although body weight and baseline plasma [K(+)] (4.0 mM) were not reduced in the 0.33% K(+) group, regulatory responses to conserve plasma [K(+)] were evident in both muscle and kidney. Insulin-stimulated clearance of K(+) from the plasma was estimated in vivo in conscious rats with the use of tail venous and arterial cannulas. During infusion of insulin.(50 mU.kg(-1).min(-1)), plasma [K(+)] level fell to 3.2 +/- 0.1 mM in the 1.0% K(+) diet group and to only 3.47 +/- 0.07 mM in the 0.33% K(+) diet group (P < 0.01) with no reduction in urinary K(+) excretion, which is evidence of insulin resistance to cellular K(+) uptake. Insulin-stimulated cellular K(+) uptake was quantitated by measuring the K(+) infusion rate necessary to clamp plasma K(+) at baseline (in micromol.kg(-1).min(-1)) during 5 mU of insulin.kg(-1).min(-1) infusion: 9.7 +/- 1.5 in 1% K(+) diet was blunted to 5.2 +/- 1.7 in the 0.33% K(+) diet group (P < 0.001). Muscle [K(+)] and Na(+)-K(+)-ATPase activity and abundance were unchanged during the 0.33% K(+) diet. Renal excretion, which was measured overnight in metabolic cages, was reduced by 80%, from 117.6 +/- 10.5 micromol/h/animal (1% K(+) diet) to 24.2 +/- 1.7 micromol/h/animal (0.33% K(+) diet) (P < 0.001). There was no significant change in total abundance of key renal K(+) transporters, but 50% increases in both renal PTK cSrc abundance and ROMK phosphorylation in the 0.33% K(+) vs. 1% K(+) diet group, previously established to be associated with internalization of ROMK. These results indicate that plasma [K(+)] can be maintained during modest K(+) restriction due to a decrease in insulin-stimulated cellular K(+) uptake as well as renal K(+) conservation

  10. Analytical expressions for the steady-state concentrations of glucose, oxygen and gluconic acid in a composite membrane for closed-loop insulin delivery.

    Science.gov (United States)

    Rajendran, L; Bieniasz, L K

    2013-02-01

    The mathematical model of Abdekhodaie and Wu (J Membr Sci 335:21-31, 2009) of glucose-responsive composite membranes for closed-loop insulin delivery is discussed. The glucose composite membrane contains nanoparticles of an anionic polymer, glucose oxidase and catalase embedded in a hydrophobic polymer. The model involves the system of nonlinear steady-state reaction-diffusion equations. Analytical expressions for the concentration of glucose, oxygen and gluconic acid are derived from these equations using the Adomian decomposition method. A comparison of the analytical approximation and numerical simulation is also presented. An agreement between analytical expressions and numerical results is observed.

  11. Dietary protein during gestation affects maternal insulin-like growth factor, insulin-like growth factor binding protein, leptin concentrations, and fetal growth in heifers.

    Science.gov (United States)

    Sullivan, T M; Micke, G C; Perkins, N; Martin, G B; Wallace, C R; Gatford, K L; Owens, J A; Perry, V E A

    2009-10-01

    The influence of supplemental protein during gestation on maternal hormones and fetal growth was determined in composite beef heifers. At AI, 118 heifers were stratified by BW within each composite genotype (BeefX = 1/2 Senepol, 1/4 Brahman, 1/8 Charolais, 1/8 Red Angus and CBX = 1/2 Senepol, 1/4 Brahman, 1/4 Charolais) into 4 treatment groups: high high (HH = 1.4 kg CP/d for first and second trimesters of gestation), high low (HL = 1.4 kg of CP/d for first trimester and 0.4 kg of CP/d for second trimester), low high (lowH = 0.4 kg CP/d for first trimester and 1.4 kg of CP/d and for second trimester), or low low (LL = 0.4 kg CP/d for first and second trimesters). Maternal plasma IGF-I and -II, total IGFBP, and leptin concentrations were determined at 14 d before AI and at d 28, 82, 179, and 271 post-AI (mean gestation length 286 d), and leptin concentrations were also determined at calving. Increased dietary protein increased maternal plasma IGF-I (P < 0.001 on d 28, 82, and 179), IGF-II (P = 0.01 on d 82; P = 0.04 on d 271), and total IGFBP (P = 0.002 on d 82; P = 0.005 on d 179; P = 0.03 on d 271). Maternal plasma IGF-I at d 271 was negatively associated with calf crown-rump length at birth (P = 0.003). BeefX had greater birth weight calves (P = 0.01), greater IGF-II (P < 0.001), increased ratios of IGF-I:total IGFBP (P = 0.008) and IGF-II:total IGFBP (P < 0.001), and reduced total IGFBP compared with CBX (P = 0.02). Increased dietary protein during second trimester increased maternal plasma leptin at calving (P = 0.005). Maternal plasma leptin near term was positively associated with heifer BCS (P = 0.02) and with calf birth weight (P = 0.04), and at calving was positively associated with heifer age at AI (P = 0.02). These findings suggest that maternal dietary protein, age, and genotype influence plasma concentrations of metabolic hormones and fetal growth in Bos indicus-influenced heifers.

  12. Cardiac Autonomic Function during Submaximal Treadmill Exercise in Adults with Down Syndrome

    Science.gov (United States)

    Mendonca, Goncalo V.; Pereira, Fernando D.; Fernhall, Bo

    2011-01-01

    This study determined whether the cardiac autonomic function of adults with Down syndrome (DS) differs from that of nondisabled persons during submaximal dynamic exercise. Thirteen participants with DS and 12 nondisabled individuals performed maximal and submaximal treadmill tests with metabolic and heart rate (HR) measurements. Spectral analysis…

  13. Is energy expenditure taken into account in human sub-maximal jumping? - a simulation study

    NARCIS (Netherlands)

    Vanrenterghem, J.; Bobbert, M.F.; Casius, L.J.R.; de Clercq, D.

    2008-01-01

    This paper presents a simulation study that was conducted to investigate whether the stereotyped motion pattern observed in human sub-maximal jumping can be interpreted from the perspective of energy expenditure. Human sub-maximal vertical countermovement jumps were compared to jumps simulated with

  14. A New Submaximal Rowing Test to Predict 2,000-m Rowing Ergometer Performance

    NARCIS (Netherlands)

    Otter, Ruby T. A.; Brink, Michel S.; Lamberts, Robert P.; Lemmink, Koen A. P. M.

    Otter, RTA, Brink, MS, Lamberts, RP, and Lemmink, KAPM. A new submaximal rowing test to predict 2,000-m rowing ergometer performance. J Strength Cond Res 29(9): 2426-2433, 2015-The purpose of this study was to assess predictive value of a new submaximal rowing test (SmRT) on 2,000-m ergometer rowing

  15. Effect of the Canadian Air Force training programme on a submaximal exercise test.

    Science.gov (United States)

    Kappagoda, C T; Linden, R J; Newell, J P

    1979-07-01

    Validation of the submaximal heart rate/oxygen consumption relationship as an index of 'cardiorespiratory fitness' requires the demonstration of systematic alterations in this relationship concomitant with interventions designed to alter physical fitness. To fulfil those criteria a longitudinal training/de-training study was undertaken. Previously sedentary adult subjects undertook the Canadian Airforce 5BX-XBX exercise programme. Submaximal exercise tests were performed before and after training, and following several weeks cessation of training. A regression line of submaximal heart rate on submaximal oxygen consumption was calculated from the data of each submaximal exercise test. Alterations in the regression lines were examined for each subject individually by testing statistically for difference in slope and elevation between any pair of lines. Subjects who undertook the training/de-training study demonstrated significant systematic alterations in the elevation of the regression lines concomitant with periods of training and de-training. The reproducibility of the submaximal heart rate/oxygen consumption relationship was examined in two additional groups of subjects. Group A repeated a submaximal test on 3 or 4 successive days; Group B were tested before and after 16 weeks of normal activity. Subjects in Group A demonstrated non significant, random alterations in the regression lines on repeated testing and subjects in Group B demonstrated random, though on occasion significant, alterations in the regression lines. The elevation of the submaximal heart rate/oxygen consumption relationship is therefore a valid index for detecting sequential changes in 'cardiorespiratory fitness' in individual subjects.

  16. The effect of long term under- and over-feeding of sheep on milk and plasma fatty acid profiles and on insulin and leptin concentrations.

    Science.gov (United States)

    Tsiplakou, Eleni; Chadio, Stella; Zervas, George

    2012-05-01

    Since sheep's milk is mainly used for cheese making and milk chemical composition and fatty acids (FA) profile affect cheese yield and quality, the objective of this study was to determine the effects of different feeding levels on milk chemical composition and FA profile, as well as on plasma FA profile, and on insulin and leptin concentrations. Twenty-four sheep were assigned to three homogeneous sub-groups. Throughout the experimental period each group was fed the same diet but in quantities which met 70% (under-feeding), 100% (control) and 130% (over-feeding) of their respective energy and crude protein requirements. The results showed that the underfed sheep had higher milk fat content compared with overfed. In blood plasma the concentrations of C18:0 and C18:1 in the underfed sheep were significantly higher compared with control and overfed sheep. The concentrations of leptin and insulin were significantly higher in overfed compared with underfed sheep. Underfeeding reduced the concentrations of short chain FA (SCFA) and medium chain FA (MCFA) and increased that of C18:0 and mono unsaturated FA (MUFA) in sheep milk fat compared with controls and overfed. The concentrations of C18:0, long chain FA (LCFA) and monounsaturated FA (MUFA) in milk were significantly higher and those of SCFA, MCFA and saturated FA (SFA) significantly lower in the underfed compared with the overfed sheep. In conclusion, long term under- and over-feeding affected the sheep milk chemical composition and FA profile which consequently has an impact on milk products yield (cheese and yogurt) and quality (human health).

  17. The Impact of Vitamin D Supplementation on Neurodegeneration, TNF-α Concentration in Hypothalamus, and CSF-to-Plasma Ratio of Insulin in High-Fat-Diet-Induced Obese Rats.

    Science.gov (United States)

    Nameni, Ghazaleh; Hajiluian, Ghazaleh; Shahabi, Parviz; Farhangi, Mahdieh Abbasalizad; Mesgari-Abbasi, Mehran; Hemmati, Mohammad-Reza; Vatandoust, Seyed Mahdi

    2017-02-01

    There is growing evidence that obesity can lead to neurodegeneration induced by pro-inflammatory cytokines such as tumor necrosis factor (TNF-α). Moreover, obesity is associated with reduced transport of insulin through the blood-brain barrier (BBB). Insulin deficiency in the brain especially in the hypothalamus region has neurodegenerative and obesity-promoting effects. Because of the anti-inflammatory and neuroprotective effects of vitamin D, in the current experimental study, we aimed to investigate the effects of vitamin D supplementation on neurodegeneration, TNF-α concentration in the hypothalamus, and cerebrospinal fluid (CSF) to serum ratio of insulin in high-fat-diet-induced obese rats. At the first phase of the study, the rats were divided into two groups: (1) normal diet (ND, 10% fat) and (2) high-fat diet (HFD, 59% fat) and were fed for 16 weeks. In the second phase, each group was subdivided into four groups including the following: ND, normal diet + vitamin D, HFD, and HFD + vitamin D. Weight was measured and recorded weekly. Vitamin D supplementation for 5 weeks at 500 IU/kg dosage was used. One week after vitamin D supplementation, daily food intake was recorded. At week 22, blood was collected to determine fasting serum glucose, vitamin D, and insulin concentrations, and the homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. CSF samples were also collected to measure insulin concentrations, and the hypothalamus was dissected to determine TNF-α concentration. HFD significantly increased TNF-α concentrations and degenerated neurons in the hypothalamus (P = 0.02). We also observed a significant reduction of CSF-to-serum ratio of insulin in HFD group (P = 0.03). The HOMA-IR test indicated significant increment of insulin resistance in HFD-fed rats (P = 0.006). Vitamin D supplementation in HFD group significantly reduced weight (P = 0.001) and food intake (P = 0.008) and increased CSF-to-serum ratio of insulin

  18. Fasting and postprandial remnant-like particle cholesterol concentrations in obese participants are associated with plasma triglycerides, insulin resistance, and body fat distribution

    DEFF Research Database (Denmark)

    van Hees, Anneke M. J.; Saris, Wim H. M.; Dallinga-Thie, Geesje M.

    2008-01-01

    (n = 613) also participated in a 10-wk weight loss program (-2510 kJ/d), being randomized to either a low-fat or a high-fat diet (20-25 vs. 40-45en% fat). Postprandial RLP-C was associated with fasting RLP-C, waist:hip ratio (WHR), HOMA(IR) (homeostasis model assessment index for insulin resistance......, independently mediated by weight loss, improvements in HOMA(IR), and the fat content of the prescribed diet. However, after inclusion of plasma triglyceride (TG), HDL-cholesterol, and FFA concentrations in the models, HOMA(IR) and WHR no longer significantly predicted fasting RLP-C, although WHR remained...... of lean and obese participants. All participants (n = 740) underwent a test meal challenge containing 95 energy % (en%) fat (energy content 50% of predicted daily resting metabolic rate). Fasting and postprandial concentrations of circulating metabolites were measured over a 3-h period. Obese participants...

  19. [Insulin resistance in children].

    Science.gov (United States)

    Witek, Joanna; Witek, Przemysław; Pańkowska, Ewa

    2011-01-01

    Insulin resistance is characterized by decreased tissue sensitivity to insulin. The hallmark of insulin resistance is decreased tissue glucose uptake despite normal or elevated insulin concentration. There has been an upward trend in the incidence of insulin resistance in developed countries, although in pediatric population it is difficult to assess. Both genetic and environmental factors play an important role in the etiology of insulin resistance, namely increased diet caloricity and decreased physical activity. Gradually, this leads to adipose tissue build-up. The role of visceral adipose tissue is of particular importance, mainly due to its significant endocrine activity, leading to adverse metabolic effects. The most important consequences of insulin resistance in children include increased incidence of type 2 diabetes, atherogenic dyslipidemia and arterial hypertension, which lead to increased cardiovascular risk. Children with insulin resistance can develop nonalcoholic steatohepatitis and sleep apnea syndrome. In case of female pediatric patients a higher incidence of polycystic ovary syndrome (PCOS) is observed. Furthermore, the authors reviewed opinions on risk factors for insulin resistance, as well as direct and indirect insulin resistance assessment methods. The article presents the principles of primary and secondary prevention of insulin resistance in children, with particular allowance for dietary recommendations and recommendations to increase physical activity, and, in selected cases, current guidelines on pharmacological treatment.

  20. Different types of compression clothing do not increase sub-maximal and maximal endurance performance in well-trained athletes.

    Science.gov (United States)

    Sperlich, Billy; Haegele, Matthias; Achtzehn, Silvia; Linville, John; Holmberg, Hans-Christer; Mester, Joachim

    2010-04-01

    Three textiles with increasing compressive surface were compared with non-compressive conventional clothing on physiological and perceptual variables during sub-maximal and maximal running. Fifteen well-trained endurance athletes (mean+/-s: age 27.1+/-4.8 years, VO(2max) 63.7+/-4.9 ml x min(-1) x kg(-1)) performed four sub-maximal (approximately 70% VO(2max)) and maximal tests with and without different compression stockings, tights, and whole-body compression suits. Arterial lactate concentration, oxygen saturation and partial pressure, pH, oxygen uptake, and ratings of muscle soreness were recorded before, during, and after all tests. In addition, we assessed time to exhaustion. Sub-maximal (P=0.22) and maximal oxygen uptake (P=0.26), arterial lactate concentration (P=0.16; 0.20), pH (P=0.23; 0.46), oxygen saturation (P=0.13; 0.26), and oxygen partial pressure (P=0.09; 0.20) did not differ between the types of clothing (effect sizes=0.00-0.45). Ratings of perceived exertion (P=0.10; 0.15), muscle soreness (P=0.09; 0.10) and time to exhaustion (P=0.16) were also unaffected by the different clothing (effect sizes=0.28-0.85). This was the first study to evaluate the effect on endurance performance of different types of compression clothing with increasing amounts of compressive surface. Overall, there were no performance benefits when using the compression garments.

  1. Reliability of oscillometric central blood pressure responses to submaximal exercise.

    Science.gov (United States)

    Lim, Weijie; Faulkner, James; Lambrick, Danielle; Stoner, Lee

    2016-06-01

    Central blood pressure responses to exercise may provide clinicians with a superior diagnostic and prognostic tool. However, to be of value in a clinical setting these assessments must be simple to conduct and reliable. Using oscillometric pulse wave analysis (PWA), determine the upper limit for between-day reliability of central SBP (cSBP) and central pressure augmentation (AIx) responses to three progressive stages of submaximal exercise in a cohort of young, healthy participants. Fifteen healthy males [25.8 years (SD 5.7), 23.9 kg/m (SD 2.5)] were tested on three different mornings in a fasted state, separated by a maximum of 14 days. Central hemodynamic variables were assessed on the left upper arm. Participants underwent three progressive stages of submaximal cycling at 50 W (low), 100 W (moderate) and 150 W (moderate-hard). During low and moderate-intensity exercise the intra-class correlation coefficient (ICC) values for cSBP (0.79-0.80) and AIx (0.81-0.85) indicated excellent reliability (ICC > 0.75). For the moderate-hard intensity AIx could not be computed, and the ICC for cSBP was adequate (0.72). Findings from this study suggest that, at least in a young, healthy cohort, oscillometric PWA can be used to reliably assess central blood pressure measurements during exercise, up to a moderate intensity. Although further work is required to verify these findings in clinical cohorts, these measurements may potentially provide clinicians with a practical option for obtaining important hemodynamic information beyond that provided by resting peripheral blood pressure.

  2. Which factors determine the freely chosen cadence during submaximal cycling?

    Science.gov (United States)

    Vercruyssen, Fabrice; Brisswalter, Jeanick

    2010-03-01

    The present review of cycling science focuses on the identification of criteria that affect the freely chosen cadence (FCC) during submaximal exercise of short and prolonged durations. Cadence selection during submaximal cycling constitutes a potential parameter affecting the endurance performance in subjects of varying aerobic fitness level and experience. The activity constraints such as specificity (e.g. cycle bout of triathlon) and exercise duration may play an important role in the selection of cadence and must be taken into consideration in the task description. The 'holistic' approach of this review is based on a multifactorial analysis considering the cycling constraints, and the physiological and biomechanical factors of cadence selection so as to establish any interrelationships between these factors. During cycle bouts of short duration (<15 min), it has been well argued that experienced cyclists, trained runners and triathletes adopt high cadences (80-100 rpm) systematically above the energetically optimal cadence (EOC) at which the oxygen uptake is minimal (55-65 rpm). The choice of a high cadence has been shown to be dependent upon several factors, such as the aerobic fitness level, the reduction in forces applied to the cranks, the lower extremity net joint moments and minimal neuromuscular fatigue. However, with increasing exercise duration the FCC has been reported to be close to the EOC exclusively in endurance athletes practising a variety of activities, suggesting an impact of training mode on the muscular adaptations and the organisation of the movement pattern. Copyright 2009 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  3. Insulin Therapy

    Science.gov (United States)

    ... Your Health Resources Drugs, Procedures & Devices Prescription Medicines Insulin Therapy Insulin Therapy Share Print When you digest food, your ... you eat into glucose (a form of sugar). Insulin allows this glucose to enter all the cells ...

  4. Reliability and Seasonal Changes of Submaximal Variables to Evaluate Professional Cyclists.

    Science.gov (United States)

    Rodríguez-Marroyo, Jose A; Pernía, Raúl; Villa, José G; Foster, Carl

    2017-11-01

    The aim of this study was to determine the reliability and validity of several submaximal variables that can be easily obtained by monitoring cyclists' performances. Eighteen professional cyclists participated in this study. In a first part (n = 15) the test-retest reliability of heart rate (HR) and rating of perceived exertion (RPE) during a progressive maximal test was measured. Derived submaximal variables based on HR, RPE, and power output (PO) responses were analyzed. In a second part (n = 7) the pattern of the submaximal variables according to cyclists' training status was analyzed. Cyclists were assessed 3 times during the season: at the beginning of the season, before the Vuelta a España, and the day after this Grand Tour. Part 1: No significant differences in maximal and submaximal variables between test-retest were found. Excellent ICCs (0.81-0.98) were obtained in all variables. Part 2: The HR and RPE showed a rightward shift from early to peak season. In addition, RPE showed a left shift after the Vuelta a España. Submaximal variables based on RPE had the best relationship with both performance and changes in performance. The present study showed the reliability of different maximal and submaximal variables used to assess cyclists' performances. Submaximal variables based on RPE seem to be the best to monitor changes in training status over a season.

  5. A Systematic Review of Submaximal Cycle Tests to Predict, Monitor, and Optimize Cycling Performance.

    Science.gov (United States)

    Capostagno, Benoit; Lambert, Michael I; Lamberts, Robert P

    2016-09-01

    Finding the optimal balance between high training loads and recovery is a constant challenge for cyclists and their coaches. Monitoring improvements in performance and levels of fatigue is recommended to correctly adjust training to ensure optimal adaptation. However, many performance tests require a maximal or exhaustive effort, which reduces their real-world application. The purpose of this review was to investigate the development and use of submaximal cycling tests that can be used to predict and monitor cycling performance and training status. Twelve studies met the inclusion criteria, and 3 separate submaximal cycling tests were identified from within those 12. Submaximal variables including gross mechanical efficiency, oxygen uptake (VO2), heart rate, lactate, predicted time to exhaustion (pTE), rating of perceived exertion (RPE), power output, and heart-rate recovery (HRR) were the components of the 3 tests. pTE, submaximal power output, RPE, and HRR appear to have the most value for monitoring improvements in performance and indicate a state of fatigue. This literature review shows that several submaximal cycle tests have been developed over the last decade with the aim to predict, monitor, and optimize cycling performance. To be able to conduct a submaximal test on a regular basis, the test needs to be short in duration and as noninvasive as possible. In addition, a test should capture multiple variables and use multivariate analyses to interpret the submaximal outcomes correctly and alter training prescription if needed.

  6. Effect of Acarbose, Sitagliptin and combination therapy on blood glucose, insulin, and incretin hormone concentrations in experimentally induced postprandial hyperglycemia of healthy cats.

    Science.gov (United States)

    Mori, Akihiro; Ueda, Kaori; Lee, Peter; Oda, Hitomi; Ishioka, Katsumi; Arai, Toshiro; Sako, Toshinori

    2016-06-01

    Acarbose (AC) and Sitagliptin (STGP) are oral hypoglycemic agents currently used either alone or in conjunction with human diabetic (Type 2) patients. AC has been used with diabetic cats, but not STGP thus far. Therefore, the objective of this study was to determine the potential use of AC or STGP alone and in combination for diabetic cats, by observing their effect on short-term post-prandial serum glucose, insulin, and incretin hormone (active glucagon-like peptide-1 (GLP-1) and total glucose dependent insulinotropic polypeptide (GIP)) concentrations in five healthy cats, following ingestion of a meal with maltose. All treatments tended (pinsulin AUC as compared to no treatment. Meanwhile, a significant increase (pinsulin and incretin hormone levels of healthy cats. Increasing active GLP-1 and reducing postprandial hyperglycemia appear to be the principal mechanisms of combined treatment. Considering the different, but complementary mechanisms of action by which AC and STGP induce lower glucose and insulin levels, combination therapy with both these agents offers great potential for treating diabetic cats in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Genetic parameter estimates for serum insulin-like growth factor I concentrations, and body weight and weight gains in Angus beef cattle divergently selected for serum insulin-like growth factor I concentration.

    Science.gov (United States)

    Davis, M E; Simmen, R C M

    2006-09-01

    Data for the current study were obtained from a divergent selection experiment in which the selection criterion was the average serum IGF-I concentrations of 3 postweaning blood samples collected from purebred Angus calves. Multiple-trait derivative-free REML procedures were used to obtain genetic parameter estimates for IGF-I concentrations and for BW and BW gains measured from birth to the conclusion of a 140-d postweaning performance test. Included in the analysis were 2,674 animals in the A(-1) matrix, 1,761 of which had valid records for IGF-I concentrations. Direct heritability estimates +/- SE for IGF-I concentration at d 28, 42, and 56 of the postweaning period and for mean IGF-I concentrations were 0.44 +/- 0.07, 0.51 +/- 0.08, 0.42 +/- 0.07, and 0.52 +/- 0.08, respectively. Heritability estimates for maternal genetic effects ranged from 0.10 +/- 0.05 to 0.20 +/- 0.06. The proportion of total phenotypic variance due to the maternal permanent environmental effect was essentially zero for all measures of IGF-I concentrations. Genetic correlations of IGF-I concentrations with weaning and post-weaning BW ranged from 0.07 +/- 0.12 to 0.32 +/- 0.11 and generally demonstrated an increasing trend during the postweaning period. Averaged across the various measures of IGF-I, the genetic correlation of IGF-I with preweaning gain was 0.14, whereas the genetic correlation with postweaning gain was 0.29. Genetic correlations between IGF-I and BW gain were positive during all time intervals, except between weaning and the beginning of the postweaning test and from d 84 to 112 of the postweaning period. Environmental and phenotypic correlations of IGF-I with BW and BW gains were generally positive, but small. These results indicate that postweaning serum IGF-I concentration is moderately to highly heritable and has small positive genetic, environmental, and phenotypic correlations with BW other than birth weight and with pre- and postweaning gain. Therefore, if IGF

  8. Diabetes, insulin and exercise

    DEFF Research Database (Denmark)

    Richter, Erik; Galbo, H

    1986-01-01

    The metabolic and hormonal adaptations to single exercise sessions and to exercise training in normal man and in patients with insulin-dependent as well as non-insulin-dependent diabetes mellitus are reviewed. In insulin-dependent (type I) diabetes good metabolic control is best obtained...... of the patient's reaction to exercise is desirable, which necessitates frequent self-monitoring of plasma glucose. It may often be necessary to diminish the insulin dose before exercise, and/or to ingest additional carbohydrate during or after exercise. In non-insulin-dependent (type II) diabetes, exercise...... by a regular pattern of life which will lead to a fairly constant demand for insulin from day to day. Exercise is by nature a perturbation that makes treatment of diabetes difficult: Muscle contractions per se tend to decrease the plasma glucose concentration whereas the exercise-induced response of the so...

  9. Exposure to a combination of heat and hyperoxia during cycling at submaximal intensity does not alter thermoregulatory responses

    Directory of Open Access Journals (Sweden)

    C Zinner

    2016-02-01

    Full Text Available In this study, we tested the hypothesis that breathing hyperoxic air (FinO2 = 0.40 while exercising in a hot environment exerts negative effects on the total tissue level of haemoglobin concentration (tHb; core (Tcore and skin (Tskin temperatures; muscle activity; heart rate; blood concentration of lactate; pH; partial pressure of oxygen (PaO2 and carbon dioxide; arterial oxygen saturation (SaO2; and perceptual responses. Ten well-trained male athletes cycled at submaximal intensity at 21°C or 33°C in randomized order: first for 20 min while breathing normal air (FinO2 = 0.21 and then 10 min with FinO2 = 0.40 (HOX. At both temperatures, SaO2 and PaO2, but not tHb, were increased by HOX. Tskin and perception of exertion and thermal discomfort were higher at 33°C than 21°C (p 0.07. Blood lactate and heart rate were higher at 33°C than 21°C. In conclusion, during 30 min of submaximal cycling at 21°C or 33°C, Tcore, Tskin and Tbody, tHb, muscle activity and ratings of perceived exertion and thermal discomfort were the same under normoxic and hyperoxic conditions. Accordingly, breathing hyperoxic air (FinO2 = 0.40 did not affect thermoregulation under these conditions.

  10. Adrenal Demedullation and Oxygen Supplementation Independently Increase Glucose-Stimulated Insulin Concentrations in Fetal Sheep With Intrauterine Growth Restriction

    OpenAIRE

    Macko, Antoni R.; Yates, Dustin T.; Chen, Xiaochuan; Shelton, Leslie A.; Kelly, Amy C.; Davis, Melissa A.; Camacho, Leticia E.; Anderson, Miranda J.; Limesand, Sean W.

    2016-01-01

    In pregnancies complicated by placental insufficiency and intrauterine growth restriction (IUGR), fetal glucose and oxygen concentrations are reduced, whereas plasma norepinephrine and epinephrine concentrations are elevated throughout the final third of gestation. Here we study the effects of chronic hypoxemia and hypercatecholaminemia on β-cell function in fetal sheep with placental insufficiency-induced IUGR that is produced by maternal hyperthermia. IUGR and control fetuses underwent a sh...

  11. Acclimatization improves submaximal exercise economy at 5533 m.

    Science.gov (United States)

    Latshang, T D; Turk, A J; Hess, T; Schoch, O D; Bosch, M M; Barthelmes, D; Merz, T M; Hefti, U; Hefti, J Pichler; Maggiorini, M; Bloch, K E

    2013-08-01

    We tested whether the better subjective exercise tolerance perceived by mountaineers after altitude acclimatization relates to enhanced exercise economy. Thirty-two mountaineers performed progressive bicycle exercise to exhaustion at 490 m and twice at 5533 m (days 6-7 and day 11), respectively, during an expedition to Mt. Muztagh Ata. Maximal work rate (W(max)) decreased from mean ± SD 356 ± 73 watts at 490 m to 191 ± 49 watts and 193 ± 45 watts at 5533 m, days 6-7 and day 11, respectively; corresponding maximal oxygen uptakes (VO2max ) were 50.7 ± 9.5, 26.3 ± 5.6, 24.7 ± 7.0 mL/min/kg (P = 0.0001 5533 m vs 490 m). On days 6-7 (5533 m), VO(2) at 75% W(max) (152 ± 37 watts) was 1.75 ± 0.45 L/min, oxygen saturation 68 ± 8%. On day 11 (5533 m), at the same submaximal work rate, VO(2) was lower (1.61 ± 0.47 L/min, P scale 50 ± 15 vs 57 ± 20, P = 0.006) and reduced symptoms of acute mountain sickness. We conclude that the better performance and subjective exercise tolerance after acclimatization were related to regression of acute mountain sickness and improved submaximal exercise economy because of lower metabolic demands for non-external work-performing functions. © 2011 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Consumption of meat is associated with higher fasting glucose and insulin concentrations regardless of glucose and insulin genetic risk scores: a meta-analysis of 50,345 Caucasians

    Science.gov (United States)

    Recent studies suggest that meat intake is associated with diabetes-related phenotypes. However, whether the associations of meat intake and glucose and insulin homeostasis are modified by genes related to glucose and insulin is unknown. We investigated the associations of meat intake and the intera...

  13. Consumption of meat is associated with higher fasting glucose and insulin concentrations regardless of glucose and insulin genetic risk scores: A meta-analysis of 50,345 Caucasians

    NARCIS (Netherlands)

    A.M. Fretts (Amanda M.); J.L. Follis (Jack ); J.A. Nettleton (Jennifer ); R.N. Lemaitre (Rozenn ); J.S. Ngwa; M.K. Wojczynski (Mary ); I.-P. Kalafati (Ioanna-Panagiota); T.V. Varga (Tibor V.); A.C. Frazier-Wood (Alexis C.); D.K. Houston (Denise); J. Lahti (Jari); U. Ericson (Ulrika); E.H. van den Hooven (Edith); V. Mikkilä (Vera); J.C. Kiefte-de Jong (Jessica); D. Mozaffarian (Dariush); K.M. Rice (Kenneth); F. Renström (Frida); K.E. North (Kari); N.M. McKeown (Nicola ); M.F. Feitosa (Mary Furlan); S. Kanoni (Stavroula); C.E. Smith (Caren); M. Garcia (Melissa); A.-M. Tiainen (Anna-Maija); E. Sonestedt (Emily); A. Manichaikul (Ani); F.J.A. van Rooij (Frank); M. Dimitriou (Maria); O. Raitakari (Olli); J.S. Pankow (James); L. Djoussé (Luc); M.A. Province (Mike); F.B. Hu (Frank); C.-Q. Lai (Chao-Qiang); M.F. Keller (Margaux); M.-M. Perälä (Mia-Maria); J.I. Rotter (Jerome I.); A. Hofman (Albert); M.J. Graff (Maud J.L.); M. Kähönen (Mika); K. Mukamal (Kenneth); I. Johansson (Ingegerd); J.M. Ordovas (Jose); Y. Liu (YongMei); S. Männistö (Satu); A.G. Uitterlinden (André); P. Deloukas (Panagiotis); I. Seppälä (Ilkka); B.M. Psaty (Bruce); L.A. Cupples (Adrienne); I.B. Borecki (Ingrid); P.W. Franks (Paul W.); D.K. Arnett (Donna); M.A. Nalls (Michael); K. Hagen (Knut); M. Orho-Melander (Marju); O.H. Franco (Oscar); T. Lehtimäki (Terho); G.V. Dedoussis (George); J.B. Meigs (James); D.S. Siscovick (David)

    2015-01-01

    textabstractBackground: Recent studies suggest that meat intake is associated with diabetes-related phenotypes. However, whether the associations of meat intake and glucose and insulin homeostasis are modified by genes related to glucose and insulin is unknown. Objective: We investigated the

  14. Cardiovascular responses during a submaximal exercise test in patients with Parkinson's disease.

    Science.gov (United States)

    Speelman, Arlène D; Groothuis, Jan T; van Nimwegen, Marlies; van der Scheer, Ellis S; Borm, George F; Bloem, Bastiaan R; Hopman, Maria T E; Munneke, Marten

    2012-01-01

    Patients with Parkinson's disease (PD) are physically less active than controls, and autonomic dysfunction may contribute to this sedentary lifestyle. Specifically, an altered cardiovascular response to physical effort may restrict physical activities. To assess the cardiovascular responses to a submaximal exercise test in PD patients and controls, 546 sedentary PD patients and 29 sedentary healthy controls performed the Åstrand-Rhyming submaximal cycle exercise test. Average heart rate was used to estimate maximal oxygen consumption (VO2max). Variables that may affect submaximal activity in PD patients, including disease severity, fatigue, and level of physical activity in daily life, were recorded. Fewer PD patients (46%) completed the submaximal exercise test successfully than the controls (86%). The estimated VO2max of patients with a successful test was 34% lower than the controls (p physical activities further.

  15. Association of apolipoprotein A5 concentration with serum insulin and triglyceride levels and coronary artery disease in Korean men

    Science.gov (United States)

    OBJECTIVE: Whereas the relation between apolipoprotein A5 (APOA5) gene polymorphisms and triglycerides (TG) levels is well established, the associations between apoA5 concentrations, TG and coronary artery disease (CAD) remain controversial. Therefore, we investigated these relations in the setting ...

  16. The Effects of Caffeine Supplementation on Physiological Responses to Submaximal Exercise in Endurance-Trained Men.

    Science.gov (United States)

    Glaister, Mark; Williams, Benjamin Henley; Muniz-Pumares, Daniel; Balsalobre-Fernández, Carlos; Foley, Paul

    2016-01-01

    The aim of this study was to evaluate the effects of caffeine on physiological responses to submaximal exercise, with a focus on blood lactate concentration ([BLa]). Using a randomised, single-blind, crossover design; 16 endurance-trained, male cyclists (age: 38 ± 8 years; height: 1.80 ± 0.05 m; body mass: 76.6 ± 7.8 kg; [Formula: see text]: 4.3 ± 0.6 L∙min-1) completed four trials on an electromagnetically-braked cycle ergometer. Each trial consisted of a six-stage incremental test (3 minute stages) followed by 30 minutes of passive recovery. One hour before trials 2-4, participants ingested a capsule containing 5 mg∙kg-1 of either caffeine or placebo (maltodextrin). Trials 2 and 3 were designed to evaluate the effects of caffeine on various physiological responses during exercise and recovery. In contrast, Trial 4 was designed to evaluate the effects of caffeine on [BLa] during passive recovery from an end-exercise concentration of 4 mmol∙L-1. Relative to placebo, caffeine increased [BLa] during exercise, independent of exercise intensity (mean difference: 0.33 ± 0.41 mmol∙L-1; 95% likely range: 0.11 to 0.55 mmol∙L-1), but did not affect the time-course of [BLa] during recovery (p = 0.604). Caffeine reduced ratings of perceived exertion (mean difference: 0.5 ± 0.7; 95% likely range: 0.1 to 0.9) and heart rate (mean difference: 3.6 ± 4.2 b∙min-1; 95% likely range: 1.3 to 5.8 b∙min-1) during exercise, with the effect on the latter dissipating as exercise intensity increased. Supplement × exercise intensity interactions were observed for respiratory exchange ratio (p = 0.004) and minute ventilation (p = 0.034). The results of the present study illustrate the clear, though often subtle, effects of caffeine on physiological responses to submaximal exercise. Researchers should be aware of these responses, particularly when evaluating the physiological effects of various experimental interventions.

  17. Validated Predictions of Metabolic Energy Consumption for Submaximal Effort Movement.

    Directory of Open Access Journals (Sweden)

    George A Tsianos

    2016-06-01

    Full Text Available Physical performance emerges from complex interactions among many physiological systems that are largely driven by the metabolic energy demanded. Quantifying metabolic demand is an essential step for revealing the many mechanisms of physical performance decrement, but accurate predictive models do not exist. The goal of this study was to investigate if a recently developed model of muscle energetics and force could be extended to reproduce the kinematics, kinetics, and metabolic demand of submaximal effort movement. Upright dynamic knee extension against various levels of ergometer load was simulated. Task energetics were estimated by combining the model of muscle contraction with validated models of lower limb musculotendon paths and segment dynamics. A genetic algorithm was used to compute the muscle excitations that reproduced the movement with the lowest energetic cost, which was determined to be an appropriate criterion for this task. Model predictions of oxygen uptake rate (VO2 were well within experimental variability for the range over which the model parameters were confidently known. The model's accurate estimates of metabolic demand make it useful for assessing the likelihood and severity of physical performance decrement for a given task as well as investigating underlying physiologic mechanisms.

  18. Effects of music tempo upon submaximal cycling performance.

    Science.gov (United States)

    Waterhouse, J; Hudson, P; Edwards, B

    2010-08-01

    In an in vivo laboratory controlled study, 12 healthy male students cycled at self-chosen work-rates while listening to a program of six popular music tracks of different tempi. The program lasted about 25 min and was performed on three occasions--unknown to the participants, its tempo was normal, increased by 10% or decreased by 10%. Work done, distance covered and cadence were measured at the end of each track, as were heart rate and subjective measures of exertion, thermal comfort and how much the music was liked. Speeding up the music program increased distance covered/unit time, power and pedal cadence by 2.1%, 3.5% and 0.7%, respectively; slowing the program produced falls of 3.8%, 9.8% and 5.9%. Average heart rate changes were +0.1% (faster program) and -2.2% (slower program). Perceived exertion and how much the music was liked increased (faster program) by 2.4% and 1.3%, respectively, and decreased (slower program) by 3.6% and 35.4%. That is, healthy individuals performing submaximal exercise not only worked harder with faster music but also chose to do so and enjoyed the music more when it was played at a faster tempo. Implications of these findings for improving training regimens are discussed.

  19. Serum vaspin concentrations are closely related to insulin resistance, and rs77060950 at SERPINA12 genetically defines distinct group with higher serum levels in Japanese population.

    Science.gov (United States)

    Teshigawara, Sanae; Wada, Jun; Hida, Kazuyuki; Nakatsuka, Atsuko; Eguchi, Jun; Murakami, Kazutoshi; Kanzaki, Motoko; Inoue, Kentaro; Terami, Takahiro; Katayama, Akihiro; Iseda, Izumi; Matsushita, Yuichi; Miyatake, Nobuyuki; McDonald, John F; Hotta, Kikuko; Makino, Hirofumi

    2012-07-01

    Vaspin is an adipokine with insulin-sensitizing effects identified from visceral adipose tissues of genetically obese rats. We investigated genetic and nongenetic factors that define serum concentrations of vaspin. Vaspin levels were measured with RIA in Japanese subjects with normal fasting plasma glucose (NFG; n = 259) and type 2 diabetes patients (T2D; n = 275). Single nucleotide polymorphisms (SNP) at SERPINA12 (vaspin) gene locus were discovered, and five SNP were genotyped in the subjects with varied body mass index (n = 1138). The level of serum vaspin in 93% of the samples was found to vary from 0.2 to nearly 2 ng/ml in NFG subjects (n = 259) and from 0.2 to nearly 3 ng/ml in T2D patients (n = 275) (Vaspin(Low) group), whereas a significant subpopulation (7%) in both groups displayed much higher levels of 10-40 ng/ml (Vaspin(High) group). In the Vaspin(Low) group, serum vaspin levels in T2D were significantly higher than healthy subjects (0.99 ± 0.04 vs. 0.86 ± 0.02 ng/ml; P population, serum vaspin levels closely correlated with homeostasis model of assessment for insulin resistance rather than anthropometric parameters. By genotyping, rs77060950 tightly linked to serum vaspin levels, i.e. CC (0.6 ± 0.4 ng/ml), CA (18.4 ± 9.6 ng/ml), and AA (30.5 ± 5.1 ng/ml) (P population are closely linked to minor allele sequence (A) of rs77060950.

  20. Neuromuscular function of the quadriceps muscle during isometric maximal, submaximal and submaximal fatiguing voluntary contractions in knee osteoarthrosis patients.

    Directory of Open Access Journals (Sweden)

    Anett Mau-Moeller

    and neuromuscular activation, but also with an impaired position and torque control at submaximal torque levels, an altered EMG-torque relationship and a higher performance fatigability of the quadriceps muscle. It is recommended that the rehabilitation includes strengthening and fatiguing exercises at maximal and submaximal force levels.

  1. Capromorelin increases food consumption, body weight, growth hormone, and sustained insulin-like growth factor 1 concentrations when administered to healthy adult Beagle dogs.

    Science.gov (United States)

    Zollers, B; Rhodes, L; Smith, R G

    2017-04-01

    This study's objective was to determine the effects in dogs of oral capromorelin, a ghrelin agonist, at different doses for 7 days on food consumption, body weight and serum concentrations of growth hormone (GH), insulin-like growth factor 1 (IGF-1), and cortisol. Adult Beagles (n = 6) were dosed with placebo BID, capromorelin at 3.0 mg/kg SID, 4.5 mg/kg SID, or 3.0 mg/kg BID. Food consumption, body weight, serum capromorelin, GH, IGF-1, and cortisol were measured at intervals on days 1, 4, 7, and 9. Capromorelin increased food consumption and body weight compared to placebo and caused increased serum GH, which returned to the baseline by 8 h postdose. The magnitude of the GH increase was less on days 4 and 7 compared to Day 1. IGF-1 concentrations increased on Day 1 in capromorelin-treated dogs and this increase was sustained through Day 7. Serum cortisol increased postdosing and returned to the baseline concentrations by 8 h. The magnitude of the increase was less on days 4 and 7 compared to Day 1. A dose of 3 mg/kg was chosen for further study in dogs based on this dose causing increased food consumption and sustained IGF-1 serum concentrations that may increase lean muscle mass when administered over extended periods. © 2016 The Authors. Journal of Veterinary Pharmacology and Therapeutics Published by John Wiley & Sons Ltd.

  2. Active immunization of pigs against growth hormone-releasing factor: effect on concentrations of growth hormone and insulin-like growth factor 1.

    Science.gov (United States)

    Armstrong, J D; Esbenshade, K L; Johnson, J L; Coffey, M T; Heimer, E; Campbell, R M; Mowles, T; Felix, A

    1990-02-01

    Cyclic gilts (96 +/- 1 kg) were used to determine the effect of active immunization against growth hormone-releasing factor GRF(1-29)-NH2 on concentrations of growth hormone (GH) and insulin-like growth factor 1 (IGF-1). Gilts were immunized against GRF conjugated to human serum albumin (GRF-HSA, n = 5) or HSA alone at 180 d of age (wk 0). Booster doses were administered at wk 9 and 13. Seven days after the second booster (wk 14), blood samples were collected at 15-min intervals for 6 h before feeding and 30, 60, 120, 180 and 240 min after feeding. Eight days after the second booster, all gilts were administered a GRF analog, [desNH2Tyr1,Ala15]-GRF(1-29)-NH2, followed by an opioid agonist, FK33-824. Blood samples were collected at 15-min intervals from -30 to 240 min after injection. Immunization against GRF-HSA resulted in antibody titers, expressed as dilution required to bind 50% of [125I]GRF, ranging from 1:11,000 to 1:60,000 (wk 11 and 14); binding was not detectable or was less than 50% at 1:100 in HSA gilts (P less than .05). Episodic release of GH was abolished by immunization against GRF-HSA (P less than .05). Mean GH was decreased (P less than .07), but basal GH concentrations were not altered (P greater than .15) by immunization against GRF-HSA. Serum concentrations of IGF-1 were similar at wk 0, but concentrations were lower in GRF-HSA than in HSA gilts (P less than .05) at wk 14.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Influence of therapy with metformin on the concentration of certain divalent cations in patients with non-insulin-dependent diabetes mellitus.

    Science.gov (United States)

    Doşa, Monica Daniela; Hangan, Laurentiu-Tony; Crauciuc, Eduard; Galeş, Cristina; Nechifor, Mihai

    2011-07-01

    Research was performed on a group of 30 patients with non-insulin-dependent diabetes mellitus (NIDDM), who never received antidiabetic medication before, and on a group of 17 healthy adults. The patients were administered treatment with metformin, 1,000 mg/day. Plasmatic and urinary concentration of magnesium have been measured, copper and zinc along with the concentrations of glucose, HDL, LDL, cholesterol, tryglicerides, HbA1c, and total erythrocyte magnesium, in advance and after 3 months of treatment. Data showed significant differences in the NIDDM group vs the control group: for plasma magnesium-1.95 ± 0.19 vs 2.20 ± 0.18 mg/dl, p magnesium-237.28 ± 34.51 vs 126.25 ± 38.22 mg/24 h, p magnesium-5.09 ± 0.63 vs 6.38 ± 0.75 mg/dl, p magnesium-5.75 ± 0.61 vs 5.09 ± 0.63 mg/dl, p magnesium-198.27 ± 27.07 vs 237.28 ± 34.51 mg/24 h, p magnesium concentration was inversely correlated with HbA1c (r = -0.438, p = 0.015). The plasma level of copper was positively correlated with HbA1c (r = 0.517, p magnesium concentration and decreasing the urinary magnesium elimination, positively correlated with the decrease of glycemia and HbA1c in NIDDM patients.

  4. Changes of plasma concentrations of insulin-like peptide 3 and testosterone, and their association with scrotal circumference during pubertal development in male goats.

    Science.gov (United States)

    Hannan, M A; Kawate, N; Fukami, Y; Weerakoon, W W P N; Büllesbach, E E; Inaba, T; Tamada, H

    2017-04-01

    Insulin-like peptide 3 (INSL3) has been used as a testis-specific biomarker for puberty in several species, but the secretory profile of INSL3 during pubertal development in small ruminants is unknown. Here we sought to determine the age-related changes in the plasma concentrations of INSL3 and testosterone and their association with scrotal circumference during pubertal development in five male Shiba goats. Blood samples and scrotal circumference measurement were taken every 2 weeks from week 10 to week 52 of each goat's lifespan. Based on the changes in scrotal circumference, data were grouped into early pubertal (10-22 weeks), late pubertal (22-34 weeks) and post-pubertal (34-52 weeks) categories. The plasma concentrations of testosterone and luteinizing hormone (LH) were measured by enzyme-immunoassays (EIAs), and we used a time-resolved fluorescence immunoassay (TRFIA) to measure plasma INSL3. The biweekly sampling showed that the plasma INSL3 secretions maintained a moderate increase during and after puberty, whereas the plasma testosterone secretions fluctuated over the same period. The comparison of the three age categories revealed a significant increase (p testosterone concentrations between the early and late pubertal periods, but a significant increase (p testosterone (0.162; p testosterone secretions were fluctuated. The scrotal circumference was more highly correlated with the INSL3 concentrations than with testosterone, implying that INSL3 is superior as a biomarker of testicular total Leydig cell volume. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Ramadan fasting and the GH/IGF-1 axis of trained men during submaximal exercise.

    Science.gov (United States)

    Bouhlel, Ezzedine; Zaouali, Monia; Miled, Abdelhedi; Tabka, Zouhair; Bigard, Xavier; Shephard, Roy

    2008-01-01

    The aim of this study was to explore possible changes in body composition, blood glucose regulation, plasma growth hormone (GH), insulin-like growth factor 1 (IGF-1), insulin-like growth factor-binding protein-3 (IGFBP-3), and insulin concentrations of trained athletes in response to the intermittent fasting and dehydration of Ramadan observance. Nine trained male rugby players (age 19 +/- 2 years, height 1.78 +/- 0.74 m) were tested 3 times: before Ramadan (C), at the end of the first week (R1), and during the fourth week (R2). They performed a progressive cycle ergometer test at each visit. The work rate was increased in 6-min stages corresponding to 20, 30, 40, 50 and 60% of W max. Substrate oxidation was evaluated by indirect calorimetry. On each occasion, substrate and plasma hormone concentrations were measured at rest and at the end of the exercise. Ramadan fasting induced a significant decrease in body mass and body fat (R2 vs. C, p < 0.001). Plasma concentrations of glucose, insulin, GH, IGF-1 and IGFBP-3 did not change significantly between C and R2, either at rest or following exercise. Ramadan fasting induces positive changes in body composition without disturbing glucose regulation or activity of the GH/IGF-1 system. 2008 S. Karger AG, Basel.

  6. Filtered molasses concentrate from sugar cane: natural functional ingredient effective in lowering the glycaemic index and insulin response of high carbohydrate foods.

    Science.gov (United States)

    Wright, Alison G; Ellis, Timothy P; Ilag, Leodevico L

    2014-12-01

    An aqueous filtered molasses concentrate (FMC) sourced from sugar cane was used as a functional ingredient in a range of carbohydrate-containing foods to reduce glycaemic response. When compared to untreated controls, postprandial glucose responses in the test products were reduced 5-20%, assessed by accredited glycaemic index (GI) testing. The reduction in glucose response in the test foods was dose-dependent and directly proportional to the ratio of FMC added to the amount of available carbohydrate in the test products. The insulin response to the foods was also reduced with FMC addition as compared to untreated controls. Inclusion of FMC in test foods did not replace any formulation ingredients; it was incorporated as an additional ingredient to existing formulations. Filtered molasses concentrate, made by a proprietary and patented process, contains many naturally occurring compounds. Some of the identified compounds are known to influence carbohydrate metabolism, and include phenolic compounds, minerals and organic acids. FMC, sourced from a by-product of sugar cane processing, shows potential as a natural functional ingredient capable of modifying carbohydrate metabolism and contributing to GI reduction of processed foods and beverages.

  7. Copeptin, a surrogate marker for arginine vasopressin secretion, is associated with higher glucose and insulin concentrations but not higher blood pressure in obese men

    DEFF Research Database (Denmark)

    Asferg, C L; Andersen, Ulrik Bjørn; Linneberg, A

    2014-01-01

    AIM: To explore the putative associations of plasma copeptin, the C-terminal portion of provasopressin and a surrogate marker for arginine vasopressin secretion, with obesity-related health problems, such as hyperlipidaemia, hyperinsulinaemia, hyperglycaemia, high blood pressure and an android fat...... distribution. METHODS: In 103 obese men (mean age ± standard deviation: 49.4 ± 10.2 years) and 27 normal weight control men (mean age: 51.5 ± 8.4 years), taking no medication, we measured 24-h ambulatory blood pressure, fasting blood concentrations of copeptin, lipids, glucose and insulin, and determined body...... blood pressure (r = 0.11, P = 0.29), 24-h diastolic blood pressure (r = 0.11, P = 0.28), BMI (r = 0.09, P = 0.37), total body fatness percentage (r = 0.10, P = 0.33), android fat mass percentage (r = 0.04, P = 0.66) or serum triglyceride concentrations (r = 0.04; P = 0.68). In contrast, plasma copeptin...

  8. Variable liver fat concentration as a proxy for body fat mobilization postpartum has minor effects on insulin-induced changes in hepatic gene expression related to energy metabolism in dairy cows.

    Science.gov (United States)

    Weber, C; Schäff, C T; Kautzsch, U; Börner, S; Erdmann, S; Bruckmaier, R M; Röntgen, M; Kuhla, B; Hammon, H M

    2017-02-01

    The liver plays a central role in adaptation for energy requirements around calving, and changes in the effects of insulin on hepatic energy metabolism contribute to metabolic adaptation in dairy cows. Hepatic insulin effects may depend on body fat mobilization. The objective of this study was to investigate the effects of insulin on the hepatic gene expression of enzymes involved in energy metabolism and factors related to nutrition partitioning in cows with high and low total liver fat concentration (LFC) after calving. Holstein cows were retrospectively grouped according to their LFC after calving as a proxy for body fat mobilization. Cows were classified as low (LLFC; LFC fat/dry matter; n = 9) and high (HLFC; LFC >24.4% fat/dry matter; n = 10) fat-mobilizing after calving. Euglycemic-hyperinsulinemic clamps [6 mU/(kg × min) of insulin for 6 h] were performed in wk 5 antepartum (ap) and wk 3 postpartum (pp). Before and at the end of the euglycemic-hyperinsulinemic clamps, liver biopsies were taken to measure the mRNA abundance of enzymes involved in carbohydrate and lipid metabolism, expression related to the somatotropic axis, and adrenergic and glucocorticoid receptors. The mRNA abundance of pyruvate carboxylase, cytosolic phosphoenolpyruvate carboxykinase (PEPCK; PCK1), acyl-CoA-dehydrogenase very long chain (ACADVL), and hydroxyl-methyl-glutaryl-CoA-synthase 1 increased, but the mRNA abundance of solute carrier family 2 (SLC2A2 and SLC2A4), growth hormone receptor 1A (GHR1A), insulin-like growth factor 1 (IGF1), sterol regulatory element binding factor 1, adrenoceptor α 1A, and glucocorticoid receptor decreased from ap to pp. Insulin treatment was associated with decreased PCK1, mitochondrial PEPCK, glucose-6-phosphatase, propionyl-CoA-carboxylase α, carnitine-palmitoyl-transferase 1A, ACADVL, and insulin receptor mRNA, but increased IGF1 and SLC2A4 mRNA ap and pp and GHR1A mRNA pp. The mRNA abundance of SLC2A4 was greater, and the mRNA abundance of GHR1

  9. Effect of chain wheel shape on crank torque, freely chosen pedal rate, and physiological responses during submaximal cycling

    DEFF Research Database (Denmark)

    Hansen, Ernst Albin; Jensen, Kurt; Hallén, Jostein

    2009-01-01

    . A musculoskeletal simulation model supported the idea that a contributing factor to the observed difference in blood lactate concentration may be slightly reduced muscle activity around the phase where peak crank torque occurs during cycling with the Biopace chain wheel. In that particular phase of the crank......The development of noncircular chain wheels for the enhancement of cycling performance has been in progress for a long time and continues apace. In this study we tested whether submaximal cycling using a non-circular (Biopace) versus a circular chain wheel resulted in lower peak crank torque...... chain wheel at 180 W at 65 and 90 rpm for recording of crank torque profiles, and at their freely chosen pedal rate for recording of pedal rate and metabolic response, including oxygen uptake and blood lactate concentration. Crank torque profiles were similar between the two chain wheels during cycling...

  10. Periodontal disease decreases insulin sensitivity and insulin signaling.

    Science.gov (United States)

    Colombo, Natalia H; Shirakashi, Daisy J; Chiba, Fernando Y; Coutinho, Maria Sara de Lima; Ervolino, Edilson; Garbin, Cléa Adas Saliba; Machado, Ubiratan Fabres; Sumida, Doris H

    2012-07-01

    The purpose of this study is to investigate whether local inflammatory events, such as periodontal disease, are able to increase tumor necrosis factor-alpha (TNF-α) plasmatic concentration and decrease insulin sensitivity and insulin signaling in non-diabetic rats. Forty-eight male Wistar rats (2 months old) were divided into two groups, with either ligature-induced periodontal disease (LPD) or control conditions (CN). Experiments were performed in both groups 28 days after ligature placement. Plasmatic concentration of glycemia and TNF-α (n = 10) were analyzed by the glucose oxidase and enzyme-linked immunosorbent assay method, respectively. Insulin sensitivity (n = 7) was measured using the insulin tolerance test. Insulin signal transduction (n = 7) was measured by pp185 tyrosine phosphorylation status in insulin-sensitive tissues using the Western blotting method. The LPD group showed decreased insulin sensitivity (P 0.05). TNF-α plasmatic concentration was higher in LPD rats compared to CN rats. In addition, a decrease in the pp185 tyrosine phosphorylation status was observed after insulin stimulus in both white adipose and skeletal muscle tissues of the LPD group compared with the CN group. LPD is able to cause alterations to both insulin signaling and insulin sensitivity, probably because of the elevation of TNF-α plasmatic concentration. Thus, the present results emphasize the importance of the prevention of local inflammatory diseases, such as periodontitis, to prevent diabetes mellitus.

  11. Effects of Submaximal Endurance Training and Vitamin D3 Supplementation on Pain Threshold in Diabetic Rats

    Directory of Open Access Journals (Sweden)

    S. Jalal Taherabadi

    2013-07-01

    Full Text Available Background: According to beneficial effects of endurance training and vitamin D3 in diabetes mellitus, purpose of this study is effects submaximal endurance training and vitamin D3 supplementation on pain threshold in streptozotocin induced diabetic rats.Materials and Methods: Male Wistar rats (250±20 g, N=40 were made diabetic by streptozotocin (60 mg/kg, subcutaneously. 72 h after injection diabetes induction was confirmed by tail vein blood glucose concentration (>300 mg/dl. Then animals were divided to five groups: diabetic control (DC, diabetic trained (DT, diabetic -vitamin D (DD, diabetic trained and vitamin D (DTD, and control (C. Animals were submitted to endurance training by treadmill and vitamin D3 treatment (twice aweek, intrapretonally for 4 weeks. 48 h after at the end of exercise and treatment protocol, we used tail-flick to assess the effects of training and vitamin D3 on thermal pain threshold. We used one way ANOVA statistical analysis to compare differences between groups, significance level of p<0.05 was considered.Results: Diabetic induced hyperalgesia were decreased significantly by vitamin D but not 4 weeks endurance exercise training. Concurrent effects of training and vitamin D on thermal pain threshold were not significantly higher than vitamin D effects alone.Conclusion: It is concluded that vitamin D administration given at the time of diabetes induction may be able to restore thermal hyperalgesia. But effects of endurance exercise training needs to more investigation in diabetic rats.

  12. Is the ventilatory threshold coincident with maximal fat oxidation during submaximal exercise in women?

    Science.gov (United States)

    Astorino, T A

    2000-09-01

    The purpose of this study was to detect the fraction of peak oxygen consumption (VO2peak) that elicits maximal rates of fat oxidation during submaximal treadmill exercise. It was hypothesized that this point would appear at a work rate just below the ventilatory threshold. subjects completed a protocol requiring them to exercise for 15 min on a treadmill at six different workloads, 25, 40, 55, 65, 75, and 85% VO2peak, over two separate visits. nine healthy, moderately-trained eumenorrheic females (age = 28.8+/-5.99 yrs, VO2peak = 47.20 +/-2.57 ml x kg(-1) x min(-1)) volunteered for the study. a one-way ANOVA with repeated measures was used to test for differences across exercise intensities in the metabolic variables (i.e. substrate oxidation, blood lactate concentration ([La-]), RER, and the contribution of fat to total energy expenditure). Following significant F ratios, post-hoc tests were used to detect differences between the means for various exercise intensities. Exercise at 75% VO2peak elicited the greatest rate of fat oxidation (4.75+/-0.49 kcal x min(-1)), and this intensity was coincident with the ventilatory threshold (76+/-7.41% VO2peak). Moreover, a significant difference (t(8) = -3.98, ppopulation has application in exercise prescription and refutes the belief that low-intensity exercise is preferred for fat metabolism.

  13. Plasma insulin-like growth factor-I concentrations in yearling chinook salmon (Oncorhynchus tshawytscha) migrating from the Snake River Basin, USA

    Science.gov (United States)

    Congleton, J.L.; Biga, P.R.; Peterson, B.C.

    2003-01-01

    During the parr-to-smolt transformation (smoltification) of juvenile salmonids, preadaptive changes in osmoregulatory and ionoregulatory ability are regulated in part by the growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis. If food intake is sufficient, plasma IGF-I increases during smoltification. On the other hand, plasma IGF-I typically decreases in fasting fish and other vertebrate animals. Because food availability is limited for juvenile salmonids undertaking an extended 6- to 12-week spring migration to and through the Snake-Columbia River hydropower system (northwestern USA), IGF-I concentrations might be expected to decrease, potentially compromising seawater tolerance. To address this possibility, yearling chinook salmon Oncorhynchus tshawytscha reared in three Snake River Basin hatcheries were sampled before release and at two downstream dams. Dry masses of migrating fish either did not increase during the migration (in 2000, an average-flow year), or decreased significantly (in 2001, a low-flow year). In both years, plasma IGF-I levels were significantly higher (1.6-fold in 2000, 3.7-fold in 2001) for fish sampled at the last dam on the lower Columbia River than for fish sampled prior to release. Plasma IGF-I concentrations in migrating fish may, nonetheless, have been nutritionally down-regulated to some degree, because plasma IGF-I concentrations in juvenile chinook salmon captured at a Snake River dam and transported to the laboratory increased in fed groups, but decreased in unfed groups. The ability of migrating smolts to maintain relatively elevated IGF-I levels despite restricted food intake and loss of body mass is likely related to smoltification-associated changes in hormonal balance. ?? 2004 Kluwer Academic Publishers.

  14. Actual Versus Predicted Cardiovascular Demands in Submaximal Cycle Ergometer Testing.

    Science.gov (United States)

    Hoehn, Amanda M; Mullenbach, Megan J; Fountaine, Charles J

    The Astrand-Rhyming cycle ergometer test (ARCET) is a commonly administered submaximal test for estimating aerobic capacity. Whereas typically utilized in clinical populations, the validity of the ARCET to predict VO 2max in a non-clinical population, especially female, is less clear. Therefore, the purpose of this study was to determine the accuracy of the ARCET in a sample of healthy and physically active college students. Subjects (13 females, 10 males) performed a maximal cycle ergometer test to volitional exhaustion to determine VO 2max . At least 48 hours later, subjects performed the ARCET protocol. Predicted VO 2max was calculated following the ARCET format using the age corrected factor. There was no significant difference (p=.045) between actual (41.0±7.97 ml/kg/min) and predicted VO 2max (40.3±7.58 ml/kg/min). When split for gender there was a significant difference between actual and predicted VO 2 for males, (45.1±7.74 vs. 42.7±8.26 ml/kg/min, p=0.029) but no significant difference observed for females, (37.9±6.9 vs. 38.5±6.77 ml/kg/min, p=0.675). The correlation between actual and predicted VO 2 was r=0.84, phealthy college population of both male and female subjects. Implications of this study suggest the ARCET can be used to assess aerobic capacity in both fitness and clinical settings where measurement via open-circuit spirometry is either unavailable or impractical.

  15. Effect of growth hormone administration to mature miniature Brahman cattle treated with or without insulin on circulating concentrations of insulin-like growth factor-I and other metabolic hormones and metabolites.

    Science.gov (United States)

    Chase, C C; Elsasser, T H; Spicer, L J; Riley, D G; Lucy, M C; Hammond, A C; Olson, T A; Coleman, S W

    2011-07-01

    Previously, we determined that a primary cause of proportional stunted growth in a line of Brahman cattle was related to an apparent refractoriness in metabolic response to GH in young animals. The objective of this study was to determine the effect of administration of GH, insulin (INS), and GH plus INS to mature miniature Brahman cows (n = 6; 9.7 ± 2.06 y; 391 ± 48.6 kg) and bulls (n = 8; 9.4 ± 2.00 y; 441 ± 54.0 kg) on circulating concentrations of metabolic hormones and metabolites, primarily IGF-I and IGF-I binding proteins. We hypothesized that IGF-I secretion could be enhanced by concomitant administration of exogenous GH and INS, and neither alone would be effective. Animals were allotted to a modified crossover design that included four treatments: control (CON), GH, INS, and GH + INS. At the start of the study, one-half of the cattle were administered GH (Posilac; 14-d slow release) and the other one-half served as CON for 7 d. Beginning on day 8, and for 7 d, INS (Novolin L) was administered (0.125 IU/kg BW) twice daily (7:00 AM and 7:00 PM) to all animals; hence, the INS and GH + INS treatments. Cattle were rested for 14 d and then were switched to the reciprocal crossover treatments. Blood samples were collected at 12-hour intervals during the study. Compared with CON, GH treatment increased (P cattle, suggesting that this line of Brahman cattle is capable of responding to bioactive GH. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Serum insulin-like growth factor-1 and C-reactive protein concentrations before and after ovariohysterectomy in bitches with pyometra.

    Science.gov (United States)

    Dąbrowski, Roman; Szczubiał, Marek; Kostro, Krzysztof; Wawron, Władysław; Ceron, Jose J; Tvarijonaviciute, Asta

    2015-03-01

    Pyometra is one of the most common diseases of the reproductive system in bitches. The inflammatory processes occurring in the uterus result in changes in concentrations of numerous serum biomarkers, which are used for monitoring the postoperative period. The aim of the present report was to study the evolution of serum levels of insulin-like growth factor-1 (IGF-1) and C-reactive protein (CRP) in bitches suffered from pyometra and after ovariohysterectomy in comparison with the control group of healthy dogs submitted to the surgery. Our results indicate that the serum level of IGF-1 is decreased (101.6 ng/mL [73.8-177.8 ng/mL]), whereas CRP is increased (114.6 μg/mL [95.3-131.6 μg/mL]) during severe inflammation. When inflammation caused by pyometra and surgery is resolved, the level of IGF-1 is increased (186.0 ng/mL [94.6-344.3 ng/mL], P < 0.05) and CRP decreased (23.3 μg/mL [9.9-77.0 μg/mL], P < 0.01), suggesting that these markers could be useful for assessment of the postoperative period in bitches. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Assessment of cardiorespiratory fitness using submaximal protocol in older adults with mood disorder and Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Natacha Alves de Oliveira

    2013-01-01

    Full Text Available BACKGROUND: Evidence has shown benefits for mental health through aerobic training oriented in percentage of VO2max, indicating the importance of this variable for clinical practice. OBJECTIVE: To validate a method for estimating VO2max using a submaximal protocol in elderly patients with clinically diagnosis as major depressive disorder (MDD and Parkinson's disease (PD. METHODS: The sample comprised 18 patients (64.22 ± 9.92 years with MDD (n = 7 and with PD (n = 11. Three evaluations were performed: I disease staging, II direct measurement of VO2max and III submaximal exercise test. Linear regression was performed to verify the accuracy of estimation in VO2max established in ergospirometry and the predicted VO2max from the submaximal test measurement. We also analyzed the correlation between the Bland-Altman procedures. RESULTS: The regression analysis showed that VO2max values estimated by submaximal protocol associated with the VO2max measured, both in absolute values (R² = 0.65; SEE = 0.26; p < 0.001 and the relative (R² = 0.56; SEE = 3.70; p < 0.001. The Bland-Altman plots for analysis of agreement of showed a good correlation between the two measures. DISCUSSION: The VO2max predicted by submaximal protocol demonstrated satisfactory criterion validity and simple execution compared to ergospirometry.

  18. Effects of 1 and 3 g cinnamon on gastric emptying, satiety, and postprandial blood glucose, insulin, glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1, and ghrelin concentrations in healthy subjects

    DEFF Research Database (Denmark)

    Hlebowicz, Joanna; Hlebowicz, Anna; Lindstedt, Sandra

    2009-01-01

    BACKGROUND: A previous study of healthy subjects showed that intake of 6 g cinnamon with rice pudding reduced postprandial blood glucose and the gastric emptying rate (GER) without affecting satiety. OBJECTIVE: The objective was to study the effect of 1 and 3 g cinnamon on GER, postprandial blood...... cinnamon (P = 0.0082 and P = 0.0138, respectively, after Bonferroni correction). CONCLUSIONS: Ingestion of 3 g cinnamon reduced postprandial serum insulin and increased GLP-1 concentrations without significantly affecting blood glucose, GIP, the ghrelin concentration, satiety, or GER in healthy subjects...... glucose, plasma concentrations of insulin and incretin hormones [glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1)], the ghrelin response, and satiety in healthy subjects. DESIGN: GER was measured by using real-time ultrasonography after ingestion of rice pudding...

  19. Association of Insulin Resistance, β-Cell Function Impairment and Calcium, Magnesium, and Fetuin-A Concentrations in Women with Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Moustafa Shatha Rouf

    2016-09-01

    Full Text Available Insulin resistance and β-cell function impairment play a role in the pathogenesis of type 2 diabetes (T2DM. Insulin signaling is inhibited by fetuin-A, an abundant plasma protein. Fetuin-A is also a candidate marker of the T2DM risk. This case-control study aimed to determine whether fetuin-A serum level is related to insulin resistance, β-cell function impairment, and total and ionized Ca and Mg serum levels in Erbil patients with T2DM.

  20. The Dynamic Roles of Visfatin and Obestatin Serum Concentration in Pancreatic Beta Cells Dysfunction (HOMA-beta) and Insulin Resistance (HOMA-IR) in Centrally Obese Men

    OpenAIRE

    Bayu Winata Putera; Cynthia Retna Sartika; Andi Wijaya

    2012-01-01

    BACKGROUND: Obesity is a major health problem in the world today. Obesity is closely associated with insulin resistance and type 2 diabetes. Epidemiological studies have shown that obese persons are in a state of insulin resistance, however, most of them do not progress to type 2 diabetes. This occurs because the beta cell function is still good enough for maintaining normal glucose level. Obestatin and visfatin are cytokines that are known to have a role in beta cell function. The aim of thi...

  1. Effect of growth hormone administration to mature miniature Brahman cattle treated with or without insulin on circulating concentrations of insulin-like growth factor-I and other metabolic hormones and metabolites

    Science.gov (United States)

    Previously, we determined that a primary cause of proportional stunted growth in a line of Brahman cattle was related to an apparent refractoriness in metabolic response to growth hormone (GH) in young animals. The objective of this study was to determine the effect of administration of GH, insulin...

  2. THE INFLUENCE OF OBESITY AND AMBIENT TEMPERATURE ON PHYSIOLOGICAL AND OXIDATIVE RESPONSES TO SUBMAXIMAL EXERCISE

    OpenAIRE

    Ahn, N.; Kim, K.

    2014-01-01

    This study investigated the effects of obesity and ambient temperature on physiological responses and markers of oxidative stress to submaximal exercise in obese and lean people. Sixteen healthy males were divided into an obese group (n=8, %fat: 27.00±3.00%) and a lean group (n=8, %fat: 13.85±2.45%). Study variables were measured during a 60 min submaximal exercise test at 60% VO2max in a neutral (21±1°C) and a cold (4±1°C) environment. Heart rate, blood lactate, rectal temperature, serum lev...

  3. Submaximal arm crank ergometry : Effects of crank axis positioning on mechanical efficiency, physiological strain and perceived discomfort

    NARCIS (Netherlands)

    van Drongelen, S; Maas, J C; Scheel-Sailer, A; Van Der Woude, L H V

    2009-01-01

    PURPOSE: To evaluate the effect of the spatial orientation of the crank axis on mechanical efficiency, physiological strain and perceived discomfort in submaximal synchronous arm crank ergometry. METHODS: Twelve able-bodied individuals performed 12 submaximal exercise bouts of 3 minutes (women: 20

  4. Serum Chemerin Concentrations Associate with Beta-Cell Function, but Not with Insulin Resistance in Individuals with Non-Alcoholic Fatty Liver Disease (NAFLD.

    Directory of Open Access Journals (Sweden)

    Erifili Hatziagelaki

    Full Text Available The novel adipokine chemerin has been related to insulin-resistant states such as obesity and non alcoholic fatty liver disease (NAFLD. However, its association with insulin resistance and beta cell function remains controversial. The main objective was to examine whether serum chemerin levels associate with insulin sensitivity and beta cell function independently of body mass index (BMI, by studying consecutive outpatients of the hepatology clinics of a European university hospital. Individuals (n=196 with NAFLD were stratified into persons with normal glucose tolerance (NGT; n=110, impaired glucose tolerance (IGT; n=51 and type 2 diabetes (T2D; n=35 and the association between serum chemerin and measures of insulin sensitivity and beta cell function as assessed during fasting and during oral glucose tolerance test (OGTT was measured. Our results showed that serum chemerin positively associated with BMI (P=0.0007 and C peptide during OGTT (P0.18. No BMI independent relationships of chemerin with fasting and OGTT derived measures of insulin sensitivity were found (P>0.5. Chemerin associated positively with fasting beta cell function as well as the OGTT derived insulinogenic index IGI_cp and the adaptation index after adjustment for age, sex and BMI (P=0.002-0.007, and inversely with the insulin/C peptide ratio (P=0.007. Serum chemerin neither related to the insulinogenic index IGI_ins nor the disposition index. In conclusion, circulating chemerin is likely linked to enhanced beta cell function but not to insulin sensitivity in patients with NAFLD.

  5. Limited Weight Loss or Simply No Weight Gain following Lifestyle-Only Intervention Tends to Redistribute Body Fat, to Decrease Lipid Concentrations, and to Improve Parameters of Insulin Sensitivity in Obese Children

    Directory of Open Access Journals (Sweden)

    Valeri Lenin

    2011-03-01

    Full Text Available Objectives. To investigate whether lifestyle-only intervention in obese children who maintain or lose a modest amount of weight redistributes parameters of body composition and reverses metabolic abnormalities. Study Design. Clinical, anthropometric, and metabolic parameters were assessed in 111 overweight or obese children (CA of 11.3 ± 2.8 years; 63 females and 48 males, during 8 months of lifestyle intervention. Patients maintained or lost weight (1–5% (group A; n: 72 or gained weight (group B. Results. Group A patients presented with a decrease in systolic blood pressure (SBP and diastolic blood pressure (DBP ( and , resp., BMI (, z-score BMI (, waist circumference (, fat mass (, LDL-C (, Tg/HDL-C ratio (, fasting and postprandial insulin (, and HOMA (, while HDL-C ( and QUICKI increased (. Conversely, group B patients had an increase in BMI (, waist circumference (, SBP (, and in QUICKI (, while fat mass (, fasting insulin (, and HOMA ( decreased. Lean mass, DBP, lipid concentrations, fasting and postprandial glucose, postprandial insulin, and ultrasensitive C-reactive protein (CRP remained stable. Conclusions. Obese children who maintain or lose a modest amount of weight following lifestyle-only intervention tend to redistribute their body fat, decrease blood pressure and lipid levels, and to improve parameters of insulin sensitivity.

  6. Intensity-dependent EMG response for the biceps brachii during sustained maximal and submaximal isometric contractions.

    Science.gov (United States)

    Carr, Joshua C; Beck, Travis W; Ye, Xin; Wages, Nathan P

    2016-09-01

    There have been recent attempts to characterize the mechanisms associated with fatigue-induced task failure. We compared the time to failure and the corresponding changes in the surface electromyogram (EMG) during sustained maximal and submaximal isometric force tasks. EMG activity was measured from the biceps brachii of 18 male participants as they sustained either a maximal or submaximal (60 % MVC) isometric contraction of the dominant elbow flexors until force could not be maintained above 55 % MVC. Intensity-dependent patterns of change were observed for EMG amplitude and mean power frequency (MNF) between the two force tasks. Interestingly, the only significant predictor of failure time was the rate of change in EMG MNF during the submaximal task (r (2) = 0.304). In addition, EMG amplitude at submaximal failure was significantly lower (p EMG response emphasize the basis of neuromuscular fatigue and task dependency. Additionally, our data suggest that the EMG MNF should be used when monitoring the progression of local muscle fatigue.

  7. Variation in heart rate during submaximal exercise: Implications for monitoring training : Implications for monitoring training

    NARCIS (Netherlands)

    Lamberts, R.P.; Lemmink, K.A.P.M.; Durandt, J.J.; Lambert, M.I.

    2004-01-01

    A change in heart rate at a controlled submaximal exercise intensity is used as a marker of training status. However, the standard error of measurement has not been studied systematically, and therefore a change in heart rate, which can be considered relevant, has not been determined. Forty-four

  8. THE EFFECT OF SUBMAXIMAL INHALATION ON MEASURES DERIVED FROM FORCED EXPIRATORY SPIROMETRY

    Science.gov (United States)

    THE EFFECT OF SUBMAXIMAL INHALATION ON MEASURES DERIVED FROM FORCED EXPIRATORY SPIROMETRY. William F. McDonnell Human Studies Division, NHEERL, U.S. Environmental Protection Agency, RTP, NC 27711. Short-term exposure to ozone results in a neurally-mediated decrease in the ab...

  9. Calibration of EMG to force for knee muscles is applicable with submaximal voluntary contractions

    NARCIS (Netherlands)

    Doorenbosch, C.A.M.; Joosten, A.; Harlaar, J.

    2005-01-01

    Purpose: In this study, the influence of using submaximal isokinetic contractions about the knee compared to maximal voluntary contractions as input to obtain the calibration of an EMG-force model for knee muscles is investigated. Methods: Isokinetic knee flexion and extension contractions were

  10. Variability of Respiration and Metabolism: Responses to Submaximal Cycling and Running.

    Science.gov (United States)

    Armstrong, Lawrence E.; Costill, David L.

    1985-01-01

    This investigation examined day-to-day variations in metabolic measurements during submaximal running and cycling. Significant differences were found in the oxygen uptake (VO2) of runners and cyclists and the minute ventilation (VE) of cyclists while running, but blood lactic acid (HLA) did not differ day to day. (Author/MT)

  11. Is an elevated submaximal heart rate associated with psychomotor slowness in young elite soccer players?

    NARCIS (Netherlands)

    Brink, Michel S.; Visscher, Chris; Schmikli, Sandor L.; Nederhof, E.; Lemmink, Koen A. P. M.

    2013-01-01

    The aim of the present study was to find early markers for overreaching that are applicable in sport practice. In a group of elite soccer players aged 1518, the stressrecovery balance and reaction times before and after exercise were assessed. Overreaching was indicated by an elevated submaximal

  12. Systolic blood pressure reactivity during submaximal exercise and acute psychological stress in youth

    Science.gov (United States)

    Background: Studies in youth show an association between systolic blood-pressure (SBP) reactivity to acute psychological stress and carotid artery intima-media thickness (CIMT). However, it has not yet been determined whether SBP reactivity during submaximal exercise is also associated with CIMT i...

  13. Reduction of insulin gene transcription in HIT-T15 beta cells chronically exposed to a supraphysiologic glucose concentration is associated with loss of STF-1 transcription factor expression.

    Science.gov (United States)

    Olson, L K; Sharma, A; Peshavaria, M; Wright, C V; Towle, H C; Rodertson, R P; Stein, R

    1995-09-26

    Chronic exposure of HIT-T15 beta cells to elevated glucose concentrations leads to decreased insulin gene transcription. The reduction in expression is accompanied by diminished binding of a glucose-sensitive transcription factor (termed GSTF) that interacts with two (A+T)-rich elements within the 5' flanking control region of the insulin gene. In this study we examined whether GSTF corresponds to the recently cloned insulin gene transcription factor STF-1, a homeodomain protein whose expression is restricted to the nucleus of endodermal cells of the duodenum and pancreas. We found that an affinity-purified antibody recognizing STF-1 supershifted the GSTF activator complex formed from HIT-T15 extracts. In addition, we demonstrated a reduction in STF-1 mRNA and protein levels that closely correlated with the change in GSTF binding in HIT-T15 cells chronically cultured under supraphysiologic glucose concentrations. The reduction in STF-1 expression in these cells could be accounted for by a change in the rate of STF-1 gene transcription, suggesting a posttranscriptional control mechanism. In support of this hypothesis, no STF-1 mRNA accumulated in HIT-T15 cells passaged in 11.1 mM glucose. The only RNA species detected was a 6.4-kb STF-1 RNA species that hybridized with 5' and 3' STF-1-specific cDNA probes. We suggest that the 6.4-kb RNA represents an STF-1 mRNA precursor and that splicing of this RNA is defective in these cells. Overall, this study suggests that reduced expression of a key transcriptional regulatory factor, STF-1, contributes to the decrease in insulin gene transcription in HIT-T15 cells chronically cultured in supraphysiologic glucose concentration.

  14. Medicinal values of fruit peels from Citrus sinensis, Punica granatum, and Musa paradisiaca with respect to alterations in tissue lipid peroxidation and serum concentration of glucose, insulin, and thyroid hormones.

    Science.gov (United States)

    Parmar, Hamendra Singh; Kar, Anand

    2008-06-01

    Peel extracts from Citrus sinensis, Punica granatum, and Musa paradisiaca were investigated for their effects on tissue lipid peroxidation (LPO) and on the concentration of thyroid hormones, insulin, and glucose in male rats. In vitro inhibition of H(2)O(2)-induced LPO in red blood cells of rats by 0.25, 0.50, 1.0, and 2.0 microg/mL C. sinensis, P. granatum, and M. paradisiaca peel extracts was observed in a dose-specific manner. Maximum inhibition was observed at 0.50 microg/mL C. sinensis, 2.0 microg/mL P. granatum, and 1.0 microg/mL M. paradisiaca. In the in vivo investigation, out of four different concentrations of each peel extract, 25, 200, and 100 mg/kg C. sinensis, P. granatum, and M. paradisiaca, respectively, were found to maximally inhibit hepatic LPO. The most effective doses were further evaluated for effects on serum triiodothyronine (T(3)), thyroxine (T(4)), insulin, and glucose concentrations. C. sinensis exhibited antithyroidal, hypoglycemic, and insulin stimulatory activities, in addition to inhibition of LPO, as it significantly decreased the serum T(4) (P paradisiaca strongly inhibited the serum level of thyroid hormones (P < .01 for both T(3) and T(4)) but increased the level of glucose (P < .05). These findings reveal the hitherto unknown potential of the tested peel extracts in the regulation of thyroid function and glucose metabolism. Besides antiperoxidative activity, C. sinensis extract has antithyroidal, hypoglycemic, and insulin stimulatory properties, which suggest its potential to ameliorate both hyperthyroidism and diabetes mellitus.

  15. The level of menadione redox-cycling in pancreatic β-cells is proportional to the glucose concentration: Role of NADH and consequences for insulin secretion

    Energy Technology Data Exchange (ETDEWEB)

    Heart, Emma [Cellular Dynamics Program, Marine Biological Laboratory, Woods Hole, MA, 02543 (United States); Palo, Meridith; Womack, Trayce [Department of Science, United States Coast Guard Academy, New London, CT, 06320 (United States); Smith, Peter J.S. [Cellular Dynamics Program, Marine Biological Laboratory, Woods Hole, MA, 02543 (United States); Institute for Life Sciences, University of Southampton (United Kingdom); Gray, Joshua P., E-mail: Joshua.p.gray@uscga.edu [Cellular Dynamics Program, Marine Biological Laboratory, Woods Hole, MA, 02543 (United States); Department of Science, United States Coast Guard Academy, New London, CT, 06320 (United States)

    2012-01-15

    Pancreatic β-cells release insulin in response to elevation of glucose from basal (4–7 mM) to stimulatory (8–16 mM) levels. Metabolism of glucose by the β-cell results in the production of low levels of reactive oxygen intermediates (ROI), such as hydrogen peroxide (H{sub 2}O{sub 2}), a newly recognized coupling factor linking glucose metabolism to insulin secretion. However, high and toxic levels of H{sub 2}O{sub 2} inhibit insulin secretion. Menadione, which produces H{sub 2}O{sub 2} via redox cycling mechanism in a dose-dependent manner, was investigated for its effect on β-cell metabolism and insulin secretion in INS-1 832/13, a rat β-cell insulinoma cell line, and primary rodent islets. Menadione-dependent redox cycling and resulting H{sub 2}O{sub 2} production under stimulatory glucose exceeded several-fold those reached at basal glucose. This was paralleled by a differential effect of menadione (0.1–10 μM) on insulin secretion, which was enhanced at basal, but inhibited at stimulatory glucose. Redox cycling of menadione and H{sub 2}O{sub 2} formation was dependent on glycolytically-derived NADH, as inhibition of glycolysis and application of non-glycogenic insulin secretagogues did not support redox cycling. In addition, activity of plasma membrane electron transport, a system dependent in part on glycolytically-derived NADH, was also inhibited by menadione. Menadione-dependent redox cycling was sensitive to the NQO1 inhibitor dicoumarol and the flavoprotein inhibitor diphenylene iodonium, suggesting a role for NQO1 and other oxidoreductases in this process. These data may explain the apparent dichotomy between the stimulatory and inhibitory effects of H{sub 2}O{sub 2} and menadione on insulin secretion. -- Highlights: ► Menadione stimulation or inhibition of insulin secretion is dependent upon applied glucose levels. ► Menadione-dependent H{sub 2}O{sub 2} production is proportional to applied glucose levels. ► Quinone-mediated redox cycling

  16. Eight weeks of intermittent hypoxic training improves submaximal physiological variables in highly trained runners.

    Science.gov (United States)

    Holliss, Ben A; Burden, Richard J; Jones, Andrew M; Pedlar, Charles R

    2014-08-01

    It is unclear whether intermittent hypoxic training (IHT) results in improvements in physiological variables associated with endurance running. Twelve highly trained runners (VO2peak 70.0 ± 3.5 ml·kg-1·min-1) performed incremental treadmill tests to exhaustion in normobaric normoxia and hypoxia (16.0% FIO2) to assess submaximal and maximal physiological variables and the limit of tolerance (T-Lim). Participants then completed 8 weeks of moderate to heavy intensity normoxic training (control [CONT]) or IHT (twice weekly 40 minutes runs, in combination with habitual training), in a single blinded manner, before repeating the treadmill tests. Submaximal heart rate decreased significantly more after IHT (-5 ± 5 b·min-1; p = 0.001) than after CONT ( -1 ± 5 b·min-1; p = 0.021). Changes in submaximal V[Combining Dot Above]O2 were significantly different between groups (p ≤ 0.05); decreasing in the IHT group in hypoxia (-2.6 ± 1.7 ml·kg-1·min-1; p = 0.001) and increasing in the CONT group in normoxia (+1.1 ± 2.1 ml·kg-1·min-1; p = 0.012). There were no VO2peak changes within either group, and while T-Lim improved post-IHT in hypoxia (p = 0.031), there were no significant differences between groups. Intermittent hypoxic training resulted in a degree of enhanced cardiovascular fitness that was evident during submaximal, but not maximal intensity exercise. These results suggest that moderate to heavy intensity IHT provides a mean of improving the capacity for submaximal exercise and may be useful for pre-acclimatization for subsequent exercise in hypoxia, but additional research is required to establish its efficacy for athletic performance at sea level.

  17. Intranasal insulin therapy: the clinical realities

    DEFF Research Database (Denmark)

    Hilsted, J; Madsbad, Sten; Hvidberg, A

    1995-01-01

    randomized trial. During both treatment periods the patients were treated with intermediate-acting insulin at bedtime. Six of the patients were withdrawn from the study during intranasal insulin therapy due to metabolic dysregulation. Serum insulin concentrations increased more rapidly and decreased more...

  18. The effect of tubing dwell time on insulin adsorption during intravenous insulin infusions.

    Science.gov (United States)

    Thompson, Cecilia D; Vital-Carona, Jessica; Faustino, E Vincent S

    2012-10-01

    Insulin adsorbs to plastic tubing, which decreases the concentration of an insulin solution delivered from an intravenous infusion set. Dwelling insulin within tubing before starting the infusion decreases adsorption but delays treatment initiation and wastes time in infusion preparation. The lack of data on dwell time effects results in wide variability in practice. We aim to determine the effect of dwell time on insulin concentration from intravenous infusion tubing. In this in vitro study, we used insulin solutions with concentrations of 0.1 unit/mL, 1 unit/mL, and 10 units/mL. Each solution dwelled in intravenous infusion sets for 0, 15, 30, or 60 min. After the dwell, we measured insulin concentrations from the solution bags and tubing. We repeated each insulin concentration-dwell time combination five times. Comparisons were performed using analyses of variance. For each of the three insulin concentrations, the mean insulin concentrations from the tubing were not significantly different between dwell times. Duration of dwell time did not affect insulin adsorption in polypropylene intravenous infusion sets. We recommend that following a 20-mL flush, insulin infusions can be started without any dwell time. Removal of dwell times may improve clinical practice by minimizing preparation time and will allow faster initiation of insulin infusion therapy.

  19. Effect of octreotide on plasma concentrations of glucose, insulin, glucagon, growth hormone, and cortisol in healthy dogs and dogs with insulinoma

    NARCIS (Netherlands)

    Robben, J.H.; Brom, W.E. van den; Mol, J.A.; Haeften, T.W. van; Rijnberk, A.

    2006-01-01

    The inhibitory effect of the somatostatin analogue octreotide on the secretion of insulin could be used in the treatment of insulinoma. However, current information on the effectiveness of octreotide in dogs is conflicting. Therefore, the endocrine effects of a single subcutaneous dose of 50 lg

  20. Impact of rosiglitazone on beta-cell function, insulin resistance, and adiponectin concentrations : results from a double-blind oral combination study with glimepiride

    NARCIS (Netherlands)

    Pfutzner, A; Schondorf, T; Seidel, D; Winkler, K; Matthaei, S; Hamann, A; Forst, T

    Addition of rosiglitazone to sulfonylurea has been shown to improve glycemic control in patients with type 2 diabetes previously treated with sulfonylurea monotherapy alone. This investigation was performed to assess the specific impact of rosiglitazone on insulin resistance, beta-cell function,

  1. Beta cell dysfunction and insulin resistance

    Directory of Open Access Journals (Sweden)

    Marlon E Cerf

    2013-03-01

    Full Text Available Beta cell dysfunction and insulin resistance are inherently complex with their interrelation for triggering the pathogenesis of diabetes also somewhat undefined. Both pathogenic states induce hyperglycemia and therefore increase insulin demand. Beta cell dysfunction results from inadequate glucose sensing to stimulate insulin secretion therefore elevated glucose concentrations prevail. Persistently elevated glucose concentrations above the physiological range result in the manifestation of hyperglycemia. With systemic insulin resistance, insulin signaling within glucose recipient tissues is defective therefore hyperglycemia perseveres. Beta cell dysfunction supersedes insulin resistance in inducing diabetes. Both pathological states influence each other and presumably synergistically exacerbate diabetes. Preserving beta cell function and insulin signaling in beta cells and insulin signaling in the glucose recipient tissues will maintain glucose homeostasis.

  2. QTL mapping of genes controlling plasma insulin and leptin concentrations: metabolic effect of obesity QTLs identified in an F2 intercross between C57BL/6J and DDD.Cg-A(y) inbred mice.

    Science.gov (United States)

    Suto, Jun-ichi

    2013-07-31

    DDD.Cg-A(y) female mice developed massive obesity as compared with B6.Cg-A(y) female mice. We previously identified quantitative trait loci (QTLs) for obesity on chromosomes 1, 6, 9 and 17 in F2 female mice, including F2A(y) (F2 mice with the A(y) allele) and F2 non- A(y) mice (F2 mice without the A(y) allele), produced by crossing C57BL/6J and DDD.Cg-A(y) strains. We here addressed the question whether the obesity QTLs share genetic bases with putative QTLs for plasma glucose, insulin and leptin concentrations. We performed QTL analyses for the first principal component (PC1) extracted from these metabolic measurements to identify the genes that contributed to the comprehensive evaluation of metabolic traits. By single QTL scans, we identified two significant QTLs for insulin concentration on chromosomes 6 and 12, three for leptin concentration on chromosomes 1, 6 and 17, and five for PC1 on chromosomes 1, 6, 12 (two loci) and 17. Although insulin and leptin concentrations and PC1 were not normally distributed in combined F2 mice, results of single QTL scans by parametric and non-parametric methods were very similar. Therefore, QTL scan by the parametric method was performed with the agouti locus genotype as a covariate. A significant QTL × covariate interaction was found for PC1 on chromosome 9. All obesity QTLs had significant metabolic effects. Thus, obesity- and diabetes-related traits in DDD.Cg-A(y) mice were largely controlled by QTLs on chromosomes 1, 6, 9, 12 and 17.

  3. Insulin Test

    Science.gov (United States)

    ... involves changes in diet and lifestyle. The American Diabetes Association recommends losing excess weight, getting regular amounts of moderate intensity physical activity, and increasing dietary fiber to lower blood insulin levels and increase the ...

  4. Insulin Test

    Science.gov (United States)

    ... to come strictly from animal sources (cow and pig pancreas cells). Most insulin used today is synthetic, ... developing type 2 diabetes , hypertension , hyperlipidemia , and/or heart disease several years down the road. Abdominal obesity, ...

  5. Changes in FGF21 Serum Concentrations and Liver mRNA Expression in an Experimental Model of Complete Lipodystrophy and Insulin-Resistant Diabetes

    Czech Academy of Sciences Publication Activity Database

    Špolcová, Andrea; Holubová, Martina; Mikulášková, Barbora; Nagelová, Veronika; Štofková, A.; Lacinová, Z.; Jurčovičová, J.; Haluzík, M.; Maletínská, Lenka; Železná, Blanka

    2014-01-01

    Roč. 63, č. 4 (2014), s. 483-490 ISSN 0862-8408 R&D Projects: GA ČR GAP303/10/1368; GA ČR GAP303/12/0576 Institutional support: RVO:61388963 Keywords : FGF21 * A-ZIP mice * lipodystrophy * insulin resistance * fatty liver * GLUT-1 Subject RIV: CE - Biochemistry Impact factor: 1.293, year: 2014

  6. [Influence of short-term intensive insulin therapy on plasma concentration of lipoprotein-associated phospholipase A(2) and secretory phospholipase A(2) in newly diagnosed type 2 diabetic patients].

    Science.gov (United States)

    Lin, X H; Xu, M T; Mai, L F; Tang, J Y; Wang, X Y; Li, Y; Yan, L

    2017-02-01

    The aim of the study was to explore the effect and its clinical relevance of short-term intensive insulin treatment on plasma concentrations of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) and secretory phospholipase A(2) (sPLA(2)) in newly diagnosed type 2 diabetes mellitus (T2DM). Ninety newly diagnosed T2DM patients were recruited and received continuous subcutaneous insulin infusion (CSII) for about 2 weeks. After CSII, sPLA(2) levels [173.78 (80.95, 278.09) μg/L] were significantly decreased compared with the levels before [219.33 (130.03, 337.30) μg/L], P<0.01, while no statistic significant changes could be viewed in Lp-PLA(2) levels. Correlation analysis showed that the changes of Lp-PLA(2) and sPLA(2) were both positively correlated with the changes of homeostasis model assessment of insulin resistance(HOMA-IR)after CSII (r=0.537, 0.493 respectively, all P<0.05). The Lp-PLA(2) and sPLA(2) level reduction after CSII might help to protect the patients from diabetic macroangiopathy. Trial registration Chinese Clinical Trial Registry, ChiCTR-TRC-10001618.

  7. Prolonged administration of recombinant human erythropoietin increases submaximal performance more than maximal aerobic capacity

    DEFF Research Database (Denmark)

    Thomsen, J J; Rentsch, R L; Robach, P

    2007-01-01

    The effects of recombinant human erythropoietin (rHuEpo) treatment on aerobic power (VO2max) are well documented, but little is known about the effects of rHuEpo on submaximal exercise performance. The present study investigated the effect on performance (ergometer cycling, 20-30 min at 80......HuEpo treatment VO2max increased (PVO2max) was increased by 54.0 and 54.3% (P... week 11), TTE was decreased by 26.8% as compared to pre rHuEpo administration. In conclusion, in healthy non-athlete subjects rHuEpo administration prolongs submaximal exercise performance by about 54% independently of the approximately 12% increase in VO2max....

  8. Racing Skiers and Swimmers’ Heart Electric Field during Ventricular Depolarization at Recovery Period after Moderate and Submaximal Physical Load

    Directory of Open Access Journals (Sweden)

    Svetlana V. Strelnikova

    2013-01-01

    Full Text Available The article presents the results of cardioelectrotopographic investigation of racing skiers and swimmers’ heart electric activity during ventricular depolarization at recovery period after moderate and submaximal physical load. Changes in ventricular depolarization time and ventricular depolarization phases ratio due to longer duration of the first and second cardioelectric potential inversions on the chest surface in racing skiers and less duration of the depolarization initial phase in swimmers were detected after moderate and submaximal load

  9. Iron Status in Chronic Heart Failure: Impact on Symptoms, Functional Class and Submaximal Exercise Capacity.

    Science.gov (United States)

    Enjuanes, Cristina; Bruguera, Jordi; Grau, María; Cladellas, Mercé; Gonzalez, Gina; Meroño, Oona; Moliner-Borja, Pedro; Verdú, José M; Farré, Nuria; Comín-Colet, Josep

    2016-03-01

    To evaluate the effect of iron deficiency and anemia on submaximal exercise capacity in patients with chronic heart failure. We undertook a single-center cross-sectional study in a group of stable patients with chronic heart failure. At recruitment, patients provided baseline information and completed a 6-minute walk test to evaluate submaximal exercise capacity and exercise-induced symptoms. At the same time, blood samples were taken for serological evaluation. Iron deficiency was defined as ferritin < 100 ng/mL or transferrin saturation < 20% when ferritin is < 800 ng/mL. Additional markers of iron status were also measured. A total of 538 heart failure patients were eligible for inclusion, with an average age of 71 years and 33% were in New York Heart Association class III/IV. The mean distance walked in the test was 285 ± 101 meters among those with impaired iron status, vs 322 ± 113 meters (P=.002). Symptoms during the test were more frequent in iron deficiency patients (35% vs 27%; P=.028) and the most common symptom reported was fatigue. Multivariate logistic regression analyses showed that increased levels of soluble transferrin receptor indicating abnormal iron status were independently associated with advanced New York Heart Association class (P < .05). Multivariable analysis using generalized additive models, soluble transferrin receptor and ferritin index, both biomarkers measuring iron status, showed a significant, independent and linear association with submaximal exercise capacity (P=.03 for both). In contrast, hemoglobin levels were not significantly associated with 6-minute walk test distance in the multivariable analysis. In patients with chronic heart failure, iron deficiency but not anemia was associated with impaired submaximal exercise capacity and symptomatic functional limitation. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  10. A Submaximal Running Test With Postexercise Cardiac Autonomic and Neuromuscular Function in Monitoring Endurance Training Adaptation.

    Science.gov (United States)

    Vesterinen, Ville; Nummela, Ari; Laine, Tanja; Hynynen, Esa; Mikkola, Jussi; Häkkinen, Keijo

    2017-01-01

    Vesterinen, V, Nummela, A, Laine, T, Hynynen, E, Mikkola, J, and Häkkinen, K. A submaximal running test with postexercise cardiac autonomic and neuromuscular function in monitoring endurance training adaptation. J Strength Cond Res 31(1): 233-243, 2017-The aim of this study was to investigate whether a submaximal running test (SRT) with postexercise heart rate recovery (HRR), heart rate variability (HRV), and countermovement jump (CMJ) measurements could be used to monitor endurance training adaptation. Thirty-five endurance-trained men and women completed an 18-week endurance training. Maximal endurance performance and maximal oxygen uptake were measured every 8 weeks. In addition, SRTs with postexercise HRR, HRV, and CMJ measurements were carried out every 4 weeks. Submaximal running test consisted of two 6-minute stages at 70 and 80% of maximum heart rate (HRmax) and a 3-minute stage at 90% HRmax, followed by a 2-minute recovery stage for measuring postexercise HRR, HRV, and CMJ test. The highest responders according to the change of maximal endurance performance showed a significant improvement in running speeds during stages 2 and 3 in SRT, whereas no changes were observed in the lowest responders. The strongest correlation was found between the change of maximal endurance performance and running speed during stage 3, whereas no significant relationships were found between the change of maximal endurance performance and the changes of postexercise HRR, HRV, and CMJ. Running speed at 90% HRmax intensity was the most sensitive variable to monitor adaptation to endurance training. The present submaximal test showed potential to monitor endurance training adaptation. Furthermore, it may serve as a practical tool for athletes and coaches to evaluate weekly the effectiveness of training program without interfering in the normal training habits.

  11. Anti-insulin antibody test

    Science.gov (United States)

    Insulin antibodies - serum; Insulin Ab test; Insulin resistance - insulin antibodies; Diabetes - insulin antibodies ... You appear to have an allergic response to insulin Insulin no longer seems to control your diabetes

  12. Characterization of Symmetry Properties of First Integrals for Submaximal Linearizable Third-Order ODEs

    Directory of Open Access Journals (Sweden)

    K. S. Mahomed

    2013-01-01

    Full Text Available The relationship between first integrals of submaximal linearizable third-order ordinary differential equations (ODEs and their symmetries is investigated. We obtain the classifying relations between the symmetries and the first integral for submaximal cases of linear third-order ODEs. It is known that the maximum Lie algebra of the first integral is achieved for the simplest equation and is four-dimensional. We show that for the other two classes they are not unique. We also obtain counting theorems of the symmetry properties of the first integrals for these classes of linear third-order ODEs. For the 5 symmetry class of linear third-order ODEs, the first integrals can have 0, 1, 2, and 3 symmetries, and for the 4 symmetry class of linear third-order ODEs, they are 0, 1, and 2 symmetries, respectively. In the case of submaximal linear higher-order ODEs, we show that their full Lie algebras can be generated by the subalgebras of certain basic integrals.

  13. The Usefulness of Submaximal Exercise Gas Exchange in Pulmonary Arterial Hypertension: A Case Series

    Directory of Open Access Journals (Sweden)

    Paul R. Woods

    2010-04-01

    Full Text Available Introduction Submaximal exercise gas exchange may be a useful tool to track responses to therapy in pulmonary arterial hypertension (PAH patients. Methods Three patients diagnosed with idiopathic PAH, on differing therapies, were included. Standard clinical tests (echocardiography; 6 minute walk were performed pre and 3-5 months after treatment. Gas exchange was measured during 3 minutes of step exercise at both time points. Results Gas exchange variables, end tidal CO 2 (P ET CO 2 and the ratio of ventilation to CO 2 production (V E /VCO 2 , during submaximal exercise were able to track patient responses to therapy over a 3-5 month period. Two patients demonstrated positive improvements, with an increased P ET CO 2 and decreased V E /VCO 2 during light exercise, in response to an altered therapeutic regime. The third patient had a worsening of gas exchange (decreased P ET CO 2 and increased V E /VCO 2 following no changes in the medical regime from the baseline visit. Conclusion Gas exchange variables measured during light submaximal exercise, such as P ET CO 2 and V E /VCO 2 , may be able to better detect small changes in functional status following treatment and could, therefore, be a useful tool to track disease severity in PAH patients. Further study is required to determine the clinical usefulness of these gas exchange variables.

  14. THE INFLUENCE OF OBESITY AND AMBIENT TEMPERATURE ON PHYSIOLOGICAL AND OXIDATIVE RESPONSES TO SUBMAXIMAL EXERCISE

    Directory of Open Access Journals (Sweden)

    N. Ahn

    2014-07-01

    Full Text Available This study investigated the effects of obesity and ambient temperature on physiological responses and markers of oxidative stress to submaximal exercise in obese and lean people. Sixteen healthy males were divided into an obese group (n=8, %fat: 27.00±3.00% and a lean group (n=8, %fat: 13.85±2.45%. Study variables were measured during a 60 min submaximal exercise test at 60% VO2max in a neutral (21±1°C and a cold (4±1°C environment. Heart rate, blood lactate, rectal temperature, serum levels of malondialdehyde (MDA and superoxide dismutase (SOD were measured at rest, during exercise and in recovery. Heart rate of both groups was significantly lower (P<0.05 in the cold than the warm environment, but there were no significant differences between the two groups. Serum SOD activity increased to a significantly greater extent (P<0.05 in the cold than the neutral environment, and remained elevated for longer during exercise in the obese group than the lean group. Serum MDA level during submaximal exercise was not significantly different between conditions or groups. Cold stress in exercise may challenge antioxidant defence mechanisms in obese subjects, but lipid peroxidation remains unchanged.

  15. Variation in heart rate during submaximal exercise: implications for monitoring training.

    Science.gov (United States)

    Lamberts, Robert P; Lemmink, Koen A P M; Durandt, Justin J; Lambert, Michael I

    2004-08-01

    A change in heart rate at a controlled submaximal exercise intensity is used as a marker of training status. However, the standard error of measurement has not been studied systematically, and therefore a change in heart rate, which can be considered relevant, has not been determined. Forty-four subjects (26.5 +/- 5.4 years; mean +/- standard deviation) participated in a submaximal running test at the same time of day for 5 consecutive days. Heart rates were determined during each of the 4 exercise intensities (2 minutes each) of increasing intensity and during the 1-minute recovery period after each stage. The repeatability of the heart rate on a day-to-day basis during the stages and recovery periods were high (intraclass correlation coefficient: 95% confidence interval R = 0.94- 0.99). The lowest variation in heart rate occurred in the fourth stage ( approximately 90% maximum heart rate) with heart rate varying 5 +/- 2 b.min(-1) (95% confidence interval for coefficient of variation = 1.1-1.4%). In conclusion, the standard error of measurement of submaximal heart rate is 1.1-1.4%. This magnitude of measurement error needs to be considered when heart rate is used as a marker of training status.

  16. [Comparison of submaximal front crawl and breast stroke swimming in relation to energy expenditure].

    Science.gov (United States)

    Sugiyama, K; Katamoto, S

    1992-11-01

    The purpose of this study was to compare the energy expenditure during submaximal front crawl (Fr) and breast stroke (Br) swimming. Six male college swimmers performed submaximal and maximal exercise tests in both styles in a swimming flume. In submaximal exercise tests, they swam at the following given velocities for 5 min, Br: 0.3, 0.5 and 0.7 m/sec; Fr: 0.3, 0.5, 0.7 and 0.9 m/sec. In maximal exercise tests, following submaximal swimming at 0.9 m/sec in Br and 1.1 m/sec in Fr, swimming velocity was increased progressively by 0.1 m/sec every 1 min until the subjects reached to voluntary exhaustion. VO2max obtained from the maximal swimming tests in Br and Fr were 4.27 and 4.18 l/min, respectively. And there was no significant difference between these two values. VO2 during Br and Fr swimming at four and five submaximal velocities were 1.06, 1.30, 1.79, 2.65 l/min and 1.17, 1.34, 1.63, 2.04, 3.05 l/min, respectively. And, it was found that VO2 at 0.3 and 0.9 m/sec were significantly different (p styles curvilinearly increased with swimming velocity, and these relationships were well fitted for the regression equation of the second order (Br: y = 3.84625x2 - 1.95914x + 1.310463,r2 = 0.999 (p < 0.05), Fr: y = 3.233446x2 - 2.28136x + 1.611524, r2 = 0.979 (p < 0.05)). It was calculated that the two curves crossed at a point on 0.49 m/sec, and that VO2 at this point was 1.27 l/min. This value equivalented to 30.4% VO2max in Br and 29.7% VO2max in Fr.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Diabetes and Insulin

    Science.gov (United States)

    ... in the abdomen just behind the stomach, produces insulin. Insulin is a hormone that takes glucose from the ... occurs when the pancreas does not produce enough insulin or when the body doesn’t use insulin ...

  18. Insulin Resistance and Prediabetes

    Science.gov (United States)

    ... After Your Baby is Born Monogenic Diabetes Prediabetes & Insulin Resistance What is insulin? Insulin is a hormone made in the pancreas, ... body absorb glucose and use it for energy. Insulin's Role in Blood Glucose Control When blood glucose ...

  19. The effect of maximal vs submaximal exertion on postprandial lipid levels in individuals with and without coronary heart disease.

    Science.gov (United States)

    Aronov, David M; Bubnova, Marina G; Perova, Natalia V; Orekhov, Alexander N; Bobryshev, Yuri V

    Decisions about fat consumption and levels of physical activity are among the everyday choices we make in life and risk of coronary heart disease (CHD) can be affected by those choices. The purpose of this study was to investigate the influence of a standard fat load combined with physical exertion of different intensities on the plasma lipid profile of CHD patients and CHD-free individuals. This study looked at the influence of different intensities of physical exercise on postprandial lipid metabolism in 20 healthy men and 36 men with diagnosis of CHD. Venous blood samples were obtained after overnight fasting, 3 hours after standard fat load (before the physical load), and immediately after maximal or submaximal physical exercise on bicycle ergometer. After fat load total cholesterol (TC) concentration did not change in either group. However, after the addition of maximal exercise, TC, triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and apolipoprotein (Apo) B increased significantly (P < .01) in both groups. After fat load and maximal exercise, there was no change in high-density lipoprotein cholesterol (HDL-C) in healthy men, but in men with CHD, HDL-C fell significantly (P < .01); and Apo AI rose in healthy men (P < .01) but dropped significantly (P < .01) in men with CHD. Submaximal physical exercise (60% of max VO2 load for 40 minutes) after fat load decreased TG level in CHD patients (P < .01) and improved other lipid parameters in both groups significantly (↓LDL-C, ↑HDL-C, ↑Apo AI, ↓Apo B, P < .01). We observed a worsening of physical work capacity in men with CHD (significant reduction of duration and total amount of work performed, maximal VO2, oxygen pulse), during maximal stress test performed 3 hours after fat load. There was a doubling of the number of abnormal stress test results (P < .01). Healthy persons showed an increase in respiratory parameters (ventilation, CO2 production, maximal VO2, and oxygen

  20. Cardiac autonomic dysfunction in chronic stroke women is attenuated after submaximal exercise test, as evaluated by linear and nonlinear analysis.

    Science.gov (United States)

    Francica, Juliana Valente; Bigongiari, Aline; Mochizuki, Luís; Scapini, Kátia Bilhar; Moraes, Oscar Albuquerque; Mostarda, Cristiano; Caperuto, Erico Chagas; Irigoyen, Maria Cláudia; De Angelis, Katia; Rodrigues, Bruno

    2015-09-29

    We evaluated cardiac autonomic modulation in women with chronic ischemic stroke (at least 4 years post-stroke) at rest and in response to submaximal exercise test. Fourteen post-stroke women (S group) and 10 healthy women (C group) participated in this study. Autonomic modulation (using linear and nonlinear analysis), blood pressure and metabolic variables at rest were evaluated immediately after the exercise test and during the recovery period (20 min). All participants underwent submaximal exercise test on cycle ergometer with gas analysis. At rest, the S group displayed higher lactate concentration, systolic (SBP) and diastolic blood pressure (DBP) values when compared to C group. Furthermore, the S group had lower heart rate variability (HRV) in time domain (SDNN: S = 30 ± 5 vs. 40 ± 8 ms; rMSSD: S = 14 ± 2 vs. C = 34 ± 3 ms), decreased high frequency band of pulse interval (S = 8.4 ± 2 vs. 33.1 ± 9 %) and 2V pattern of symbolic analysis (S = 17.3 ± 1 vs. 30 ± 3 %) (both indicators of cardiac vagal modulation) when compared to C group. Immediately after exercise, S group presented higher values of lactate, SBP, DBP and double product when compared to C group, as well as decreased heart rate recovery (HRR) measured at the first, second and third minutes. At recovery time, all HRV parameters in time and frequency domains improved in the S group; however, HF band remained lower when compared to C group. After the exercise test, women with chronic stroke presented reduced heart rate variability, reduced cardiac vagal modulation, as well as reduced HRR, while displayed an improvement of heart rate variability and cardiac vagal modulation when compared to their baseline. These results reinforce the importance of a physically active lifestyle for cardiovascular autonomic disorders observed in chronic stroke women.

  1. Insulin Resistance Induced by Hyperinsulinemia Coincides with a Persistent Alteration at the Insulin Receptor Tyrosine Kinase Domain

    Science.gov (United States)

    Catalano, Karyn J.; Maddux, Betty A.; Szary, Jaroslaw; Youngren, Jack F.; Goldfine, Ira D.; Schaufele, Fred

    2014-01-01

    Insulin resistance, the diminished response of target tissues to insulin, is associated with the metabolic syndrome and a predisposition towards diabetes in a growing proportion of the worldwide population. Under insulin resistant states, the cellular response of the insulin signaling pathway is diminished and the body typically responds by increasing serum insulin concentrations to maintain insulin signaling. Some evidence indicates that the increased insulin concentration may itself further dampen insulin response. If so, insulin resistance would worsen as the level of circulating insulin increases during compensation, which could contribute to the transition of insulin resistance to more severe disease. Here, we investigated the consequences of excess insulin exposure to insulin receptor (IR) activity. Cells chronically exposed to insulin show a diminished the level of IR tyrosine and serine autophosphorylation below that observed after short-term insulin exposure. The diminished IR response did not originate with IR internalization since IR amounts at the cell membrane were similar after short- and long-term insulin incubation. Förster resonance energy transfer between fluorophores attached to the IR tyrosine kinase (TK) domain showed that a change in the TK domain occurred upon prolonged, but not short-term, insulin exposure. Even though the altered ‘insulin refractory’ IR TK FRET and IR autophosphorylation levels returned to baseline (non-stimulated) levels after wash-out of the original insulin stimulus, subsequent short-term exposure to insulin caused immediate re-establishment of the insulin-refractory levels. This suggests that some cell-based ‘memory’ of chronic hyperinsulinemic exposure acts directly at the IR. An improved understanding of that memory may help define interventions to reset the IR to full insulin responsiveness and impede the progression of insulin resistance to more severe disease states. PMID:25259572

  2. Insulin in the brain: sources, localization and functions.

    Science.gov (United States)

    Ghasemi, Rasoul; Haeri, Ali; Dargahi, Leila; Mohamed, Zahurin; Ahmadiani, Abolhassan

    2013-02-01

    Historically, insulin is best known for its role in peripheral glucose homeostasis, and insulin signaling in the brain has received less attention. Insulin-independent brain glucose uptake has been the main reason for considering the brain as an insulin-insensitive organ. However, recent findings showing a high concentration of insulin in brain extracts, and expression of insulin receptors (IRs) in central nervous system tissues have gathered considerable attention over the sources, localization, and functions of insulin in the brain. This review summarizes the current status of knowledge of the peripheral and central sources of insulin in the brain, site-specific expression of IRs, and also neurophysiological functions of insulin including the regulation of food intake, weight control, reproduction, and cognition and memory formation. This review also considers the neuromodulatory and neurotrophic effects of insulin, resulting in proliferation, differentiation, and neurite outgrowth, introducing insulin as an attractive tool for neuroprotection against apoptosis, oxidative stress, beta amyloid toxicity, and brain ischemia.

  3. Met-enkephalin, beta-endorphin and cortisol responses to sub-maximal exercise after sleep disturbances.

    Science.gov (United States)

    Mougin, F; Simon-Rigaud, M L; Mougin, C; Bourdin, H; Jacquier, M C; Henriet, M T; Davenne, D; Kantelip, J P; Magnin, P; Gaillard, R C

    1992-01-01

    The present study compared the effects of partial sleep deprivation and the effects of an intake of a hypnotic compound (zolpidem) prior to bedtime, on sleep and on hormonal and metabolic adaptations to subsequent exercise. Sleep deprivation consisted of a delayed bedtime and an early getting-up time. Eight young subjects, who slept well and were highly trained athletes, were enrolled in this study. Sleep was recorded polygraphically and the following afternoon exercise was performed on a cycle ergometer for 30 min at 75% of maximal oxygen consumption (VO2max) after a 10-min warm up. Met-enkephalin, beta-endorphin, cortisol, and lactate concentrations were measured at rest and during exercise. The data obtained after experimental sleep, with and without medication were compared with those obtained in the reference condition with normal sleep. Both types of sleep reduction decreased the total sleep time, stage 2 sleep, and rapid eye movement sleep, whereas zolpidem administration did not modify either the duration of sleep or the sleep stages. After the reference night, plasma met-enkephalin did not show any significant change at the end of the submaximal exercise, whereas beta-endorphin, cortisol, and lactic acid concentrations increased significantly in all subjects. The changes in concentration in beta-endorphin were significantly related to the changes in cortisol (r = 0.78; P less than 0.01) and to the changes in plasma lactic acid (r = 0.58; P less than 0.05). Cortisol concentrations were also related to lactic acid values (r = 0.94; P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Mulberry-extract improves glucose tolerance and decreases insulin concentrations in normoglycaemic adults: Results of a randomised double-blind placebo-controlled study.

    Directory of Open Access Journals (Sweden)

    Mark Lown

    Full Text Available High sugar and refined carbohydrate intake is associated with weight gain, increased incidence of diabetes and is linked with increased cardiovascular mortality. Reducing the health impact of poor quality carbohydrate intake is a public health priority. Reducose, a proprietary mulberry leaf extract (ME, may reduce blood glucose responses following dietary carbohydrate intake by reducing absorption of glucose from the gut.A double-blind, randomised, repeat measure, phase 2 crossover design was used to study the glycaemic and insulinaemic response to one reference product and three test products at the Functional Food Centre, Oxford Brooks University, UK. Participants; 37 adults aged 19-59 years with a BMI ≥ 20kg/m2 and ≤ 30kg/m2. The objective was to determine the effect of three doses of mulberry-extract (Reducose versus placebo on blood glucose and insulin responses when co-administered with 50g maltodextrin in normoglycaemic healthy adults. We also report the gastrointestinal tolerability of the mulberry extract.Thirty-seven participants completed the study: The difference in the positive Incremental Area Under the Curve (pIAUC (glucose (mmol / L x h for half, normal and double dose ME compared with placebo was -6.1% (-18.2%, 5.9%; p = 0.316, -14.0% (-26.0%, -2.0%; p = 0.022 and -22.0% (-33.9%, -10.0%; p<0.001 respectively. The difference in the pIAUC (insulin (mIU / L x h for half, normal and double dose ME compared with placebo was -9.7% (-25.8%, 6.3%; p = 0.234, -23.8% (-39.9%, -7.8%; p = 0.004 and -24.7% (-40.8%, -8.6%; p = 0.003 respectively. There were no statistically significant differences between any of the 4 groups in the odds of experiencing one or more gastrointestinal symptoms (nausea, abdominal cramping, distension or flatulence.Mulberry leaf extract significantly reduces total blood glucose rise after ingestion of maltodextrin over 120 minutes. The pattern of effect demonstrates a classical dose response curve with

  5. Insulin binding to erythrocytes after acute 16-methyleneprednisolone ingestion.

    Science.gov (United States)

    Dwenger, A; Holle, W; Zick, R; Trautschold, I

    1982-10-01

    The binding of [125I]insulin to erythrocytes, glucose and insulin were determined before and 1, 7 and 35 days after ingestion of 2 X 60-methyleneprednisolone. None of two groups of volunteers (7 males, 4 females showed clear alterations of the insulin binding parameters (Ka and R0), or of the fasting cortisol, glucose and insulin concentrations. These results exclude the possibility that the diabetogenic effect of glucocorticoides is accompanied by an alteration of the insulin receptor characteristics of erythrocytes.

  6. Insulin Resistance

    DEFF Research Database (Denmark)

    Jensen, Benjamin Anderschou Holbech

    Insulin resistance (IR) is escalating with alarming pace and is no longer restricted to westernized countries. As a forerunner for some of the most serious threats to human health including metabolic syndrome, cardiovascular diseases, and type 2-diabetes, the need for new treatment modalities...

  7. Plasma insulin disturbances in primary hyperparathyroidism

    Science.gov (United States)

    Kim, Hakjoong; Kalkhoff, Ronald K.; Costrini, Nicholas V.; Cerletty, James M.; Jacobson, Mitchell

    1971-01-01

    Plasma insulin dynamics were evaluated in 10 patients with primary hyperparathyroidism before and after parathyroidectomy and correction of hypercalcemia. Before surgery fasting plasma insulin concentrations and insulin responses to administered glucose, tolbutamide, and glucagon were significantly greater than postoperative values. Hyperinsulinemia was not associated with altered glucose curves during glucose or glucagon tolerance tests, but a relatively greater insulin response to tolbutamide resulted in an increased hypoglycemic effect following its administration. The glucose-lowering action of intravenous insulin was slightly impaired before treatment. Intramuscular injections of parathormone to six normal men for 8 days induced mild hypercalcemia and hypophosphatemia and reproduced augmented plasma insulin responses to oral glucose and intravenous tolbutamide. 4-hr intravenous infusions of calcium to another group of six normal men raised serum calcium concentrations above 11 mg/100 ml. This did not alter glucose or insulin curves during oral glucose tolerance but markedly accentuated insulin responses to tolbutamide and potentiated its hypoglycemic effect. When highly purified parathormone was incubated with isolated pancreatic islets of male rats, glucose-stimulated insulin secretion was unaffected. These findings suggest that chronic hypercalcemia of hyperparathyroidism sustains a form of endogenous insulin resistance that necessitates augmented insulin secretion to maintain plasma glucose homeostasis. This state is insufficient to oppose tolbutamide-induced hypoglycemia because of an additional direct, selective enhancement of hypercalcemia on pancreatic beta cell responsiveness to the sulfonylurea. The possible direct role of parathormone in these events has not been established. PMID:5129311

  8. Determinants of renal potassium excretion in critically ill patients : The role of insulin therapy

    NARCIS (Netherlands)

    Hoekstra, Miriam; Yeh, Lu; Oude Lansink, Annemieke; Vogelzang, Mathijs; Stegeman, Coen A.; Rodgers, Michael G. G.; van der Horst, Iwan C. C.; Wietasch, Gotz; Zijlstra, Felix; Nijsten, Maarten W. N.

    Objectives: Insulin administration lowers plasma potassium concentration by augmenting intracellular uptake of potassium. The effect of insulin administration on renal potassium excretion is unclear. Some studies suggest that insulin has an antikaliuretic effect although plasma potassium levels were

  9. Study on the Changes in Enzyme and Insulin-like Growth Factor-1 Concentrations in Blood Serum and Growth Characteristics of Velvet Antler during the Antler Growth Period in Sika Deer (

    Directory of Open Access Journals (Sweden)

    Jaehyun Park

    2015-09-01

    Full Text Available This study was conducted to investigate changes in blood enzyme parameters and to evaluate the relationship between insulin-like growth factor-1 (IGF-1, antler growth and body weight during the antler growth of sika deer (Cervus nippon. Serum enzyme activity and IGF-1 concentrations were measured in blood samples collected from the jugular and femoral veins at regular intervals during the antler growth period. Blood samples were taken in the morning from fasted stags (n = 12 which were healthy and showed no clinical signs of disease. Alfalfa was available ad libitum and concentrates were given at 1% of body weight to all stags. The experimental diet was provided at 9 am with water available at all times. There were no significant differences in alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase during antler growth, but alkaline phosphatase concentrations increased with antler growth progression, and the highest alkaline phosphatase concentration was obtained 55 days after antler casting. Serum IGF-1 concentrations measured from blood samples taken from the jugular vein during antler growth, determined that levels of IGF-1 was associated with body weight and antler growth patterns. Serum IGF-1 concentrations were higher at the antler cutting date than other sampling dates. Antler length increased significantly during antler growth (p<0.001, and there was a similar trend to between right and left beams. Body weight increased with antler growth but was not significant. Consequently it appeared that serum alkaline phosphatase concentration was related to antler growth and both antler growth and body weight were associated positively with IGF-1 concentrations during antler growth.

  10. Effects of Pedal Speed and Crank Length on Pedaling Mechanics during Submaximal Cycling

    Science.gov (United States)

    BARRATT, PAUL RICHARD; MARTIN, JAMES C.; ELMER, STEVE J.; KORFF, THOMAS

    2016-01-01

    ABSTRACT During submaximal cycling, the neuromuscular system has the freedom to select different intermuscular coordination strategies. From both a basic science and an applied perspective, it is important to understand how the central nervous system adjusts pedaling mechanics in response to changes in pedaling conditions. Purpose To determine the effect of changes in pedal speed (a marker of muscle shortening velocity) and crank length (a marker of muscle length) on pedaling mechanics during submaximal cycling. Methods Fifteen trained cyclists performed submaximal isokinetic cycling trials (90 rpm, 240 W) using pedal speeds of 1.41 to 1.61 m·s−1 and crank lengths of 150 to 190 mm. Joint powers were calculated using inverse dynamics. Results Increases in pedal speed and crank length caused large increases knee and hip angular excursions and velocities (P 0.05). Joint moments and joint powers were less affected by changes in the independent variables, but some interesting effects and trends were observed. Most noteworthy, knee extension moments and powers tended to decrease, whereas hip extension power tended to increase with an increase in crank length. Conclusions The distribution of joint moments and powers is largely maintained across a range of pedaling conditions. The crank length induced differences in knee extension moments, and powers may represent a trade-off between the central nervous system’s attempts to simultaneously minimize muscle metabolic and mechanical stresses. These results increase our understanding of the neural and mechanical mechanisms underlying multi-joint task performance, and they have practical relevance to coaches, athletes, and clinicians. PMID:26559455

  11. [Submaximal exercise capacity and quality of life in exclusive water-pipe smokers].

    Science.gov (United States)

    Ben Saad, H; Babba, M; Boukamcha, R; Latiri, I; Knani, J; Slama, R; Bougmiza, I; Zbidi, A; Tabka, Z

    2010-05-01

    It is well known that oxidative stress is increased significantly by regular water-pipe smoking (WPS). This could lead to muscle dysfunction and thus to impairments of exercise and quality of life (QOL). Considering the impressive number of WP smokers, we intend to investigate the potential effect of WPS on submaximal exercise capacity and QOL. (1). To evaluate the submaximal exercise capacity by the 6-minutes walking test (6-MWT). (2). To compare the deficiency, incapacity and QOL data of exclusive WPS with those of two control groups (never smokers and exclusive cigarette smokers). (3). To determine the factors influencing the 6-minutes walk distance (6-MWD) of WPS subjects. A multicentre study including 180 exclusive WPS [> or =5 WP-year] men aged > or =40 years. Cigar or cigarette smoking, contraindications to the 6-MWT or cortico-steroid therapy will be exclusion criteria. QOL evaluation, spirometry, electrocardiogram and two 6-MWT will be performed. Signs of exercise impairment will be: 6-MWD or =5/10, haemoglobin saturation fall > or =5 points. Data from WPS subjects will be compared with those from 90 never smoking subjects and 90 exclusives cigarettes smokers. (1). WPS will affect significantly the submaximal exercise capacity. (2). Resting spirometric, 6-MWT and QOL data of exclusive WPS subjects will be significantly reduced compared to never smoking subjects. (3). The 6-MWD's of exclusive WPS subjects will be significantly influenced by cumulative WP consumption, by resting spirometric data, by obesity and by physical activity score. Copyright 2010 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  12. The Impact of a Submaximal Level of Exercise on Balance Performance in Older Persons

    Science.gov (United States)

    2014-01-01

    Objective. The purpose of this study was to determine the impact of a submaximal level of exercise on balance performance under a variety of conditions. Material and Method. Thirteen community-dwelling older persons with intact foot sensation (age = 66.69 ± 8.17 years, BMI = 24.65 ± 4.08 kg/m2, female, n = 6) volunteered to participate. Subjects' balance performances were measured using the Modified Clinical Test of Sensory Integration of Balance (mCTSIB) at baseline and after test, under four conditions of stance: (1) eyes-opened firm-surface (EOF), (2) eyes-closed firm-surface (ECF), (3) eyes-opened soft-surface (EOS), and (4) eyes-closed soft-surface (ECS). The 6-minute walk test (6MWT) protocol was used to induce the submaximal level of exercise. Data was analyzed using the Wilcoxon Signed-Rank Test. Results. Balance changes during EOF (z = 0.00, P = 1.00) and ECF (z = −1.342, P = 0.180) were not significant. However, balance changes during EOS (z = −2.314, P = 0.021) and ECS (z = −3.089, P = 0.02) were significantly dropped after the 6MWT. Conclusion. A submaximal level of exercise may influence sensory integration that in turn affects balance performance, particularly on an unstable surface. Rehabilitation should focus on designing intervention that may improve sensory integration among older individuals with balance deterioration in order to encourage functional activities. PMID:25383386

  13. Effects of submaximal and supramaximal interval training on determinants of endurance performance in endurance athletes.

    Science.gov (United States)

    Paquette, M; Le Blanc, O; Lucas, S J E; Thibault, G; Bailey, D M; Brassard, P

    2017-03-01

    We compared the effects of submaximal and supramaximal cycling interval training on determinants of exercise performance in moderately endurance-trained men. Maximal oxygen consumption (VO2max ), peak power output (Ppeak ), and peak and mean anaerobic power were measured before and after 6 weeks (3 sessions/week) of submaximal (85% maximal aerobic power [MP], HIIT85 , n = 8) or supramaximal (115% MP, HIIT115 , n = 9) interval training to exhaustion in moderately endurance-trained men. High-intensity training volume was 47% lower in HIIT115 vs HIIT85 (304 ± 77 vs 571 ± 200 min; P training was generally associated with increased VO2max (HIIT85 : +3.3 ± 3.1 mL/kg/min; HIIT115 : +3.3 ± 3.6 ml/kg/min; Time effect P = 0.002; Group effect: P = 0.95), Ppeak (HIIT85 : +18 ± 9 W; HIIT115 : +16 ± 27 W; Time effect P = 0.045; Group effect: P = 0.49), and mean anaerobic power (HIIT85 : +0.42 ± 0.69 W/kg; HIIT115 : +0.55 ± 0.65 W/kg; Time effect P = 0.01; Group effect: P = 0.18). Six weeks of submaximal and supramaximal interval training performed to exhaustion seems to equally improve VO2max and anaerobic power in endurance-trained men, despite half the accumulated time spent at the target intensity. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Hypotension and heart rate variability after resistance exercise performed maximal and submaximal order

    Directory of Open Access Journals (Sweden)

    Victor Gonçalves Corrêa Neto

    2017-06-01

    Full Text Available The aim of the study was verified the blood pressure responses and the cardiac autonomic modulation after the strength exercise in two different conditions (maximal and submaximal. The subjects were divided in three groups, such as: maximal repetitions (age: 20.5 ± 0.6 years, weight: 63.7 ± 14.8, height: 1.7 ± 0.1, body mass index: 22.8 ± 4.5 Kilogram per square meter (kg/m², submaximal repetitions (age: 25 ± 4.1 years, weight: 69.1 ± 12.8, height: 1.8 ± 0.1, body mass index: 22.2 ± 1.7 (kg/m²  and a control group (age: 23.7 ± 3.8 years, weight: 64.2 ± 15, height: 1.7 ± 0.1, body mass index: 21.8 ± 1.9 (kg/m². The blood pressure and the Heart Rate R-R intervals were measured before and during one hour after the session, with 10-minutes intervals length between measurements. The analyze of variance did not showed significant differences between experimental protocols to blood pressure (p > 0.05. However, the effect size was able to show that the most intense training caused a reduction in systolic blood pressure at times. Regarding cardiac autonomic response, the group that exercised the submaximal form exhibited a significant increase in LF / HF (p = 0.022 when 20 minutes’ post-exercise. There was a not significant difference in cardiac autonomic modulation between protocols. The high intensity protocol has caused blood pressure reductions in more moments and it was over safer in relation to cardiac autonomic modulation, since it did not cause increased sympathetic activity during recovery.

  15. Metformin potentiates the antigluconeogenic action of insulin.

    Science.gov (United States)

    Wollen, N; Bailey, C J

    1988-01-01

    The interaction of metformin and insulin in the control of hepatic gluconeogenesis was examined in isolated hepatocytes from 48h starved rats using lactate (10(-2) mol/l) with pyruvate (10(-3) mol/l) as substrate. During 1 h incubations in the absence of added insulin, 10(-2) and 10(-3) mol/l metformin reduced gluconeogenesis by 65% and 59% respectively, but lower concentrations of metformin were not effective. Insulin alone (10(-6)-10(-8) mol/l) reduced (37%-16%) gluconeogenesis. The effect of insulin was enhanced (further reductions of 11%-24%) by 5 x 10(-4) mol/l metformin, although this concentration of metformin was not effective in the absence of insulin. At lower insulin concentrations (10(-9) and 10(-10) mol/l) which did not significantly affect gluconeogenesis alone, 5 x 10(-4) mol/l metformin decreased gluconeogenesis (32% and 28% respectively). At 10(-10) mol/l insulin, metformin concentrations of 10(-3)-10(-7) mol/l decreased gluconeogenesis by 60-20%. The results suggest that therapeutic concentrations of metformin may act synergistically with physiological concentrations of insulin to suppress hepatic gluconeogenesis.

  16. Effects of wheel and hand-rim size on submaximal propulsion in wheelchair athletes.

    Science.gov (United States)

    Mason, Barry S; Van Der Woude, Lucas H V; Tolfrey, Keith; Lenton, John P; Goosey-Tolfrey, Victoria L

    2012-01-01

    This study aimed to investigate the effects of fixed gear ratio wheel sizes on the physiological and biomechanical responses to submaximal wheelchair propulsion. Highly trained wheelchair basketball players (N = 13) propelled an adjustable sports wheelchair in three different wheel sizes (24, 25, and 26 inches) on a motor-driven treadmill. Each wheel was equipped with force-sensing hand-rims (SMARTWheel), which collected kinetic and temporal data. Oxygen uptake (V˙O2) and HR responses were measured with high-speed video footage collected to determine three-dimensional upper body joint kinematics. Mean power output and work per cycle decreased progressively with increasing wheel size (P wheelchair propulsion.

  17. Comparison of the YMCA and a Custom Submaximal Exercise Test for Determining VO2max.

    Science.gov (United States)

    Jamnick, Nicholas A; By, Savanny; Pettitt, Cherie D; Pettitt, Robert W

    2016-02-01

    The maximal oxygen uptake (VO2max) is deemed the highest predictor for all-cause mortality, and therefore, an ability to assess VO2max is important. The YMCA submaximal test is one of the most widely used tests to estimate VO2max; however, it has questionable validity. We validated a customized submaximal test that accounts for the nonlinear rise in VO2 relative to power output and compared its accuracy against the YMCA protocol. Fifty-six men and women performed a graded exercise test with a subsequent exhaustive, square wave bout for the verification of "true" VO2max. In counterbalanced order, subjects then completed the YMCA test and our new Mankato submaximal exercise test (MSET). The MSET consisted of a 3-min stage estimated at 35% VO2max and a second 3-min stage estimated at either 65% or 70% VO2max, where VO2max was estimated with a regression equation using sex, body mass index, age, and self-reported PA-R. VO2 values from the graded exercise test and square wave verification bout did not differ with the highest value used to identify "true" VO2max (45.1 ± 8.89 mL · kg(-1) · min(-1)). The MSET (43.6 ± 8.6 mL · kg(-1) · min(-1)) did not differ from "true" VO2max, whereas the YMCA test (41.1 ± 9.6 mL · kg(-1) · min(-1)) yielded an underestimation (P = 0.002). The MSET was moderately correlated with "true" VO2max (ICC = 0.73, CV of 11.3%). The YMCA test was poorly correlated with "true" VO2max (ICC = 0.29, CV of 15.1%). To our knowledge, this is the first study to examine submaximal exercise protocols versus a verified VO2max protocol. The MSET yielded better estimates of VO2max because of the protocol including a stage exceeding gas exchange threshold.

  18. Low doses of caffeine reduce heart rate during submaximal cycle ergometry

    Directory of Open Access Journals (Sweden)

    Wetter Thomas J

    2007-10-01

    Full Text Available Abstract Background The purpose of this study was to examine the cardiovascular effects of two low-levels of caffeine ingestion in non habitual caffeine users at various submaximal and maximal exercise intensities. Methods Nine male subjects (19–25 yr; 83.3 ± 3.1 kg; 184 ± 2 cm, underwent three testing sessions administered in a randomized and double-blind fashion. During each session, subjects were provided 4 oz of water and a gelatin capsule containing a placebo, 1.5 mg/kg caffeine, or 3.0 mg/kg caffeine. After thirty minutes of rest, a warm-up (30 Watts for 2 min the pedal rate of 60 rpm was maintained at a steady-state output of 60 watts for five minutes; increased to 120 watts for five minutes and to 180 watts for five minutes. After a 2 min rest the workload was 180 watts for one minute and increased by 30 watts every minute until exhaustion. Heart rate (HR was measured during the last 15-seconds of each minute of submaximal exercise. Systolic blood pressure (BP was measured at rest and during each of the three sub-maximal steady state power outputs. Minute ventilation (VE, Tidal volume (VT, Breathing frequency (Bf, Rating of perceived exertion (RPE, Respiratory exchange ratio (RER, and Oxygen consumption (VO2 were measured at rest and during each minute of exercise. Results Caffeine at 1.5 and 3.0 mg/kg body weight significantly lowered (p E, VT, VO2, RPE, maximal power output or time to exhaustion. Conclusion In non habitual caffeine users it appears that consuming a caffeine pill (1.5 & 3.0 mg/kg at a dose comparable to 1–3 cups of coffee lowers heart rate during submaximal exercise but not at near maximal and maximal exercise. In addition, this caffeine dose also only appears to affect systolic blood pressure at rest but not during cycling exercise.

  19. Aerosolized liposomes with dipalmitoyl phosphatidylcholine enhance pulmonary absorption of encapsulated insulin compared with co-administered insulin.

    Science.gov (United States)

    Chono, Sumio; Togami, Kohei; Itagaki, Shirou

    2017-11-01

    We have previously shown that aerosolized liposomes with dipalmitoyl phosphatidylcholine (DPPC) enhance the pulmonary absorption of encapsulated insulin. In this study, we aimed to compare insulin encapsulated into the liposomes versus co-administration of empty liposomes and unencapsulated free insulin, where the DPCC liposomes would serve as absorption enhancer. The present study provides the useful information for development of noninvasive treatment of diabetes. Co-administration of empty DPPC liposomes and unencapsulated free insulin was investigated in vivo to assess the potential enhancement in protein pulmonary absorption. Co-administration was compared to DPPC liposomes encapsulating insulin, and free insulin. DPPC liposomes enhanced the pulmonary absorption of unencapsulated free insulin; however, the enhancing effect was lower than that of the DPPC liposomes encapsulating insulin. The mechanism of the pulmonary absorption of unencapsulated free insulin by DPPC liposomes involved the opening of epithelial cell space in alveolar mucosa, and not mucosal cell damage, similar to that of the DPPC liposomes encapsulating insulin. In an in vitro stability test, insulin in the alveolar mucus layer that covers epithelial cells was stable. These findings suggest that, although unencapsulated free insulin spreads throughout the alveolar mucus layer, the concentration of insulin released near the absorption surface is increased by the encapsulation of insulin into DPPC liposomes and the absorption efficiency is also increased. We revealed that the encapsulation of insulin into DPPC liposomes is more effective for pulmonary insulin absorption than co-administration of DPPC liposomes and unencapsulated free insulin.

  20. The Insuline Analogues

    OpenAIRE

    Garrido Carrasco, Elizabeth; Servicio de Endocrinología, Hospital Nacional Edgardo Rebagliati Martins, Lima, Perú

    2014-01-01

    Insulin analogues are a new pharmaceutical family, designed to overcome deficiencies that still exist with the rDNA insulin. There are rapid-acting insulin analogues such as lispro insulin and insulin aspart. They avoid postprandial and nocturnal hypoglycemia. There are also intermediate-acting insulin analogues like NPL and Mix 25 (a mixture between NPL and lispro), which join the neutral protamine insulin length of action and the fast onset of the rapid-acting analogue lispro. Finally, ther...

  1. Rapid changes in plasma androgens during insulin withdrawal in male type 1 (insulin-dependent) diabetics

    DEFF Research Database (Denmark)

    Madsbad, S; Gluud, C; Bennett, Patrick

    1986-01-01

    Plasma concentrations of testosterone, androstenedione and dihydrotestosterone were measured in 15 Type 1 (insulin-dependent) diabetics with (n = 8) and without (n = 7) B-cell function during 12 h of insulin withdrawal and compared with those of 8 normal subjects. Before insulin withdrawal...... the patients without B-cell function were more metabolically decompensated from after 4 h of insulin withdrawal compared with patients with B-cell function, no significant differences were found in androgen concentrations between the two groups although a tendency to lower concentrations were seen in the group...... without B-cell function....

  2. Relationship between blood serum insulin-like growth factor I concentration and postweaning feed efficiency of crossbred cattle at three levels of dietary intake.

    Science.gov (United States)

    Stick, D A; Davis, M E; Loerch, S C; Simmen, R C

    1998-02-01

    Blood serum concentration of IGF-I was analyzed to determine its relationship with individual postweaning feed efficiency (gain/feed) of 36 crossbred steer calves fed at three levels of feed intake (n = 12 at each level). Diets consisted of a corn silage-based growing diet for 84 d followed by a 91% concentrate finishing diet for 56 d. Dietary intake levels were at 80, 90, or 100% of ad libitum. Diets were formulated to ensure equal daily intake of protein, vitamins, and minerals across intake treatment levels. Intake was measured daily; ADG, DMI, and feed efficiency were calculated at 28-d intervals, through d 140. Individual weights and serum samples were collected at the beginning of the study and at 28-d intervals thereafter. The IGF-I concentrations were determined with a RIA. Data were analyzed as a multivariate split-plot in time. Imposed dietary intake restrictions did not affect serum IGF-I concentration (P = .90) or individual feed efficiency (P = .36), even though the least squares means for IGF-I concentration tended to decrease and the feed efficiency means tended to increase under the restricted intake levels. Serum IGF-I concentration, ADG, and feed efficiency were affected (P Residual correlations between IGF-I concentrations at adjacent 28-d sampling times averaged .72. Diet intake level x sampling time interactions existed for ADG (P = .02) and feed efficiency (P residual correlations of .28 (P feed efficiency, respectively. Regression analysis indicated that a 1 ng/mL increase in serum IGF-I concentration was associated with a .00135 kg/d increase in ADG (P feed increase in feed efficiency (P = .04). These results support the hypothesis that serum IGF-I plays a role in growth and in efficiency of feed utilization in beef cattle.

  3. Fasting insulin has a stronger association with an adverse cardiometabolic risk profile than insulin resistance: the RISC study

    DEFF Research Database (Denmark)

    de Rooij, Susanne R; Dekker, Jacqueline M; Kozakova, Michaela

    2009-01-01

    OBJECTIVE: Fasting insulin concentrations are often used as a surrogate measure of insulin resistance. We investigated the relative contributions of fasting insulin and insulin resistance to cardiometabolic risk and preclinical atherosclerosis. DESIGN AND METHODS: The Relationship between Insulin...... of the metabolic syndrome in 1177 participants. Carotid artery intima media thickness (IMT) was measured by ultrasound to assess preclinical atherosclerosis. RESULTS: Fasting insulin was correlated with all elements of the metabolic syndrome. Insulin sensitivity (M/I) was correlated with most elements. The odds...... ratio for the metabolic syndrome of those in the highest quartile of fasting insulin compared with those in the lower quartiles was 5.4 (95% confidence interval (CI) 2.8-10.3, adjusted for insulin sensitivity) in men and 5.1 (2.6-9.9) in women. The odds ratio for metabolic syndrome of those with insulin...

  4. Cognitive Performance Enhancement Induced by Caffeine, Carbohydrate and Guarana Mouth Rinsing during Submaximal Exercise

    Directory of Open Access Journals (Sweden)

    Laura Pomportes

    2017-06-01

    Full Text Available The aim of this study was to investigate the influence of serial mouth rinsing (MR with nutritional supplements on cognitive performance (i.e., cognitive control and time perception during a 40-min submaximal exercise. Twenty-four participants completed 4 counterbalanced experimental sessions, during which they performed MR with either placebo (PL, carbohydrate (CHO: 1.6 g/25 mL, guarana complex (GUAc: 0.4 g/25 mL or caffeine (CAF: 67 mg/25 mL before and twice during exercise. The present study provided some important new insights regarding the specific changes in cognitive performance induced by nutritional supplements. The main results were: (1 CHO, CAF and GUA MR likely led participants to improve temporal performance; (2 CAF MR likely improved cognitive control; and (3 CHO MR led to a likely decrease in subjective perception of effort at the end of the exercise compared to PL, GUA and CAF. Moreover, results have shown that performing 40-min submaximal exercise enhances information processing in terms of both speed and accuracy, improves temporal performance and does not alter cognitive control. The present study opens up new perspectives regarding the use of MR to optimize cognitive performance during physical exercise.

  5. Achilles tendinopathy alters stretch shortening cycle behaviour during a sub-maximal hopping task.

    Science.gov (United States)

    Debenham, James R; Travers, Mervyn J; Gibson, William; Campbell, Amity; Allison, Garry T

    2016-01-01

    To describe stretch shortening cycle behaviour of the ankle and lower limb in patients with Achilles tendinopathy (AT) and establish differences with healthy volunteers. Between-subjects case-controlled. Fifteen patients with AT (mean age 41.2±12.7 years) and 11 healthy volunteers (CON) (mean age 23.2±6.7 years) performed sub-maximal single-limb hopping on a custom built sledge-jump system. Using 3D motion analysis and surface EMG, temporal kinematic (lower limb stiffness, ankle angle at 80ms pre-contact, ankle angle at contact, peak ankle angle, ankle stretch amplitude) and EMG measures (onset, offset and peak times relative to contact) were captured. Data between AT and CON were compared statistically using a linear mixed model. Patients with AT exhibited significantly increased lower limb stiffness when compared to healthy volunteers (pbehaviour during sub-maximal hopping when compared with healthy volunteers. Patients with AT hop with greater lower limb stiffness, in a greater degree of ankle dorsiflexion and have a greater stretch amplitude. Likewise, delayed muscle activity is evident. These findings have implications in terms of informing the understanding of the pathoaetiology and management of AT. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  6. Reliability of heart rate variability threshold and parasympathetic reactivation after a submaximal exercise test

    Directory of Open Access Journals (Sweden)

    Carlos Janssen Gomes da Cruz

    Full Text Available Abstract The objective of this study was to evaluate reproducibility of heart rate variability threshold (HRVT and parasympathetic reactivation in physically active men (n= 16, 24.3 ± 5.1 years. During the test, HRVT was assessed by SD1 and r-MSSD dynamics. Immediately after exercise, r-MSSD was analyzed in segments of 60 seconds for a period of five minutes. High absolute and relatively reproducible analysis of HRVT were observed, as assessed by SD1 and r-MSSD dynamics (ICC = 0.92, CV = 10.8, SEM = 5.8. During the recovery phase, a moderate to high reproducibility was observed for r-MSSD from the first to the fifth minute (ICC = 0.69-0.95, CV = 7.5-14.2, SEM = 0.07-1.35. We conclude that HRVT and r-MSSD analysis after a submaximal stress test are highly reproducible measures that might be used to assess the acute and chronic effects of exercise training on cardiac autonomic modulation during and/or after a submaximal stress test.

  7. VO2@RER1.0: a novel submaximal cardiopulmonary exercise index.

    Science.gov (United States)

    Chin, Clifford; Kazmucha, Jeffrey; Kim, Nancy; Suryani, Reny; Olson, Inger

    2010-01-01

    Maximal oxygen consumption (VO2max) is the "gold standard" by which to assess functional capacity; however, it is effort dependent. VO2@RER1.0 is defined when VO2 = VCO2. Between December 22, 1997 and November 9, 2004, 305 pediatric subjects underwent cycle ergometer cardiopulmonary exercise testing, exercised to exhaustion, and reached a peak respiratory exchange ratio > or = 1.10. Group 1 subjects achieved a peak VO2 > or = 80% of predicted VO2max; group 2 subjects achieved a peak VO2 subjects achieved a peak VO2 between 61 and 79% of predicted VO2max. Linear regression analysis was performed for VO2@RER1.0 as a function of predicted VO2 for group 1 subjects. A -2 SD regression line and equation was created. VO2@RER1.0 data from groups 2 and 3 were plotted onto the normative graph. Contingency table and relative-risk analysis showed that an abnormal VO2@RER1.0 predicted an abnormal peak VO2(positive-predictive value 83%, negative-predictive value 85%, sensitivity 84%, and specificity 84%). VO2@RER1.0 is a highly sensitive, specific, and predictive submaximal index of functional capacity. This submaximal index is easy to identify without subjectivity. This index may aid in the evaluation of subjects who cannot exercise to maximal parameters.

  8. [Sub-maximal aerobic capacity and quality of life of patients with rheumatoid arthritis].

    Science.gov (United States)

    Lataoui, S; Belghali, S; Zeglaoui, H; Bouajina, E; Ben Saad, H

    2017-01-01

    Studies about sub-maximal aerobic capacity of patients with rheumatoid arthritis are scarce. To assess the sub-maximal aerobic capacity of these patients through the 6-min walk test, estimated age of the "muscular and cardiorespiratory" chain. Thirty-seven consecutive patients (aged 20 to 60 years) with newly diagnosed rheumatoid arthritis will be included. Non-inclusion criteria will be: use of drugs (e.g.; methotrexate, beta-blockers), orthopaedic or rheumatologic conditions (other than rheumatoid arthritis) that may alter walking ability and recent infections. Exclusion criteria will be: 6-min walking test contra-indications and imperfect performance of the required lung function and walking maneuvers. Signs of walking intolerance will be: test interruption, distance ≤lower limit of normal, dyspnea score ≥5/10 (visual analogue scale) at the end of the test, haemoglobin oxygen saturation (SpO2) drop ≥5%, cardiac frequency at the end of the test ≤60% of maximum predicted. An estimated "muscular and cardiorespiratory chain" age higher than the chronological one will be considered as a sign of accelerated ageing. A high percentage of patients suffering from rheumatoid arthritis would show evidences of walking limitation and accelerated "muscular and cardiorespiratory chain" ageing. There would be a significant correlation between the walking test and clinical, biological, radiological and pulmonary function data and the patients' quality-of-life status. Copyright © 2016 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  9. [Insulin secretion: mechanisms of regulation].

    Science.gov (United States)

    Radosavljević, Tatjana; Todorović, Vera; Sikić, Branka

    2004-01-01

    REGULATION OF INSULIN SECRETION: Beta cells are unique endocrine cells. They respond positively, in terms of insulin secretion, not only to changes in the extracellular glucose concentration, but also to activators of the phospholipase C (cholecystokinin or acetylcholine), and to activators of adenylate cyclase (glucagon, glucagon-like peptide-1, or gastric inhibitory polypeptide). Major messengers which mediate glucose action for insulin release are Ca2+, adenosine triphosphate (ATP) and diacylglycerol (DAG). MAJOR PATHWAYS OF INSULIN RELEASE STIMULATION: There are four major pathways involved in stimulation of insulin release. The first pathway is KATP channel-dependent pathway in which increased blood glucose concentrations and increased b-cell metabolism result in a change in intracellular ATP/ADP ratio. This is a contributory factor in closure of ATP-dependent K+ channels, depolarization of b-cell membrane, in increased voltage-dependent L-type Ca2+ channel activity. Increased Ca2+ influx results in increased intracellular Ca2+ and stimulated insulin release. KATP channel-independent pathway augments Ca(2+) -stimulated insulin secretion of KATP channel-dependent pathway. Major potentiation of release results from hormonal and peptidergic activation of receptors linked to adenylyl cyclase. Adenylyl cyclase activity is stimulated by hormones such as vasoactive intestinal peptide (VIP), glucagon-like peptide-1 (GLP-1), and so on. These hormones, acting via G protein, stimulate adenylyl cyclase, thus causing a rise in cyclic adenosine monophosphate (cAMP) and activation of protein kinase A (PKA). Increased activity of PKA results in potentiation of insulin secretion.

  10. Nanowired Delivery of Growth Hormone Attenuates Pathophysiology of Spinal Cord Injury and Enhances Insulin-Like Growth Factor-1 Concentration in the Plasma and the Spinal Cord.

    Science.gov (United States)

    Muresanu, Dafin F; Sharma, Aruna; Lafuente, José V; Patnaik, Ranjana; Tian, Z Ryan; Nyberg, Fred; Sharma, Hari S

    2015-10-01

    Previous studies from our laboratory showed that topical application of growth hormone (GH) induced neuroprotection 5 h after spinal cord injury (SCI) in a rat model. Since nanodelivery of drugs exerts superior neuroprotective effects, a possibility exists that nanodelivery of GH will induce long-term neuroprotection after a focal SCI. SCI induces GH deficiency that is coupled with insulin-like growth factor-1 (IGF-1) reduction in the plasma. Thus, an exogenous supplement of GH in SCI may enhance the IGF-1 levels in the cord and induce neuroprotection. In the present investigation, we delivered TiO2-nanowired growth hormone (NWGH) after a longitudinal incision of the right dorsal horn at the T10-11 segments in anesthetized rats and compared the results with normal GH therapy on IGF-1 and GH contents in the plasma and in the cord in relation to blood-spinal cord barrier (BSCB) disruption, edema formation, and neuronal injuries. Our results showed a progressive decline in IGF-1 and GH contents in the plasma and the T9 and T12 segments of the cord 12 and 24 h after SCI. Marked increase in the BSCB breakdown, as revealed by extravasation of Evans blue and radioiodine, was seen at these time points after SCI in association with edema and neuronal injuries. Administration of NWGH markedly enhanced the IGF-1 levels and GH contents in plasma and cord after SCI, whereas normal GH was unable to enhance IGF-1 or GH levels 12 or 24 h after SCI. Interestingly, NWGH was also able to reduce BSCB disruption, edema formation, and neuronal injuries after trauma. On the other hand, normal GH was ineffective on these parameters at all time points examined. Taken together, our results are the first to demonstrate that NWGH is quite effective in enhancing IGF-1 and GH levels in the cord and plasma that may be crucial in reducing pathophysiology of SCI.

  11. Impact of a Submaximal Warm-Up on Endurance Performance in Highly Trained and Competitive Male Runners

    Science.gov (United States)

    Zourdos, Michael C.; Bazyler, Caleb D.; Jo, Edward; Khamoui, Andy V.; Park, Bong-Sup; Lee, Sang-Rok; Panton, Lynn B.; Kim, Jeong-Su

    2017-01-01

    Purpose: The purpose of this investigation was to examine the effects of a submaximal running warm-up on running performance in male endurance athletes (n = 16, M[subscript age] = 21 ± 2 years, M[subscript VO2max] = 69.3 ± 5.1 mL/kg/min). Method: Endurance performance was determined by a 30-min distance trial after control and submaximal running…

  12. Low-dose baclofen therapy raised plasma insulin-like growth factor-1 concentrations, but not into the normal range in a predictable and sustained manner in men with chronic spinal cord injury.

    Science.gov (United States)

    Bauman, William A; La Fountaine, Michael F; Cirnigliaro, Christopher M; Kirshblum, Steven C; Spungen, Ann M

    2013-09-01

    To evaluate, whether once-daily oral baclofen administration increases and/or sustains plasma insulin-like growth factor-1 (IGF-1) concentration in 11 men with chronic spinal cord injury (SCI) and IGF-1 deficiency (i.e. Plasma IGF-1 and self-reported side effects were measured at baseline and every other week for the duration of the study. The subjects were 43 ± 12 years old, had duration of injury of 20 ± 12 years; eight subjects had a complete motor injury, and eight had paraplegia. Nine of 11 subjects completed the 20 mg/day treatment and 5 subjects completed the 40 mg/day treatment. Plasma IGF-1 levels improved with each baclofen dose; however, only one subject increased from baseline and remained above the targeted physiological range of 250 ng/ml throughout treatment. A significant increase in IGF-1concentration was observed between baseline and week 2 (154 ± 63 vs. 217 ± 69 ng/ml; P plasma IGF-1 concentrations in the physiological range in men with chronic SCI.

  13. Insulin Resistance

    DEFF Research Database (Denmark)

    Jensen, Benjamin Anderschou Holbech

    Insulin resistance (IR) is escalating with alarming pace and is no longer restricted to westernized countries. As a forerunner for some of the most serious threats to human health including metabolic syndrome, cardiovascular diseases, and type 2-diabetes, the need for new treatment modalities...... with IR independent of weight gain. In conclusion, the data presented in the current thesis, supported by a thorough review of available literature, advocate that 1) Inflammation is a triggering event fueling IR; 2) Commensal microbes can, when mistreated, aggravate IR and glucose intolerance; and 3) Diet...

  14. Identification of the signals for glucose-induced insulin secretion in INS1 (832/13) β-cells using metformin-induced metabolic deceleration as a model.

    Science.gov (United States)

    Lamontagne, Julien; Al-Mass, Anfal; Nolan, Christopher J; Corkey, Barbara E; Madiraju, S R Murthy; Joly, Erik; Prentki, Marc

    2017-11-24

    Metabolic deceleration in pancreatic β-cells is associated with inhibition of glucose-induced insulin secretion (GIIS), but only in the presence of intermediate/submaximal glucose concentrations. Here, we used acute metformin treatment as a tool to induce metabolic deceleration in INS1 (832/13) β-cells, with the goal of identifying key pathways and metabolites involved in GIIS. Metabolites and pathways previously implicated as signals for GIIS were measured in the cells at 2-25 mm glucose, with or without 5 mm metformin. We defined three criteria to identify candidate signals: 1) glucose-responsiveness, 2) sensitivity to metformin-induced inhibition of the glucose effect at intermediate glucose concentrations, and 3) alleviation of metformin inhibition by elevated glucose concentrations. Despite the lack of recovery from metformin-induced impairment of mitochondrial energy metabolism (glucose oxidation, O 2 consumption, and ATP production), insulin secretion was almost completely restored at elevated glucose concentrations. Meeting the criteria for candidates involved in promoting GIIS were the following metabolic indicators and metabolites: cytosolic NAD + /NADH ratio (inferred from the dihydroxyacetone phosphate:glycerol-3-phosphate ratio), mitochondrial membrane potential, ADP, Ca 2+ , 1-monoacylglycerol, diacylglycerol, malonyl-CoA, and HMG-CoA. On the contrary, most of the purine and nicotinamide nucleotides, acetoacetyl-CoA, H 2 O 2 , reduced glutathione, and 2-monoacylglycerol were not glucose-responsive. Overall these results underscore the significance of mitochondrial energy metabolism-independent signals in GIIS regulation; in particular, the candidate lipid signaling molecules 1-monoacylglycerol, diacylglycerol, and malonyl-CoA; the predominance of K ATP /Ca 2+ signaling control by low ADP·Mg 2+ rather than by high ATP levels; and a role for a more oxidized state (NAD + /NADH) in the cytosol during GIIS that favors high glycolysis rates. © 2017 by

  15. Controlled release of insulin from folic acid-insulin complex nanoparticles.

    Science.gov (United States)

    Gupta, Rajat; Mohanty, Sanat

    2017-06-01

    Associative interactions between folic acid and proteins are well known. This work leverages these interactions to engineer folic acid nanoparticles for controlled release of insulin during diabetes therapy. The insulin-loaded folic acid nanoformulation is synthesized during this study to achieve better insulin loading and encapsulation than previous strategies. The maximum insulin loading in the FA particles was kept at 6mg with less than 10% insulin loss during the synthesis process which is significantly better compare to previous strategies. The folic acid nanoparticles of 50-150nm size are further characterized in the present study. The release behaviour of insulin from the nanoparticles has been studied to quantify released insulin and folic acid with time using high performance liquid chromatography. Insulin release results suggest that more than 90% of the insulin is encapsulated and released within 24h from folic acid nanoparticles. The analysis of folic acid release along with insulin release indicates that the particles are formed by folic acid-insulin complexation at the molecular level. The release of insulin from nanoparticles is controllable with the change in the crosslinking salt concentration as well as the amount of folic acid loaded during particle synthesis. These results prove that folic acid nanocarriers are capable to control the release of therapeutic proteins. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Pretreatment insulin-like growth factor-I concentrations predict radiographic osteoarthritis in acromegalic patients with long-term cured disease

    NARCIS (Netherlands)

    Biermasz, N. R.; Wassenaar, M. J. E.; van der Klaauw, A. A.; Pereira, A. M.; Smit, J. W. A.; Roelfsema, F.; Wolterbeek, R.; Kroon, H. M.; Kloppenburg, M.; Romijn, J. A.

    2009-01-01

    The aim of the study was to identify factors influencing the development of osteoarthritis during long-term control of acromegaly, focusing on disease-specific parameters, GH and IGF-I concentrations, and duration of disease, adjusted for the well-known determinants of primary osteoarthritis. We

  17. Clinical utility of insulin and insulin analogs

    Science.gov (United States)

    Sanlioglu, Ahter D.; Altunbas, Hasan Ali; Balci, Mustafa Kemal; Griffith, Thomas S.; Sanlioglu, Salih

    2013-01-01

    Diabetes is a pandemic disease characterized by autoimmune, genetic and metabolic abnormalities. While insulin deficiency manifested as hyperglycemia is a common sequel of both Type-1 and Type-2 diabetes (T1DM and T2DM), it does not result from a single genetic defect—rather insulin deficiency results from the functional loss of pancreatic β cells due to multifactorial mechanisms. Since pancreatic β cells of patients with T1DM are destroyed by autoimmune reaction, these patients require daily insulin injections. Insulin resistance followed by β cell dysfunction and β cell loss is the characteristics of T2DM. Therefore, most patients with T2DM will require insulin treatment due to eventual loss of insulin secretion. Despite the evidence of early insulin treatment lowering macrovascular (coronary artery disease, peripheral arterial disease and stroke) and microvascular (diabetic nephropathy, neuropathy and retinopathy) complications of T2DM, controversy exists among physicians on how to initiate and intensify insulin therapy. The slow acting nature of regular human insulin makes its use ineffective in counteracting postprandial hyperglycemia. Instead, recombinant insulin analogs have been generated with a variable degree of specificity and action. Due to the metabolic variability among individuals, optimum blood glucose management is a formidable task to accomplish despite the presence of novel insulin analogs. In this article, we present a recent update on insulin analog structure and function with an overview of the evidence on the various insulin regimens clinically used to treat diabetes. PMID:23584214

  18. Inflammation and Insulin Resistance

    OpenAIRE

    de Luca, Carl; Olefsky, Jerrold M.

    2007-01-01

    Obesity-induced chronic inflammation is a key component in the pathogenesis of insulin resistance and the Metabolic syndrome. In this review, we focus on the interconnection between obesity, inflammation and insulin resistance. Pro-inflammatory cytokines can cause insulin resistance in adipose tissue, skeletal muscle and liver by inhibiting insulin signal transduction. The sources of cytokines in insulin resistant states are the insulin target tissue themselves, primarily fat and liver, but t...

  19. Insulin requirement in non-insulin-dependent diabetes mellitus: relation to simple tests of islet B-cell function and insulin sensitivity

    DEFF Research Database (Denmark)

    Gjessing, H J; Matzen, L E; Pedersen, P C

    1988-01-01

    Evaluation of simple tests of islet B-cell function and insulin sensitivity as predictors of metabolic control was performed during 3 months of insulin withdrawal in 25 insulin-treated diabetic subjects. All patients had a glucagon stimulated plasma C-peptide concentration above 0.33 nmol....../l and a fasting plasma C-peptide concentration above 0.20 nmol/l a few days before insulin withdrawal. Insulin sensitivity was measured as the glucose disappearance rate (k) during an intravenous insulin tolerance test. Two patients were considered insulin-requiring due to high fasting blood glucose levels......-peptide levels the predictive value of a positive test was 100% while the predictive value of a negative test was as low as 33% or 27% depending on whether fasting or stimulated C-peptide concentration was used. Including the k value in the prediction only increased the predictive values of negative tests to 40...

  20. Insulin alters the permeability of sheep pleura.

    Science.gov (United States)

    Kouritas, V K; Hatzoglou, C; Ioannou, M; Gourgoulianis, K I; Molyvdas, P A

    2010-05-01

    Insulin promotes ion transportation across epithelia, mainly kidneys, leading to water and electrolyte abnormalities, possibly causing 'insulin oedema syndrome', which rarely presents as pleural effusion. Direct stimulation of sheep pleura by insulin and the possible electrophysiology mechanisms involved were investigated. Sheep visceral and parietal pleural specimens were mounted between Ussing chambers. Insulin solutions (10 (-9) to 10 (-5) M), L-NAME, Nitroprussid sodium, amiloride and ouabain were used. Trans-mesothelial Resistance was determined. Immunohistochemistry for presence of Insulin Receptors was performed. Insulin increased Trans-mesothelial Resistance within 1st minute when added mesothelially of visceral (p=0.008) and parietal pleura (p=0.046) for concentrations higher than 10 (-7) M. L-NAME or Nitroprussid sodium didn't but amiloride and ouabain inhibited insulin's effect. Immunohistochemistry revealed the presence of Insulin Receptors. Insulin changes the permeability of sheep pleura by altering its electrophysiology and may interfere in pleural effusion formation. Involvement of Insulin Receptors may be suggested.

  1. Modest hyperglycemia prevents interstitial dispersion of insulin in skeletal muscle.

    Science.gov (United States)

    Kolka, Cathryn M; Castro, Ana Valeria B; Kirkman, Erlinda L; Bergman, Richard N

    2015-02-01

    Insulin injected directly into skeletal muscle diffuses rapidly through the interstitial space to cause glucose uptake, but this is blocked in insulin resistance. As glucotoxicity is associated with endothelial dysfunction, the observed hyperglycemia in diet-induced obese dogs may inhibit insulin access to muscle cells, and exacerbate insulin resistance. Here we asked whether interstitial insulin diffusion is reduced in modest hyperglycemia, similar to that induced by a high fat diet. During normoglycemic (100 mg/dl) and moderately hyperglycemic (120 mg/dl) clamps in anesthetized canines, sequential doses of insulin were injected into the vastus medialis of one hindlimb; the contra-lateral limb served as a control. Plasma samples were collected and analyzed for insulin content. Lymph vessels of the hind leg were also catheterized, and lymph samples were analyzed as an indicator of interstitial insulin concentration. Insulin injection increased lymph insulin in normoglycemic animals, but not in hyperglycemic animals. Muscle glucose uptake was elevated in response to hyperglycemia, however the insulin-mediated glucose uptake in normoglycemic controls was not observed in hyperglycemia. Modest hyperglycemia prevented intra-muscularly injected insulin from diffusing through the interstitial space reduced insulin-mediated glucose uptake. Hyperglycemia prevents the appearance of injected insulin in the interstitial space, thus reducing insulin action on skeletal muscle cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Insulin pulsatility after the intravenous glucose bolus

    Directory of Open Access Journals (Sweden)

    Nedeljković-Beleslin Biljana

    2016-01-01

    Full Text Available OBJECTIVE: The aim of the study was to assess whether sudden change in blood glucose concentration in healthy subject would produce insulin secretory pattern similar to one in type 2 diabetic subjects (T2D. DESIGN: The concept of the study was to 'reset' the pancreas and empty the stored insulin pool, so that subtle derangements of the pulsatile insulin secretion could be studied. METHODS: The study group included 6 control and 7 T2D subjects. For insulin and glucose determination, blood was sampled for 60 minutes with 2 minutes inter-sample interval. To increase blood glucose an intravenous glucose bolus was given (0.3 g/kg body weight. RESULTS: The average glucose level in the T2D group was significantly higher, but the average insulin concentration was not different between the groups. Insulin half-life, pulse amplitude, number of pulses and interpulse interval did not differ between the groups. CONCLUSIONS: Therefore, the sudden increase in blood glucose causes insulin secretory pattern to become similar in the healthy and in the T2D subjects. However, the defect in the insulin secretion or glucose sensing inherent to β-cell exists, as the insufficient quantity of insulin is secreted in response to the increased glucose level.

  3. Blunted Maximal and Submaximal Responses to Cardiopulmonary Exercise Tests in Patients With Parkinson Disease.

    Science.gov (United States)

    Kanegusuku, Hélcio; Silva-Batista, Carla; Peçanha, Tiago; Nieuwboer, Alice; Silva, Natan D; Costa, Luiz A; de Mello, Marco T; Piemonte, Maria E; Ugrinowitsch, Carlos; Forjaz, Cláudia L

    2016-05-01

    To investigate submaximal and maximal responses during maximal cardiopulmonary exercise tests in subjects with Parkinson disease (PD). Cross-sectional. A PD association. A sample (N=68) of subjects with PD (n=48; mean age, 66±8y; modified Hoehn and Yahr stage between 2 and 3; "on" state of medication) and age-matched controls without PD (n=20; mean age, 64±9y). Maximal cardiopulmonary exercise test on a cycle ergometer. Oxygen uptake (V˙o2), systolic blood pressure (SBP), and heart rate assessed at rest, submaximal intensities (ie, anaerobic threshold [AT] and respiratory compensation point), and maximal intensity (peak exercise). Compared with control subjects, subjects with PD had lower V˙o2, heart rate, and SBP at respiratory compensation point and peak exercise (V˙o2: 14.6±3.6mL⋅kg⋅min vs 17.9±5.5mL⋅kg⋅min and 17.7±4.8mL⋅kg⋅min vs 21.5±6.6mL⋅kg⋅min; heart rate: 119±17beats/min vs 139±12beats/min and 132±20beats/min vs 158±13beats/min; SBP: 151±17mmHg vs 172±20mmHg and 166±21mmHg vs 187±24mmHg; P≤.05). They also had lower heart rate at AT (102±14beats/min vs 110±13beats/min; P≤.05), whereas V˙o2 and SBP at this intensity were similar to those of control subjects. Subjects with PD demonstrated blunted metabolic and cardiovascular responses to submaximal and maximal exercise tests, especially at intensities above AT, which are in line with autonomic disturbances present in patients with PD. Future studies need to determine how this affects performance, participation, and responses of these patients to exercise training at different intensities. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  4. Aerobic interval training reduces vascular resistances during submaximal exercise in obese metabolic syndrome individuals.

    Science.gov (United States)

    Mora-Rodriguez, Ricardo; Fernandez-Elias, V E; Morales-Palomo, F; Pallares, J G; Ramirez-Jimenez, M; Ortega, J F

    2017-08-12

    The aim of this study was to determine the effects of high-intensity aerobic interval training (AIT) on exercise hemodynamics in metabolic syndrome (MetS) volunteers. Thirty-eight, MetS participants were randomly assigned to a training (TRAIN) or to a non-training control (CONT) group. TRAIN consisted of stationary interval cycling alternating bouts at 70-90% of maximal heart rate during 45 min day(-1) for 6 months. CONT maintained baseline physical activity and no changes in cardiovascular function or MetS factors were detected. In contrast, TRAIN increased cardiorespiratory fitness (14% in VO2PEAK; 95% CI 9-18%) and improved metabolic syndrome (-42% in Z score; 95% CI 83-1%). After TRAIN, the workload that elicited a VO2 of 1500 ml min(-1) increased 15% (95% CI 5-25%; P < 0.001). After TRAIN when subjects pedaled at an identical submaximal rate of oxygen consumption, cardiac output increased by 8% (95% CI 4-11%; P < 0.01) and stroke volume by 10% (95% CI, 6-14%; P < 0.005) being above the CONT group values at that time point. TRAIN reduced submaximal exercise heart rate (109 ± 15-106 ± 13 beats min(-1); P < 0.05), diastolic blood pressure (83 ± 8-75 ± 8 mmHg; P < 0.001) and systemic vascular resistances (P < 0.01) below CONT values. Double product was reduced only after TRAIN (18.2 ± 3.2-17.4 ± 2.4 bt min(-1) mmHg 10(-3); P < 0.05). The data suggest that intense aerobic interval training improves hemodynamics during submaximal exercise in MetS patients. Specifically, it reduces diastolic blood pressure, systemic vascular resistances, and the double product. The reduction in double product, suggests decreased myocardial oxygen demands which could prevent the occurrence of adverse cardiovascular events during exercise in this population. CLINICALTRIALS. NCT03019796.

  5. Prognostic value of treadmill stress echocardiography at extremes of exercise performance: submaximal high exercise capacity ≥ 10 metabolic equivalents.

    Science.gov (United States)

    Yao, Siu-Sun; Agarwal, Vikram; Chaudhry, Farooq A

    2014-03-01

    Submaximal stress testing or achieving High exercise capacity (≥ 10 metabolic equivalents, METS) is a predictor of favorable prognosis. The purpose of this study was to evaluate the prognostic value of submaximal or high exercise capacity stress echocardiography. We evaluated 1781 patients (55 ± 13 years; 59% male) undergoing treadmill stress echocardiography divided into 811 patients with submaximal (high exercise capacity (≥ 10 METS). Resting left ventricular ejection fraction and regional wall motion were assessed. The left ventricle was divided into 16 segments and scored on 5-point scale of wall motion. Abnormal stress echocardiography was defined as stress-induced ischemia (wall-motion score of ≥ 1 grade). Follow-up (3.3 ± 1.5 years) for nonfatal myocardial infarction (MI) (n = 40) and cardiac death (n = 52) were obtained. By univariate analysis, echocardiographic variables of ejection fraction, peak wall-motion score index (WMSI) and number of new ischemic wall-motion abnormalities were significant predictors of cardiac events. Cumulative survival was significantly worse in patients with abnormal (ischemic) versus normal (nonischemic) stress echocardiography in submaximal (4.4%/year vs. 1.3%/year, P high exercise capacity (1.5%/year vs. 0.2%/year, P high exercise capacity studies. © 2013, Wiley Periodicals, Inc.

  6. Leptin responses to bovine interferon- α and insulin in cattle

    African Journals Online (AJOL)

    To confirm the leptin response to insulin, mature adipocytes were isolated from abdominal adipose tissue of 3 cows and incubated for 24 h with insulin in vitro. Insulin stimulated leptin expression in dose dependent manner with peak expression at 100 nM concentration. These results, strongly postulate that leptin secretion ...

  7. Pretreatment insulin-like growth factor-I concentrations predict radiographic osteoarthritis in acromegalic patients with long-term cured disease.

    Science.gov (United States)

    Biermasz, N R; Wassenaar, M J E; van der Klaauw, A A; Pereira, A M; Smit, J W A; Roelfsema, F; Wolterbeek, R; Kroon, H M; Kloppenburg, M; Romijn, J A

    2009-07-01

    The aim of the study was to identify factors influencing the development of osteoarthritis during long-term control of acromegaly, focusing on disease-specific parameters, GH and IGF-I concentrations, and duration of disease, adjusted for the well-known determinants of primary osteoarthritis. We conducted a follow-up study. We studied 67 patients with adequate biochemical control of acromegaly for a mean of almost 13 yr. Study parameters were the results of radiological assessment of the spine, hip, knee, and hand. Osteoarthritis was defined as radiological osteoarthritis using the scoring system developed by Kellgren and Lawrence. Correlations between potential factors of influence and osteoarthritis were performed by analysis of covariance and adjusted for age, gender, and body mass index. Patients with pretreatment IGF-I sd scores in the highest tertile had an almost 4-fold increased risk for radiological osteoarthritis of the hip when compared with patients in the lowest tertile. After adjustment for age, gender, BMI, and disease duration, pretreatment IGF-I sd scores predicted radiographic osteoarthritis in all joint sites. Osteoarthritis was not predicted by other factors, including pretreatment GH levels, type of treatment, and duration of follow-up. This is the first study to document pretreatment IGF-I concentration as a predictor of radiographic osteoarthritis in acromegalic patients with long-term disease control.

  8. Cycling on rollers: Kreitler fan resistance at submaximal levels of effort.

    Science.gov (United States)

    Reiser, R F; Hart, C R

    2008-03-01

    The goal of this investigation was to characterize the commercially available fan unit for the KreitlerAlloy rollers at submaximal levels of effort (cyclist rode six times at each of three fan inlet settings (closed, half, and full open) and five fan speeds (900, 1800, 2700, 3600, and 4500 rpm). Fan power requirements were isolated by subtracting roller resistance from separate trials. Power requirements relative to fan inlet and fan speed possessed a significant interaction with the main effects for each also significant (all p or = 0.997). Fan resistance was virtually non existent at 900 rpm. Fan resistance then significantly increased with increasing fan speed and inlet opening. At 4500 rpm power requirements of the fan reached 269 +/- 6, 352 +/- 7, and 406 +/- 9 W with the inlet closed, half, and fully open, respectively (p training and testing environments.

  9. Brief note about plasma catecholamines kinetics and submaximal exercise in untrained standardbreds

    Directory of Open Access Journals (Sweden)

    Paolo Baragli

    2010-03-01

    Full Text Available Four untrained standardbred horses performed a standardized exercise test on the treadmill and an automated blood collection system programmed to obtain blood samples every 15 s was used for blood collection in order to evaluate the kinetics of adrenaline and noradrenaline. The highest average values obtained for adrenaline and noradrenaline were 15.0 ± 3.0 and 15.8 ± 2.8 nmol/l respectively, with exponential accumulation of adrenaline (r = 0.977 and noradrenaline (r = 0.976 during the test. Analysis of the correlation between noradrenaline and adrenaline for each phase of the test shows that correlation coefficient decreases as the intensity of exercise increases (from r = 0.909 to r = 0.788. This suggests that during submaximal exercise, the process for release, distribution and clearance of adrenaline into blood circulation differs from that of noradrenaline.

  10. The validity of submaximal ratings of perceived exertion to predict one repetition maximum.

    Science.gov (United States)

    Eston, Roger; Evans, Harrison James Llewelyn

    2009-01-01

    The One Repetition Maximum (1-RM) test is commonly used to assess strength. However, direct assessments of 1-RM are time consuming and unsafe for novice lifters. Whilst various equations exist to predict 1-RM, there is limited research on the validity of these equations. The purpose of this study was to assess the validity of using sub-maximal ratings of perceived exertion (RPE) to predict 1-RM in young adults, using the Borg 6-20 RPE Scale. Twenty healthy participants (ten male (Mean ± SD, 20.8 ± 0.6 y, 75.7 ± 9.3 kg, 1.8 ± 0.07 m) and ten female (20.3 ± 0.7 y, 68.4 ± 10.0 kg, 1.68 ± 0.03 m)) completed two trials involving resistance exercises for both the upper and lower body. In the first trial the 1-RM for the bilateral biceps curl (BC) and the bilateral knee extension (KE) were determined for each participant. In the second trial, participants performed blinded repetitions which were equivalent to 20, 40 and 60 % of 1-RM for both exercises. The RPE was recorded immediately after two repetitions had been completed at each intensity. The order of intensity of the repetitions was randomly assigned with participants wearing blindfolds to exclude the possibility of pre-determined judgments about load and RPE. Individual RPE recorded at each intensity was subjected to linear regression analysis and the line of best fit was extrapolated to RPE 20 to predict 1-RM in both exercises. There was no significant difference (p > 0.05) between the 1-RM predicted from RPE 20 and measured 1-RM for both exercises for the men and women. Measured and predicted values for men were 46.0 ± 4.6 and 45.2 ± 6. 1 kg for biceps curl, and 46.3 ± 3.8 and 43.0 ± 7.1 kg for knee extension, respectively. Measured and predicted values for women were 18.6 ± 5.7 and 19.3 ± 5.6 kg for biceps curl, and 25.5 ± 9.6 and 27.2 ± 12.6 kg for knee extension, respectively. Pearson product-moment correlation coefficients between actual and predicted 1-RM for the BC and KE were 0.97 and 0

  11. Dietary insulin index and insulin load in relation to biomarkers of glycemic control, plasma lipids, and inflammation markers123

    OpenAIRE

    Nimptsch, Katharina; Jennie C. Brand-Miller; Franz, Mary; Sampson, Laura; Willett, Walter C.; Giovannucci, Edward

    2011-01-01

    Background: Dietary glycemic index and load are widely used to estimate the effect of carbohydrate-containing foods on postprandial blood glucose concentrations and as surrogates for insulin response. The food insulin index (II) directly quantifies the postprandial insulin secretion of a food and takes into account foods with a low or no carbohydrate content.

  12. Angiotensin II Inhibits Insulin Binding to Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Su-Jin Oh

    2011-06-01

    Full Text Available BackgroundInsulin-mediated glucose uptake in insulin target tissues is correlated with interstitial insulin concentration, rather than plasma insulin concentration. Therefore, insulin delivery to the interstitium of target tissues is very important, and the endothelium may also play an important role in the development of insulin resistance.MethodsAfter treating bovine aortic endothelial cells with angiotensin II (ATII, we observed the changes in insulin binding capacity and the amounts of insulin receptor (IR on the cell membranes and in the cytosol.ResultsAfter treatment of 10-7M ATII, insulin binding was decreased progressively, up to 60% at 60 minutes (P<0.05. ATII receptor blocker (eprosartan dose dependently improved the insulin binding capacity which was reduced by ATII (P<0.05. At 200 µM, eprosartan fully restored insulin binding capacity, althogh it resulted in only a 20% to 30% restoration at the therapeutic concentration. ATII did not affect the total amount of IR, but it did reduce the amount of IR on the plasma membrane and increased that in the cytosol.ConclusionATII decreased the insulin binding capacity of the tested cells. ATII did not affect the total amount of IR but did decrease the amount of IR on the plasma membrane. Our data indicate that ATII decreases insulin binding by translocating IR from the plasma membrane to the cytosol. The binding of insulin to IR is important for insulin-induced vasodilation and transendothelial insulin transport. Therefore, ATII may cause insulin resistance through this endothelium-based mechanism.

  13. Fasting insulin, insulin resistance and risk of hypertension in the general population: A meta-analysis.

    Science.gov (United States)

    Wang, Feng; Han, Lili; Hu, Dayi

    2017-01-01

    Studies on the association of fasting insulin concentrations or insulin resistance with subsequent risk of hypertension have yielded conflicting results. To quantitatively assess the association of fasting insulin concentrations or homeostasis model assessment insulin resistance (HOMA-IR) with incident hypertension in a general population by performing a meta-analysis. We searched the PubMed and Embase databases until August 31, 2016 for prospective observational studies investigating the elevated fasting insulin concentrations or HOMA-IR with subsequent risk of hypertension in the general population. Pooled risk ratio (RR) and 95% confidence interval (CI) of hypertension was calculated for the highest versus the lowest category of fasting insulin or HOMA-IR. Eleven studies involving 10,230 hypertension cases were identified from 55,059 participants. Meta-analysis showed that the pooled adjusted RR of hypertension was 1.54 (95% CI 1.34-1.76) for fasting insulin concentrations and 1.43 (95% CI 1.27-1.62) for HOMA-IR comparing the highest to the lowest category. Subgroup analysis results showed that the association of fasting insulin concentrations with subsequent risk of hypertension seemed more pronounced in women (RR 2.07; 95% CI 1.19-3.60) than in men (RR 1.48; 95% CI 1.17-1.88). This meta-analysis suggests that elevated fasting insulin concentrations or insulin resistance as estimated by homeostasis model assessment is independently associated with an exacerbated risk of hypertension in the general population. Early intervention of hyperinsulinemia or insulin resistance may help clinicians to identify the high risk of hypertensive population. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. A new submaximal cycle ergometer test for prediction of VO2max.

    Science.gov (United States)

    Ekblom-Bak, E; Björkman, F; Hellenius, M-L; Ekblom, B

    2014-04-01

    Maximal oxygen uptake (VO2max) is an important, independent predictor of cardiovascular health and mortality. Despite this, it is rarely measured in clinical practice. The aim of this study was to create and evaluate a submaximal cycle ergometry test based on change in heart rate (HR) between a lower standard work rate and an individually chosen higher work rate. In a mixed population (n = 143) with regard to sex (55% women), age (21-65 years), and activity status (inactive to highly active), a model included change in HR per unit change in power, sex, and age for the best estimate of VO2max. The association between estimated and observed VO2max for the mixed sample was r = 0.91, standard error of estimate = 0.302 L/min, and mean measured VO2max = 3.23 L/min. The corresponding coefficient of variation was 9.3%, a significantly improved precision compared with one of the most commonly used submaximal exercise tests, the Åstrand test, which in the present study was estimated to be 18.1%. Test-retest reliability analysis over 1 week revealed no mean difference in the estimated VO2max (-0.02 L/min, 95% confidence interval: -0.07-0.03). The new test is low-risk, easily administered, and valid for a wide capacity range, and is therefore suitable in situations as health evaluations in the general population. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Haemodynamic changes induced by submaximal exercise before a dive and its consequences on bubble formation

    Science.gov (United States)

    Blatteau, Jean‐Eric; Boussuges, Alain; Gempp, Emmanuel; Pontier, Jean‐Michel; Castagna, Olivier; Robinet, Claude; Galland, Francois‐Michel; Bourdon, Lionel

    2007-01-01

    Objectives To evaluate the effects of a submaximal exercise performed 2 h before a simulated dive on bubble formation and to observe the haemodynamic changes and their influence on bubble formation. Participants and methods 16 trained divers were compressed in a hyperbaric chamber to 400 kPa for 30 min and decompressed at a rate of 100 kPa/min with a 9 min stop at 130 kPa (French Navy MN90 procedure). Each diver performed two dives 3 days apart, one without exercise and one with exercise before the dive. All participants performed a 40 min constant‐load submaximal and calibrated exercise, which consisted of outdoor running 2 h before the dive. Circulating bubbles were detected with a precordial Doppler at 30, 60 and 90 min after surfacing. Haemodynamic changes were evaluated with Doppler echocardiography. Results A single bout of strenuous exercise 2 h before a simulated dive significantly reduced circulating bubbles. Post‐exercise hypotension (PEH) was observed after exercise with reductions in diastolic and mean blood pressure (DBP and MBP), but total peripheral resistance was unchanged. Stroke volume was reduced, whereas cardiac output was unchanged. Simulated diving caused a similar reduction in cardiac output independent of pre‐dive exercise, suggesting that pre‐dive exercise only changed DBP and MBP caused by reduced stroke volume. Conclusion A single bout of strenuous exercise 2 h before a dive significantly reduced the number of bubbles in the right heart of divers and protected them from decompression sickness. Declining stroke volume and moderate dehydration induced by a pre‐dive exercise might influence inert gas load and bubble formation. PMID:17138641

  16. Muscle vibration sustains motor unit firing rate during submaximal isometric fatigue in humans.

    Science.gov (United States)

    Griffin, L; Garland, S J; Ivanova, T; Gossen, E R

    2001-09-15

    1. In keeping with the 'muscular wisdom hypothesis', many studies have documented that the firing rate of the majority of motor units decreased during fatiguing isometric contractions. The present study investigated whether the application of periodic muscle vibration, which strongly activates muscle spindles, would alter the modulation of motor unit firing rate during submaximal fatiguing isometric contractions. 2. Thirty-three motor units from the lateral head of the triceps brachii muscle were recorded from 10 subjects during a sustained isometric 20 % maximal voluntary contraction (MVC) of the elbow extensors. Vibration was interposed on the contraction for 2 s every 10 s. Twenty-two motor units were recorded from the beginning of the fatigue task. The discharge rate of the majority of motor units remained constant (12/22) or increased (4/22) with fatigue. Six motor units demonstrated a reduction in discharge rate that later returned toward initial values; these motor units had higher initial discharge rates than the other 16 motor units. 3. In a second series of experiments, four subjects held a sustained isometric 20 % MVC for 2 min and then vibration was applied as above for the remainder of the contraction. In this case, motor units initially demonstrated a decrease in firing rate that increased after the vibration was applied. Thus muscle spindle disfacilitation of the motoneurone pool may be associated with the decline of motor unit discharge rate observed during the first 2 min of the contraction. 4. In a third set of experiments, seven subjects performed the main experiment on one occasion and repeated the fatigue task without vibration on a second occasion. Neither the endurance time of the fatiguing contraction nor the MVC torque following fatigue was affected by the application of vibration. This finding calls into question the applicability of the muscular wisdom hypothesis to submaximal contractions.

  17. On the alterations in serum concentration of somatotropin and insuline-like growth factor 1 in lactating cows after the treatment with a little studied recombinant bovine somatotropin.

    Science.gov (United States)

    Castigliego, L; Grifoni, G; Rosati, R; Iannone, G; Armani, A; Gianfaldoni, D; Guidi, A

    2009-08-01

    A study was performed to delineate bST and IGF-1 variation, over a whole lactation, in cows treated with a nowadays widely commercialised but little studied sustained release formulation of recombinant bST. Total bST levels were found to be exceptionally high in the first days after administration, but decreased rapidly in the second week after injection. The increase in the IGF-1 serum concentration was significant for almost the entire biweekly cycle. Based on this study, the peaks of ST (often above 100 ng/ml) are considered particularly unlikely to be found in non-treated bovines, even under pathological conditions, especially when detected in a number of animals within a herd. Notwithstanding the great heterogeneity of results on this topic, these data suggest that tests against fraud involving the use of rbST in dairy products may be regarded as a feasible possibility.

  18. [Adverse reactions to insulin].

    Science.gov (United States)

    Liñana, J J; Montoro, F J; Hernández, M D; Basomba, A

    1997-07-01

    The prevalence of allergic reactions to insuline has decreased during the last few years. Probably this is due to the use of the newly-developed recombinant human insuline. At present, adverse reactions to insuline occur in 5-10% of patients on therapy with insuline. Adverse reactions may be local (more frequent) or systemic (rare). Insuline resistance consists in a different type of immunological reaction. Diagnosis of allergy to insuline is based on clinical history and cutaneous and serological tests. Treatment depends upon the severity of the reaction. When insuline is indispensable despite a previous allergic reaction, a desensitization protocol may be implemented.

  19. Insulin causes insulin-receptor internalization in human erythrocyte ghosts.

    OpenAIRE

    Kelleher, R S; Murray, E F; Peterson, S W

    1987-01-01

    The effect of incubation with insulin on insulin-receptor internalization by erythrocyte ghosts was investigated. The number of surface insulin receptors decreased by 30-40% after incubation of ghosts with insulin. Total insulin-receptor binding to solubilized ghosts was the same in insulin-incubated and control ghosts, whereas insulin binding to an internal vesicular fraction was substantially increased in insulin-incubated ghosts. Our findings suggest that erythrocyte-ghost insulin receptor...

  20. Insulin and the Brain

    Directory of Open Access Journals (Sweden)

    Grosu Cristina

    2017-12-01

    Full Text Available The brain represents an important site for the action of insulin. Besides the traditionally known importance in glucoregulation, insulin has significant neurotrophic properties and influences the brain activity: insulin influences eating behavior, regulates the storage of energy and several aspects concerning memory and knowledge. Insulin resistance and hyperinsulinism could be associated with brain aging, vascular and metabolic pathologies. Elucidating the pathways and metabolism of brain insulin could have a major impact on future targeted therapies.

  1. A suicide by insulin injection: Case report

    Directory of Open Access Journals (Sweden)

    Nikolić Slobodan

    2006-01-01

    Full Text Available Suicide by injection of insulin overdose is uncommon. Insulin has been used as an agent for suicide both in diabetics and healthy subjects. The methods of postmortem forensic diagnosis of insulin overdose were reviewed. Police investigation could be crucial to document the amount and type of insulin used. In addition, the complete forensic autopsy, microscopic analysis of tissue samples, consecutive chemical-toxicological investigation and appropriate laboratory tests are required to make proper diagnosis in these cases. To assess pre-mortem hypoglycemic state at the time of dying, it is necessary to establish postmortal concentrations of glucose, lactate and potassium in vitreous humor. Since the use of insulin for medical treatment, only two cases with diagnosis of suicidal insulin overdose were confirmed at the Institute of Forensic Medicine in Belgrade. In this paper, the authors present one such case. An 84-year-old male was found dead in his flat. He had diabetes mellitus during the last fifty years, and he used insulin twenty years. A few empty insulin ampullae's and plastic syringes were found nearby deceased, on the room-table during the crime scene investigation, as well as his suicidal note. The forensic autopsy, microscopic, chemical-toxicological and biochemical analyses of tissue and body-liquid samples as well as police investigation indicated suicide due to insulin-overdose.

  2. Insulin Signaling in Type 2 Diabetes

    Science.gov (United States)

    Brännmark, Cecilia; Nyman, Elin; Fagerholm, Siri; Bergenholm, Linnéa; Ekstrand, Eva-Maria; Cedersund, Gunnar; Strålfors, Peter

    2013-01-01

    Type 2 diabetes originates in an expanding adipose tissue that for unknown reasons becomes insulin resistant. Insulin resistance reflects impairments in insulin signaling, but mechanisms involved are unclear because current research is fragmented. We report a systems level mechanistic understanding of insulin resistance, using systems wide and internally consistent data from human adipocytes. Based on quantitative steady-state and dynamic time course data on signaling intermediaries, normally and in diabetes, we developed a dynamic mathematical model of insulin signaling. The model structure and parameters are identical in the normal and diabetic states of the model, except for three parameters that change in diabetes: (i) reduced concentration of insulin receptor, (ii) reduced concentration of insulin-regulated glucose transporter GLUT4, and (iii) changed feedback from mammalian target of rapamycin in complex with raptor (mTORC1). Modeling reveals that at the core of insulin resistance in human adipocytes is attenuation of a positive feedback from mTORC1 to the insulin receptor substrate-1, which explains reduced sensitivity and signal strength throughout the signaling network. Model simulations with inhibition of mTORC1 are comparable with experimental data on inhibition of mTORC1 using rapamycin in human adipocytes. We demonstrate the potential of the model for identification of drug targets, e.g. increasing the feedback restores insulin signaling, both at the cellular level and, using a multilevel model, at the whole body level. Our findings suggest that insulin resistance in an expanded adipose tissue results from cell growth restriction to prevent cell necrosis. PMID:23400783

  3. Clinical Pharmacokinetics and Pharmacodynamics of Insulin Glargine 300 U/mL.

    Science.gov (United States)

    Clements, Jennifer N; Threatt, Tiffaney; Ward, Eileen; Shealy, Kayce M

    2017-05-01

    Concentrated insulin analogs have recently been approved and are available for clinical use in the management of diabetes mellitus. One new product is insulin glargine U-300 (Sanofi), a basal concentrated insulin of 300 U/mL. Several studies have been conducted and completed evaluating blood samples for the pharmacokinetics of insulin glargine U-300 and euglycemic clamp procedures for the pharmacodynamics. This concentrated insulin has a low within-day variability and high day-to-day reproducibility, allowing for a more constant and prolonged duration of action, compared with insulin glargine U-100 (100 U/mL). Insulin glargine U-300 is equally effective, when compared with insulin glargine U-100 for glycemic control in patients with type 1 and 2 diabetes mellitus. Insulin glargine U-300 has a similar efficacy profile to insulin glargine U-100 for glycemic control, yet with lower rates of nocturnal and severe hypoglycemia. Insulin glargine U-300 can be considered an acceptable basal insulin for patients with type 1 and 2 diabetes mellitus, and it has a potential role among patients who are naïve to insulin therapy or require titration of basal insulin. Titration of insulin glargine U-300 would result in less volume and a lower risk of hypoglycemia, compared with insulin glargine U-100. This article evaluates and summarizes the pharmacokinetics and pharmacodynamics of insulin glargine U-300, for patients with type 1 or 2 diabetes mellitus, and summarizes its application to clinical practice.

  4. Alteration in insulin action

    DEFF Research Database (Denmark)

    Tanti, J F; Gual, P; Grémeaux, T

    2004-01-01

    Insulin resistance, when combined with impaired insulin secretion, contributes to the development of type 2 diabetes. Insulin resistance is characterised by a decrease in insulin effect on glucose transport in muscle and adipose tIssue. Tyrosine phosphorylation of insulin receptor substrate 1 (IRS......-1) and its binding to phosphatidylinositol 3-kinase (PI 3-kinase) are critical events in the insulin signalling cascade leading to insulin-stimulated glucose transport. Modification of IRS-1 by serine phosphorylation could be one of the mechanisms leading to a decrease in IRS-1 tyrosine...... to phosphorylate these serine residues have been identified. These exciting results suggest that serine phosphorylation of IRS-1 is a possible hallmark of insulin resistance in biologically insulin responsive cells or tIssues. Identifying the pathways by which "diabetogenic" factors activate IRS-1 kinases...

  5. Insulin-Responsive Glucagon Delivery for Prevention of Hypoglycemia.

    Science.gov (United States)

    Yu, Jicheng; Zhang, Yuqi; Sun, Wujin; Kahkoska, Anna R; Wang, Jinqiang; Buse, John B; Gu, Zhen

    2017-05-01

    Hypoglycemia, the state of abnormally low blood glucose level, is an acute complication of insulin and sulfonylurea therapy in diabetes management. Frequent insulin dosing and boluses during daily diabetes care leads to an increased risk of dangerously low glucose levels, which can cause behavioral and cognitive disturbance, seizure, coma, and even death. This study reports an insulin-responsive glucagon delivery method based on a microneedle (MN)-array patch for the prevention of hypoglycemia. The controlled release of glucagon is achieved in response to elevated insulin concentration by taking advantage of the specific interaction between insulin aptamer and target insulin. Integrating a painless MN-array patch, it is demonstrated that this insulin-triggered glucagon delivery device is able to prevent hypoglycemia following a high-dose insulin injection in a chemically induced type 1 diabetic mouse model. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. THE VALIDITY OF SUBMAXIMAL RATINGS OF PERCEIVED EXERTION TO PREDICT ONE REPETITION MAXIMUM

    Directory of Open Access Journals (Sweden)

    Harrison James Llewelyn Evans

    2009-12-01

    Full Text Available The One Repetition Maximum (1-RM test is commonly used to assess strength. However, direct assessments of 1-RM are time consuming and unsafe for novice lifters. Whilst various equations exist to predict 1-RM, there is limited research on the validity of these equations. The purpose of this study was to assess the validity of using sub-maximal ratings of perceived exertion (RPE to predict 1-RM in young adults, using the Borg 6-20 RPE Scale. Twenty healthy participants (ten male (Mean ± SD, 20.8 ± 0.6 y, 75.7 ± 9.3 kg, 1.8 ± 0.07 m and ten female (20.3 ± 0.7 y, 68.4 ± 10.0 kg, 1.68 ± 0.03 m completed two trials involving resistance exercises for both the upper and lower body. In the first trial the 1-RM for the bilateral biceps curl (BC and the bilateral knee extension (KE were determined for each participant. In the second trial, participants performed blinded repetitions which were equivalent to 20, 40 and 60 % of 1-RM for both exercises. The RPE was recorded immediately after two repetitions had been completed at each intensity. The order of intensity of the repetitions was randomly assigned with participants wearing blindfolds to exclude the possibility of pre-determined judgments about load and RPE. Individual RPE recorded at each intensity was subjected to linear regression analysis and the line of best fit was extrapolated to RPE 20 to predict 1-RM in both exercises. There was no significant difference (p > 0.05 between the 1-RM predicted from RPE 20 and measured 1-RM for both exercises for the men and women. Measured and predicted values for men were 46.0 ± 4.6 and 45.2 ± 6. 1 kg for biceps curl, and 46.3 ± 3.8 and 43.0 ± 7.1 kg for knee extension, respectively. Measured and predicted values for women were 18.6 ± 5.7 and 19.3 ± 5.6 kg for biceps curl, and 25.5 ± 9.6 and 27.2 ± 12.6 kg for knee extension, respectively. Pearson product-moment correlation coefficients between actual and predicted 1-RM for the BC and KE were 0

  7. A New Submaximal Rowing Test to Predict 2,000-m Rowing Ergometer Performance.

    Science.gov (United States)

    Otter, Ruby T A; Brink, Michel S; Lamberts, Robert P; Lemmink, Koen A P M

    2015-09-01

    The purpose of this study was to assess predictive value of a new submaximal rowing test (SmRT) on 2,000-m ergometer rowing time-trial performance in competitive rowers. In addition, the reliability of the SmRT was investigated. Twenty-four competitive male rowers participated in this study. After determining individual HRmax, all rowers performed an SmRT followed by a 2,000-m rowing ergometer time trial. In addition, the SmRT was performed 4 times (2 days in between) to determine the reliability. The SmRT consists of two 6-minute stages of rowing at 70 and 80% HRmax, followed by a 3-minute stage at 90% HRmax. Power was captured during the 3 stages, and 60 seconds of heart rate recovery (HRR60s) was measured directly after the third stage. Results showed that predictive value of power during the SmRT on 2,000-m rowing time also increased with stages. CVTEE% is 2.4, 1.9, and 1.3%. Pearson correlations (95% confidence interval [95% CI]) were -0.73 (-0.88 to -0.45), -0.80 (-0.94 to -0.67), and -0.93 (-0.97 to -0.84). 2,000-m rowing time and HRR60s showed no relationship. Reliability of power during the SmRT improved with the increasing intensity of the stages. The coefficient of variation (CVTEM%) was 9.2, 5.6, and 0.4%. Intraclass correlation coefficients (ICC) and 95% CI were 0.91 (0.78-0.97), 0.92 (0.81-0.97), and 0.99 (0.97-1.00). The CVTEM% and ICC of HRR60s were 8.1% and 0.93 (0.82-0.98). In conclusion, the data of this study shows that the SmRT is a reliable test that it is able to accurately predict 2,000-m rowing time on an ergometer. The SmRT is a practical and valuable submaximal test for rowers, which can potentially assist with monitoring, fine-tuning and optimizing training prescription in rowers.

  8. Thermal dissociation and unfolding of insulin

    DEFF Research Database (Denmark)

    Huus, Kasper; Havelund, Svend; Olsen, Helle B

    2005-01-01

    The thermal stability of human insulin was studied by differential scanning microcalorimetry and near-UV circular dichroism as a function of zinc/protein ratio, to elucidate the dissociation and unfolding processes of insulin in different association states. Zinc-free insulin, which is primarily...... dimeric at room temperature, unfolded at approximately 70 degrees C. The two monomeric insulin mutants Asp(B28) and Asp(B9),Glu(B27) unfolded at higher temperatures, but with enthalpies of unfolding that were approximately 30% smaller. Small amounts of zinc caused a biphasic thermal denaturation pattern...... of insulin. The biphasic denaturation is caused by a redistribution of zinc ions during the heating process and results in two distinct transitions with T(m)'s of approximately 70 and approximately 87 degrees C corresponding to monomer/dimer and hexamer, respectively. At high zinc concentrations (>or=5 Zn(2...

  9. Metabolism and insulin signaling in common metabolic disorders and inherited insulin resistance.

    Science.gov (United States)

    Højlund, Kurt

    2014-07-01

    Type 2 diabetes, obesity and polycystic ovary syndrome (PCOS) are common metabolic disorders which are observed with increasing prevalences, and which are caused by a complex interplay between genetic and environmental factors, including increased calorie intake and physical inactivity. These metabolic disorders are all characterized by reduced plasma adiponectin and insulin resistance in peripheral tissues. Quantitatively skeletal muscle is the major site of insulin resistance. Both low plasma adiponectin and insulin resistance contribute to an increased risk of type 2 diabetes and cardiovascular disease. In several studies, we have investigated insulin action on glucose and lipid metabolism, and at the molecular level, insulin signaling to glucose transport and glycogen synthesis in skeletal muscle from healthy individuals and in obesity, PCOS and type 2 diabetes. Moreover, we have described a novel syndrome characterized by postprandial hyperinsulinemic hypoglycemia and insulin resistance. This syndrome is caused by a mutation in the tyrosine kinase domain of the insulin receptor gene (INSR). We have studied individuals with this mutation as a model of inherited insulin resistance. Type 2 diabetes, obesity and PCOS are characterized by pronounced defects in the insulin-stimulated glucose uptake, in particular glycogen synthesis and to a lesser extent glucose oxidation, and the ability of insulin to suppress lipid oxidation. In inherited insulin resistance, however, only insulin action on glucose uptake and glycogen synthesis is impaired. This suggests that the defects in glucose and lipid oxidation in the common metabolic disorders are secondary to other factors. In young women with PCOS, the degree of insulin resistance was similar to that seen in middle-aged patients with type 2 diabetes. This supports the hypothesis of an unique pathogenesis of insulin resistance in PCOS. Insulin in physiological concentrations stimulates glucose uptake in human skeletal

  10. Several submaximal exercise tests are reliable, valid and acceptable in people with chronic pain, fibromyalgia or chronic fatigue: a systematic review

    Directory of Open Access Journals (Sweden)

    Julia Ratter

    2014-09-01

    [Ratter J, Radlinger L, Lucas C (2014 Several submaximal exercise tests are reliable, valid and acceptable in people with chronic pain, fibromyalgia or chronic fatigue: a systematic review. Journal of Physiotherapy 60: 144–150

  11. Evaluation of Exercise Response in a Young, High Risk Population: Submaximal Invasive Cardiopulmonary Exercise Testing (ICPET) in Active Duty Soldiers

    Science.gov (United States)

    2017-03-17

    Submaximal Invasive Cardiopulmonary Exercise Testing iCPET in AD Soldiers presented at/published to American College of Cardiology’s 661h Annual...disclaimer statement for research involving animals . as required by AFMAN 40-401 IP : " The experiments reported herein were conducted according to the...principles set forth in the National Institute of Health Publication No. 80-23, Guide for the Care and Use of Laboratory Animals and the Animal

  12. Application of "living high-training low" enhances cardiac function and skeletal muscle oxygenation during submaximal exercises in athletes.

    Science.gov (United States)

    Park, Hun-Young; Nam, Sang-Seok

    2017-03-31

    The aim of this study was to determine the efficiency of the application of living high-training low (LHTL) on cardiac function and skeletal muscle oxygenation during submaximal exercises compared with that of living low-training low (LLTL) in athletes. Male middle- and long-distance runners (n = 20) were randomly assigned into the LLTL group (n = 10, living at 1000-m altitude and training at 700-1330-m altitude) and the LHTL group (n = 10, living at simulated 3000-m altitude and training at 700-1330-m altitude). Their cardiac function and skeletal muscle oxygenation during submaximal exercises at sea level before and after training at each environmental condition were evaluated. There was a significant interaction only in the stroke volume (SV); however, the heart rate (HR), end-diastolic volume (EDV), and end-systolic volume (ESV) showed significant main effects within time; HR and SV significantly increased during training in the LHTL group compared with those in the LLTL group. EDV also significantly increased during training in both groups; however, the LHTL group had a higher increase than the LLTL group. ESV significantly increased during training in the LLTL group. There was no significant difference in the ejection fraction and cardiac output. The skeletal muscle oxygen profiles had no significant differences but improved in the LHTL group compared with those in the LLTL group. LHTL can yield favorable effects on cardiac function by improving the HR, SV, EDV, and ESV during submaximal exercises compared with LLTL in athletes.

  13. Reduced peripheral arterial blood flow with preserved cardiac output during submaximal bicycle exercise in elderly heart failure

    Directory of Open Access Journals (Sweden)

    Leng Xiaoyan

    2009-11-01

    Full Text Available Abstract Background Older heart failure (HF patients exhibit exercise intolerance during activities of daily living. We hypothesized that reduced lower extremity blood flow (LBF due to reduced forward cardiac output would contribute to submaximal exercise intolerance in older HF patients. Methods and Results Twelve HF patients both with preserved and reduced left ventricular ejection fraction (LVEF (aged 68 ± 10 years without large (aorta or medium sized (iliac or femoral artery vessel atherosclerosis, and 13 age and gender matched healthy volunteers underwent a sophisticated battery of assessments including a peak exercise oxygen consumption (peak VO2, b physical function, c cardiovascular magnetic resonance (CMR submaximal exercise measures of aortic and femoral arterial blood flow, and d determination of thigh muscle area. Peak VO2 was reduced in HF subjects (14 ± 3 ml/kg/min compared to healthy elderly subjects (20 ± 6 ml/kg/min (p = 0.01. Four-meter walk speed was 1.35 ± 0.24 m/sec in healthy elderly verses 0.98 ± 0.15 m/sec in HF subjects (p p ≤ 0.03. Conclusion During CMR submaximal bike exercise in the elderly with heart failure, mechanisms other than low cardiac output are responsible for reduced lower extremity blood flow.

  14. Linear growth in relation to the circulating concentration of insulin-like growth factor-I in young children with acyanotic congenital heart disease with left to right shunts before versus after surgical intervention.

    Science.gov (United States)

    Soliman, Ashraf T; Elawwa, Ahmed; Khella, Aiman; Saeed, Saad; Yassin, Haytham

    2012-09-01

    The aim was to determine the degree of linear growth retardation of patients with congenital acyanotic heart disease at presentation and the magnitude of catch-up growth, if any, in relation to their echocardiographic changes and insulin-like growth factor- I (IGF-I) concentration before versus after surgical intervention. This prospective study recorded the anthropometric data and measured the circulating IGF-I, free thyroxin (FT4), and thyrotropin (TSH) of 27 infants and children with congenital acyanotic heart disease with left to right shunt (10 with VSD, 8 with ASD, 9 PDA) without heart failure, or severe pulmonary hypertension, before and 12 months or more after surgical or catheter intervention. Eighty normal age and sex- matched normal siblings of these patients were included as controls for the auxologic data. At presentation, patients' mean age = 35.6 ± 26 months, height SDS (HtSDS) = -1.6 ± 1.1, and body mass index (BMI) = 15.1 ± 2.5. They were significantly shorter and with lower BMI compared to normal controls (HtSDS = 0.25 ± 0.3, BMI = 16.4 ± 1.5). One year or more after catheter or surgical treatment, the HtSDS and BMI increased significantly in patients to -0.55 ± 0.9 and 15.9 ± 1.5, respectively). IGF-I levels increased from 46.8 ± 29 mcg/L before to 77.3 ± 47.6 mcg/L after intervention. No significant change has been detected in circulating FT4 or TSH concentrations. The HtSDS after treatment was correlated with the IGF-I concentration (r = 0.804, P congenital acyanotic heart diseases, early surgical interference and weight gain have beneficial effect on postoperative growth spurt. This catch-up growth appears to be mediated through activation of the GH/IGF-I system and suggests an important role of increasing BMI (an indicator of nutrition) as an imperative factor.

  15. Evaluation of insulin secretion and action in New World camelids.

    Science.gov (United States)

    Firshman, Anna M; Cebra, Christopher K; Schanbacher, Barbara J; Seaquist, Elizabeth R

    2013-01-01

    To measure and compare insulin secretion and sensitivity in healthy alpacas and llamas via glucose clamping techniques. 8 llamas and 8 alpacas. Hyperinsulinemic euglycemic clamping (HEC) and hyperglycemic clamping (HGC) were performed on each camelid in a crossover design with a minimum 48-hour washout period between clamping procedures. The HEC technique was performed to measure insulin sensitivity. Insulin was infused IV at 6 mU/min/kg for 4 hours, and an IV infusion of glucose was adjusted to maintain blood glucose concentration at 150 mg/dL. Concentrations of blood glucose and plasma insulin were determined throughout. The HGC technique was performed to assess insulin secretion in response to exogenous glucose infusion. An IV infusion of glucose was administered to maintain blood glucose concentration at 320 mg/dL for 3 hours, and concentrations of blood glucose and plasma insulin were determined throughout. Alpacas and llamas were not significantly different with respect to whole-body insulin sensitivity during HEC or in pancreatic β-cell response during HGC. Alpacas and llamas had markedly lower insulin sensitivity during HEC and markedly lower pancreatic β-cell response during HGC, in comparison with many other species. New World camelids had lower glucose-induced insulin secretion and marked insulin resistance in comparison with other species. This likely contributes to the disorders of fat and glucose metabolism that are common to camelids.

  16. "Tailored" submaximal step test for VO2max prediction in healthy older adults.

    Science.gov (United States)

    Pogliaghi, Silvia; Bellotti, Cecilia; Paterson, Donald H

    2014-04-01

    The authors developed and validated a "tailored" version of the Astrand-Rhyming step test (tA-R) and a new equation for VO2max prediction in older adults (OA). Sixty subjects (age 68 ± 4 yr, 30 male, 30 female) performed their tA-R step test (5-min, 30-cm step, tailored stepping rate) and an incremental cycling test to exhaustion. VO2max was (a) predicted using the standard A-R equation (predicted VO2max), (b) predicted based on the authors' new multiple linear equation (equation VO2max), and (c) directly measured by incremental cycling test (direct VO2max). Agreement among values of VO2max was evaluated by Bland-Altman analysis. The predicted VO2max was not significantly different from the direct VO2max, yet with relatively large imprecision. The equation VO2max allowed more precise as well as accurate predictions of VO2max compared with standard A-R prediction. The "tailored" version of the Astrand-Rhyming step test and the new prediction equation appear suitable for a rapid (5-min), safe (submaximal), accurate, and precise VO2max prediction in healthy OA.

  17. Predictability of maximum voluntary isometric knee extension force from submaximal contractions in older adults.

    Science.gov (United States)

    Stackhouse, Scott K; Stevens, Jennifer E; Johnson, Christopher D; Snyder-Mackler, Lynn; Binder-Macleod, Stuart A

    2003-01-01

    The purposes of this study were to develop and test a model describing the relationship between the central activation ratio (CAR; a measure of voluntary muscle activation) and percent maximum voluntary contraction (%MVC) force for old adults and to provide a method for more accurate determination of voluntary muscle activation failure. Twenty-one adults (ages 64-81) performed isometric testing of the quadriceps at 25%, 50%, 75%, and 100% MVC. During each contraction, a 100-HZ, 120-ms train of electrical pulses was delivered to the quadriceps muscle to quantify voluntary muscle activation. Similar to a young, healthy population (ages 20-35), a curvilinear relationship existed between the CAR and %MVC force for older adults. Predictions of subjects' MVCs using the linear model of CAR-%MVC force relationship generally demonstrated poor agreement with actual MVCs. Predictions of MVC from submaximal contractions (25%, 50%, and 75%) using a previously identified curvilinear young adult CAR-%MVC relationship were good [ICC (2,1): 0.81, 0.96, and 0.82, respectively]. Similar agreement was obtained from the curvilinear older adult CAR-%MVC relationship. These data suggest that the CAR-%MVC relationship is similar in young and older adult subjects and that curvilinear models of this relationship can predict MVC forces in older adults more accurately. Reexamination of the relationship between the CAR and %MVC force may allow a more accurate determination of how failure of voluntary muscle activation contributes to weakness in old adults.

  18. Live high:train low increases muscle buffer capacity and submaximal cycling efficiency.

    Science.gov (United States)

    Gore, C J; Hahn, A G; Aughey, R J; Martin, D T; Ashenden, M J; Clark, S A; Garnham, A P; Roberts, A D; Slater, G J; McKenna, M J

    2001-11-01

    This study investigated whether hypoxic exposure increased muscle buffer capacity (beta(m)) and mechanical efficiency during exercise in male athletes. A control (CON, n=7) and a live high:train low group (LHTL, n=6) trained at near sea level (600 m), with the LHTL group sleeping for 23 nights in simulated moderate altitude (3000 m). Whole body oxygen consumption (VO2) was measured under normoxia before, during and after 23 nights of sleeping in hypoxia, during cycle ergometry comprising 4 x 4-min submaximal stages, 2-min at 5.6 +/- 0.4 W kg(-1), and 2-min 'all-out' to determine total work and VO(2peak). A vastus lateralis muscle biopsy was taken at rest and after a standardized 2-min 5.6 +/- 0.4 W kg(-1) bout, before and after LHTL, and analysed for beta(m) and metabolites. After LHTL, beta(m) was increased (18%, P buffer capacity. Further, reduced VO2 during normoxic exercise after LHTL suggests that improved exercise efficiency is a fundamental adaptation to LHTL.

  19. Relationship between the Pedaling Biomechanics and Strain of Bicycle Frame during Submaximal Tests

    Directory of Open Access Journals (Sweden)

    Aneliya V. Manolova

    2015-06-01

    Full Text Available The aim of this study was to analyse the effect of forces applied to pedals and cranks on the strain imposed to an instrumented bicycle motocross (BMX frame. Using results from a finite element analysis to determine the localisation of highest stress, eight strain gauges were located on the down tube, the seat tube and the right chain stay. Before the pedaling tests, static loads were applied to the frame during bench tests. Two pedaling conditions have been analysed. In the first, the rider was in static standing position on the pedals and applied maximal muscular isometric force to the right pedal. The second pedaling condition corresponds to three pedaling sprint tests at submaximal intensities at 150, 300 and 550 W on a cycle-trainer. The results showed that smaller strain was observed in the pedaling condition than in the rider static standing position condition. The highest strains were located in the seat tube and the right chain stay near the bottom bracket area. The maximum stress observed through all conditions was 41 MPa on the right chain stay. This stress was 11 times lower than the yield stress of the frame material (460 MPa. This protocol could help to adapt the frame design to the riders as a function of their force and mechanical power output. These results could also help design BMX frames for specific populations (females and rider morphology.

  20. Stability Ball Sitting versus Chair Sitting During Sub-maximal Arm Ergometry.

    Science.gov (United States)

    Marks, Charles R C; Hylland, Kristina E; Terrell, Jacob

    It was predicted that sitting on a stability ball during arm ergometry would elevate cardiovascular parameters when compared to sitting on a chair and that this would be associated with greater recruitment of trunk and leg skeletal muscles. Open-circuit spirometry, videotaping, blood pressure, heart rate, and EMG were conducted during rest and four minute stages of 15 W, 30 W, and 45 W using a Monark arm ergometer. Twenty-six apparently healthy adults exercised twice, once sitting on a stability ball and the other sitting on a chair (order randomized), with 45 to 60 minutes of rest between. ANOVA for repeated measures and paired-t testing were used for analysis. Oxygen consumption was significantly 10 to 16% higher during exercise while sitting on the stability ball. There were no significant differences between sitting modes for heart rate, SBP, and DBP. Also, resting and exercise rectus femoris and 45 W external oblique EMGs were significantly higher on the stability ball. Finally, the knee was significantly more extended with the feet farther apart and more forward on the stability ball. The stability ball significantly elevates oxygen consumption during sub-maximal arm cranking without significantly increasing heart rate or blood pressure and this is associated with increased thigh muscle activation and lower leg repositioning.

  1. Suicide by Insulin?

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_165701.html Suicide by Insulin? Self-harm and suicidal behavior may ... higher rates of depression, the researchers explained. And suicide or suicide attempts using insulin or other diabetes ...

  2. Insulin C-peptide

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003701.htm Insulin C-peptide test To use the sharing features ... a product that is created when the hormone insulin is produced and released into the body. The ...

  3. High-mix insulins

    Directory of Open Access Journals (Sweden)

    Sanjay Kalra

    2015-01-01

    Full Text Available Premix insulins are commonly used insulin preparations, which are available in varying ratios of different molecules. These drugs contain one short- or rapid-acting, and one intermediate- or long-acting insulin. High-mix insulins are mixtures of insulins that contain 50% or more than 50% of short-acting insulin. This review describes the clinical pharmacology of high-mix insulins, including data from randomized controlled trials. It suggests various ways, in which high-mix insulin can be used, including once daily, twice daily, thrice daily, hetero-mix, and reverse regimes. The authors provide a rational framework to help diabetes care professionals, identify indications for pragmatic high-mix use.

  4. Insulin pump (image)

    Science.gov (United States)

    The catheter at the end of the insulin pump is inserted through a needle into the abdominal ... with diabetes. Dosage instructions are entered into the pump's small computer and the appropriate amount of insulin ...

  5. Classifying insulin regimens

    DEFF Research Database (Denmark)

    Neu, A; Lange, K; Barrett, T

    2015-01-01

    defined. The proposed new classification for insulin management will be comprehensive, simple, and catchy. Currently available terms were included. This classification may offer the opportunity to compare therapeutic strategies without the currently existing confusion on the insulin regimen....

  6. Insulin sensitivity and albuminuria

    DEFF Research Database (Denmark)

    Pilz, Stefan; Rutters, Femke; Nijpels, Giel

    2014-01-01

    OBJECTIVE: Accumulating evidence suggests an association between insulin sensitivity and albuminuria, which, even in the normal range, is a risk factor for cardiovascular diseases. We evaluated whether insulin sensitivity is associated with albuminuria in healthy subjects. RESEARCH DESIGN...... albuminuria. This finding suggests that reduced insulin sensitivity either is simply related to or might causally contribute to the initial pathogenesis of albuminuria....

  7. Carcinogenicity of insulin analogues

    NARCIS (Netherlands)

    Braak, Sebastiaan Johannes ter

    2015-01-01

    There is epidemiological evidence that the use of some insulin analogues by diabetic patients is correlated with an increased cancer risk. In vitro exposure experiments revealed that insulin glargine (LANTUS) was the only commercial insulin analogue with an increased mitogenic potential. In the

  8. Glycosphingolipids and insulin resistance

    NARCIS (Netherlands)

    Langeveld, Mirjam; Aerts, Johannes M. F. G.

    2009-01-01

    Obesity is associated with an increased risk for insulin resistance, a state characterized by impaired responsiveness of liver, muscle and adipose tissue to insulin. One class of lipids involved in the development of insulin resistance are the (glyco)sphingolipids. Ceramide, the most simple

  9. C-Peptide, Baseline and Postprandial Insulin Resistance after a Carbohydrate-Rich Test Meal - Evidence for an Increased Insulin Clearance in PCOS Patients?

    Science.gov (United States)

    Stassek, J; Erdmann, J; Ohnolz, F; Berg, F D; Kiechle, M; Seifert-Klauss, V

    2017-01-01

    Introduction Known characteristics of patients with PCOS include infertility, menstrual disorders, hirsutism and also often insulin resistance. These symptoms increase with increasing body weight. In the LIPCOS study ( L ifestyle I ntervention for Patients with Polycystic Ovary Syndrome [ PCOS ]) long-term changes of the PCOS in dependence on pregnancy and parenthood were systematically assessed. In the framework of the LIPCOS study, PCOS patients were given a standardised carbohydrate-rich test meal in order to examine glucose homeostasis and insulin secretion. The results were compared with those of a eumenorrhoeic control group who all had corresponding BMI values and corresponding ages. Methods and Patients 41 PCOS patients (without diabetes) and 68 controls received a standardised carbohydrate-rich test meal (260 kcal, 62 % carbohydrates, 32 % fat, 6 % proteins) in order to generate a submaximal insulin and glucose stimulation. The values were determined at baseline and postprandial after 60, 120 and 180 minutes. In addition, the corresponding C-peptide levels were recorded. Results In the PCOS patients (n = 41), the insulin secretion test after a standardised test meal showed almost identical baseline and postprandial insulin levels when compared with those of the age- and BMI-matched eumenorrhoeic controls (n = 68). In the PCOS patients, the baseline and postprandial glucose levels were significantly elevated (92.88 ± 10.28 [PCOS] vs. 85.07 ± 9.42 mg/dL [controls]; p PCOS patients formally exhibit a higher fasting insulin resistance than controls. In spite of the higher stimulated C-peptide levels, the insulin levels did not increase more strongly with increasing glucose levels than in controls which may be indicative of a higher insulin clearance in PCOS patients.

  10. Glucose-induced insulin secretion: nutritional prevention and novel avenues for therapy.

    Science.gov (United States)

    Polakof, Sergio; Comte, Blandine

    2012-01-01

    Insulin resistance, the most important pathophysiological feature in various prediabetic and diabetic states is partly related to impaired glucose-stimulated insulin secretion and insulin modulation of pancreatic beta cell with peripheral impaired insulin response. This chapter concentrates on aspects of potential new strategies in the treatment of the disease going from nutritional preventive approaches towards currently utilized drugs for treatment that target the pancreatic beta cells with potentiation of glucose-stimulated insulin secretion.

  11. Changing over to U-100 insulin

    Directory of Open Access Journals (Sweden)

    F. Bonnici

    1982-09-01

    Full Text Available A new preparation of insulin containing 100 units per millilitre (U-100 is being introduced in South Africa. Since it was first used in 1922, insulin has been available in at least eight different concentrations but, over the years, only the 40 U/ml and 80 U/ml have been in common usage, the 20 U/ml having a certain vogue in the United Kingdom only.

  12. Low-protein vegetarian diet does not have a short-term effect on blood acid–base status but raises oxygen consumption during submaximal cycling

    Directory of Open Access Journals (Sweden)

    Hietavala Enni-Maria

    2012-11-01

    Full Text Available Abstract Background Acid–base balance refers to the equilibrium between acids and bases in the human body. Nutrition may affect acid–base balance and further physical performance. With the help of PRAL (potential renal acid load, a low-protein vegetarian diet (LPVD was designed to enhance the production of bases in body. The aim of this study was to investigate if LPVD has an effect on blood acid–base status and performance during submaximal and maximal aerobic cycling. Methods Nine healthy, recreationally active men (age 23.5 ± 3.4 yr participated in the study and were randomly divided into two groups in a cross-over study design. Group 1 followed LPVD for 4 days and group 2 ate normally (ND before performing a cycle ergometer test. The test included three 10-min stages at 40, 60 and 80% of VO2max. The fourth stage was performed at 100% of VO2max until exhaustion. After 10–16 days, the groups started a second 4-day diet, and at the end performed the similar ergometer test. Venous blood samples were collected at the beginning and at the end of both diet periods and after every stage cycled. Results Diet caused no significant difference in venous blood pH, strong ion difference (SID, total concentration of weak acids (Atot, partial pressure of CO2 (pCO2 or HCO3- at rest or during cycling between LPVD and ND. In the LPVD group, at rest SID significantly increased over the diet period (38.6 ± 1.8 vs. 39.8 ± 0.9, p=0.009. Diet had no significant effect on exercise time to exhaustion, but VO2 was significantly higher at 40, 60 and 80% of VO2max after LPVD compared to ND (2.03 ± 0.25 vs. 1.82 ± 0.21 l/min, p=0.035; 2.86 ± 0.36 vs. 2.52 ± 0.33 l/min, p Conclusion There was no difference in venous blood acid–base status between a 4-day LPVD and ND. VO2 was increased during submaximal cycling after LPVD suggesting that the exercise economy was poorer. This had no further effect on maximal aerobic performance. More studies are needed to

  13. Rac1 Signaling Is Required for Insulin-Stimulated Glucose Uptake and Is Dysregulated in Insulin-Resistant Murine and Human Skeletal Muscle

    Science.gov (United States)

    Sylow, Lykke; Jensen, Thomas E.; Kleinert, Maximilian; Højlund, Kurt; Kiens, Bente; Wojtaszewski, Jørgen; Prats, Clara; Schjerling, Peter; Richter, Erik A.

    2013-01-01

    The actin cytoskeleton–regulating GTPase Rac1 is required for insulin-stimulated GLUT4 translocation in cultured muscle cells. However, involvement of Rac1 and its downstream signaling in glucose transport in insulin-sensitive and insulin-resistant mature skeletal muscle has not previously been investigated. We hypothesized that Rac1 and its downstream target, p21-activated kinase (PAK), are regulators of insulin-stimulated glucose uptake in mouse and human skeletal muscle and are dysregulated in insulin-resistant states. Muscle-specific inducible Rac1 knockout (KO) mice and pharmacological inhibition of Rac1 were used to determine whether Rac1 regulates insulin-stimulated glucose transport in mature skeletal muscle. Furthermore, Rac1 and PAK1 expression and signaling were investigated in muscle of insulin-resistant mice and humans. Inhibition and KO of Rac1 decreased insulin-stimulated glucose transport in mouse soleus and extensor digitorum longus muscles ex vivo. Rac1 KO mice showed decreased insulin and glucose tolerance and trended toward higher plasma insulin concentrations after intraperitoneal glucose injection. Rac1 protein expression and insulin-stimulated PAKThr423 phosphorylation were decreased in muscles of high fat–fed mice. In humans, insulin-stimulated PAK activation was decreased in both acute insulin-resistant (intralipid infusion) and chronic insulin-resistant states (obesity and diabetes). These findings show that Rac1 is a regulator of insulin-stimulated glucose uptake and a novel candidate involved in skeletal muscle insulin resistance. PMID:23423567

  14. Partially folded intermediates in insulin fibrillation.

    Science.gov (United States)

    Ahmad, Atta; Millett, Ian S; Doniach, Sebastian; Uversky, Vladimir N; Fink, Anthony L

    2003-10-07

    Native zinc-bound insulin exists as a hexamer at neutral pH. Under destabilizing conditions, the hexamer dissociates, and is very prone to forming fibrils. Insulin fibrils exhibit the typical properties of amyloid fibrils, and pose a problem in the purification, storage, and delivery of therapeutic insulin solutions. We have carried out a systematic investigation of the effect of guanidine hydrochloride (Gdn.HCl)-induced structural perturbations on the mechanism of fibrillation of insulin. At pH 7.4, the addition of as little as 0.25 M Gdn.HCl leads to dissociation of insulin hexamers into dimers. Moderate concentrations of Gdn.HCl lead to formation of a novel partially unfolded dimer state, which dissociates into a partially unfolded monomer state. High concentrations of Gdn.HCl resulted in unfolded monomers with some residual structure. The addition of even very low concentrations of Gdn.HCl resulted in substantially accelerated fibrillation, although the yield of fibrils decreased at high concentrations. Accelerated fibrillation correlated with the population of the expanded (partially folded) monomer, which existed up to >6 M Gdn.HCl, accounting for the formation of substantial amounts of fibrils under such conditions. In the presence of 20% acetic acid, where insulin exists as the monomer, fibrillation was also accelerated by Gdn.HCl. The enhanced fibrillation of the monomer was due to the increased ionic strength at low denaturant concentrations, and due to the presence of the partially unfolded, expanded conformation at Gdn.HCl concentrations above 1 M. The data suggest that under physiological conditions, the fibrillation of insulin involves both changes in the association state (with rate-limiting hexamer dissociation) and conformational changes, leading to formation of the amyloidogenic expanded monomer intermediate.

  15. Maternal periodontal disease in rats decreases insulin sensitivity and insulin signaling in adult offspring.

    Science.gov (United States)

    Shirakashi, Daisy J; Leal, Rosana P; Colombo, Natalia H; Chiba, Fernando Y; Garbin, Cléa A S; Jardim, Elerson G; Antoniali, Cristina; Sumida, Doris H

    2013-03-01

    Periodontal disease during pregnancy has been recognized as one of the causes of preterm and low-birth-weight (PLBW) babies. Several studies have demonstrated that PLBW babies are prone to developing insulin resistance as adults. Although there is controversy over the association between periodontal disease and PLBW, the phenomenon known as programming can translate any stimulus or aggression experienced during intrauterine growth into physiologic and metabolic alterations in adulthood. The purpose of the present study is to investigate whether the offspring of rats with periodontal disease develop insulin resistance in adulthood. Ten female Wistar rats were divided into periodontal disease (PED) and control (CN) groups. All rats were mated at 7 days after induction of periodontal disease. Male offspring were divided into two groups: 1) periodontal disease offspring (PEDO; n = 24); and 2) control offspring (CNO; n = 24). Offspring body weight was measured from birth until 75 days. When the offspring reached 75 days old, the following parameters were measured: 1) plasma concentrations of glucose, insulin, fructosamine, lipase, amylase, and tumor necrosis factor-α (TNF-α); 2) insulin sensitivity (IS); and 3) insulin signal transduction (IST) in insulin-sensitive tissues. Low birth weight was not detected in the PEDO group. However, plasma concentrations of glucose, insulin, fructosamine, lipase, amylase, and TNF-α were increased and IS and IST were reduced (P periodontal disease may induce insulin resistance and reduce IST in adult offspring, but such alterations are not attributable to low birth weight.

  16. Binge Drinking Induces Whole-Body Insulin Resistance by Impairing Hypothalamic Insulin Action

    Science.gov (United States)

    Lindtner, Claudia; Scherer, Thomas; Zielinski, Elizabeth; Filatova, Nika; Fasshauer, Martin; Tonks, Nicholas K.; Puchowicz, Michelle; Buettner, Christoph

    2013-01-01

    Individuals with a history of binge drinking have an increased risk of developing the metabolic syndrome and type 2 diabetes. Whether binge drinking impairs glucose homeostasis and insulin action is unknown. To test this, we treated Sprague-Dawley rats daily with alcohol (3 g/kg) for three consecutive days to simulate human binge drinking and found that these rats developed and exhibited insulin resistance even after blood alcohol concentrations had become undetectable. The animals were resistant to insulin for up to 54 hours after the last dose of ethanol, chiefly a result of impaired hepatic and adipose tissue insulin action. Because insulin regulates hepatic glucose production and white adipose tissue lipolysis, in part through signaling in the central nervous system, we tested whether binge drinking impaired brain control of nutrient partitioning. Rats that had consumed alcohol exhibited impaired hypothalamic insulin action, defined as the ability of insulin infused into the mediobasal hypothalamus to suppress hepatic glucose production and white adipose tissue lipolysis. Insulin signaling in the hypothalamus, as assessed by insulin receptor and AKT phosphorylation, decreased after binge drinking. Quantitative polymerase chain reaction showed increased hypothalamic inflammation and expression of protein tyrosine phosphatase 1B (PTP1B), a negative regulator of insulin signaling. Intracerebroventricular infusion of CPT-157633, a small-molecule inhibitor of PTP1B, prevented binge drinking–induced glucose intolerance. These results show that, in rats, binge drinking induces systemic insulin resistance by impairing hypothalamic insulin action and that this effect can be prevented by inhibition of brain PTP1B. PMID:23363978

  17. Escitalopram ameliorates hypercortisolemia and insulin resistance in low birth weight men with limbic brain alterations

    DEFF Research Database (Denmark)

    Buhl, Christian Selmer; Stødkilde-Jørgensen, Hans; Videbech, Poul

    2017-01-01

    weight controls (NBW) (Part 1). Second aim was to investigate the effects of Escitalopram vs. placebo treatment in LBW with regards to LHPA-axis and insulin sensitivity (Part 2). DESIGN SETTING, PARTICIPANTS AND INTERVENTION: Maximal (Rdmax) and sub-maximal (Rdsubmax) rates of insulin-stimulated glucose......-blinded treatment with Escitalopram 20mg/day or placebo for 3 months followed by a complete reexamination. MAIN OUTCOME MEASURES (Part 2): Changes in Rdmax/Rdsubmax and plasma free cortisol 24-hour AUC. RESULTS: In LBW vs. NBW Rdsubmax and Rdmax were ∼16% (P=0.01) and ∼12% (P=0.01) lower, respectively, and 24-hour...... free cortisol levels were ∼20% higher (p=0.02) primarily driven by a ∼99% increase at 05.00 am (pEscitalopram vs. placebo, however, normalized free cortisol...

  18. The Effect of Submaximal Exercise Preceded by Single Whole-Body Cryotherapy on the Markers of Oxidative Stress and Inflammation in Blood of Volleyball Players

    Science.gov (United States)

    Mila-Kierzenkowska, Celestyna; Szpinda, Michał; Augustyńska, Beata; Woźniak, Bartosz

    2013-01-01

    The aim of the study was to determine the effect of single whole-body cryotherapy (WBC) session applied prior to submaximal exercise on the activity of antioxidant enzymes, the concentration of lipid peroxidation products, total oxidative status, and the level of cytokines in blood of volleyball players. The study group consisted of 18 male professional volleyball players, who were subjected to extremely cold air (−130°C) prior to exercise performed on cycloergometer. Blood samples were taken five times: before WBC, after WBC procedure, after exercise preceded by cryotherapy (WBC exercise), and before and after exercise without WBC (control exercise). The activity of catalase statistically significantly increased after control exercise. Moreover, the activity of catalase and superoxide dismutase was lower after WBC exercise than after control exercise (P cryotherapy prior to exercise may have some antioxidant and anti-inflammatory properties. The relations between the level of studied oxidative stress and inflammatory markers may testify to the contribution of reactive oxygen species in cytokines release into the blood system in response to exercise and WBC. PMID:24489985

  19. The Effect of Submaximal Exercise Preceded by Single Whole-Body Cryotherapy on the Markers of Oxidative Stress and Inflammation in Blood of Volleyball Players

    Directory of Open Access Journals (Sweden)

    Celestyna Mila-Kierzenkowska

    2013-01-01

    Full Text Available The aim of the study was to determine the effect of single whole-body cryotherapy (WBC session applied prior to submaximal exercise on the activity of antioxidant enzymes, the concentration of lipid peroxidation products, total oxidative status, and the level of cytokines in blood of volleyball players. The study group consisted of 18 male professional volleyball players, who were subjected to extremely cold air (−130∘C prior to exercise performed on cycloergometer. Blood samples were taken five times: before WBC, after WBC procedure, after exercise preceded by cryotherapy (WBC exercise, and before and after exercise without WBC (control exercise. The activity of catalase statistically significantly increased after control exercise. Moreover, the activity of catalase and superoxide dismutase was lower after WBC exercise than after control exercise (P<0.001. After WBC exercise, the level of IL-6 and IL-1β was also lower (P<0.001 than after control exercise. The obtained results may suggest that cryotherapy prior to exercise may have some antioxidant and anti-inflammatory properties. The relations between the level of studied oxidative stress and inflammatory markers may testify to the contribution of reactive oxygen species in cytokines release into the blood system in response to exercise and WBC.

  20. Metformin and insulin receptors

    Energy Technology Data Exchange (ETDEWEB)

    Vigneri, R.; Gullo, D.; Pezzino, V.

    The authors evaluated the effect of metformin (N,N-dimethylbiguanide), a biguanide known to be less toxic than phenformin, on insulin binding to its receptors, both in vitro and in vivo. Specific /sup 125/I-insulin binding to cultured IM-9 human lymphocytes and MCF-7 human breast cancer cells was determined after preincubation with metformin. Specific /sup 125/I-insulin binding to circulating monocytes was also evaluated in six controls, eight obese subjects, and six obese type II diabetic patients before and after a short-term treatment with metformin. Plasma insulin levels and blood glucose were also measured on both occasions. Metformin significantly increased insulin binding in vitro to both IM-9 lymphocytes and MCF-7 cells; the maximum increment was 47.1% and 38.0%, respectively. Metformin treatment significantly increased insulin binding in vivo to monocytes of obese subjects and diabetic patients. Scatchard analysis indicated that the increased binding was mainly due to an increase in receptor capacity. Insulin binding to monocytes of normal controls was unchanged after metformin as were insulin levels in all groups; blood glucose was significantly reduced after metformin only in diabetic patients. These data indicate that metformin increases insulin binding to its receptors in vitro and in vivo. The effect in vivo is observed in obese subjects and in obese type II diabetic patients, paralleling the clinical effectiveness of this antidiabetic agent, and is not due to receptor regulation by circulating insulin, since no variation in insulin levels was recorded.

  1. Acute Warm-up Effects in Submaximal Athletes: An EMG Study of Skilled Violinists.

    Science.gov (United States)

    McCrary, J Matt; Halaki, Mark; Sorkin, Evgeny; Ackermann, Bronwen J

    2016-02-01

    Warm-up is commonly recommended for injury prevention and performance enhancement across all activities, yet this recommendation is not supported by evidence for repetitive submaximal activities such as instrumental music performance. The objective of this study is to quantify the effects of cardiovascular, core muscle, and musical warm-ups on muscle activity levels, musical performance, and subjective experience in skilled violinists. Fifty-five undergraduate, postgraduate, or professional violinists performed five randomly ordered 45-s musical excerpts of varying physical demands both before and after a randomly assigned 15-min, moderate-intensity cardiovascular, core muscle, musical (technical violin exercises), or inactive control warm-up protocol. Surface EMG data were obtained for 16 muscles of the trunk, shoulders, and right arm during each musical performance. Sound recording and perceived exertion (RPE) data were also obtained. Sound recordings were randomly ordered and rated for performance quality by blinded adjudicators. Questionnaire data regarding participant pain sites and fitness levels were used to stratify participants according to pain and fitness levels. Data were analyzed using two- and three-factor ANCOVA (surface EMG and sound recording) and Wilcoxon matched pairs tests (RPE). None of the three warm-up protocols had significant effects on muscle activity levels (P ≥ 0.10). Performance quality did not significantly increase (P ≥ 0.21). RPE significantly decreased (P 0.23). Acute physiological and musical benefits from cardiovascular, core muscle, and musical warm-ups in skilled violinists are limited to decreases in RPE. This investigation provides data from the performing arts in support of sports medical evidence suggesting that warm-up only effectively enhances maximal strength and power performance.

  2. Cortical and spinal mechanisms of task failure of sustained submaximal fatiguing contractions.

    Directory of Open Access Journals (Sweden)

    Petra S Williams

    Full Text Available In this and the subsequent companion paper, results are presented that collectively seek to delineate the contribution that supraspinal circuits have in determining the time to task failure (TTF of sustained submaximal contractions. The purpose of this study was to compare adjustments in supraspinal and spinal excitability taken concurrently throughout the performance of two different fatigue tasks with identical mechanical demands but different TTF (i.e., force-matching and position-matching tasks. On separate visits, ten healthy volunteers performed the force-matching or position-matching task at 15% of maximum strength with the elbow flexors to task failure. Single-pulse transcranial magnetic stimulation (TMS, paired-pulse TMS, paired cortico-cervicomedullary stimulation, and brachial plexus electrical stimulation were delivered in a 6-stimuli sequence at baseline and every 2-3 minutes throughout fatigue-task performance. Contrary to expectations, the force-matching task TTF was 42% shorter (17.5 ± 7.9 min than the position-matching task (26.9 ± 15.11 min; p0.05. Therefore, failure occurred after a similar mean decline in motorneuron excitability developed (p0.10 and an index of upstream excitation of the motor cortex remained constant (p>0.40. Together, these results suggest that as fatigue develops prior to task failure, the increase in corticospinal excitability observed in relationship to the decrease in spinal excitability results from a combination of decreasing intracortical inhibition with constant levels of intracortical facilitation and upstream excitability that together eventually fail to provide the input to the motor cortex necessary for descending drive to overcome the spinal cord resistance, thereby contributing to task failure.

  3. Cortical and Spinal Mechanisms of Task Failure of Sustained Submaximal Fatiguing Contractions

    Science.gov (United States)

    Williams, Petra S.; Hoffman, Richard L.; Clark, Brian C.

    2014-01-01

    In this and the subsequent companion paper, results are presented that collectively seek to delineate the contribution that supraspinal circuits have in determining the time to task failure (TTF) of sustained submaximal contractions. The purpose of this study was to compare adjustments in supraspinal and spinal excitability taken concurrently throughout the performance of two different fatigue tasks with identical mechanical demands but different TTF (i.e., force-matching and position-matching tasks). On separate visits, ten healthy volunteers performed the force-matching or position-matching task at 15% of maximum strength with the elbow flexors to task failure. Single-pulse transcranial magnetic stimulation (TMS), paired-pulse TMS, paired cortico-cervicomedullary stimulation, and brachial plexus electrical stimulation were delivered in a 6-stimuli sequence at baseline and every 2–3 minutes throughout fatigue-task performance. Contrary to expectations, the force-matching task TTF was 42% shorter (17.5±7.9 min) than the position-matching task (26.9±15.11 min; pmuscle fatigue (p = 0.59). There were no task-specific differences for the total amount or rate of change in the neurophysiologic outcome variables over time (p>0.05). Therefore, failure occurred after a similar mean decline in motorneuron excitability developed (p0.10) and an index of upstream excitation of the motor cortex remained constant (p>0.40). Together, these results suggest that as fatigue develops prior to task failure, the increase in corticospinal excitability observed in relationship to the decrease in spinal excitability results from a combination of decreasing intracortical inhibition with constant levels of intracortical facilitation and upstream excitability that together eventually fail to provide the input to the motor cortex necessary for descending drive to overcome the spinal cord resistance, thereby contributing to task failure. PMID:24667484

  4. TEST-RETEST RELIABILITY OF THE AEROBIC POWER INDEX SUBMAXIMAL EXERCISE TEST IN CANCER PATIENTS

    Directory of Open Access Journals (Sweden)

    Bonnie J. Furzer

    2012-12-01

    Full Text Available The purpose of this study was to investigate the reliability of the Aerobic Power Index (API submaximal cardiorespiratory exercise test, as well as associated variables of oxygen uptake (ml·kg-1·min-1 and ratings of perceived exertion (RPE in cancer patients who are generally unable to complete maximal or lengthy aerobic fitness tests. Twenty male and female participants (11 male; 9 female aged between 18 and 70 y (mean = 53.28 ± 11. 82 y were recruited with medical consent within 4 weeks of completing chemotherapy treatment for a lymphohaematopoietic cancer (LHC. Of the twenty recruited participants' 2 were excluded from analysis due to disease relapse or complications unrelated to testing occurring within the month following testing. Intra-class correlation coefficient (ICC scores for power output (W·kg-1 and oxygen uptake (ml·kg-1·min-1 were highly reliable (R1 = 0.96 and 0.96, respectively and the ICC for RPE was moderately reliable (R1 = 0.83. Technical error of measurement results for power output (W·kg-1, oxygen uptake (ml·kg-1·min-1 and RPE were 0.11W·kg-1, 1.18 ml·kg-1·min-1 and 1.0 respectively. A Pearson's product-moment correlation demonstrated a strong relationship between power output (W·kg-1 and oxygen uptake (ml·kg-1·min-1 for both trials (r = 0.93 and 0.89, respectively. Results demonstrate that the API test is a highly reliable protocol for use with a LHC population and can be considered a clinically feasible, safe and tolerable exercise test

  5. A submaximal test for the assessment of knee extensor endurance capacity.

    Science.gov (United States)

    De Ruiter, Cornelis J; Mallee, Max I P; Leloup, Lara E C; De Haan, Arnold

    2014-02-01

    We aimed to develop an undemanding test for endurance capacity of the knee extensor muscles, which can also be applied to frail participants. We hypothesized 1) that the first objective indications for peripheral fatigue during incremental unilateral repetitive isometric knee extensor contractions could be used to assess a fatigue threshold (FT), 2) that torque at FT would depend on training status, and 3) that this torque could easily be sustained for 30 min. Five trained and five untrained participants performed 5-min bouts of 60 repetitive contractions (3-s on and 2-s off). Torque, set at 25% maximal voluntary contraction (MVC), was increased by 5% MVC in subsequent bouts. The highest torque for which rectified surface EMG remained stable during the bout was defined as the FT. On separate occasions, 30-min bouts were performed at and above the FT to assess sustainable torque. Changes in gas exchange parameters, HR, and RPE were monitored to corroborate FT. At FT (RPE = 5.7 ± 1.7), torque was higher (P MVC) than in untrained participants (30.5% ± 1.8% MVC). Sustainable torque was ∼4% higher than (P MVC, significant increases in rectified surface EMG and V˙O2 were found. During incremental knee extensor contractions, FT could be assessed at a submaximal exercise intensity. FT was higher in trained than in untrained participants and was related to exercise sustainability. With the use of FT, changes in endurance capacity of single muscle groups can potentially also be determined in frail participants for whom exercise performed until exhaustion is unwarranted.

  6. The Effect of Acute Sub-Maximal Endurance Exercise on Serum Angiogenic Indices in Sedentary Men

    Directory of Open Access Journals (Sweden)

    Kamal Ranjbar

    2014-06-01

    Full Text Available Background: Endurance training increases capillary density of skeletal muscle, but the molecular mechanism of this process is not yet clear. Therefore, the purpose of this study was to investigate the effect of acute sub maximal endurance exercise on serum levels of vascular endothelial growth factor (VEGF and matrix metaloproteinases 2 and 9 (MMP-2 and MMP-9 in sedentary men. Materials and Methods: Twelve healthy men (22.37±2.30 years, BMI=23.16 ±2.61 kg/mP 2 P participated in this study. Subjects exercised for 1h at 70% of VOR2R max, 3 days after the VOR2R max determination. Antecubital vein blood was collected at rest, immediately and 2h after the exercise. Serum VEGF, MMP-2 and MMP-9 were measured by ELISA methods5T. Results: Serum levels of VEGF and MMP-2 decreased immediately after the exercise. 2 hours after the exercise, serum levels of VEGF remained at a lower level but serum MMP-2 returned to its basal level. Also, serum levels of MMP-9 did not change significantly in response to exercise5T. Conclusion: Acute sub-maximal endurance exercise decreased the main factors involved in development of capillary density in sedentary men. This might to due to the fact that, sub maximal exercise could not provide the two main stimulating factors of angiogenesis, i.e. Shear stress and hypoxia. It could also be explained by the fact that the mechanism of development of capillary network following regular endurance training is different from that following an acute exercise5T.5T

  7. INSULIN THERAPY TODAY

    Directory of Open Access Journals (Sweden)

    Saša Živić

    2002-05-01

    Full Text Available The insulin classification regarding the duration of its effect gradually be-comes outdated; it is necessary to speak first about the insulin therapy regimes. The intensified insulin therapy regarding the type of multiple daily insulin injections be-comes an indisputable standard. The progress in the "protein engineering" with the formation of a wide spectrum of insulin analogues provides for moving forward to-wards modern diabetology and the concept of strict individualization of the insulin therapy. The experience becomes a pattern in creating two existing formulas of the insulin "short" analogues, namely HUMALAG with the replacement of the proline and lysinane places with those of 28 and 29, and NOVORAPID with aspartic acid at the 28th place in the B chain. The most recent long-effect analogues are created by amino acid changes with the glycine residual at the position A21 and two ariginines added to the positions B31 and B32 - insulin "glargin" - LANTUS. The development of short and long effect analogues imposed the logical need for formulating "new" fixed insulin combination's as well. New combination's are made of two kinds of ac-tual insulin, namely, the fast-effect analogues of the aspart type or lystroinsulin and protamine-retarded preparations - neutral protamine - lystroinsulin. Three kinds of combinations are made.

  8. Linear growth in relation to the circulating concentration of insulin-like growth factor-I in young children with acyanotic congenital heart disease with left to right shunts before versus after surgical intervention

    Directory of Open Access Journals (Sweden)

    Ashraf T Soliman

    2012-01-01

    Full Text Available Objectives: The aim was to determine the degree of linear growth retardation of patients with congenital acyanotic heart disease at presentation and the magnitude of catch-up growth, if any, in relation to their echocardiographic changes and insulin-like growth factor- I (IGF-I concentration before versus after surgical intervention. Materials and Methods: This prospective study recorded the anthropometric data and measured the circulating IGF-I, free thyroxin (FT4, and thyrotropin (TSH of 27 infants and children with congenital acyanotic heart disease with left to right shunt (10 with VSD, 8 with ASD, 9 PDA without heart failure, or severe pulmonary hypertension, before and 12 months or more after surgical or catheter intervention. Eighty normal age and sex- matched normal siblings of these patients were included as controls for the auxologic data. Results: At presentation, patients′ mean age = 35.6 ± 26 months, height SDS (HtSDS = -1.6 ± 1.1, and body mass index (BMI = 15.1 ± 2.5. They were significantly shorter and with lower BMI compared to normal controls (HtSDS = 0.25 ± 0.3, BMI = 16.4 ± 1.5. One year or more after catheter or surgical treatment, the HtSDS and BMI increased significantly in patients to -0.55 ± 0.9 and 15.9 ± 1.5, respectively. IGF-I levels increased from 46.8 ± 29 mcg/L before to 77.3 ± 47.6 mcg/L after intervention. No significant change has been detected in circulating FT4 or TSH concentrations. The HtSDS after treatment was correlated with the IGF-I concentration (r = 0.804, P < 0.001. The change in the HtSDS after intervention was correlated significantly with BMI (r = 0.594, P 0.001 and negatively with age (r = -0.52, P< 0.01. The shunt size was correlated negatively with BMI and HtSDS before intervention (r = -0.35, P < 0.01 and 0.01 and r = -0.461, P < 0.05, respectively. GVSDS after intervention surgery was correlated with BMI after intervention (r = 0.495, P < 0.001 and negatively with the age at

  9. Quantifying Na(I)-insulin and K(I)-insulin non-covalent complexes by ESI-MS method and calculation of their equilibrium constants.

    Science.gov (United States)

    Gülfen, Mustafa; Özdemir, Abdil; Lin, Jung-Lee; Chen, Chung-Hsuan

    2017-10-01

    In this study, the dissociation and formation equilibrium constants of Na(I)-insulin and K(I)-insulin complexes have been calculated after the quantifying them on ESI mass spectrometer. The ESI-MS spectra of the complexes were measured by using the solvents as 50% MeOH in water and 100% water. The effect of pH on the Na(I)-insulin and K(I)-insulin complex formation were examined. Serial binding of Na(I) and K(I) ions to the insulin molecule were observed in the ESI-MS measurements. The first formation equilibrium constants were calculated as Kf1: 5.48×103 1/M for Na(I)-insulin complex and Kf1: 4.87×103 1/M for K(I)-insulin in water. The binding capability of Na(I) ions to insulin molecule is higher than the capability of K(I) ions. In case of a comparison together with Ca(II)-insulin and Mg(II)-insulin, the formation equilibrium constants (Kf1) are in order of Ca(II)-insulin>Mg(II)-insulin>Na(I)-insulin>K(I)-insulin in water. The results showed that Na(I) and K(I) ions are involved in the formation of the non-covalent complexes with insulin molecule, since high extracellular and intracellular concentrations of them in the body. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Abnormalities in insulin secretion in type 2 diabetes mellitus.

    Science.gov (United States)

    Guillausseau, P-J; Meas, T; Virally, M; Laloi-Michelin, M; Médeau, V; Kevorkian, J-P

    2008-02-01

    Type 2 diabetes mellitus is a multifactorial disease, due to decreased glucose peripheral uptake, and increased hepatic glucose production, due to reduced both insulin secretion and insulin sensitivity. Multiple insulin secretory defects are present, including absence of pulsatility, loss of early phase of insulin secretion after glucose, decreased basal and stimulated plasma insulin concentrations, excess in prohormone secretion, and progressive decrease in insulin secretory capacity with time. beta-cell dysfunction is genetically determined and appears early in the course of the disease. The interplay between insulin secretory defect and insulin resistance is now better understood. In subjects with normal beta-cell function, increase in insulin is compensated by an increase in insulin secretion and plasma glucose levels remain normal. In subjects genetically predisposed to type 2 diabetes, failure of beta-cell to compensate leads to a progressive elevation in plasma glucose levels, then to overt diabetes. When permanent hyperglycaemia is present, progressive severe insulin secretory failure with time ensues, due to glucotoxicity and lipotoxicity, and oxidative stress. A marked reduction in beta-cell mass at post-mortem examination of pancreas of patients with type 2 diabetes has been reported, with an increase in beta-cell apoptosis non-compensated by neogenesis.

  11. Insulin resistance in aging is related to abdominal obesity.

    Science.gov (United States)

    Kohrt, W M; Kirwan, J P; Staten, M A; Bourey, R E; King, D S; Holloszy, J O

    1993-02-01

    Studies have shown that insulin resistance increases with age, independent of changes in total adiposity. However, there is growing evidence that the development of insulin resistance may be more closely related to abdominal adiposity. To evaluate the independent effects of aging and regional and total adiposity on insulin resistance, we performed hyperinsulinemic euglycemic clamps on 17 young (21-33 yr) and 67 older (60-72 yr) men and women. We assessed FFM and total and regional adiposity by hydrodensitometry and anthropometry. Insulin-stimulated GDRs at a plasma insulin concentration of approximately 450 pM averaged 45.6 +/- 3.3 mumol.kg FFM-1 x min-1 (mean +/- SE) in the young subjects, 45.6 +/- 10.0 mumol.kg FFM-1 x min-1 in 24 older subjects who were insulin sensitive, and 23.9 +/- 11.7 mumol.kg FFM-1 x min-1 in 43 older subjects who were insulin resistant. Few significant differences were apparent in skin-fold and circumference measurements between young and insulin-sensitive older subjects, but measurements at most central body sites were significantly larger in the insulin-resistant older subjects. Waist girth accounted for > 40% of the variance in insulin action, whereas age explained only 10-20% of the total variance and < 2% of the variance when the effects of waist circumference were statistically controlled. These results suggest that insulin resistance is more closely associated with abdominal adiposity than with age.

  12. Epidermal growth factor in rat milk is dependent on insulin

    DEFF Research Database (Denmark)

    Thulesen, J; Poulsen, Steen Seier; Nexo, E

    1993-01-01

    Epidermal growth factor (EGF) was measured in milk from four groups of rats: untreated diabetic, insulin-treated diabetic, insulin-treated normal and control rats. In the untreated diabetic group the volume of milk, and the concentration of EGF and the total output of EGF were significantly decre...... of EGF from the mammary glands is dependent on insulin and that the decrement in milk-EGF from diabetic rats is selective when compared to the content of protein in milk....

  13. Comparing the Effects of Rest and Massage on Return to Homeostasis Following Submaximal Aerobic Exercise: a Case Study.

    Science.gov (United States)

    Resnick, Portia B

    2016-03-01

    Postexercise massage can be used to help promote recovery from exercise on the cellular level, as well as systemically by increasing parasympathetic activity. No studies to date have been done to assess the effects of massage on postexercise metabolic changes, including excess postexercise oxygen consumption (EPOC). The purpose of this study was to compare the effects of massage recovery and resting recovery on a subject's heart rate variability and selected metabolic effects following a submaximal treadmill exercise session. One healthy 24-year-old female subject performed 30 minutes of submaximal treadmill exercise prior to resting or massage recovery sessions. Metabolic data were collected throughout the exercise sessions and at three 10 minute intervals postexercise. Heart rate variability was evaluated for 10 minutes after each of two 30-minute recovery sessions, either resting or massage. Heart rate returned to below resting levels (73 bpm) with 30 and 60 minutes of massage recovery (72 bpm and 63 bpm, respectively) compared to 30 and 60 minutes of resting recovery (77 bpm and 74 bpm, respectively). Heart rate variability data showed a more immediate shift to the parasympathetic state following 30 minutes of massage (1.152 LF/HF ratio) versus the 30-minute resting recovery (6.91 LF/HF ratio). It took 60 minutes of resting recovery to reach similar heart rate variability levels (1.216 LF/HF) found after 30 minutes of massage. Ventilations after 30 minutes of massage recovery averaged 7.1 bpm compared to 17.9 bpm after 30 minutes of resting recovery. No differences in EPOC were observed through either the resting or massage recovery based on the metabolic data collected. Massage was used to help the subject shift into parasympathetic activity more quickly than rest alone following a submaximal exercise session.

  14. Comparing the Effects of Rest and Massage on Return to Homeostasis Following Submaximal Aerobic Exercise: a Case Study

    Science.gov (United States)

    Resnick, Portia B.

    2016-01-01

    Introduction Postexercise massage can be used to help promote recovery from exercise on the cellular level, as well as systemically by increasing parasympathetic activity. No studies to date have been done to assess the effects of massage on postexercise metabolic changes, including excess postexercise oxygen consumption (EPOC). The purpose of this study was to compare the effects of massage recovery and resting recovery on a subject’s heart rate variability and selected metabolic effects following a submaximal treadmill exercise session. Methods One healthy 24-year-old female subject performed 30 minutes of submaximal treadmill exercise prior to resting or massage recovery sessions. Metabolic data were collected throughout the exercise sessions and at three 10 minute intervals postexercise. Heart rate variability was evaluated for 10 minutes after each of two 30-minute recovery sessions, either resting or massage. Results Heart rate returned to below resting levels (73 bpm) with 30 and 60 minutes of massage recovery (72 bpm and 63 bpm, respectively) compared to 30 and 60 minutes of resting recovery (77 bpm and 74 bpm, respectively). Heart rate variability data showed a more immediate shift to the parasympathetic state following 30 minutes of massage (1.152 LF/HF ratio) versus the 30-minute resting recovery (6.91 LF/HF ratio). It took 60 minutes of resting recovery to reach similar heart rate variability levels (1.216 LF/HF) found after 30 minutes of massage. Ventilations after 30 minutes of massage recovery averaged 7.1 bpm compared to 17.9 bpm after 30 minutes of resting recovery. Conclusions No differences in EPOC were observed through either the resting or massage recovery based on the metabolic data collected. Massage was used to help the subject shift into parasympathetic activity more quickly than rest alone following a submaximal exercise session. PMID:26977215

  15. The effect of menstruation on chosen physiological and biochemical reactions caused by the physical effort with the submaximal intensity

    Directory of Open Access Journals (Sweden)

    P Zieliński

    2003-03-01

    Full Text Available The aim of this work was to determine the influence of the menstruation phase on changes of respective indicators of the gas exchange and on biochemical parameters of blood during physical efforts with the sub-maximal intensity. Fifteen female students of the Academy of Physical Education took part in the study. Girls were aged from 19 to 22 years old and did not practice sports. The effort tests were conducted in the follicular and luteal phase of two succeeding menstrual cycles. As far the aerobic capacity determination is concerned, one cyclo-ergometric test with graded effort was conducted and it was performed till the “refusal”. It allowed to mark a threshold (TDMA and a maximal level of physiological and biochemical indicators. Basing on the results of the graded test individual loads were determined for every next effort trial (repeated 4 times in every phase of the two succeeding menstrual cycles. The aim of this trial was to evaluate the reaction of women’s constitution on work with the sub-maximal intensity. The above trial consisted on two 10 min efforts divided with the 2 min pause (the first effort with the intensity of 80% of the TDMA threshold, second with the intensity bigger about 30-40% of difference between TDMA and a maximal load established by the graded test. The research did not reveal statistically significant differentiation as considering effort changes of basic physiological and biochemical indicators, determining reaction of women’s organisms on work with the sub- and over- threshold intensity (TDMA. It showed that menstruation has not significant effect on the level of changes of analysed parameters caused by the physical effort with the sub-maximal intensity.

  16. Incorporating a Generic Model of Subcutaneous Insulin Absorption into the AIDA v4 Diabetes Simulator 3. Early Plasma Insulin Determinations

    Science.gov (United States)

    Lehmann, Eldon D.; Tarín, Cristina; Bondia, Jorge; Teufel, Edgar; Deutsch, Tibor

    2009-01-01

    Introduction AIDA is an interactive educational diabetes simulator that has been available without charge via the Internet for over 12 years. Recent articles have described the incorporation of a novel generic model of insulin absorption into AIDA as a way of enhancing its capabilities. The basic model components to be integrated have been overviewed, with the aim being to provide simulations of regimens utilizing insulin analogues, as well as insulin doses greater than 40 IU (the current upper limit within the latest release of AIDA [v4.3a]). Some preliminary calculated insulin absorption results have also recently been described. Methods This article presents the first simulated plasma insulin profiles from the integration of the generic subcutaneous insulin absorption model, and the currently implemented model in AIDA for insulin disposition. Insulin absorption has been described by the physiologically based model of Tarín and colleagues. A single compartment modeling approach has been used to specify how absorbed insulin is distributed in, and eliminated from, the human body. To enable a numerical solution of the absorption model, a spherical subcutaneous depot for the injected insulin dose has been assumed and spatially discretized into shell compartments with homogeneous concentrations, having as its center the injection site. The number of these compartments will depend on the dose and type of insulin. Insulin inflow arises as the sum of contributions to the different shells. For this report the first bench testing of plasma insulin determinations has been done. Results Simulated plasma insulin profiles are provided for currently available insulin preparations, including a rapidly acting insulin analogue (e.g., lispro/Humalog or aspart/Novolog), a short-acting (regular) insulin preparation (e.g., Actrapid), intermediate-acting insulins (both Semilente and neutral protamine Hagedorn types), and a very long-acting insulin analogue (e.g., glargine/Lantus), as

  17. The effect of long-term oral L-carnitine administration on insulin sensitivity, glucose disposal, plasma concentrations of leptin and acylcarnitines, and urinary acylcarnitine excretion in warmblood horses

    NARCIS (Netherlands)

    Kranenburg, L C; Westermann, C M; de Sain-van der Velden, M G M; de Graaf-Roelfsema, E; Buyse, J; Janssens, G P J; van den Broek, J; van der Kolk, J H

    2014-01-01

    BACKGROUND: Insulin resistance in horses is an emerging field of interest as it is thought to be a contributing factor in the pathogenesis of many equine conditions. OBJECTIVES: The objectives of the present study were to determine the effects of long-term oral administration of L-carnitine on

  18. [Value of combined subcutaneous infusion of insulin and metformin in 10 insulin-dependent obese diabetics].

    Science.gov (United States)

    Leblanc, H; Marre, M; Billault, B; Passa, P

    1987-01-01

    Combined continuous subcutaneous insulin infusion (CSII) and metformin (M) was tested in 10 overweighted insulin requiring diabetic patients (body mass index 27.9 +/- 4.9 kg/m2). They were still poorly controlled (HbA1 9.6 +/- 0.8%) despite large doses of lente insulin (Novo) (51.7 +/- 19.6 IU/24 h) injected once daily. With CSII after two weeks on placebo (P) they were enrolled in a randomized double blind cross-over trial with two successive one month periods of M (2550 mg/day) or P. At the end of the two-weeks period CSII--initial P, the daily regular insulin requirement decreased significantly (40.1 +/- 18.1). During M and P body weight and HbA1 were unchanged (respectively 28.6 +/- 6.0 vs 29.0 +/- 59 kg/m2 and 7.7 +/- 1.1 vs 7.7 +/- 0.8%). With M daily insulin requirements decreased significantly (32.0 +/- 16.8 vs 38.4 +/- 18.2 IU, p less than 0.05). During test-meals, M compared to placebo also reduced peripheral free insulin concentrations (-24.9 +/- 26.0%) while plasma glucose and C peptide remained comparable. In the conditions of this study, combined CSII and M reduced the insulin resistance observed in overweighted insulin requiring diabetic patients.

  19. [Insulin therapy and sports].

    Science.gov (United States)

    Aigner, A

    1997-01-01

    Physical work effects a transitory enhanced affinity of insulin to its receptor in the stressed muscles and thereby a better efficiency. Therefore, in sports lasting for 30 min and more the basal and/or bolus doses of insulin have to be reduced in order to prevent hypoglycemia. An alternative supply of additional carbohydrates prior to physical work is often not practicable. Injections of insulin into areas of the body not involved in muscular work do not give sufficient warranty against hypoglycemic reactions. A new short-acting insulin-analogue (Lispro) shows a reduced effect on blood glucose levels after 3 h as compared to regular insulin. Therefore, it could be of advantage for insulin dependent diabetics doing their exercise at this time.

  20. Insulin aspart pharmacokinetics

    DEFF Research Database (Denmark)

    Rasmussen, Christian Hove; Roge, Rikke Meldgaard; Ma, Zhulin

    2014-01-01

    Background: Insulin aspart (IAsp) is used by many diabetics as a meal-time insulin to control postprandial glucose levels. As is the case with many other insulin types, the pharmacokinetics (PK), and consequently the pharmacodynamics (PD), is associated with clinical variability, both between...... to investigate and quantify the properties of the subcutaneous depot. Data from Brange et al. (1990) are used to determine the effects of insulin chemistry in subcutis on the absorption rate. Intravenous (i.v.) bolus and infusion PK data for human insulin are used to understand and quantify the systemic...... distribution and elimination (Porksen et al., 1997; Sjostrand et al., 2002). PK and PD profiles for type 1 diabetics from Chen et al. (2005) are analyzed to demonstrate the effects of IAsp antibodies in terms of bound and unbound insulin. PK profiles from Thorisdottir et al. (2009) and Ma et al. (2012b...

  1. Flexibility in insulin prescription

    Directory of Open Access Journals (Sweden)

    Sanjay Kalra

    2016-01-01

    Full Text Available This communication explores the concept of flexibility, a propos insulin preparations and insulin regimes used in the management of type 2 diabetes. The flexibility of an insulin regime or preparation is defined as their ability to be injected at variable times, with variable injection-meal time gaps, in a dose frequency and quantum determined by shared decision making, with a minimal requirement of glucose monitoring and health professional consultation, with no compromise on safety, efficiency and tolerability. The relative flexibility of various basal, prandial and dual action insulins, as well as intensive regimes, is compared. The biopsychosocial model of health is used to assess the utility of different insulins while encouraging a philosophy of flexible insulin usage.

  2. Submaximal cardiopulmonary thresholds on a robotics-assisted tilt table, a cycle and a treadmill: a comparative analysis.

    Science.gov (United States)

    Saengsuwan, Jittima; Nef, Tobias; Laubacher, Marco; Hunt, Kenneth J

    2015-11-10

    The robotics-assisted tilt table (RATT), including actuators for tilting and cyclical leg movement, is used for rehabilitation of severely disabled neurological patients. Following further engineering development of the system, i.e. the addition of force sensors and visual bio-feedback, patients can actively participate in exercise testing and training on the device. Peak cardiopulmonary performance parameters were previously investigated, but it also important to compare submaximal parameters with standard devices. The aim of this study was to evaluate the feasibility of the RATT for estimation of submaximal exercise thresholds by comparison with a cycle ergometer and a treadmill. 17 healthy subjects randomly performed six maximal individualized incremental exercise tests, with two tests on each of the three exercise modalities. The ventilatory anaerobic threshold (VAT) and respiratory compensation point (RCP) were determined from breath-by-breath data. VAT and RCP on the RATT were lower than the cycle ergometer and the treadmill: oxygen uptake (V'O2) at VAT was [mean (SD)] 1.2 (0.3), 1.5 (0.4) and 1.6 (0.5) L/min, respectively (p < 0.001); V'O2 at RCP was 1.7 (0.4), 2.3 (0.8) and 2.6 (0.9) L/min, respectively (p = 0.001). High correlations for VAT and RCP were found between the RATT vs the cycle ergometer and RATT vs the treadmill (R on the range 0.69-0.80). VAT and RCP demonstrated excellent test-retest reliability for all three devices (ICC from 0.81 to 0.98). Mean differences between the test and retest values on each device were close to zero. The ventilatory equivalent for O2 at VAT for the RATT and cycle ergometer were similar and both were higher than the treadmill. The ventilatory equivalent for CO2 at RCP was similar for all devices. Ventilatory equivalent parameters demonstrated fair-to-excellent reliability and repeatability. It is feasible to use the RATT for estimation of submaximal exercise thresholds: VAT and RCP on the RATT were lower than the

  3. Evaluation of the American College of Sports Medicine submaximal treadmill running test for predicting VO2max.

    Science.gov (United States)

    Marsh, Clare E

    2012-02-01

    The purpose of this study was to assess the validity of the American College of Sports Medicine's (ACSM's) submaximal treadmill running test in predicting VO2max. Twenty-one moderately well-trained men aged 18-34 years performed 1 maximal treadmill test to determine maximal oxygen uptake (M VO2max) and 2 submaximal treadmill tests using 4 stages of continuous submaximal exercise. Estimated VO2max was predicted by extrapolation to age-predicted maximal heart rate (HRmax) and calculated in 2 ways: using data from all submaximal stages between 110 b·min(-1) and 85% HRmax (P VO2max-All), and using data from the last 2 stages only (P VO2max-2). The measured VO2max was overestimated by 3% on average for the group but was not significantly different to predicted VO2max (1-way analysis of variance [ANOVA] p = 0.695; M VO2max = 53.01 ± 5.38; P VO2max-All = 54.27 ± 7.16; P VO2max-2 = 54.99 ± 7.69 ml·kg(-1)·min(-1)), although M VO2max was not overestimated in all the participants--it was underestimated in 30% of observations. Pearson's correlation, standard error of estimate (SEE), and total error (E) between measured and predicted VO2max were r = 0.646, 4.35, 4.08 ml·kg(-1)·min(-1) (P VO2max-All) and r = 0.642, 4.21, 3.98 ml·kg(-1)·min(-1) (P VO2max-2) indicating that the accuracy in prediction (error) was very similar whether using P VO2max-All or P VO2max-2, with up to 70% of the participants predicted scores within 1 SEE (∼4 ml·kg(-1)·min(-1)) of M VO2max. In conclusion, the ACSM equation provides a reasonably good estimation of VO2max with no difference in predictive accuracy between P VO2max-2 and P VO2max-All, and hence, either approach may be equally useful in tracking an individual's aerobic fitness over time. However, if a precise knowledge of VO2max is required, then it is recommended that this be measured directly.

  4. History of insulin

    Directory of Open Access Journals (Sweden)

    Celeste C. Quianzon

    2012-07-01

    Full Text Available The advancement of diabetes treatment has gone from crude extracts of insulin and accidental discovery of sulfa-like drugs in antibiotics to the development of drugs based on improved understanding of the pathophysiology of diabetes mellitus. This article will review the history of the discovery and development of insulin. A companion focusing on non-insulin diabetes agents will follow in the next issue of JCHIMP.

  5. Insulin resistance and atherosclerosis

    OpenAIRE

    Semenkovich, Clay F.

    2006-01-01

    Considerable evidence supports the association between insulin resistance and vascular disease, and this has led to wide acceptance of the clustering of hyperlipidemia, glucose intolerance, hypertension, and obesity as a clinical entity, the metabolic syndrome. While insulin resistance, by promoting dyslipidemia and other metabolic abnormalities, is part of the proatherogenic milieu, it is possible that insulin resistance itself in the vascular wall does not promote atherosclerosis. Recent fi...

  6. Insulin, cognition, and dementia

    Science.gov (United States)

    Cholerton, Brenna; Baker, Laura D.; Craft, Suzanne

    2015-01-01

    Cognitive disorders of aging represent a serious threat to the social and economic welfare of current society. It is now widely recognized that pathology related to such conditions, particularly Alzheimer’s disease, likely begins years or decades prior to the onset of clinical dementia symptoms. This revelation has led researchers to consider candidate mechanisms precipitating the cascade of neuropathological events that eventually lead to clinical Alzheimer’s disease. Insulin, a hormone with potent effects in the brain, has recently received a great deal of attention for its potential beneficial and protective role in cognitive function. Insulin resistance, which refers to the reduced sensitivity of target tissues to the favorable effects of insulin, is related to multiple chronic conditions known to impact cognition and increase dementia risk. With insulin resistance-associated conditions reaching epidemic proportions, the prevalence of Alzheimer’s disease and other cognitive disorders will continue to rise exponentially. Fortunately, these chronic insulin-related conditions are amenable to pharmacological intervention. As a result, novel therapeutic strategies that focus on increasing insulin sensitivity in the brain may be an important target for protecting or treating cognitive decline. The following review will highlight our current understanding of the role of insulin in brain, potential mechanisms underlying the link between insulin resistance and dementia, and current experimental therapeutic strategies aimed at improving cognitive function via modifying the brain’s insulin sensitivity. PMID:24070815

  7. Substrate utilization during submaximal exercise in children with a severely obese parent

    Directory of Open Access Journals (Sweden)

    Eaves Audrey D

    2012-05-01

    Full Text Available Abstract Background We have reported a reduction in fatty acid oxidation (FAO at the whole-body level and in skeletal muscle in severely obese (BMI ≥ 40 kg/m2 individuals; this defect is retained in cell culture suggesting an inherent component. The purpose of the current study was to determine if an impairment in whole-body fatty acid oxidation (FAO was also evident in children with a severely obese parent. Methods Substrate utilization during submaximal exercise (cycle ergometer was determined in children ages 8–12 y with a severely obese parent (OP, n = 13 or two lean/non-obese (BMI range of 18 to 28 kg/m2 parents (LP, n = 13. A subgroup of subjects (n = 3/group performed 4 weeks of exercise training with substrate utilization measured after the intervention. Results The children did not differ in age (LP vs. OP, respectively (10.7 ± 0.5 vs. 10.2 ± 0.5 y, BMI percentile (65.3 ± 5.2 vs. 75.9 ± 7, Tanner Stage (1.4 ± 0.2 vs. 1.5 ± 0.2, VO2peak (40.3 ± 2.7 vs. 35.6 ± 2.6 ml/kg/min or physical activity levels (accelerometer. At the same absolute workload of 15 W (~38% VO2peak, RER was significantly (P ≤ 0.05 lower in LP vs. OP (0.83 ± 0.02 vs. 0.87 ± 0.01 which was reflected in a reduced reliance on FAO for energy production in the OP group (58.6 ± 5.1 vs. 43.1 ± 4.0% of energy needs during exercise from FAO. At a higher exercise intensity (~65% VO2peak there were no differences in substrate utilization between LP and OP. After exercise training RER tended to decrease (P = 0.06 at the 15 W workload, suggesting an increased reliance on FAO regardless of group. Conclusions These findings suggest that the decrement in FAO with severe obesity has an inherent component that may be overcome with exercise training.

  8. Analysing visual pattern of skin temperature during submaximal and maximal exercises

    Science.gov (United States)

    Balci, Gorkem Aybars; Basaran, Tahsin; Colakoglu, Muzaffer

    2016-01-01

    Aims of this study were to examine our hypotheses assuming that (a) skin temperature patterns would differ between submaximal exercise (SE) and graded maximal exercise test (GXT) and (b) thermal kinetics of Tskin occurring in SE and GXT might be similar in a homogenous cohort. Core temperature (Tcore) also observed in order to evaluate thermoregulatory responses to SE and GXT. Eleven moderately to well-trained male athletes were volunteered for the study (age: 22.2 ± 3.7 years; body mass: 73.8 ± 6.9 kg; height: 181 ± 6.3 cm; body surface area 1.93 ± 0.1 m2; body fat: 12.6% ± 4.2%; V ˙ O2max: 54 ± 9.9 mL min-1 kg-1). Under stabilized environmental conditions in climatic chamber, GXT to volitional exhaustion and 20-min SE at 60% of VO2max were performed on cycle ergometer. Thermal analyses were conducted in 2-min intervals throughout exercise tests. Tskin was monitored by a thermal camera, while Tcore was recorded via an ingestible telemetric temperature sensor. Thermal kinetic analyses showed that Tskin gradually decreased till the 7.58 ± 1.03th minutes, and then initiated to increase till the end of SE (Rsqr = 0.97), while Tskin gradually decreased throughout the GXT (Rsqr = 0.89). Decrease in the level of Tskin during the GXT was significantly below from the SE [F (4, 40) = 2.67, p = 0.07, ηp2 = 0.211]. In the meantime, Tcore continuously increased throughout the SE and GXT (p 0.05). However, total heat energies were calculated as 261.5 kJ/m2 and 416 kJ/m2 for GXT and SE, respectively (p exercises as expected. Tskin curves patterns found to be associated amongst participants at both GXT and SE. Therefore, Tskin kinetics may ensure an important data for monitoring thermoregulation in exercise.

  9. Gender differences in substrate utilization during submaximal exercise in endurance-trained subjects.

    Science.gov (United States)

    Roepstorff, Carsten; Steffensen, Charlotte H; Madsen, Marianne; Stallknecht, Bente; Kanstrup, Inge-Lis; Richter, Erik A; Kiens, Bente

    2002-02-01

    Substrate utilization across the leg during 90 min of bicycle exercise at 58% of peak oxygen uptake (VO(2 peak)) was studied in seven endurance-trained males and seven endurance-trained, eumenorrheic females by applying arteriovenous catheterization, stable isotopes, and muscle biopsies. The female and male groups were matched according to VO(2 peak) per kilogram of lean body mass, physical activity level, and training history of the subjects. All subjects consumed the same diet, well controlled in terms of nutrient composition as well as energy content, for 8 days preceding the experiment, and all females were tested in the midfollicular phase of the menstrual cycle. During exercise, respiratory exchange ratio (RER) and leg respiratory quotient (RQ) were similar in females and males. Myocellular triacylglycerol (TG) degradation was negligible in males but amounted to 12.4 +/- 3.2 mmol/kg dry wt in females and corresponded to 25.0 +/- 6.0 and 5.0 +/- 7.3% of total oxygen uptake in females and males, respectively (P < 0.05). Utilization of plasma fatty acids (12.0 +/- 2.5 and 9.6 +/- 1.5%), blood glucose (13.6 +/- 1.5 and 14.3 +/- 1.5%), and glycogen (48.5 +/- 4.9 and 42.8 +/- 2.1%) were similar in females and males. Thus, in females, measured substrate oxidation accounted for 99% of the leg oxygen uptake, whereas in males 28% of leg oxygen uptake was unaccounted for in terms of measured oxidized lipid substrates. These findings may indicate that males utilized additional lipid sources, presumably very low density lipoprotein-TG or TG located between muscle fibers. On the basis of RER and leg RQ, it is concluded that no gender difference existed in the relative contribution from carbohydrate and lipids to the oxidative metabolism across the leg during submaximal exercise at the same relative workload. However, an effect of gender appears to occur in the utilization of the different lipid sources.

  10. Normobaric Hypoxia and Submaximal Exercise Effects on Running Memory and Mood State in Women.

    Science.gov (United States)

    Seo, Yongsuk; Gerhart, Hayden D; Stavres, Jon; Fennell, Curtis; Draper, Shane; Glickman, Ellen L

    2017-07-01

    An acute bout of exercise can improve cognitive function in normoxic and hypoxic conditions. However, limited research supports the improvement of cognitive function and mood state in women. The purpose of this study was to examine the effects of hypoxia and exercise on working memory and mood state in women. There were 15 healthy women (age = 22 ± 2 yr) who completed the Automated Neuropsychological Assessment Metrics-4th Edition (ANAM), including the Running Memory Continuous Performance Task (RMCPT) and Total Mood Disturbance (TMD) in normoxia (21% O2), at rest in normoxia and hypoxia (12.5% O2), and during cycling exercise at 60% and 40% Vo2max in hypoxia. RMCPT was not significantly impaired at 30 (100.3 ± 17.2) and 60 (96.6 ± 17.3) min rest in hypoxia compared to baseline in normoxia (97.0 ± 17.0). However, RMCPT was significantly improved during exercise (106.7 ± 20.8) at 60% Vo2max compared to 60 min rest in hypoxia. Following 30 (-89.4 ± 48.3) and 60 min of exposure to hypoxia (-79.8 ± 55.9) at rest, TMD was impaired compared with baseline (-107.1 ± 46.2). TMD was significantly improved during exercise (-108.5 ± 42.7) at 40% Vo2max compared with 30 min rest in hypoxia. Also, RMCPT was significantly improved during exercise (104.0 ± 19.1) at 60% Vo2max compared to 60 min rest in hypoxia (96.6 ± 17.3). Hypoxia and an acute bout of exercise partially influence RMCPT and TMD. Furthermore, a moderate-intensity bout of exercise (60%) may be a more potent stimulant for improving cognitive function than low-intensity (40%) exercise. The present data should be considered by aeromedical personnel performing cognitive tasks in hypoxia.Seo Y, Gerhart HD, Stavres J, Fennell C, Draper S, Glickman EL. Normobaric hypoxia and submaximal exercise effects on running memory and mood state in women. Aerosp Med Hum Perform. 2017; 88(7):627-632.

  11. Insulin sensitivity in clinically healthy individuals with microalbuminuria

    DEFF Research Database (Denmark)

    Jensen, J S; Borch-Johnsen, K; Jensen, G

    1996-01-01

    glucose, tobacco and alcohol consumption, physical activity, and age and sex, fasting serum insulin concentration was the only variable independently associated with insulin sensitivity (r = -0.55; P = 0.0001). It is concluded that microalbuminuria is not associated with impaired insulin sensitivity...... excretion rate (UAER) of 6.6 to 150 micrograms/min) and 24 age- and sex-matched controls with normoalbuminuria (UAER rate on 2 mU/(kg body weight x min). Insulin sensitivity...... (whole body glucose disposal) was similar in the two groups ((mean (95% C.I.)) 351 (321-381) vs. 364 (339-388) mg/(m2 x min); P = 0.51). Among urinary albumin excretion rate, blood pressure, serum lipid concentrations, body mass index waist-hip ratio, fasting concentrations of serum insulin and blood...

  12. Insulin sensitivity in clinically healthy individuals with microalbuminuria

    DEFF Research Database (Denmark)

    Jensen, J S; Borch-Johnsen, K; Jensen, G

    1996-01-01

    excretion rate (UAER) of 6.6 to 150 micrograms/min) and 24 age- and sex-matched controls with normoalbuminuria (UAER body weight x min). Insulin sensitivity...... (whole body glucose disposal) was similar in the two groups ((mean (95% C.I.)) 351 (321-381) vs. 364 (339-388) mg/(m2 x min); P = 0.51). Among urinary albumin excretion rate, blood pressure, serum lipid concentrations, body mass index waist-hip ratio, fasting concentrations of serum insulin and blood...... glucose, tobacco and alcohol consumption, physical activity, and age and sex, fasting serum insulin concentration was the only variable independently associated with insulin sensitivity (r = -0.55; P = 0.0001). It is concluded that microalbuminuria is not associated with impaired insulin sensitivity...

  13. Changes in erythrocyte insulin receptors in normal dogs and keeshond dogs with inheritable, early onset, insulin dependent diabetes mellitus

    Energy Technology Data Exchange (ETDEWEB)

    Klaassen, J.K.

    1986-01-01

    Validation of a procedure to evaluate insulin receptors on erythrocytes (RBC-IR) in dogs is described. The specific binding of (/sup 125/I)iodoinsulin to RBC-IR of normal dogs is significantly greater than binding in keeshonds with an inheritable form of early onset diabetes mellitus. This decreased binding was due to a significant decrease in RBC-IR affinity in the diabetic keeshonds. To determine the effect on RBC-IR, normal dogs were treated with either dexamethasone (0.1 mg/kg) or prednisone (0.3 mg/kg) for 10 days: concentrations of plasma cortisol, glucose, and insulin, plus binding characteristics of RBC-IR were determined. In the dexamethasone treated group, plasma glucose concentrations were elevated significantly by day 6 and continued through day 10. Insulin concentrations were elevated significantly by day 3 and remained elevated through day 10. In the prednisone treated group, glucose concentrations were elevated significantly by day 3, while insulin concentrations were elevated significantly by day 8. Maximum binding of RBC-IR was unaffected by prednisone and neither affinities nor receptor numbers were significantly different from day 1. No changes in plasma cortisol concentration were seen. Diabetic keeshonds on daily insulin treatment were removed from exogenous insulin therapy for 48 hours. Significant increases in glucose concentrations were observed, but no significant changes in cortisol, insulin, average receptor binding affinity, or RBC-IR number per cell occurred.

  14. Oleanolic acid enhances insulin secretion in pancreatic beta-cells.

    NARCIS (Netherlands)

    Teodoro, T.; Zhang, L.; Alexander, T.; Yue, J.; Vranic, M.; Volchuk, A.

    2008-01-01

    We investigated the effect of oleanolic acid, a plant-derived triterpenoid, on insulin secretion and content in pancreatic beta-cells and rat islets. Oleanolic acid significantly enhanced insulin secretion at basal and stimulatory glucose concentrations in INS-1 832/13 cells and enhanced acute

  15. Justification for antioxidant preconditioning (or how to protect insulin ...

    Indian Academy of Sciences (India)

    Insulin resistance is characterized by impaired glucose utilization in the peripheral tissues, accelerated muscle protein degradation, impaired antioxidant defences and extensive cell death. Apparently, both insulin and IGF-1 at physiological concentrations support cell survival by phosphatidylinositol 3 kinase-dependent ...

  16. Test retest reliability and minimal detectable change of a novel submaximal graded exercise test in the measurement of graded exercise test duration.

    Science.gov (United States)

    Taylor, James D; Bandy, William D; Whittemore, Joe D

    2011-05-01

    Measurement of graded exercise test duration is clinically important and can be assessed by maximal graded exercise testing. Yet, limitations of maximal graded exercise testing exist. An alternative to maximal graded exercise testing is submaximal graded exercise testing. However, no studies have investigated the reliability of a submaximal graded exercise test in the measurement of graded exercise test duration. The purpose of this study was to determine the test-retest reliability and minimal detectable change (MDC) of a novel submaximal graded exercise test in the measurement of graded exercise test duration. Fifteen people (4 men, 11 women) with a mean age of 26.20 years (SD = 9.04) participated in this study. A novel submaximal graded exercise test was used to measure graded exercise test duration for each participant. Endpoints of the test were either 85% of age-predicted maximum heart rate or voluntarily stopping the test, whichever endpoint occurred first. Heart rate and graded exercise test duration were constantly measured throughout the test. Graded exercise test duration was defined as the total duration (minutes) of the test. For all participants, the submaximal graded exercise test was conducted at baseline and 48-72 hours thereafter. The intraclass correlation coefficient for the test-retest reliability of the test in determining graded exercise test duration was 0.94 (95% CI = 0.83-0.98). The MDC of the test in the measurement of graded exercise test duration was 0.86 minutes. The results suggest that clinicians can use this novel submaximal graded exercise test to reliably measure graded exercise test duration with a measurement error, as expressed by the MDC, of 0.86 minutes.

  17. Isokinetic performance capacity of trunk muscles. Part II: Coefficient of variation in isokinetic measurement in maximal effort and in submaximal effort.

    Science.gov (United States)

    Luoto, S; Hupli, M; Alaranta, H; Hurri, H

    1996-12-01

    It has been claimed that with the aid of isokinetic trunk strength measuring devices it is possible to distinguish true muscular weakness from submaximal effort in the test. This proposition is based on the presumption that in the isokinetic trunk strength test identical performances can only be reproduced by maximal effort. The purpose of this study was to investigate whether it is possible to distinguish maximal effort from submaximal with the aid of the coefficient of variation (CV) in an isokinetic trunk muscle strength test. The study group included 35 (21 male and 14 female) subjects of whom 12 were healthy, 10 had a mild low-back pain and 13 had a more severe chronic low-back pain. The subjects performed five consecutive bendings both with maximal (100%) and submaximal (50%) efforts at a speed of 90 degrees/second. In maximal effort only healthy subjects reached an average level of CV close to 10% both in extension and in flexion. In the chronic low-back pain group the average CV was close to 20%. The difference in CV was statistically significant (p < 0.05-0.02) between the healthy and the chronic low-back pain subjects. In the submaximal effort all health groups had a CV of approximately 20% or more and no significant differences were found. The group of slightly variable measurements (CV = 11-20%) was remarkably large in both the maximal and submaximal effort. The results suggest that an effort with a CV of 11-20% cannot be classified as definitely submaximal or maximal. When the CV is less than 10% the effort can be fairly certainly classified as maximal.

  18. Oxygen uptake efficiency slope, a new submaximal parameter in evaluating exercise capacity in chronic heart failure patients.

    Science.gov (United States)

    Van Laethem, Christophe; Bartunek, Jozef; Goethals, Marc; Nellens, Paul; Andries, Erik; Vanderheyden, Marc

    2005-01-01

    The oxygen uptake efficiency slope (OUES) is a new submaximal parameter which objectively predicts the maximal exercise capacity in children and healthy subjects. However, the usefulness of OUES in adult patients with and without advanced heart failure remains undetermined. The present study investigates the stability and the usefulness of OUES in adult cardiac patients with and without heart failure. Forty-five patients with advanced heart failure (group A) and 35 patients with ischemic heart disease but normal left ventricular ejection fraction (group B) performed a maximal exercise test. PeakVO2 and percentage of predicted peakVO2 were markers of maximal exercise capacity, whereas OUES, ventilatory anaerobic threshold (VAT), and slope VE/VCO2 were calculated as parameters of submaximal exercise. Group A patients had lower peakVO2 (P slope VE/VCO2 (P slope VE/VCO2, and OUES (all P slope VE/VCO2 (r = -.492, P failure patients unable to perform a maximal exercise test. Further studies are needed to confirm our hypothesis.

  19. Comparing VO2max determined by using the relation between heart rate and accelerometry with submaximal estimated VO2max.

    Science.gov (United States)

    Tönis, T M; Gorter, K; Vollenbroek-Hutten, M M R; Hermens, H

    2012-08-01

    An exploratory study to identify parameters that can be used for estimating a subject's cardio-respiratory physical fitness level, expressed as VO2max, from a combination of heart rate and 3D accelerometer data. Data were gathered from 41 healthy subjects (23 male, 18 female) aged between 20 and 29 years. The measurement protocol consisted of a sub-maximal single stage treadmill walking test for VO2max estimation followed by a walking test at two different speeds (4 and 5.5 kmh-1) for parameter determination. The relation between measured heart rate and accelerometer output at different walking speeds was used to get an indication of exercise intensity and the corresponding heart rate at that intensity. Regression analysis was performed using general subject measures (age, gender, weight, length, BMI) and intercept and slope of the relation between heart rate and accelerometer output during walking as independent variables to estimate the VO2max. A linear regression model using a combination of the slope and intercept parameters, together with gender revealed the highest percentage of explained variance (R2 = 0.90) and had a standard error of the estimate (SEE) of 2.052 mL O2kg-1min-1 with VO2max. Results are comparable with current commonly used sub-maximal laboratory tests to estimate VO2max. The combination of heart rate and accelerometer data seems promising for ambulant estimation of VO2max-.

  20. Regadenoson in Europe: first-year experience of regadenoson stress combined with submaximal exercise in patients undergoing myocardial perfusion scintigraphy.

    Science.gov (United States)

    Brinkert, M; Reyes, E; Walker, S; Latus, K; Maenhout, A; Mizumoto, R; Nkomo, C; Standbridge, K; Wechalekar, K; Underwood, S R

    2014-03-01

    Regadenoson was approved for clinical use in Europe in 2011. Since then, it has become the default form of stress at our institution. We have assessed the side-effect profile and tolerability of regadenoson in patients undergoing clinically indicated myocardial perfusion scintigraphy between July 2011 and July 2012. Clinical, stress and imaging data were recorded prospectively. Symptoms during stress were recorded and defined as mild, moderate or severe. An adverse event was defined as any symptom that persisted for more than 30 min or that required investigation or treatment. Of 1,764 consecutive patients, 1,581 (90%) received regadenoson combined with submaximal exercise unless contraindicated. Symptoms were common (63%) but transient and well-tolerated. The severity of symptoms was recorded in most patients as mild (84%). Dyspnoea (36%) and chest discomfort (12%) were the commonest side effects. Adverse events were reported in eight patients (0.5%), thought to be vasovagal in seven of these. All patients recovered fully without sequelae. There were no deaths, myocardial infarction or hospital admissions. Regadenoson stress was performed in 206 patients (12%) with asthma or chronic obstructive pulmonary disease (COPD) without bronchospasm or any other major side effect. We studied the symptom profile of regadenoson in the largest European cohort to date. Regadenoson combined with submaximal exercise was well tolerated, notably also in patients with asthma or COPD. The majority of regadenoson-related adverse events were vasovagal episodes without sequelae.

  1. Identification of insulin in the tear film and insulin receptor and IGF-1 receptor on the human ocular surface.

    Science.gov (United States)

    Rocha, Eduardo M; Cunha, Daniel A; Carneiro, Everardo M; Boschero, Antonio C; Saad, Mário J A; Velloso, Lício A

    2002-04-01

    Insulin produces pleiotropic effects on sensitive tissues, including the ocular surface, through the tyrosine kinase insulin receptor. Cerebrospinal fluid and secreted fluids, such as milk and saliva, have been reported to contain insulin. In the present study, the presence of insulin was examined in tear film, and the expression of insulin and insulin-like growth factor (IGF)-1 receptor was examined in the human cornea and conjunctiva. Stimulated tear samples collected from 33 volunteers (17 men, 16 women), aged 23 to 51 years, who were fed or fasted for 12 hours, were assayed for total protein and insulin content by the biuret dye test and a radioimmunoassay, respectively. Frozen sections of human cornea (n = 4) and conjunctiva (n = 3) were incubated with anti-insulin receptor and anti-IGF-1 receptor antibodies and developed with a secondary antibody-peroxidase conjugate. Insulin was detected in all tear samples analyzed, the mean concentration being 0.404 +/- 0.129 ng/mL. There were no gender-related differences. In fed subjects, tears tended toward a higher insulin content than those in fasted individuals. There was no linear correlation between insulin and total protein content (mean, 4.61 +/- 0.79 mg/mL) in the tear film. Insulin and IGF-1 receptors were detected in the plasma membrane and cytoplasm of corneal and conjunctival epithelial cells. To the best of the authors' knowledge, this study represents the first demonstration of insulin in human tear film and the presence of insulin and IGF-1 receptor on the human ocular surface. These results suggest that the pancreatic hormone may play a metabolic and/or mitogenic role on the ocular surface.

  2. Plasma testosterone and androstenedione in insulin dependent patients at time of diagnosis and during the first year of insulin treatment

    DEFF Research Database (Denmark)

    Gluud, C; Madsbad, S; Krarup, T

    1982-01-01

    Ten male patients and 6 female patients with newly diagnosed insulin dependent diabetes mellitus and significant ketosis were studied before and during the first year of insulin treatment. At onset plasma concentrations of testosterone and androstenedione were significantly (P less than 0...

  3. Insulin sensitivity in post-obese women

    DEFF Research Database (Denmark)

    Toubro, S; Western, P; Bülow, J

    1994-01-01

    1. Both increased and decreased sensitivity to insulin has been proposed to precede the development of obesity. Therefore, insulin sensitivity was measured during a 2 h hyperinsulinaemia (100 m-units min-1 m-2) euglycaemic (4.5 mmol/l) glucose clamp combined with indirect calorimetry in nine weig...... metabolism is unaltered in the post-obese state. The study, however, points to an increased antilipolytic insulin action in post-obese subjects, which may favour fat storage and lower lipid oxidation rate postprandially.(ABSTRACT TRUNCATED AT 250 WORDS)......1. Both increased and decreased sensitivity to insulin has been proposed to precede the development of obesity. Therefore, insulin sensitivity was measured during a 2 h hyperinsulinaemia (100 m-units min-1 m-2) euglycaemic (4.5 mmol/l) glucose clamp combined with indirect calorimetry in nine weight......-1 kg-1, not significant). Basal plasma concentrations of free fatty acids were similar, but at the end of the clamp free fatty acids were lower in the post-obese women than in the control women (139 +/- 19 and 276 +/- 48 mumol/l, P = 0.02). 3. We conclude that the insulin sensitivity of glucose...

  4. Characterization of glucose-mediated insulin release from implantable polymers.

    Science.gov (United States)

    Brown, L R; Edelman, E R; Fischel-Ghodsian, F; Langer, R

    1996-12-01

    We characterized a glucose-sensitive, controlled-release insulin delivery system. Insulin release rates increased when glucose was perfused in the release media surrounding the matrix. The system was composed of solid, particulate insulin, incorporated into an ethylene-vinyl acetate copolymer (EVAc) matrix. Feedback control was mediated by the glucose oxidase enzyme immobilized to Sepharose beads, which were incorporated along with insulin into the EVAc matrix. When glucose in solution entered the insulin delivery system, gluconic acid was produced, causing a drop in the microenvironmental pH of the matrix. This fall in pH resulted in a rise in insulin solubility and consequently a rise in the insulin release rate from the matrix. Insulin concentrations increased in vitro and in vivo in response to glucose infusion. The increased insulin release was shown to consist of a finite pulse of insulin that required an optimal recovery period of 1 h to achieve a maximal repeated response to a glucose stimulus. Repeated pulses were demonstrated over a 4 h period. An optimum enzyme ratio was also determined.

  5. Human adipose tissue expresses intrinsic circadian rhythm in insulin sensitivity.

    Science.gov (United States)

    Carrasco-Benso, Maria P; Rivero-Gutierrez, Belen; Lopez-Minguez, Jesus; Anzola, Andrea; Diez-Noguera, Antoni; Madrid, Juan A; Lujan, Juan A; Martínez-Augustin, Olga; Scheer, Frank A J L; Garaulet, Marta

    2016-09-01

    In humans, insulin sensitivity varies according to time of day, with decreased values in the evening and at night. Mechanisms responsible for the diurnal variation in insulin sensitivity are unclear. We investigated whether human adipose tissue (AT) expresses intrinsic circadian rhythms in insulin sensitivity that could contribute to this phenomenon. Subcutaneous and visceral AT biopsies were obtained from extremely obese participants (body mass index, 41.8 ± 6.3 kg/m(2); 46 ± 11 y) during gastric-bypass surgery. To assess the rhythm in insulin signaling, AKT phosphorylation was determined every 4 h over 24 h in vitro in response to different insulin concentrations (0, 1, 10, and 100 nM). Data revealed that subcutaneous AT exhibited robust circadian rhythms in insulin signaling (P circadian rhythms were detected in visceral AT (P = 0.643). Here, we demonstrate the relevance of the time of the day for how sensitive AT is to the effects of insulin. Subcutaneous AT shows an endogenous circadian rhythm in insulin sensitivity that could provide an underlying mechanism for the daily rhythm in systemic insulin sensitivity.-Carrasco-Benso, M. P., Rivero-Gutierrez, B., Lopez-Minguez, J., Anzola, A., Diez-Noguera, A., Madrid, J. A., Lujan, J. A., Martínez-Augustin, O., Scheer, F. A. J. L., Garaulet, M. Human adipose tissue expresses intrinsic circadian rhythm in insulin sensitivity. © FASEB.

  6. Endurance training inhibits insulin clearance and IDE expression in Swiss mice.

    Directory of Open Access Journals (Sweden)

    José M Costa-Júnior

    Full Text Available Endurance training improves peripheral insulin sensitivity in the liver and the skeletal muscle, but the mechanism for this effect is poorly understood. Recently, it was proposed that insulin clearance plays a major role in both glucose homeostasis and insulin sensitivity. Therefore, our goal was to determine the mechanism by which endurance training improves insulin sensitivity and how it regulates insulin clearance in mice.Mice were treadmill-trained for 4 weeks at 70-80% of maximal oxygen consumption (VO2 max for 60 min, 5 days a week. The glucose tolerance and the insulin resistance were determined using an IPGTT and an IPITT, respectively, and the insulin decay rate was calculated from the insulin clearance. Protein expression and phosphorylation in the liver and the skeletal muscle were ascertained by Western blot.Trained mice exhibited an increased VO2 max, time to exhaustion, glucose tolerance and insulin sensitivity. They had smaller fat pads and lower plasma concentrations of insulin and glucose. Endurance training inhibited insulin clearance and reduced expression of IDE in the liver, while also inhibiting insulin secretion by pancreatic islets. There was increased phosphorylation of both the canonical (IR-AKT and the non-canonical (CaMKII-AMPK-ACC insulin pathways in the liver of trained mice, whereas only the CaMKII-AMPK pathway was increased in the skeletal muscle.Endurance training improved glucose homeostasis not only by increasing peripheral insulin sensitivity but also by decreasing insulin clearance and reducing IDE expression in the liver.

  7. Eight-week aerobic training effects on Apelin-13 and insulin resistance in overweight men

    Directory of Open Access Journals (Sweden)

    Rahman Soori

    2017-06-01

    Full Text Available Background & aims: Obesity as a pandemic disease is the high accumulation of adipose tissue which secrets different hormones such as apelin. Apelin as an adipocytokine increases in obesity. Aerobic training induced apelin responses are not clarify well. So, we aimed to determine the effect of eight weeks aerobic training on Apelin-13 and insulin resistance in overweight men. Methods: Current study was quasi-experiment design. Twenty-six overweight men with BMI between 27-30 kg/m2 were randomly enrolled in the present study following public call announcement and match to inclusion criteria. They accidently divided into submaximal-aerobic and control groups. The submaximal-aerobic group carried out exercise training for 24 continuous sessions (with 50-70% of maximum heart rate and 3 sessions/per-week for eight weeks. The anthropometrical, VO2max and blood sampling assessments performed and later assessments were completed 24 hours after last training period. Then, whole of data were analyzed by Stata software at P0.05. In addition, there were direct and significant relationship between anthropometrical indices and HbA1c with Apelin-13 (p<0.05. Conclusions: Obesity increases the possibility of metabolic diseases and insulin resistance. In the current study we represented that the internal factors of exercise, such as intensity, had meaningful effects on anthropometric features of overweight individuals but it was not enough for exercise induced-apelin-13 and insulin resistance changes.  According to this record, longer and higher intense exercise compare with the current study's protocol were recommended to beneficially decrease and control the incidence and catch the type II diabetes and cardiovascular diseases.

  8. Stimulation of myenteric plexus neurite outgrowth by insulin and insulin-like growth factors I and II.

    Science.gov (United States)

    Mulholland, M W; Romanchuk, G; Simeone, D M; Flowe, K

    1992-01-01

    A defined culture medium containing insulin, insulin-like growth factor I (IGF-I) or insulin-like growth factor II (IGF-II) supported morphological development of myenteric plexus neurons derived from neonatal guinea pigs. Insulin increased neurite outgrowth 3-fold at concentrations as low as 0.2 nM. Similar significant and dose-dependent increases in neurite outgrowth were noted with IGF-I and IGF-II. Stimulation of neurite outgrowth was abolished by exposure to cytosine arabinofuranoside, an agent toxic to non-neuronal cells, implying that trophic effects of insulin or insulin-like growth factors require the presence of non-neuronal elements in culture.

  9. DGKζ deficiency protects against peripheral insulin resistance and improves energy metabolism.

    Science.gov (United States)

    Benziane, Boubacar; Borg, Melissa L; Tom, Robby Z; Riedl, Isabelle; Massart, Julie; Björnholm, Marie; Gilbert, Marc; Chibalin, Alexander V; Zierath, Juleen R

    2017-12-01

    Diacylglycerol kinases (DGKs) regulate the balance between diacylglycerol (DAG) and phosphatidic acid. DGKζ is highly abundant in skeletal muscle and induces fiber hypertrophy. We hypothesized that DGKζ influences functional and metabolic adaptations in skeletal muscle and whole-body fuel utilization. DAG content was increased in skeletal muscle and adipose tissue, but unaltered in liver of DGKζ KO mice. Linear growth, body weight, fat mass, and lean mass were reduced in DGKζ KO versus wild-type mice. Conversely, male DGKζ KO and wild-type mice displayed a similar robust increase in plantaris weight after functional overload, suggesting that DGKζ is dispensable for muscle hypertrophy. Although glucose tolerance was similar, insulin levels were reduced in high-fat diet (HFD)-fed DGKζ KO versus wild-type mice. Submaximal insulin-stimulated glucose transport and p-Akt Ser 473 were increased, suggesting enhanced skeletal muscle insulin sensitivity. Energy homeostasis was altered in DGKζ KO mice, as evidenced by an elevated respiratory exchange ratio, independent of altered physical activity or food intake. In conclusion, DGKζ deficiency increases tissue DAG content and leads to modest growth retardation, reduced adiposity, and protection against insulin resistance. DGKζ plays a role in the control of growth and metabolic processes, further highlighting specialized functions of DGK isoforms in type 2 diabetes pathophysiology. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

  10. Short-term insulin treatment prevents the diabetogenic action of streptozotocin in rats

    DEFF Research Database (Denmark)

    Thulesen, J; Orskov, C; Holst, J J

    1997-01-01

    on the diabetogenic action of streptozotocin (60 mg/kg). Four groups of rats were studied: 1) a group that received streptozotocin (STZ), 2) a group that received insulin pretreatment and streptozotocin (INS + STZ), 3) a group that received insulin (INS), and 4) a control group (CTRL). Insulin treatment reduced...... the beta-cell immunoreactivity (IR) of insulin and GLUT2, which, thus, was reduced in INS + STZ rats at the time of streptozotocin injection. In STZ rats, plasma insulin concentrations after 3 weeks as well as insulin concentrations in pancreatic tissue samples were significantly lower than those in CTRL.......9 pmol/liter (P = 0.08); tissue, 0.46 +/- 0.02 vs. 37.90 +/- 2.13 nmol/g (P pancreatic tissues were in accordance with the results obtained by RIA. We conclude that exogenous insulin suppresses the expression of GLUT2 and insulin in beta...

  11. Differential effects of insulin injections and insulin infusions on levels ...

    African Journals Online (AJOL)

    Studies have shown that while injections of insulin cause an increase in fat mass, infusions of insulin increase fat mass. The aim of this paper was to test the hypothesis that if an increase in glycogen is an indicator of an impending increase in adipose mass, then insulin infusions should not increase glycogen, while insulin ...

  12. Cold exposure enhances fat utilization but not non-esterified fatty acids, glycerol or catecholamines availability during submaximal walking and running.

    Science.gov (United States)

    Gagnon, Dominique D; Rintamäki, Hannu; Gagnon, Sheila S; Cheung, Stephen S; Herzig, Karl-Heinz; Porvari, Katja; Kyröläinen, Heikki

    2013-01-01

    Cold exposure modulates the use of carbohydrates (CHOs) and fat during exercise. This phenomenon has mostly been observed in controlled cycling studies, but not during walking and running when core temperature and oxygen consumption are controlled, as both may alter energy metabolism. This study aimed at examining energy substrate availability and utilization during walking and running in the cold when core temperature and oxygen consumption are maintained. Ten lightly clothed male subjects walked or ran for 60-min, at 50% and 70% of maximal oxygen consumption, respectively, in a climatic chamber set at 0°C or 22°C. Thermal, cardiovascular, and oxidative responses were measured every 15-min during exercise. Blood samples for serum non-esterified fatty acids (NEFAs), glycerol, glucose, beta-hydroxybutyrate (BHB), plasma catecholamines, and serum lipids were collected immediately prior, and at 30- and 60-min of exercise. Skin temperature strongly decreased while core temperature did not change during cold trials. Heart rate (HR) was also lower in cold trials. A rise in fat utilization in the cold was seen through lower respiratory quotient (RQ) (-0.03 ± 0.02), greater fat oxidation (+0.14 ± 0.13 g · min(-1)) and contribution of fat to total energy expenditure (+1.62 ± 1.99 kcal · min(-1)). No differences from cold exposure were observed in blood parameters. During submaximal walking and running, a greater reliance on derived fat sources occurs in the cold, despite the absence of concurrent alterations in NEFAs, glycerol, or catecholamine concentrations. This disparity may suggest a greater reliance on intra-muscular energy sources such as triglycerides during both walking and running.

  13. Cold exposure enhances fat utilization but not non-esterified fatty acids, glycerol or catecholamines availability during submaximal walking and running

    Directory of Open Access Journals (Sweden)

    Dominique Daniel Gagnon

    2013-05-01

    Full Text Available Cold exposure modulates the use of carbohydrates and fat during exercise. This phenomenon has mostly been observed in controlled cycling studies, but not during walking and running when core temperature and oxygen consumption are controlled, as both may alter energy metabolism. This study aimed at examining energy substrate availability and utilization during walking and running in the cold when core temperature and oxygen consumption are maintained. Ten lightly clothed male subjects walked or ran for 60-min, at 50% and 70% of maximal oxygen consumption, respectively, in a climatic chamber set at 0°C or 22°C. Thermal, cardiovascular, and oxidative responses were measured every 15-min during exercise. Blood samples for serum non-esterified fatty acids, glycerol, glucose, beta-hydroxybutyrate, plasma catecholamines, and serum lipids were collected immediately prior, and at 30- and 60-min of exercise. Skin temperature strongly decreased while core temperature did not change during cold trials. Heart rate was also lower in cold trials. A rise in fat utilization in the cold was seen through lower respiratory quotient (-0.03 ± 0.02, greater fat oxidation (+0.14 ± 0.13 g•min-1 and contribution of fat to total energy expenditure (+1.62 ± 1.99 kcal•min-1. No differences from cold exposure were observed in blood parameters. During submaximal walking and running, a greater reliance on derived fat sources occurs in the cold, despite the absence of concurrent alterations in non-esterified fatty acids, glycerol, or catecholamine concentrations. This disparity may suggest a greater reliance on intra-muscular energy sources such as triglycerides during both walking and running.

  14. Rac1 signaling is required for insulin-stimulated glucose uptake and is dysregulated in insulin-resistant murine and human skeletal muscle

    DEFF Research Database (Denmark)

    Sylow, Lykke; Jensen, Thomas Elbenhardt; Kleinert, Maximilian

    2013-01-01

    The actin-cytoskeleton-regulating GTPase Rac1 is required for insulin-stimulated GLUT4 translocation in cultured muscle cells. However, involvement of Rac1 and its downstream signaling in glucose transport in insulin sensitive and insulin resistant mature skeletal muscle has not previously been...... inhibition of Rac1 were used to determine whether Rac1 regulates insulin-stimulated glucose transport in mature skeletal muscle. Furthermore, Rac1 and PAK1 expression and signalling were investigated in muscle of insulin resistant mice and humans.Inhibition and KO of Rac1 decreased insulin-stimulated glucose...... transport in mouse soleus and EDL muscles ex vivo. Rac1 KO mice showed decreased insulin and glucose tolerance and trended towards higher plasma insulin concentrations following intraperitoneal glucose injection. Rac1 protein expression and PAK(Thr423) phosphorylation were decreased in muscles of high fat...

  15. Insulin in diabetes prevention.

    Science.gov (United States)

    Ramiya, V K; Maclaren, N K

    1997-01-01

    Insulin-dependent diabetes (IDD) is a chronic immune-endocrine disease in which there is a progressive destruction of insulin-secreting pancreatic beta cells, caused primarily by autoreactive T cells. Many islet cell proteins including insulin, glutamic acid decarboxylase, and tyrosine phosphatase antigens (IA-2) are targeted by the autoimmune responses in IDD patients. Since its discovery 75 years ago, insulin has been the major player in the clinical management of hyperglycaemia in these patients. The morbidity and mortality associated with IDD derives mainly from the complications of the disease. However, routine insulin injections seldom achieve a consistent, near-normal glucose level, where multiple daily doses of the hormone involve considerable restrictions to a normal lifestyle. In terms of economics, the management of diabetes is expensive, and in the USA diabetes alone accounts for one seventh of the healthcare budget. These clinical, lifestyle and economic issues emphasize the need to investigate alternative preventative measures in IDD treatment. Recent reports suggest a pivotal role for insulin in various aspects of the immune system. In this study, insulin and B-chain were used to modulate autoimmune responses in non-obese diabetic mice, findings which have therapeutic implications in man.

  16. Insulin and insulin-like growth factor-1 induce pronounced hypertrophy of skeletal myofibers in tissue culture

    Science.gov (United States)

    Vandenburgh, Herman H.; Karlisch, Patricia; Shansky, Janet

    1990-01-01

    Skeletal myofibers differentiated from primary avian myoblasts in tissue culture can be maintained in positive nitrogen balance in a serum-free medium for at least 6 to 7 days when embedded in a three dimensional collagen gel matrix. The myofibers are metabolically sensitive to physiological concentrations of insulin but these concentrations do not stimulate cell growth. Higher insulin concentrations stimulate both cell hyperplasia and myofiber hypertrophy. Cell growth results from a long term 42 percent increase in total protein synthesis and a 38 percent increase in protein degradation. Myofiber diameters increase by 71 to 98 percent after 6 to 7 days in insulin-containing medium. Insulin-like growth factor-1 but not insulin-like growth factor-2, at 250 ng/ml, is as effective as insulin in stimulating cell hyperplasia and myofiber hypertrophy. This model system provides a new method for studying the long-term anabolic effects of insulin and insulin-like growth factors on myofiber hypertrophy under defined tissue culture conditions.

  17. Faster in and faster out: accelerating insulin absorption and action by insulin infusion site warming.

    Science.gov (United States)

    Cengiz, Eda; Weinzimer, Stuart A; Sherr, Jennifer L; Tichy, Eileen M; Carria, Lori; Cappiello, Darryll; Steffen, Amy; Tamborlane, William V

    2014-01-01

    This study was undertaken to investigate the effect of an insulin infusion site warming device, the InsuPatch(40)(™) (IP(40)) (InsuLine Medical Ltd., Petach-Tikvah, Israel), on insulin aspart pharmacodynamics (PD) and pharmacokinetics (PK) in adolescents with type 1 diabetes. Seventeen subjects with type 1 diabetes (age, 15±1 years; hemoglobin A1c, 7.5±0.2% [58±2.2 mmol/mol]) underwent two euglycemic clamps performed on separate mornings with and without IP(40) activation with warming temperature at 40°C. On both days, the basal infusion was suspended, and glucose levels were maintained between 90 and 100 mg/dL by a variable rate dextrose infusion for up to 5 h after a 0.2 U/kg bolus of insulin aspart. Time to peak insulin action and time to half-maximal action occurred earlier with a greater early glucodynamic effect (area under the curve [AUC] for glucose infusion rate from 0 to 30 min) with IP(40) than without the IP(40), whereas the AUC for the time-action profile and the peak action did not differ with and without infusion site warming. PK parameters were in agreement with PD parameters, namely, a significantly earlier time to reach the maximum increment in insulin concentrations and greater early bioavailability (AUC for the change in insulin concentration from 0 to 30 min) with the IP(40). The tail of the plasma insulin response curve was also shortened with infusion site warming, with the time to reach baseline insulin concentration occurring significantly earlier (P=0.04). Our data demonstrate that skin warming around the infusion site to 40°C with the IP(40) is an effective means to accelerate absorption and action of rapid-acting insulin. These improvements in time-action responses have the potential to enhance the performance of open- and closed-loop insulin delivery systems.

  18. The Insulin-Like Growth Factor System in Obesity, Insulin Resistance and Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Moira S. Lewitt

    2014-12-01

    Full Text Available The insulin-like growth factor (IGF system, acting in concert with other hormone axes, is important in normal metabolism. In obesity, the hyperinsulinaemia that accompanies peripheral insulin resistance leads to reduced growth hormone (GH secretion, while total IGF-I levels are relatively unchanged due to increased hepatic GH sensitivity. IGF-binding protein (IGFBP-1 levels are suppressed in relation to the increase in insulin levels in obesity and low levels predict the development of type 2 diabetes several years later. Visceral adiposity and hepatic steatosis, along with a chronic inflammation, contribute to the IGF system phenotype in individuals with metabolic syndrome and type 2 diabetes mellitus, including changes in the normal inverse relationship between IGFBP-1 and insulin, with IGFBP-1 concentrations that are inappropriately normal or elevated. The IGF system is implicated in the vascular and other complications of these disorders and is therefore a potential therapeutic target.

  19. Effect of tequila on homocysteine, insulin secretion, insulin sensitivity, and metabolic profile in healthy men.

    Science.gov (United States)

    González-Ortiz, Manuel; Pascoe-González, Sara; Kam-Ramos, Angélica M; Martínez-Abundis, Esperanza

    2005-01-01

    The purpose of this study is to identify the effect of a low dose of tequila on homocysteine, insulin secretion, insulin sensitivity, and metabolic profile in healthy young men. An open clinical trial was carried out in eight healthy nonobese, young male volunteers. The study was divided in two phases. The first one evaluated metabolic changes, including insulin secretion and sensitivity due to acute administration of 30 ml of straight tequila. The second phase of the study evaluated metabolic effects due to the daily administration of 30 ml of tequila during 30 days. There were no significant metabolic changes after the single oral administration of 30 ml of straight tequila. After the administration of tequila during 30 days, a significant increase in homocysteine levels and a tendency to increase the glucose concentration and to decrease the insulin sensitivity were found. Detrimental metabolic changes were observed with the daily administration of 30 ml of tequila during 30 days.

  20. Determinação das concentrações séricas de glicose e insulina de cães em choque endotóxico Evaluation of glucose and insulin serum concentrations of dogs in endotoxic shock

    Directory of Open Access Journals (Sweden)

    Márcia Mery Kogika

    2001-10-01

    therapy suggested by many authors includes glucose and insulin replacement to improve tissue glucose utilization; however, there are some contradictions about insulin serum concentration values in patients with septic shock, making questionable the need for insulin replacement. This study evaluated glucose serum concentration changes in dogs with septic shock and insulin serum concentrations (absolute and relative ratios in the hypoglycemic group obtaining information that may help the therapy of hypodinamic shock. Twenty-five dogs seen in the emergency room of the Veterinary Teaching Hospital of Universidade de São Paulo showing signs of endotoxic shock due to a hemorragic gastroenteritis (presumptive diagnosis of parvovirus infection were evaluated in this study. There were 52% hypoglycemic animals, 36% normoglycemic and 12% were hyperglycemic. Out of 13 hypoglycemic dogs, 3 had absolute and relative hyperinsulinemia and only relative hyperinsulinemia in 6 dogs. Absolute hypoinsulinemia was observed in 2 animals. The finding that more than a half of the animals in the hypodinamic state of shock presented absolute or relative hyperinsulinemia, denoted the demand of carefull laboratorial evaluation of the patient prior to insulin administration. The administration should be reserved for animals with periferic resistance or decrease in insulin serum concentration.

  1. Molecular mechanism of insulin resistance

    Indian Academy of Sciences (India)

    PRAKASH

    studies in β cell-specific IR knockout mice, which develop peripheral insulin resistance and diabetes, most probably due to the changes in the pattern of insulin secretion (Kulkarni et al 1999). FFA also affects downstream insulin signalling molecules. It inhibits insulin activation of IRS-1-associated PI3K activity in muscle.

  2. Decreased acylcarnitine content improves insulin sensitivity in experimental mice models of insulin resistance.

    Science.gov (United States)

    Liepinsh, Edgars; Makrecka-Kuka, Marina; Makarova, Elina; Volska, Kristine; Svalbe, Baiba; Sevostjanovs, Eduards; Grinberga, Solveiga; Kuka, Janis; Dambrova, Maija

    2016-11-01

    The important pathological consequences of insulin resistance arise from the detrimental effects of accumulated long-chain fatty acids and their respective acylcarnitines. The aim of this study was to test whether exercise combined with decreasing the content of long-chain acylcarnitines represents an effective strategy to improve insulin sensitivity in diabetes. We used a novel compound, 4-[ethyl(dimethyl)ammonio]butanoate (methyl-GBB), treatment and exercise to decrease acylcarnitine contents in the plasma and muscles in the insulin resistance models of high fat diet (HFD) fed C57BL/6 mice and db/db mice. The methyl-GBB treatment induced a substantial decrease in all acylcarnitine concentrations in both fed and fasted states as well as when it was combined with exercise. In the HFD fed mice methyl-GBB treatment improved both glucose and insulin tolerance. Methyl-GBB administration, exercise and the combination of both improved insulin sensitivity and reduced blood glucose levels in db/db mice. Methyl-GBB administration and the combination of the drug and exercise activated the PPARα/PGC1α signaling pathway and stimulated the corresponding target gene expression. Insulin insensitivity in db/db mice was not induced by significantly increased fatty acid metabolism, while increased insulin sensitivity by both treatments was not related to decreased fatty acid metabolism in muscles. The pharmacologically reduced long-chain acylcarnitine content represents an effective strategy to improve insulin sensitivity. The methyl-GBB treatment and lifestyle changes via increased physical activity for one hour a day have additive insulin sensitizing effects in db/db mice. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Bioactives in Blueberries Improve Insulin Sensitivity in Obese, Insulin-Resistant Men and Women1234

    Science.gov (United States)

    Stull, April J.; Cash, Katherine C.; Johnson, William D.; Champagne, Catherine M.; Cefalu, William T.

    2010-01-01

    Dietary supplementation with whole blueberries in a preclinical study resulted in a reduction in glucose concentrations over time. We sought to evaluate the effect of daily dietary supplementation with bioactives from blueberries on whole-body insulin sensitivity in men and women. A double-blinded, randomized, and placebo-controlled clinical study design was used. After screening to resolve study eligibility, baseline (wk 0) insulin sensitivity was measured on 32 obese, nondiabetic, and insulin-resistant subjects using a high-dose hyperinsulinemic-euglycemic clamp (insulin infusion of 120 mU(861 pmol)⋅m−2⋅min−1). Serum inflammatory biomarkers and adiposity were measured at baseline. At the end of the study, insulin sensitivity, inflammatory biomarkers, and adiposity were reassessed. Participants were randomized to consume either a smoothie containing 22.5 g blueberry bioactives (blueberry group, n = 15) or a smoothie of equal nutritional value without added blueberry bioactives (placebo group, n = 17) twice daily for 6 wk. Both groups were instructed to maintain their body weight by reducing ad libitum intake by an amount equal to the energy intake of the smoothies. Participants’ body weights were evaluated weekly and 3-d food records were collected at baseline, the middle, and end of the study. The mean change in insulin sensitivity improved more in the blueberry group (1.7 ± 0.5 mg⋅kg FFM−1⋅min−1) than in the placebo group (0.4 ± 0.4 mg⋅kg FFM−1⋅min−1) (P = 0.04). Insulin sensitivity was enhanced in the blueberry group at the end of the study without significant changes in adiposity, energy intake, and inflammatory biomarkers. In conclusion, daily dietary supplementation with bioactives from whole blueberries improved insulin sensitivity in obese, nondiabetic, and insulin-resistant participants. PMID:20724487

  4. Monitoring Training Progress During Exercise Training in Cancer Survivors : A Submaximal Exercise Test as an Alternative for a Maximal Exercise Test?

    NARCIS (Netherlands)

    May, Anne M.; van Weert, Ellen; Korstjens, Irene; Hoekstra-Weebers, Josette E.; van der Schans, Cees P.; Zonderland, Maria L.; Mesters, Ilse; van den Borne, Bart; Ros, Wynand J.

    May AM, van Weert E, Korstjens 1, Hoekstra-Weebers JE, van der Schans CP, Zonderland ML, Mesters 1, van den Borne B, Ros WJ. Monitoring training progress during exercise training in cancer survivors: a submaximal exercise test as an alternative for a maximal exercise test? Arch Phys Med Rehabil

  5. Assessment of muscle endurance of the knee extensor muscles in adolescents with spastic cerebral palsy using a submaximal repetitions-to-fatigue protocol.

    Science.gov (United States)

    Eken, Maaike M; Dallmeijer, Annet J; Doorenbosch, Caroline A; Dekkers, Hurnet; Becher, Jules G; Houdijk, Han

    2014-10-01

    To compare muscle endurance in adolescents with spastic cerebral palsy (CP) with typically developing (TD) peers using a submaximal repetitions-to-fatigue (RTF) protocol. Cross sectional. Human motion laboratory. Adolescents with spastic CP (n=16; Gross Motor Function Classification System levels I or II) and TD adolescents (n=18) within the age range of 12 to 19 years old. Not applicable. Each participant performed 3 RTF tests at different submaximal loads, ranging from 50% to 90% of their maximal voluntary knee extension torque. The relation between the number of repetitions (repetition maximum [RM]) and imposed submaximal relative (percent of maximal voluntary torque [%MVT]) and absolute (Nm/kg) torque was quantified. To compare adolescents with CP with TD adolescents, a mixed linear model was used to construct load endurance curves. Surface electromyography of quadriceps muscles was measured to assess changes in normalized amplitude and median frequency (MF) as physiological indicators of muscle fatigue. Adolescents with CP showed a larger decrease in %MVT per RM than TD adolescents (Pmuscles in all tests for both groups. Electromyographic MF decreased significantly (Pmuscle fatigue were reached. Adolescents with CP show slightly lower muscle endurance compared with TD adolescents on a submaximal RTF protocol, which is in contrast with earlier findings in a maximal voluntary fatigue protocol. Accordingly, adolescents with CP have a reduced capacity to endure activities at similar relative loads compared with TD adolescents. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  6. Effects of intranasal insulin on hepatic fat accumulation and energy metabolism in humans.

    Science.gov (United States)

    Gancheva, Sofiya; Koliaki, Chrysi; Bierwagen, Alessandra; Nowotny, Peter; Heni, Martin; Fritsche, Andreas; Häring, Hans-Ulrich; Szendroedi, Julia; Roden, Michael

    2015-06-01

    Studies in rodents suggest that insulin controls hepatic glucose metabolism through brain-liver crosstalk, but human studies using intranasal insulin to mimic central insulin delivery have provided conflicting results. In this randomized controlled crossover trial, we investigated the effects of intranasal insulin on hepatic insulin sensitivity (HIS) and energy metabolism in 10 patients with type 2 diabetes and 10 lean healthy participants (CON). Endogenous glucose production was monitored with [6,6-(2)H2]glucose, hepatocellular lipids (HCLs), ATP, and inorganic phosphate concentrations with (1)H/(31)P magnetic resonance spectroscopy. Intranasal insulin transiently increased serum insulin levels followed by a gradual lowering of blood glucose in CON only. Fasting HIS index was not affected by intranasal insulin in CON and patients. HCLs decreased by 35% in CON only, whereas absolute hepatic ATP concentration increased by 18% after 3 h. A subgroup of CON received intravenous insulin to mimic the changes in serum insulin and blood glucose levels observed after intranasal insulin. This resulted in a 34% increase in HCLs without altering hepatic ATP concentrations. In conclusion, intranasal insulin does not affect HIS but rapidly improves hepatic energy metabolism in healthy humans, which is independent of peripheral insulinemia. These effects are blunted in patients with type 2 diabetes. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  7. Dichloroacetate therapy attenuates the blood lactate response to submaximal exercise in patients with defects in mitochondrial energy metabolism.

    Science.gov (United States)

    Duncan, G E; Perkins, L A; Theriaque, D W; Neiberger, R E; Stacpoole, P W

    2004-04-01

    We determined acute and chronic effects of dichloroacetate (DCA) on maximal (MAX) and submaximal (SUB) exercise responses in patients with abnormal mitochondrial energetics. Subjects (n = 9) completed a MAX treadmill bout 1 h after ingesting 25 mg/kg DCA or placebo (PL). A 15-min SUB bout was completed the next day while receiving the same treatment. After a 1-d washout, MAX and SUB were repeated while receiving the alternate treatment (acute). Gas exchange and heart rate were measured throughout all tests. Blood lactate (Bla) was measured 0, 3, and 10 min after MAX, and 5, 10, and 15 min during SUB. MAX and SUB were repeated after 3 months of daily DCA or PL. After a 2-wk washout, a final MAX and SUB were completed after 3 months of alternate treatment (chronic). Average Bla during SUB was lower (P abnormal mitochondrial energetics.

  8. Enhanced insulin secretion and insulin sensitivity in young lambs with placental insufficiency-induced intrauterine growth restriction.

    Science.gov (United States)

    Camacho, Leticia E; Chen, Xiaochuan; Hay, William W; Limesand, Sean W

    2017-08-01

    Intrauterine growth restriction (IUGR) is associated with persistent metabolic complications, but information is limited for IUGR infants. We determined glucose-stimulated insulin secretion (GSIS) and insulin sensitivity in young lambs with placental insufficiency-induced IUGR. Lambs with hyperthermia-induced IUGR ( n = 7) were compared with control lambs ( n = 8). GSIS was measured at 8 ± 1 days of age, and at 15 ± 1 days, body weight-specific glucose utilization rates were measured with radiolabeled d-glucose during a hyperinsulinemic-euglycemic clamp (HEC). IUGR lambs weighed 23% less ( P insulin concentrations were not different between IUGR and controls for either study. First-phase insulin secretion was enhanced 2.3-fold in IUGR lambs compared with controls. However, second-phase insulin concentrations, glucose-potentiated arginine-stimulated insulin secretion, and β-cell mass were not different, indicating that IUGR β-cells have an intrinsic enhancement in acute GSIS. Compared with controls, IUGR lambs had higher body weight-specific glucose utilization rates and greater insulin sensitivity at fasting (1.6-fold) and hyperinsulinemic periods (2.4-fold). Improved insulin sensitivity for glucose utilization was not due to differences in skeletal muscle insulin receptor and glucose transporters 1 and 4 concentrations. Plasma lactate concentrations during HEC were elevated in IUGR lambs compared with controls, but no differences were found for glycogen content or citrate synthase activity in liver and muscle. Greater insulin sensitivity for glucose utilization and enhanced acute GSIS in young lambs are predicted from fetal studies but may promote conditions that exaggerate glucose disposal and lead to episodes of hypoglycemia in IUGR infants. Copyright © 2017 the American Physiological Society.

  9. AMPK and insulin action

    DEFF Research Database (Denmark)

    Frøsig, Christian; Jensen, Thomas Elbenhardt; Jeppesen, Jacob

    2013-01-01

    The 5'-AMP-activated protein kinase (AMPK) is considered "a metabolic master-switch" in skeletal muscle reducing ATP- consuming processes whilst stimulating ATP regeneration. Within recent years, AMPK has also been proposed as a potential target to attenuate insulin resistance, although the exact...... role of AMPK is not well understood. Here we hypothesized that mice lacking a2AMPK activity in muscle would be more susceptible to develop insulin resistance associated with ageing alone or in combination with high fat diet. Young (~4 month) or old (~18 month) wild type and muscle specific a2AMPK...... kinase-dead mice on chow diet as well as old mice on 17 weeks of high fat diet were studied for whole body glucose homeostasis (OGTT, ITT and HOMA-IR), insulin signaling and insulin-stimulated glucose uptake in muscle. We demonstrate that high fat diet in old mice results in impaired glucose homeostasis...

  10. Ekstrak Air Tapak Dara Menurunkan Kadar Gula dan Meningkatkan Jumlah Sel Beta Pankreas Kelinci Hiperglikemia (THE WATER EXTRACT OF TAPAK DARA DECREASES BLOOD GLUCOSE CONCENTRATION AND INCREASES INSULIN PRODUCTION BY PANCREATIC BETA-CELLS ON HYPERGLYCEMIC

    Directory of Open Access Journals (Sweden)

    Srikayati Widyastuti

    2012-03-01

    Full Text Available The present study was carried out to investigate the effects of tapak dara (Catharanthus roseus onblood glucose level and insulin profile in hyperglicemic rabbits. Fifeteen local male rabbits were used forthis study. The rabbits were randomly divided into five groups. Group 1 (K-, a control negative group;group 2 (K+, a control positive hipergliccemia; group 3 (KT1 and group 4 (KT2, were groups hiperglicemiaand treated with water extract of tapak dara doses 1 and 2 g/kg bw, respectively; and group 5 (KO, a grouphiperglicemia that treated with glibenclamide 2 mg/kg bw. The result showed water extract of tapak daradose 1 g/kgbw could not decrease the blood glucose level in hyperglycemic rabbits, while dose 2 g/kg bwcould decline blood glucose level in rabbits. This decline had no significantly difference compared withglibenclamide treatment (P> 0.05. Immunohistchemistry result indicated that water extract of tapakdara could stimulate beta cells pancreas to produce insulin.

  11. Circulating omentin concentration increases after weight loss

    Directory of Open Access Journals (Sweden)

    Ricart Wifredo

    2010-04-01

    Full Text Available Abstract Background Omentin-1 is a novel adipokine expressed in visceral adipose tissue and negatively associated with insulin resistance and obesity. We aimed to study the effects of weight loss-induced improved insulin sensitivity on circulating omentin concentrations. Methods Circulating omentin-1 (ELISA concentration in association with metabolic variables was measured in 35 obese subjects (18 men, 17 women before and after hypocaloric weight loss. Results Baseline circulating omentin-1 concentrations correlated negatively with BMI (r = -0.58, p Conclusion As previously described with adiponectin, circulating omentin-1 concentrations increase after weight loss-induced improvement of insulin sensitivity.

  12. Insulin and insulin signaling play a critical role in fat induction of insulin resistance in mouse

    Science.gov (United States)

    Ning, Jie; Hong, Tao; Yang, Xuefeng; Mei, Shuang; Liu, Zhenqi; Liu, Hui-Yu

    2011-01-01

    The primary player that induces insulin resistance has not been established. Here, we studied whether or not fat can cause insulin resistance in the presence of insulin deficiency. Our results showed that high-fat diet (HFD) induced insulin resistance in C57BL/6 (B6) mice. The HFD-induced insulin resistance was prevented largely by the streptozotocin (STZ)-induced moderate insulin deficiency. The STZ-induced insulin deficiency prevented the HFD-induced ectopic fat accumulation and oxidative stress in liver and gastrocnemius. The STZ-induced insulin deficiency prevented the HFD- or insulin-induced increase in hepatic expression of long-chain acyl-CoA synthetases (ACSL), which are necessary for fatty acid activation. HFD increased mitochondrial contents of long-chain acyl-CoAs, whereas it decreased mitochondrial ADP/ATP ratio, and these HFD-induced changes were prevented by the STZ-induced insulin deficiency. In cultured hepatocytes, we observed that expressions of ACSL1 and -5 were stimulated by insulin signaling. Results in cultured cells also showed that blunting insulin signaling by the PI3K inhibitor LY-294002 prevented fat accumulation, oxidative stress, and insulin resistance induced by the prolonged exposure to either insulin or oleate plus sera that normally contain insulin. Finally, knockdown of the insulin receptor prevented the oxidative stress and insulin resistance induced by the prolonged exposure to insulin or oleate plus sera. Together, our results show that insulin and insulin signaling are required for fat induction of insulin resistance in mice and cultured mouse hepatocytes. PMID:21586696

  13. Torque decrease during submaximal evoked contractions of the quadriceps muscle is linked not only to muscle fatigue.

    Science.gov (United States)

    Matkowski, Boris; Lepers, Romuald; Martin, Alain

    2015-05-01

    The aim of this study was to analyze the neuromuscular mechanisms involved in the torque decrease induced by submaximal electromyostimulation (EMS) of the quadriceps muscle. It was hypothesized that torque decrease after EMS would reflect the fatigability of the activated motor units (MUs), but also a reduction in the number of MUs recruited as a result of changes in axonal excitability threshold. Two experiments were performed on 20 men to analyze 1) the supramaximal twitch superimposed and evoked at rest during EMS (Experiment 1, n = 9) and 2) the twitch response and torque-frequency relation of the MUs activated by EMS (Experiment 2, n = 11). Torque loss was assessed by 15 EMS-evoked contractions (50 Hz; 6 s on/6 s off), elicited at a constant intensity that evoked 20% of the maximal voluntary contraction (MVC) torque. The same stimulation intensity delivered over the muscles was used to induce the torque-frequency relation and the single electrical pulse evoked after each EMS contraction (Experiment 2). In Experiment 1, supramaximal twitch was induced by femoral nerve stimulation. Torque decreased by ~60% during EMS-evoked contractions and by only ~18% during MVCs. This was accompanied by a rightward shift of the torque-frequency relation of MUs activated and an increase of the ratio between the superimposed and posttetanic maximal twitch evoked during EMS contraction. These findings suggest that the torque decrease observed during submaximal EMS-evoked contractions involved muscular mechanisms but also a reduction in the number of MUs recruited due to changes in axonal excitability. Copyright © 2015 the American Physiological Society.

  14. Interaction of insulin with SDS/CTAB catanionic Vesicles

    Energy Technology Data Exchange (ETDEWEB)

    Tah, Bidisha; Pal, Prabir; Talapatra, G.B., E-mail: spgbt@iacs.res.in

    2014-01-15

    In the present study, a novel method was used for entrapping the protein, insulin into the catanionic SDS/CTAB vesicle membrane. The anionic SDS and cationic CTAB formed catanionic vesicles at particular concentration (35:65 by volume). In this study, vesicle membrane can be considered as model membrane. The vesicle formation and entrapment efficiency depend on the pH of the aqueous solution. The insulin molecules have attached with the vesicular membrane at pH 7.0. However, at acidic pH, the vesicles were ruptured and the insulin did not entrap into the vesicle membrane, whereas at alkaline pH insulin became fibriller. The scanning electron microscope (SEM), Dynamic light scattering (DLS), and Zeta potential studies established the self-assembled structure formation of insulin and catanionic vesicles. To know the protein confirmations, Circular dichroism (CD) was also employed. The temperature dependent steady state and time resolved emission spectroscopy show that at room temperature (25 °C), apart from the 305 nm tyrosine fluorescence, a new emission peak at 450 nm was observed only in case of insulin-vesicle system, and was assigned as the tyrosine phosphorescence. This phosphorescence peak is the signature of the entrapment of insulin into the vesicle membrane. Highlights: • SDS-CTAB based catanionic vesicle has been fabricated. • Insulin has been successfully immobilized on these vesicles. • Immobilized insulin shows room temperature phosphorescence.

  15. Retinol binding protein 4, obesity, and insulin resistance in adolescents

    Directory of Open Access Journals (Sweden)

    Ronaldi Noor

    2017-02-01

    Full Text Available Background Obesity is a global problem. Even in poor and developing countries, obesity has reached alarming levels. In childhood, obesity may lead to insulin resistance. Retinol binding protein (RBP4, secreted primarily by liver and adipose tissues, was recently proposed as a link between obesity and insulin resistance. The role of RBP4 in pediatric obesity and its relationship with insulin resistance have not been well elucidated. Objective To compare RBP4 levels in obese and lean adolescents and to assess for a relationship between RBP4 levels and insulin resistance. Method This cross-sectional study was conducted in three senior high schools in Padang, West Sumatera, Indonesia. Subjects were adolescents aged 14-18 years, who were obese or normal weight (n=56. We measured subjects’ body mass index (BMI and serum RBP4 concentrations. Insulin resistance was assessed using the homeostasis model assessment of insulin resistance (HOMA-IR index. Results Similar RBP4 levels were found in the obese and normoweight groups (P>0.05. Higher RBP4 levels were found in the insulin resistant compared to the non-insulin resistant group, but the difference was not significant (P > 0.05. Conclusion There is no significant difference in mean RBP4 levels in obese adolescents compared to normoweight adolescents. Nor are mean RBP4 levels significantly different between obese adolescents with and without insulin resistance.

  16. A review of biodegradable polymeric systems for oral insulin delivery.

    Science.gov (United States)

    Luo, Yue Yuan; Xiong, Xiang Yuan; Tian, Yuan; Li, Zi Ling; Gong, Yan Chun; Li, Yu Ping

    2016-07-01

    Currently, repeated routine subcutaneous injections of insulin are the standard treatment for insulin-dependent diabetic patients. However, patients' poor compliance for injections often fails to achieve the stable concentration of blood glucose. As a protein drug, the oral bioavailability of insulin is low due to many physiological reasons. Several carriers, such as macromolecules and liposomes have been used to deliver drugs in vivo. In this review article, the gastrointestinal barriers of oral insulin administration are described. Strategies for increasing the bioavailability of oral insulin, such absorption enhancers, enzyme inhibitors, enteric coatings are also introduced. The potential absorption mechanisms of insulin-loaded nanoparticles across the intestinal epithelium, including intestinal lymphatic route, transcellular route and paracellular route are discussed in this review. Natural polymers, such as chitosan and its derivates, alginate derivatives, γ-PGA-based materials and starch-based nanoparticles have been exploited for oral insulin delivery; synthetic polymers, such as PLGA, PLA, PCL and PEA have also been developed for oral administration of insulin. This review focuses on recent advances in using biodegradable natural and synthetic polymers for oral insulin delivery along with their future prospects.

  17. Insulin and the Lung

    DEFF Research Database (Denmark)

    Singh, Suchita; Prakash, Y S; Linneberg, Allan

    2013-01-01

    Obesity, metabolic syndrome, and asthma are all rapidly increasing globally. Substantial emerging evidence suggests that these three conditions are epidemiologically and mechanistically linked. Since the link between obesity and asthma appears to extend beyond mechanical pulmonary disadvantage...... and highlights the molecular consequences of insulin-related metabolic signaling cascades that could adversely affect lung structure and function. Examples include airway smooth muscle proliferation and contractility and regulatory signaling networks that are associated with asthma. These aspects of insulin...

  18. Insulin and Glucagon

    DEFF Research Database (Denmark)

    Holst, Jens Juul; Holland, William; Gromada, Jesper

    2017-01-01

    In August 2016, several leaders in glucagon biology gathered for the European Association for the Study of Diabetes Hagedorn Workshop in Oxford, England. A key point of discussion focused on the need for basal insulin to allow for the therapeutic benefit of glucagon blockade in the treatment...... of the discussion as a consensus was reached. Agents that antagonize glucagon may be of great benefit for the treatment of diabetes; however, sufficient levels of basal insulin are required for their therapeutic efficacy....

  19. Relationship between Optimum Mini-doses of Glucagon and Insulin Levels when Treating Mild Hypoglycaemia in Patients with Type 1 Diabetes - A Simulation Study

    DEFF Research Database (Denmark)

    Ranjan, Ajenthen; Wendt, Sabrina Lyngbye; Schmidt, Signe

    2017-01-01

    Hypoglycaemia remains the main limiting factor in type 1 diabetes management. We developed an insulin-dependent glucagon dosing regimen for treatment of mild hypoglycaemia based on simulations. A validated glucose-insulin-glucagon model was used to describe seven virtual patients with insulin pump......-treated type 1 diabetes. In each simulation, one of ten different and individualized subcutaneous insulin boluses was administered to decrease plasma glucose (PG) from 7.0 to ≤3.9 mmol/l. Insulin levels were estimated as ratio of actual to baseline serum insulin concentration (se/ba-insulin), insulin on board...... (IOB) or percentage of IOB to total daily insulin dose (IOB/TDD). Insulin bolus sizes were chosen to provide pre-defined insulin levels when PG reached 3.9 mmol/l, where one of 17 subcutaneous glucagon boluses was administered. Optimum glucagon bolus to treat mild hypoglycaemia at varying insulin...

  20. Antibody-Mediated Insulin Resistance: When Insulin and Insulin Receptor Act as Autoantigens in Humans.

    Science.gov (United States)

    Liminet, Christelle; Vouillarmet, Julien; Chikh, Karim; Disse, Emmanuel

    2016-10-01

    We report the case of a patient with diabetes presenting a severe insulin-resistance syndrome due to the production of insulin autoantibodies by a lymphocytic lymphoma. We describe the various mechanisms leading to the production of insulin autoantibodies and insulin receptor autoantibodies and review the therapeutic possibilities. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

  1. Autotaxin Is Regulated by Glucose and Insulin in Adipocytes.

    Science.gov (United States)

    D'Souza, Kenneth; Kane, Daniel A; Touaibia, Mohamed; Kershaw, Erin E; Pulinilkunnil, Thomas; Kienesberger, Petra C

    2017-04-01

    Autotaxin (ATX) is an adipokine that generates the bioactive lipid, lysophosphatidic acid. Despite recent studies implicating adipose-derived ATX in metabolic disorders including obesity and insulin resistance, the nutritional and hormonal regulation of ATX in adipocytes remains unclear. The current study examined the regulation of ATX in adipocytes by glucose and insulin and the role of ATX in adipocyte metabolism. Induction of insulin resistance in adipocytes with high glucose and insulin concentrations increased ATX secretion, whereas coincubation with the insulin sensitizer, rosiglitazone, prevented this response. Moreover, glucose independently increased ATX messenger RNA (mRNA), protein, and activity in a time- and concentration-dependent manner. Glucose also acutely upregulated secreted ATX activity in subcutaneous adipose tissue explants. Insulin elicited a biphasic response. Acute insulin stimulation increased ATX activity in a PI3Kinase-dependent and mTORC1-independent manner, whereas chronic insulin stimulation decreased ATX mRNA, protein, and activity. To examine the metabolic role of ATX in 3T3-L1 adipocytes, we incubated cells with the ATX inhibitor, PF-8380, for 24 hours. Whereas ATX inhibition increased the expression of peroxisome proliferator-activated receptor-γ and its downstream targets, insulin signaling and mitochondrial respiration were unaffected. However, ATX inhibition enhanced mitochondrial H2O2 production. Taken together, this study suggests that ATX secretion from adipocytes is differentially regulated by glucose and insulin. This study also suggests that inhibition of autocrine/paracrine ATX-lysophosphatidic acid signaling does not influence insulin signaling or mitochondrial respiration, but increases reactive oxygen species production in adipocytes. Copyright © 2017 Endocrine Society.

  2. Detemir insulin for the treatment of diabetes mellitus in dogs.

    Science.gov (United States)

    Fracassi, Federico; Corradini, Sara; Hafner, Michaela; Boretti, Felicitas S; Sieber-Ruckstuhl, Nadia S; Reusch, Claudia E

    2015-07-01

    To investigate the effects of insulin detemir in dogs with diabetes mellitus. Prospective, uncontrolled clinical trial. 10 client-owned dogs with naturally occurring diabetes mellitus. Dogs were treated with insulin detemir SC every 12 hours for 6 months. Follow-up evaluations were done at 1, 2, 4, 12, and 24 weeks and included evaluation of clinical signs and measurement of blood glucose concentration curves and serum fructosamine concentrations. Insulin detemir administration resulted in a significant decrease in blood glucose and serum fructosamine concentrations at 6 months, compared with pretreatment values. Median insulin dosage at the end of the study was 0.12 U/kg (0.055 U/lb; range, 0.05 to 0.34 U/kg [0.023 to 0.155 U/lb], SC, q 12 h). Hypoglycemia was identified in 22% (10/45) of the blood glucose concentration curves, and 6 episodes of clinical hypoglycemia in 4 dogs were recorded. A subjective improvement in clinical signs was observed in all dogs during the 6-month study period. On the basis of clinical signs and blood glucose concentration curves, efficacy of insulin detemir at the end of the study was considered good in 5 dogs, moderate in 3, and poor in 2. Results suggested that SC injection of insulin detemir every 12 hours may be a viable treatment for diabetes mellitus in dogs. Insulin detemir dosages were lower than reported dosages of other insulin types needed to maintain glycemic control, suggesting that insulin detemir should be used with caution, especially in small dogs.

  3. Combining insulin with metformin or an insulin secretagogue in non-obese patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Lund, Søren S; Tarnow, Lise; Frandsen, Merete

    2009-01-01

    OBJECTIVES: To study the effect of insulin treatment in combination with metformin or an insulin secretagogue, repaglinide, on glycaemic regulation in non-obese patients with type 2 diabetes. DESIGN: Randomised, double blind, double dummy, parallel trial. SETTING: Secondary care in Denmark between...... 2003 and 2006. PARTICIPANTS: Non-obese patients (BMI .../l. The target of HbA(1c) concentration was less than 6.5%. Treatment was intensified to two or three insulin injections a day if glycaemic targets were not reached. MAIN OUTCOME MEASURE: HbA(1c) concentration. RESULTS: Of the 459 patients who were eligible, 102 were randomised, and 97 completed the trial...

  4. Enhanced skeletal muscle lipid oxidative efficiency in insulin-resistant vs insulin-sensitive nondiabetic, nonobese humans.

    Science.gov (United States)

    Galgani, Jose E; Vasquez, Karla; Watkins, Guillermo; Dupuy, Aude; Bertrand-Michel, Justine; Levade, Thierry; Moro, Cedric

    2013-04-01

    Skeletal muscle insulin resistance is proposed to result from impaired skeletal muscle lipid oxidative capacity. However, there is no evidence indicating that muscle lipid oxidative capacity is impaired in healthy otherwise insulin-resistant individuals. The objective of the study was to assess muscle lipid oxidative capacity in young, nonobese, glucose-tolerant, insulin-resistant vs insulin-sensitive individuals. In 13 insulin-sensitive [by Matsuda index (MI) (22.6 ± 0.6 [SE] kg/m(2)); 23 ± 1 years; MI 5.9 ± 0.1] and 13 insulin-resistant (23.2 ± 0.6 kg/m(2); 23 ± 3 years; MI 2.2 ± 0.1) volunteers, skeletal muscle biopsy, blood extraction before and after an oral glucose load, and dual-energy x-ray absorptiometry were performed. Skeletal muscle mitochondrial to nuclear DNA ratio, oxidative phosphorylation protein content, and citrate synthase and β-hydroxyacyl-CoA dehydrogenase activities were assessed. Muscle lipids and palmitate oxidation ((14)CO2 and (14)C-acid soluble metabolites production) at 4 [1-(14)C]palmitate concentrations (45-520 μM) were also measured. None of the muscle mitochondrial measures showed differences between groups, except for a higher complex V protein content in insulin-resistant vs insulin-sensitive volunteers (3.5 ± 0.4 vs 2.2 ± 0.4; P = .05). Muscle ceramide content was significantly increased in insulin-resistant vs insulin-sensitive individuals (P = .04). Total palmitate oxidation showed a similar concentration-dependent response in both groups (P = .69). However, lipid oxidative efficiency (CO2 to (14)C-acid soluble metabolites ratio) was enhanced in insulin-resistant vs insulin-sensitive individuals, particularly at the highest palmitate concentration (0.24 ± 0.04 vs 0.12 ± 0.02; P = .02). We found no evidence of impaired muscle mitochondrial oxidative capacity in young, nonobese, glucose-tolerant, otherwise insulin-resistant vs insulin-sensitive individuals. Enhanced muscle lipid oxidative efficiency in insulin

  5. Zn2+ chelation by serum albumin improves hexameric Zn2+-insulin dissociation into monomers after exocytosis.

    Directory of Open Access Journals (Sweden)

    José A G Pertusa

    Full Text Available β-cells release hexameric Zn2+-insulin into the extracellular space, but monomeric Zn2+-free insulin appears to be the only biologically active form. The mechanisms implicated in dissociation of the hexamer remain unclear, but they seem to be Zn2+ concentration-dependent. In this study, we investigate the influence of albumin binding to Zn2+ on Zn2+-insulin dissociation into Zn2+-free insulin and its physiological, methodological and therapeutic relevance. Glucose and K+-induced insulin release were analyzed in isolated mouse islets by static incubation and perifusion experiments in the presence and absence of albumin and Zn2+ chelators. Insulin tolerance tests were performed in rats using different insulin solutions with and without Zn2+ and/or albumin. Albumin-free buffer does not alter quantification by RIA of Zn2+-free insulin but strongly affects RIA measurements of Zn2+-insulin. In contrast, accurate determination of Zn2+-insulin was obtained only when bovine serum albumin or Zn2+ chelators were present in the assay buffer solution. Albumin and Zn2+ chelators do not modify insulin release but do affect insulin determination. Preincubation with albumin or Zn2+ chelators promotes the conversion of "slow" Zn2+-insulin into "fast" insulin. Consequently, insulin diffusion from large islets is ameliorated in the presence of Zn2+ chelators. These observations support the notion that the Zn2+-binding properties of albumin improve the dissociation of Zn2+-insulin into subunits after exocytosis, which may be useful in insulin determination, insulin pharmacokinetic assays and islet transplantation.

  6. Molecular biocoding of insulin

    Directory of Open Access Journals (Sweden)

    Lutvo Kuric

    2010-07-01

    Full Text Available Lutvo KuricNovi Travnik, Kalinska, Bosnia and Herzegovina Abstract: This paper discusses cyberinformation studies of the amino acid composition of insulin, in particular the identification of scientific terminology that could describe this phenomenon, ie, the study of genetic information, as well as the relationship between the genetic language of proteins and theoretical aspects of this system and cybernetics. The results of this research show that there is a matrix code for insulin. It also shows that the coding system within the amino acid language gives detailed information, not only on the amino acid “record”, but also on its structure, configuration, and various shapes. The issue of the existence of an insulin code and coding of the individual structural elements of this protein are discussed. Answers to the following questions are sought. Does the matrix mechanism for biosynthesis of this protein function within the law of the general theory of information systems, and what is the significance of this for understanding the genetic language of insulin? What is the essence of existence and functioning of this language? Is the genetic information characterized only by biochemical principles or it is also characterized by cyberinformation principles? The potential effects of physical and chemical, as well as cybernetic and information principles, on the biochemical basis of insulin are also investigated. This paper discusses new methods for developing genetic technologies, in particular more advanced digital technology based on programming, cybernetics, and informational laws and systems, and how this new technology could be useful in medicine, bioinformatics, genetics, biochemistry, and other natural sciences.Keywords: human insulin, insulin model, biocode, genetic code, amino acids

  7. Insulin Signaling in Insulin Resistance States and Cancer: A Modeling Analysis.

    Directory of Open Access Journals (Sweden)

    Alessandro Bertuzzi

    Full Text Available Insulin resistance is the common denominator of several diseases including type 2 diabetes and cancer, and investigating the mechanisms responsible for insulin signaling impairment is of primary importance. A mathematical model of the insulin signaling network (ISN is proposed and used to investigate the dose-response curves of components of this network. Experimental data of C2C12 myoblasts with phosphatase and tensin homologue (PTEN suppressed and data of L6 myotubes with induced insulin resistance have been analyzed by the model. We focused particularly on single and double Akt phosphorylation and pointed out insulin signaling changes related to insulin resistance. Moreover, a new characterization of the upstream signaling of the mammalian target of rapamycin complex 2 (mTORC2 is presented. As it is widely recognized that ISN proteins have a crucial role also in cell proliferation and death, the ISN model was linked to a cell population model and applied to data of a cell line of acute myeloid leukemia treated with a mammalian target of rapamycin inhibitor with antitumor activity. The analysis revealed simple relationships among the concentrations of ISN proteins and the parameters of the cell population model that characterize cell cycle progression and cell death.

  8. Effect of metformin on peripheral insulin sensitivity in non insulin dependent diabetes mellitus.

    Science.gov (United States)

    Prager, R; Schernthaner, G; Graf, H

    1986-12-01

    To test whether metformin treatment might improve peripheral insulin sensitivity in non insulin dependent diabetes, we measured peripheral glucose uptake in 12 non insulin dependent diabetics before (A) and after 4 weeks (B) of metformin therapy (2 X 850 mg/day) by the hyperinsulinemic clamp technique (80 mU/m2/min). In addition, insulin binding to monocytes was compared between A and B. Diabetic control, evaluated by measurement of fasting blood glucose and glycosylated hemoglobin, was significantly improved by metformin treatment (P less than 0.01). Insulin binding to monocytes was not significantly influenced by metformin (A-4.53% vs. B-5.12%, n.s. at insulin tracer concentration). Peripheral glucose utilisation improved slightly, but significantly after 4 weeks of metformin therapy (A: 4.4 +/- 0.6 mg/kg/min, B: 5.4 +/- 0.8 mg/kg/min, p less than 0.01). Improvement in peripheral glucose utilisation correlated significantly with improved metabolic control, estimated by fasting blood glucose measurements (p less than 0.01).

  9. Insulin and HOMA in Spanish prepubertal children: relationship with lipid profile.

    Science.gov (United States)

    Garcés, Carmen; Cano, Beatriz; Granizo, Juan J; Benavente, Mercedes; Viturro, Enrique; Gutiérrez-Guisado, Javier; de Oya, Iria; Lasunción, Miguel A; de Oya, Manuel

    2005-10-01

    The effects of insulin or insulin resistance on the lipid profile seem to change with age. The aim of this study was to analyze insulin levels and an insulin resistance index and to investigate the relationship between these and the lipid profile in a population-based sample of Spanish prepubertal children. 1048 (524 boys and 524 girls) randomly selected prepubertal children were studied. Children were 6 to 8 years old with a mean age of 6.7. Plasma lipid, FFA and insulin levels were measured. The homeostatic model assessment (HOMA) was calculated as an indicator of insulin resistance. When analyzing percentile values of insulin, HOMA and FFA by sex, we observed that girls had significantly higher insulin concentrations than boys (except at the 10th percentile) and significantly higher FFA (except at the 90th percentile) with no significant differences between sexes for HOMA. Multivariate regression analyses showed that insulin was positively associated with glucose, triglycerides and apoB in boys but not in girls, and negatively associated with FFA in both genders. We report here data about the distribution of insulin in the Spanish prepubertal population. The higher levels of insulin in prepubertal girls could indicate that girls start to be more insulin resistant than boys at this age, although other manifestations of insulin resistance are not yet detectable.

  10. Peripheral Insulin Doesn’t Alter Appetite of Broiler Chicks

    Directory of Open Access Journals (Sweden)

    Lei Liu

    2016-09-01

    Full Text Available An experiment was conducted to investigate the effect of peripheral insulin treatment on appetite in chicks. Six-d-age chicks with ad libitum feeding or fasting for 3 h before injection received a subcutaneous injection of 0, 1, 3, 5, 10, or 20 IU of insulin or vehicle (saline. The results showed peripheral insulin treatment (1 to 20 IU did not alter significantly the feed intake in chicks under either ad libitum feeding or fasting conditions within 4 h (p>0.05. Compared with the control, plasma glucose concentration was significantly decreased after insulin treatment of 3, 5, 10, and 20 IU for 4 h in chicks with ad libitum feeding (p0.05. All results suggest peripheral administration of insulin has no effect on appetite in chicks.

  11. Role of AMPK in Regulating Muscle Insulin Sensitivity

    DEFF Research Database (Denmark)

    Kjøbsted, Rasmus

    in response to exercise and contraction. It is considered an important sensor of cellular energy-fuel status and fulfills the purpose of regulating energy-fuel homeostasis. Based on this, the aim of the present PhD was to investigate the involvement of AMPK in regulating insulin sensitivity following acute...... signaling in skeletal muscle of type 2 diabetic patients in response to exercise. Interestingly, we observe that AMPK activity and phosphorylation of TBC1D4 Ser318, Ser341 and Ser704 are increased 3 hours into exercise recovery - a time point when post-exercise improvements in muscle insulin sensitivity...... that induces a half-maximal biological response (e.g., glucose uptake). Accordingly, the concentration of insulin that induces half-maximal glucose uptake is reduced with increased insulin sensitivity. Skeletal muscle from both healthy and type 2 diabetic individuals display enhanced muscle insulin sensitivity...

  12. Insulin aspart in diabetic pregnancy

    DEFF Research Database (Denmark)

    Mathiesen, Elisabeth R

    2008-01-01

    in insulin requirements during pregnancy necessitate short-acting insulins for postprandial control of hyperglycemia. The fast-acting insulin analogue insulin aspart has been tested in a large, randomized trial of pregnant women with Type 1 diabetes and offers benefits in control of postprandial......Pregnancy in women with diabetes is associated with an increased risk of obstetric complications and perinatal mortality. Maintenance of near-normal glycemia during pregnancy can bring the prevalence of fetal, neonatal and maternal complications closer to that of the nondiabetic population. Changes...... and no increase in insulin antibodies was found. Thus, the use of insulin aspart in pregnancy is regarded safe....

  13. New Insulins and New Aspects in Insulin Delivery.

    Science.gov (United States)

    Woo, Vincent C

    2015-08-01

    The major abnormality in both type 1 and type 2 diabetes is insulin deficiency. The methods of replacing insulin have improved throughout the decades, but hypoglycemia is still the limiting factor for many individuals with diabetes, and it prevents them from achieving ideal glycemic targets. New insulin and newer delivery systems are being developed that can improve some of the limitations of current insulins or make the delivery of insulins more acceptable for some patients. Extending the duration of action of basal insulins and shortening the peak of fast-acting insulins may have advantages for individuals with diabetes. Different delivery systems may make insulin more acceptable to patients and may have other advantages, which may aid in attaining better glycemic control. Copyright © 2015 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

  14. Improved insulin sensitivity after exercise: focus on insulin signaling

    DEFF Research Database (Denmark)

    Frøsig, Christian; Richter, Erik

    2009-01-01

    After a single bout of exercise, the ability of insulin to stimulate glucose uptake is markedly improved locally in the previously active muscles. This makes exercise a potent stimulus counteracting insulin resistance characterizing type 2 diabetes (T2D). It is believed that at least part...... of the mechanism relates to an improved ability of insulin to stimulate translocation of glucose transporters (GLUT4) to the muscle membrane after exercise. How this is accomplished is still unclear; however, an obvious possibility is that exercise interacts with the insulin signaling pathway to GLUT4...... translocation allowing for a more potent insulin response. Parallel to unraveling of the insulin signaling cascade, this has been investigated within the past 25 years. Reviewing existing studies clearly indicates that improved insulin action can occur independent of interactions with proximal insulin signaling...

  15. Insulin detemir versus insulin glargine for type 2 diabetes mellitus

    NARCIS (Netherlands)

    Swinnen, Sanne G.; Simon, Airin C. R.; Holleman, Frits; Hoekstra, Joost B.; DeVries, J. Hans

    2011-01-01

    Chronically elevated blood glucose levels are associated with significant morbidity and mortality. Many diabetes patients will eventually require insulin treatment to maintain good glycaemic control. There are still uncertainties about the optimal insulin treatment regimens for type 2 diabetes, but

  16. Insulin Inclusion into a Tragacanth Hydrogel: An Oral Delivery System for Insulin

    Directory of Open Access Journals (Sweden)

    Mokhamad Nur

    2018-01-01

    Full Text Available Nanoparticles or microparticles created by physical complexation between two polyelectrolytes may have a prospective use as an excipient for oral insulin administration. Natural polymers such as tragacanth, alginate, dextran, pullulan, hyaluronic acid, gelatin and chitosan can be potential candidates for this purpose. In this research, insulin particles were prepared by the inclusion of insulin into a tragacanth hydrogel. The effect of the pH and concentration relationship involving polyelectrolytes offering individual particle size and zeta potential was assessed by zetasizer and scanning electron microscopy (SEM. Insulin–tragacanth interactions at varying pH (3.7, 4.3, 4.6, or 6, and concentration (0.1%, 0.5%, or 1% w/w were evaluated by differential scanning calorimetry (DSC and ATR Fourier transform infrared (ATR-FTIR analysis. Individual and smaller particles, approximately 800 nm, were acquired at pH 4.6 with 0.5% of tragacanth. The acid gelation test indicated that insulin could be entrapped in the physical hydrogel of tragacanth. DSC thermograms of insulin–tragacanth showed shifts on the same unloaded tragacanth peaks and suggested polyelectrolyte–protein interactions at a pH close to 4.3–4.6. FTIR spectra of tragacanth–insulin complexes exhibited amide absorption bands featuring in the protein spectra and revealed the creation of a new chemical substance.

  17. Lipid induced insulin resistance affects women less than men and is not accompanied by inflammation or impaired proximal insulin signaling

    DEFF Research Database (Denmark)

    Høeg, Louise D; Sjøberg, Kim Anker; Jeppesen, Jacob

    2011-01-01

    AbstractObjective: We have previously shown that overnight fasted women have higher insulin stimulated whole body and leg glucose uptake despite a higher intramyocellular triacylglycerol concentration than men. Women also express higher muscle mRNA levels of proteins related to lipid metabolism...... (60%) after intralipid infusion. Hepatic glucose production was decreased during the clamp similarly in women and men irrespective of intralipid infusion. Intralipid did not impair insulin or AMPK signaling in muscle and subcutaneous fat, did not cause accumulation of muscle lipid intermediates...... ratio was decreased by intralipid. Conclusion: Intralipid infusion causes less insulin resistance of muscle glucose uptake in women than in men. This insulin resistance is not due to decreased canonical insulin signaling, accumulation of lipid intermediates, inflammation or direct inhibition of glucose...

  18. Development of insulin delivery systems.

    Science.gov (United States)

    Siddiqui, N I; Siddiqui, Ni; Rahman, S; Nessa, A

    2008-01-01

    Delivery system of insulin is vital for its acceptance and adherence to therapy for achieving the glycemic targets. Enormous developments have occurred in the delivery system of insulin during the last twenty years and each improvement was aimed at two common goals: patients convenience and better glycemic control. Till to date, the various insulin delivery systems are: syringes/vials, injection aids, jet injectors, transmucosal delivery, transdermal delivery, external insulin infusion pump, implantable insulin pumps, insulin pens and insulin inhalers. Syringe/vial is the oldest and conventional method, still widely used and relatively cheaper. Modern plastic syringes are disposable, light weight with microfine needle for patients convenience and comfort. Oral route could be the most acceptable and viable, if the barriers can be overcome and under extensive trial. Insulin pen device is an important milestone in the delivery system of insulin as it is convenient, discrete, painless, attractive, portable with flexible life style and improved quality of life. More than 80% of European diabetic patients are using insulin pen. Future digital pen will have better memory option, blood glucose monitoring system, insulin dose calculator etc. Insulin infusion pump is a good option for the children, busy patients with flexible lifestyle and those who want to avoid multiple daily injections. Pulmonary route of insulin delivery is a promising, effective, non-invasive and acceptable alternative method. Exubera, the world first insulin inhaler was approved by FDA in 28 January 2006. But due to certain limitations, it has been withdrawn from the market in October 2007. The main concern of inhaled insulin are: long term pulmonary safety issues, cost effectiveness and user friendly device. In future, more acceptable and cost effective insulin inhaler will be introduced. Newer avenues are under extensive trial for better future insulin delivery systems.

  19. Prolonged submaximal eccentric exercise is associated with increased levels of plasma IL-6

    DEFF Research Database (Denmark)

    Rohde, Thomas; MacLean, D A; Richter, Erik

    1997-01-01

    To study the relationship between exercise-related muscle proteolysis and the cytokine response, a prolonged eccentric exercise model of one leg was used. Subjects performed two trials [a branched-chain amino acid (BCAA) supplementation and a control trial]. The release of amino acids from muscle...... during and after the eccentric exercise was decreased in the BCAA trial, suggesting a suppression of net muscle protein degradation. The plasma concentrations of interleukin (IL)-6 increased from 0.75 +/- 0.19 (preexercise) to 5.02 +/- 0.96 pg/ml (2 h postexercise) in the control trial and in the BCAA...... supplementation trial from 1.07 +/- 0.41 to 4.15 +/- 1.21 pg/ml. Eccentric exercise had no effect on the concentrations of neutrophils, lymphocytes, CD16+/CD56+, CD4+, CD8+, CD14+/CD38+, lymphocyte proliferative response, or cytotoxic activities. BCAA supplementation reduced the concentration of CD14+/CD38+ cells...

  20. Increased pulsatility, process irregularity, and nocturnal trough concentrations of growth hormone in amenorrheic compared to eumenorrheic athletes.

    Science.gov (United States)

    Waters, D L; Qualls, C R; Dorin, R; Veldhuis, J D; Baumgartner, R N

    2001-03-01

    Amenorrheic athletes exhibit a spectrum of neuroendocrine disturbances, including alterations in the GH-insulin-like growth factor I (IGF-I) axis. Whether these changes are due to exercise or amenorrhea is incompletely characterized. The present study investigates spontaneous (overnight) and exercise-stimulated GH secretion and associated IGF-binding proteins (IGFBPs) in amenorrheic (AA; n = 5), and eumenorrheic athletes ( n = 5) matched for age, percent body fat (dual energy x-ray absorptiometry), training history, and maximal oxygen consumption. Each volunteer participated in two hospital admissions consisting of a 50-min submaximal exercise bout (70% maximal oxygen consumption) and an 8-h nocturnal sampling period. Deconvolution analysis of serum GH concentration time series revealed increases in the half-life of GH (60%) and the number of secretory bursts (85%) as well as a decrease in their half-duration (50%) and the mass of GH secreted per pulse (300%) in the AA cohort. Time occupancy at elevated trough GH concentrations was significantly increased, and GH pulsatility (approximate entropy) was more irregular in the AA group. During exercise, AA exhibited a reversal of the normal relationship between IGF-I and GH, and a 4- to 5-fold blunting of stimulated peak and integrated GH secretion. Fasting levels of plasma IGF-I, IGFBP-3, and IGFBP-1 appeared to be unaffected by menstrual status. In ensemble, this phenotype of GH release in amenorrheic athletes suggests disrupted neuroregulation of episodic GH secretion, possibly reflecting decreased somatostinergic inhibition basally, and reduced GHRH output in response to exercise compared with eumenorrheic athletes. Accordingly, we postulate that the amenorrheic state, beyond the exercise experience per se, alters the neuroendocrine control of GH output in amenorrheic athletes.

  1. Insulin, androgen, and gonadotropin concentrations, body mass index, and waist to hip ratio in the first years after menarche in girls with regular menstrual cycles, irregular menstrual cycles, or oligomenorrhea

    NARCIS (Netherlands)

    Hooff, M.H.A. van; Voorhorst, F.J.; Kaptein, M.B.H.; Hirasing, R.A.; Koppenaal, C.; Schoemaker, J.

    2000-01-01

    Data on changes in hormone concentrations during the first years after menarche are scarce. We studied the relation between gynecological age (age minus age at menarche), hormone concentrations, and body measurements from the 1st to the 6th yr after menarche in 229 observations of girls with regular

  2. Chemical and thermal stability of insulin

    DEFF Research Database (Denmark)

    Huus, Kasper; Havelund, Svend; Olsen, Helle B

    2006-01-01

    To study the correlation between the thermal and chemical stability of insulin formulations with various insulin hexamer ligands.......To study the correlation between the thermal and chemical stability of insulin formulations with various insulin hexamer ligands....

  3. PACAP stimulates insulin secretion but inhibits insulin sensitivity in mice

    NARCIS (Netherlands)

    Filipsson, K; Pacini, G; Scheurink, AJW; Ahren, B

    Although pituitary adenylate cyclase-activating polypeptide (PACAP) stimulates insulin secretion, its net influence on glucose homeostasis in vivo has not been established. We therefore examined the action of PACAP-27 and PACAP-38 on insulin secretion, insulin sensitivity, and glucose disposal as

  4. Dissociation between insulin secretion and DNA synthesis in cultured pancreatic islets

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    1985-01-01

    Glucose has been suggested to be the most important stimulus for beta cell replication in vivo and in vitro. In order to study the relationship between insulin secretion and DNA synthesis, newborn rat islets were cultured in the presence of different concentrations of glucose, theophylline and 3......M glucose in spite of a dose dependent increase in insulin release. 5 mM theophylline potentiated the glucose induced insulin release but lowered both 3H-Tdr synthesis and insulin content in the islets. In contrast, 0.05 mM IBMX induced a significant stimulation of both insulin release and 3H...

  5. A Review of the Security of Insulin Pump Infusion Systems

    Energy Technology Data Exchange (ETDEWEB)

    Klonoff, David C. [Mills-Peninsula Health Services; Paul, Nathanael R [ORNL; Kohno, Tadayoshi [University of Washington, Seattle

    2011-01-01

    Insulin therapy has enabled diabetic patients to maintain blood glucose control to lead healthier lives. Today, rather than manually injecting insulin using syringes, a patient can use a device, such as an insulin pump, to programmatically deliver insulin. This allows for more granular insulin delivery while attaining blood glucose control. The insulin pump system features have increasingly benefited patients, but the complexity of the resulting system has grown in parallel. As a result security breaches that can negatively affect patient health are now possible. Rather than focus on the security of a single device, we concentrate on protecting the security of the entire system. In this paper we describe the security issues as they pertain to an insulin pump system that includes an embedded system of components including the insulin pump, continuous glucose management system, blood glucose monitor, and other associated devices (e.g., a mobile phone or personal computer). We detail not only the growing wireless communication threat in each system component, but we also describe additional threats to the system (e.g., availability and integrity). Our goal is to help create a trustworthy infusion pump system that will ultimately strengthen pump safety, and we describe mitigating solutions to address identified security issues both for now and in the future.

  6. A review of the security of insulin pump infusion systems.

    Science.gov (United States)

    Paul, Nathanael; Kohno, Tadayoshi; Klonoff, David C

    2011-11-01

    Insulin therapy has enabled patients with diabetes to maintain blood glucose control to lead healthier lives. Today, rather than injecting insulin manually using syringes, a patient can use a device such as an insulin pump to deliver insulin programmatically. This allows for more granular insulin delivery while attaining blood glucose control. Insulin pump system features have increasingly benefited patients, but the complexity of the resulting system has grown in parallel. As a result, security breaches that can negatively affect patient health are now possible. Rather than focus on the security of a single device, we concentrate on protecting the security of the entire system. In this article, we describe the security issues as they pertain to an insulin pump system that includes an embedded system of components, which include the insulin pump, continuous glucose management system, blood glucose monitor, and other associated devices (e.g., a mobile phone or personal computer). We detail not only the growing wireless communication threat in each system component, but also describe additional threats to the system (e.g., availability and integrity). Our goal is to help create a trustworthy infusion pump system that will ultimately strengthen pump safety, and we describe mitigating solutions to address identified security issues. © 2011 Diabetes Technology Society.

  7. Low ethanol consumption increases insulin sensitivity in Wistar rats

    Directory of Open Access Journals (Sweden)

    D.T. Furuya

    2003-01-01

    Full Text Available Several human studies suggest that light-to-moderate alcohol consumption is associated with enhanced insulin sensitivity, but these studies are not free of conflicting results. To determine if ethanol-enhanced insulin sensitivity could be demonstrated in an animal model, male Wistar rats were fed a standard chow diet and received drinking water without (control or with different ethanol concentrations (0.5, 1.5, 3, 4.5 and 7%, v/v for 4 weeks ad libitum. Then, an intravenous insulin tolerance test (IVITT was performed to determine insulin sensitivity. Among the ethanol groups, only the 3% ethanol group showed an increase in insulin sensitivity based on the increase of the plasma glucose disappearance rate in the IVITT (30%, P<0.05. In addition, an intravenous glucose tolerance test (IVGTT was performed in control and 3% ethanol animals. Insulin sensitivity was confirmed in 3% ethanol rats based on the reduction of insulin secretion in the IVGTT (35%, P<0.05, despite the same glucose profile. Additionally, the 3% ethanol treatment did not impair body weight gain or plasma aspartate aminotransferase and alanine aminotransferase activities. Thus, the present study established that 3% ethanol in the drinking water for 4 weeks in normal rats is a model of increased insulin sensitivity, which can be used for further investigations of the mechanisms involved.

  8. Alginate/chitosan nanoparticles are effective for oral insulin delivery.

    Science.gov (United States)

    Sarmento, B; Ribeiro, A; Veiga, F; Sampaio, P; Neufeld, R; Ferreira, D

    2007-12-01

    To evaluate the pharmacological activity of insulin-loaded alginate/chitosan nanoparticles following oral dosage in diabetic rats. Nanoparticles were prepared by ionotropic pre-gelation of an alginate core followed by chitosan polyelectrolyte complexation. In vivo activity was evaluated by measuring the decrease in blood glucose concentrations in streptozotocin induced, diabetic rats after oral administration and flourescein (FITC)-labelled insulin tracked by confocal microscopy. Nanoparticles were negatively charged and had a mean size of 750 nm, suitable for uptake within the gastrointestinal tract due to their nanosize range and mucoadhesive properties. The insulin association efficiency was over 70% and insulin was released in a pH-dependent manner under simulated gastrointestinal conditions. Orally delivered nanoparticles lowered basal serum glucose levels by more than 40% with 50 and 100 IU/kg doses sustaining hypoglycemia for over 18 h. Pharmacological availability was 6.8 and 3.4% for the 50 and 100 IU/kg doses respectively, a significant increase over 1.6%, determined for oral insulin alone in solution and over other related studies at the same dose levels. Confocal microscopic examinations of FITC-labelled insulin nanoparticles showed clear adhesion to rat intestinal epithelium, and internalization of insulin within the intestinal mucosa. The results indicate that the encapsulation of insulin into mucoadhesive nanoparticles was a key factor in the improvement of its oral absorption and oral bioactivity.

  9. Impaired insulin-stimulated nonoxidative glucose metabolism in pancreas-kidney transplant recipients. Dose-response effects of insulin on glucose turnover

    DEFF Research Database (Denmark)

    Christiansen, E; Vestergaard, H; Tibell, A

    1996-01-01

    Insulin resistance is a characteristic feature in recipients of a pancreas transplant, but the relative contribution of the liver and peripheral tissues to this abnormality within a spanning range of insulin concentrations is unknown. To assess the impact of insulin action on glucose metabolism....... The overall effects of insulin on whole-body glucose metabolism, determined as the glucose infusion rates versus the corresponding steady-state serum insulin concentrations, demonstrated a rightward shift in the dose-response curves of the transplanted groups compared with those of normal subjects. The dose......, this finding could only explain in part the degree of impairment in nonoxidative glucose metabolism. No differences were found in total hexokinase activity in muscle between normal subjects and the transplant groups at basal insulinemia or after insulin stimulation. During hyperinsulinemia, glucagon...

  10. Heavy strength training improves running and cycling performance following prolonged submaximal work in well-trained female athletes.

    Science.gov (United States)

    Vikmoen, Olav; Rønnestad, Bent R; Ellefsen, Stian; Raastad, Truls

    2017-03-01

    The purpose of this study was to investigate the effects of adding heavy strength training to female duathletes' normal endurance training on both cycling and running performance. Nineteen well-trained female duathletes ( V O 2max cycling: 54 ± 3 ml∙kg -1 ∙min -1 , VO 2max running: 53 ± 3 ml∙kg -1 ∙min -1 ) were randomly assigned to either normal endurance training ( E , n  = 8) or normal endurance training combined with strength training ( E+S , n  = 11). The strength training consisted of four lower body exercises [3 × 4-10 repetition maximum (RM)] twice a week for 11 weeks. Running and cycling performance were assessed using 5-min all-out tests, performed immediately after prolonged periods of submaximal work (3 h cycling or 1.5 h running). E+S increased 1RM in half squat (45 ± 22%) and lean mass in the legs (3.1 ± 4.0%) more than E Performance during the 5-min all-out test increased in both cycling (7.0 ± 4.5%) and running (4.7 ± 6.0%) in E+S, whereas no changes occurred in E The changes in running performance were different between groups. E+S reduced oxygen consumption and heart rate during the final 2 h of prolonged cycling, whereas no changes occurred in E No changes occurred during the prolonged running in any group. Adding strength training to normal endurance training in well-trained female duathletes improved both running and cycling performance when tested immediately after prolonged submaximal work. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  11. Degradation of pro-insulin-receptor proteins by proteasomes.

    Science.gov (United States)

    Cruz, Miguel; Velasco, Eduardo; Kumate, Jesús

    2004-01-01

    Type-2 diabetes is characterized by hyperinsulinemia, peripheral insulin resistance, and diminished tyrosine phosphorylation activity. It has been recently shown that proteasomes are implicated in the degradation of the insulin receptor substrate-1 (IRS-1) but not in that of the insulin receptor (IR). However, it is unknown whether proteasomes are involved in pro-IR degradation. We used CHO-IR and the 3T3-L1 cells treated with insulin at different concentrations and compared the proteasome activity of IRS-1, IR, and pro-IR degradation either in presence or in absence of lactacystin. A total of 100 nM of insulin allowed degradation of IRS-1 after 6 h of incubation. At 1,000 nM of insulin, pro-IR degradation began at 1 h of incubation, similar to IRS-1 degradation. Surprisingly, at a higher concentration (10 microM) of insulin, a drastic decrease of proteins was observed from the first minute of incubation. This activity was blocked by lactacystin, a specific proteasome inhibitor. According to these results, we propose that pro-IR is degraded by proteasomes.

  12. Role of Ceramide in Apoptosis and Development of Insulin Resistance.

    Science.gov (United States)

    Kuzmenko, D I; Klimentyeva, T K

    2016-09-01

    This review presents data on the functional biochemistry of ceramide, one of the key sphingolipids with properties of a secondary messenger. Molecular mechanisms of the involvement of ceramide in apoptosis in pancreatic β-cells and its role in the formation of insulin resistance in pathogenesis of type 2 diabetes are reviewed. One of the main predispositions for the development of insulin resistance and diabetes is obesity, which is associated with ectopic fat deposition and significant increase in intracellular concentrations of cytotoxic ceramides. A possible approach to the restoration of tissue sensitivity to insulin in type 2 diabetes based on selective reduction of the content of cytotoxic ceramides is discussed.

  13. Oral Insulin - Fact or Fiction?

    Indian Academy of Sciences (India)

    Insulin is a major protein hormone secreted by the p-cells of the pancreas and is important for the control of diabetes. Insulin is usually administered to diabetic patients through subcutaneous injection. This mode of therapy has certain inherent disadvantages such as local pain, itching and insulin lipodystrophy around the ...

  14. Molecular mechanism of insulin resistance

    Indian Academy of Sciences (India)

    Free fatty acids are known to play a key role in promoting loss of insulin sensitivity, thereby causing insulin resistance and type 2 diabetes. However, the underlying mechanism involved is still unclear. In searching for the cause of the mechanism, it has been found that palmitate inhibits insulin receptor (IR) gene expression, ...

  15. Insulin Resistance in Alzheimer's Disease

    Science.gov (United States)

    Dineley, Kelly T; Jahrling, Jordan B; Denner, Larry

    2014-01-01

    Insulin is a key hormone regulating metabolism. Insulin binding to cell surface insulin receptors engages many signaling intermediates operating in parallel and in series to control glucose, energy, and lipids while also regulating mitogenesis and development. Perturbations in the function of any of these intermediates, which occur in a variety of diseases, cause reduced sensitivity to insulin and insulin resistance with consequent metabolic dysfunction. Chronic inflammation ensues which exacerbates compromised metabolic homeostasis. Since insulin has a key role in learning and memory as well as directly regulating ERK, a kinase required for the type of learning and memory compromised in early Alzheimer's disease (AD), insulin resistance has been identified as a major risk factor for the onset of AD. Animal models of AD or insulin resistance or both demonstrate that AD pathology and impaired insulin signaling form a reciprocal relationship. Of note are human and animal model studies geared toward improving insulin resistance that have led to the identification of the nuclear receptor and transcription factor, peroxisome proliferator-activated receptor gamma (PPARγ) as an intervention tool for early AD. Strategic targeting of alternate nodes within the insulin signaling network has revealed disease-stage therapeutic windows in animal models that coalesce with previous and ongoing clinical trial approaches. Thus, exploiting the connection between insulin resistance and AD provides powerful opportunities to delineate therapeutic interventions that slow or block the pathogenesis of AD. PMID:25237037

  16. Molecular mechanisms of insulin resistance

    African Journals Online (AJOL)

    basis of insulin resistance could ultimately lead to a better understanding of the causation of these conditions and the design of rational therapy to ameliorate them. Here, particular attention is devoted to the initial events that follow the binding of insulin to its receptor, including changes in insulin receptor phosphorylation.

  17. Bile acid TUDCA improves insulin clearance by increasing the expression of insulin-degrading enzyme in the liver of obese mice.

    Science.gov (United States)

    Vettorazzi, Jean Franciesco; Kurauti, Mirian Ayumi; Soares, Gabriela Moreira; Borck, Patricia Cristine; Ferreira, Sandra Mara; Branco, Renato Chaves Souto; Michelone, Luciana de Souza Lima; Boschero, Antonio Carlos; Junior, Jose Maria Costa; Carneiro, Everardo Magalhães

    2017-11-01

    Disruption of insulin secretion and clearance both contribute to obesity-induced hyperinsulinemia, though reduced insulin clearance seems to be the main factor. The liver is the major site for insulin degradation, a process mainly coordinated by the insulin-degrading enzyme (IDE). The beneficial effects of taurine conjugated bile acid (TUDCA) on insulin secretion as well as insulin sensitivity have been recently described. However, the possible role of TUDCA in insulin clearance had not yet been explored. Here, we demonstrated that 15 days treatment with TUDCA reestablished plasma insulin to physiological concentrations in high fat diet (HFD) mice, a phenomenon associated with increased insulin clearance and liver IDE expression. TUDCA also increased IDE expression in human hepatic cell line HepG2. This effect was not observed in the presence of an inhibitor of the hepatic membrane bile acid receptor, S1PR2, nor when its downstream proteins were inhibited, including IR, PI3K and Akt. These results indicate that treatment with TUDCA may be helpful to counteract obesity-induced hyperinsulinemia through increasing insulin clearance, likely through enhanced liver IDE expression in a mechanism dependent on S1PR2-Insulin pathway activation.

  18. Approach to the determination of insulin-like-growth-factor-I (IGF-I) concentration in plasma by high-performance liquid chromatography-ion trap mass spectrometry: use of a deconvolution algorithm for the quantification of multiprotonated molecules in electrospray ionization.

    Science.gov (United States)

    Bobin, S; Popot, M A; Bonnaire, Y; Tabet, J C

    2001-11-01

    The insulin-like-growth-factor-I (IGF-I) peptide is known to be a marker for growth hormone administration. The development of a quantification method by electrospray ionization mass spectrometry (ESI-MS) coupled with high-performance liquid chromatography (HPLC) is required. This paper describes a method to quantify IGF-I using the internal standard R3 IGF-I in its oxidized forms. A deconvolution software was used to quantify the set of multi-charged molecules recorded on an ESI ion trap mass spectrometer. The results (i.e., linearity, reproducibility and concentration range) were obtained on standard samples and the described LC-ESI-MS method should be applicable to biological samples.

  19. Consumption of a diet low in advanced glycation end products for 4 weeks improves insulin sensitivity in overweight women

    DEFF Research Database (Denmark)

    Mark, Alicja Budek; Poulsen, Malene Wibe; Andersen, Stine

    2014-01-01

    of either fructose or glucose drinks. Glucose and insulin concentrations-after fasting and 2 h after an oral glucose tolerance test-were measured before and after the intervention. Homeostasis model assessment of insulin resistance (HOMA-IR) and insulin sensitivity index were calculated. Dietary and urinary...

  20. Insulin diffusion and self-association characterized by real-time UV imaging and Taylor dispersion analysis

    DEFF Research Database (Denmark)

    Jensen, Sabrine S; Jensen, Henrik; Cornett, Claus

    2014-01-01

    , self-association, and apparent size of insulin were further characterized by Taylor dispersion analysis, size exclusion chromatography, and dynamic light scattering. At low insulin concentrations and pH 3.0, the hydrodynamic radius of insulin was determined by Taylor dispersion analysis to 1.5±0.1nm...

  1. Serum concentrations of free and total insulin-like growth factor-I, IGF binding proteins -1 and -3 and IGFBP-3 protease activity in boys with normal or precocious puberty

    DEFF Research Database (Denmark)

    Juul, A; Flyvbjerg, Allan; Frystyk, Jan

    1996-01-01

    Circulating IGF-I and IGF binding protein-3 (IGFBP-3) levels both increase in puberty where growth velocity is high. The amount of free IGF-I is dependent on the IGF-I level and on the concentrations of the specific IGFBPs. Furthermore, IGFBP-3 proteolysis regulates the bioavailability of IGF......-I. However, the concentration of free IGF-I and possible IGFBP-3 proteolytic activity in puberty has not previously been studied....

  2. Developing new VO2max prediction models from maximal, submaximal and questionnaire variables using support vector machines combined with feature selection.

    Science.gov (United States)

    Abut, Fatih; Akay, Mehmet Fatih; George, James

    2016-12-01

    Maximal oxygen uptake (VO2max) is an essential part of health and physical fitness, and refers to the highest rate of oxygen consumption an individual can attain during exhaustive exercise. In this study, for the first time in the literature, we combine the triple of maximal, submaximal and questionnaire variables to propose new VO2max prediction models using Support Vector Machines (SVM's) combined with the Relief-F feature selector to predict and reveal the distinct predictors of VO2max. For comparison purposes, hybrid models based on double combinations of maximal, submaximal and questionnaire variables have also been developed. By utilizing 10-fold cross-validation, the performance of the models has been calculated using multiple correlation coefficient (R) and root mean square error (RMSE). The results show that the best values of R and RMSE, with 0.94 and 2.92mLkg-1min-1 respectively, have been obtained by combining the triple of relevantly identified maximal, submaximal and questionnaire variables. Compared with the results of the rest of hybrid models in this study and the other prediction models in literature, the reported values of R and RMSE have been found to be considerably more accurate. The predictor variables gender, age, maximal heart rate (MX-HR), submaximal ending speed (SM-ES) of the treadmill and Perceived Functional Ability (Q-PFA) questionnaire have been found to be the most relevant variables in predicting VO2max. The results have also been compared with that of Multilayer Perceptron (MLP) and Tree Boost (TB), and it is seen that SVM significantly outperforms other regression methods for prediction of VO2max. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Evaluation of Maximal Oxygen Uptake and Submaximal Estimates of VO2max Before, During, and After Long Duration International Space Station Missions

    Science.gov (United States)

    2008-01-01

    Evaluation of Maximal Oxygen Uptake and Submaximal Estimates of VO2max Before, During, and After Long Duration International Space Station Missions (VO2max) will document changes in maximum oxygen uptake for crewmembers onboard the International Space Station (ISS) on long-duration missions, greater than 90 days. This investigation will establish the characteristics of VO2max during flight and assess the validity of the current methods of tracking aerobic capacity change during and following the ISS missions.

  4. Insulin som trickster

    DEFF Research Database (Denmark)

    Lassen, Aske Juul

    2011-01-01

    grænser nedbrydes i en konstant penetrering af huden, når blodsukkeret måles eller insulinen indsprøjtes. Insulin analyseres som en tricksterfigur, der udøver et grænsearbejde på kroppen, leger med dens kategorier og vender forholdet mellem gift og medicin, frihed og ufrihed, kunstighed og naturlighed...

  5. A Case of Possible Hypersensitivity Reactions to Human Insulin

    Directory of Open Access Journals (Sweden)

    Adamescu Eduard

    2016-03-01

    Full Text Available Background: Insulin therapy is commonly used in diabetic patients. It represents the only option for patients with type 1 diabetes mellitus and could be part of the treatment plan for the patient with type 2 diabetes mellitus. Clinical appearance of hypersensitivity reactions to insulin vary significantly, depending on the immune mechanism involved. Many skin prick tests could be interpreted as positive reactions (either by using inappropriate concentrations or due to other mast cell degranulation causes.

  6. Alginate/Chitosan Nanoparticles are Effective for Oral Insulin Delivery

    OpenAIRE

    B.; Sarmento; Ribeiro, A.; Veiga, F.; Sampaio, P.; Neufeld, R; Ferreira, D.

    2007-01-01

    Abstract Purpose To evaluate the pharmacological activity of insulin-loaded alginate/chitosan nanoparticles following oral dosage in diabetic rats. Methods Nanoparticles were prepared by ionotropic pre-gelation of an alginate core followed by chitosan polyelectrolyte complexation. In vivo activity was evaluated by measuring the decrease in blood glucose concentrations in streptozotocin induced, diabetic rats after oral administration and flourescein (FITC)-labelled insulin tracked by con...

  7. Sustained Treatment with Insulin Detemir in Mice Alters Brain Activity and Locomotion.

    Directory of Open Access Journals (Sweden)

    Tina Sartorius

    Full Text Available Recent studies have identified unique brain effects of insulin detemir (Levemir®. Due to its pharmacologic properties, insulin detemir may reach higher concentrations in the brain than regular insulin. This might explain the observed increased brain stimulation after acute insulin detemir application but it remained unclear whether chronic insulin detemir treatment causes alterations in brain activity as a consequence of overstimulation.In mice, we examined insulin detemir's prolonged brain exposure by continuous subcutaneous (s.c. application using either micro-osmotic pumps or daily s.c. injections and performed continuous radiotelemetric electrocorticography and locomotion recordings.Acute intracerebroventricular injection of insulin detemir activated cortical and locomotor activity significantly more than regular insulin in equimolar doses (0.94 and 5.63 mU in total, suggesting an enhanced acute impact on brain networks. However, given continuously s.c., insulin detemir significantly reduced cortical activity (theta: 21.3±6.1% vs. 73.0±8.1%, P<0.001 and failed to maintain locomotion, while regular insulin resulted in an increase of both parameters.The data suggest that permanently-increased insulin detemir levels in the brain convert its hyperstimulatory effects and finally mediate impairments in brain activity and locomotion. This observation might be considered when human studies with insulin detemir are designed to target the brain in order to optimize treatment regimens.

  8. Insulin Resistance and Hypogonadism

    Directory of Open Access Journals (Sweden)

    Shahana Shermin

    2013-05-01

    Full Text Available Backgound: The number of hypogonads is increasing day by day. It may be due to sedentary life style with increased obesity, increased tension or stressed lifestyle among all groups of populations. Visceral obesity is associated with insulin resistance, diabetes mellitus and also with hypogonadism.Objective: This study was carried out to determine the proportion of insulin resistance among male subjects with hypogonadism in different age groups along with status of erectile quality among diabetics and non diabetics.Materials and method: This cross sectional study among 161 adult male subjects aged ≥ 20 to ≤ 60 years were purposively selected from Bangladesh Institute of Research and Rehabilitation in Diabetes Endocrine and Metabolic Disorders (BIRDEM, Dhaka, Bangladesh between May 2009 to September 2010. Glycemic status and insulin resistance (by HOMA-R were done and relevant history were documented.Results: The highest proportion (38.9% of hypogonadism was in ≥ 50 years age group whereas highest proportion (39.6% of the eugonads was in the age group of 40 to 49 years. More than half of the hypogonad subjects had weak erectile quality (54.0% which were followed by absent erectile quality in 32.7% and 13.3% subjects had normal erectile quality. Among the eugonad subjects 41.7% had normal erectile quality, 41.6% subjects had weak erectile quality and 16.7% subjects had no erectile quality. More than ninety percent of the hypogonad subjects and about 60% of the eugonad subjects had insulin resistance. The average HOMA-R was more in the subjects with hypogonadism with diabetes which was highly significant (p-value < 0.001.Conclusion: Hypogonadism is associated with insulin resistance.

  9. Effects of Submaximal Aerobic Exercise on Regulatory T Cell Markers of Male Patients Suffering from Ischemic Heart Disease.

    Science.gov (United States)

    Raygan, Fariba; Sayyah, Mansour; Janesar Qamsari, Seyed Mohammad Reza; Nikoueinejad, Hassan; Sehat, Mojtaba

    2017-02-01

    There are confirmed beneficiary effects of exercise on atherosclerotic inflammation of ischemia-associated heart diseases. The purpose of this study was to evaluate the effect of aerobic exercise on T-regulatory cell markers of IL-35 as well as FoxP3 and T-helper2 marker of IL-33 in patients with ischemic heart disease (IHD). This research was performed on 44 asymptomatic male patients with ischemic heart disease. The participants were randomly assigned into two groups of submaximal aerobic exercise and control group. Blood samples were collected before and after the termination of the exercise protocol. Serum levels of IL-35 and IL-33 as well as the amount of FoxP3 gene expression in peripheral blood mononuclear cells were measured by Elisa and Real time PCR, respectively. Serum levels of IL-35 (p=0.001) as well as the amount of FoxP3 gene expression increased significantly (p=0.012)  in exercise group even after controlling the likely confounding effects of age, length of ischemia, duration of the disease, and the amount of such factors before exercise (p≤0.042). It seems that exercise may yield a better control of atherosclerotic inflammation in patients with ischemic heart disease through the induction of regulatory T cells.

  10. Identification of patients at low risk of dying after acute myocardial infarction, by simple clinical and submaximal exercise test criteria.

    Science.gov (United States)

    Campbell, S; A'Hern, R; Quigley, P; Vincent, R; Jewitt, D; Chamberlain, D

    1988-09-01

    A consecutive series of 559 hospital survivors of acute myocardial infarction aged less than 66 years were studied; 93 were designated prospectively as low-risk because they were suitable for early submaximal exercise testing and had none of the following clinical or exercise test 'risk factors': (1) angina for at least one month prior to infarction; (2) symptomatic ventricular arrhythmias, or (3) recurrent ischaemic pain, both after the first 24 h of infarction; (4) cardiac failure; (5) cardiomegaly; and (6) an abnormal exercise test (angina, ST-depression or poor blood pressure response). Altogether 301 patients were exercised; their mortality over a median follow-up of 2.4 years was 10.2%, versus 24.6% in the 258 patients not exercised (P = 0.0005). Absence of clinical 'risk factors' alone, in the exercised patients, identified 156 with a mortality of 5.4% versus 15.6% in the 145 with at least one clinical 'risk factor' (P = 0.004). The fully defined low-risk group comprised 93 of the former patients who had neither clinical nor exercise test 'risk factors'. None of these patients died compared with 19 of those with at least one 'risk factor' (mortality = 14.7%; P = 0.002). Their respective rates of non-fatal reinfarction were similar and never exceeded 5% per annum. Therefore, simple clinical and exercise test criteria can positively identify low-risk patients after infarction in whom secondary prevention may be inappropriate.

  11. Interaction effects of time of day and sub-maximal treadmill exercise on the main determinants of blood fluidity.

    Science.gov (United States)

    Ahmadizad, Sajad; Bassami, Minoo

    2010-01-01

    The purpose of this study was to investigate the effects of time of day on responses of the main determinants of blood rheology to acute endurance exercise. Ten healthy male subjects (age, 26.9 +/- 5.5 yr) performed two bouts of running at 65% of VO2peak for 45 min on a motorised treadmill in the morning (08:00 h) and evening (20:00 h), which were followed by 30 min recovery. The two exercise trials were performed in two separate days with 7 days intervening. Haemorheological variables were measured before, immediately after exercise and after recovery. Haematocrit, haemoglobin and RBC count were increased significantly (p evening trials and normalised following recovery, irrespective of time of day. Plasma viscosity increased significantly (F2,18 = 12.4, p exercise in both trials and returned to pre-exercise level at the end of recovery. Baseline values (p exercise were significantly affected by time of day. Neither a significant main effect of exercise nor a significant (p > 0.05) time-of-day effect was found for plasma proteins. It was concluded that sub-maximal running at 08:00 or 20:00 h does not induce different responses in the main determinant of blood rheology.

  12. Endurance and fatigue characteristics in the neck muscles during sub-maximal isometric test in patients with cervical radiculopathy.

    Science.gov (United States)

    Halvorsen, Marie; Abbott, Allan; Peolsson, Anneli; Dedering, Åsa

    2014-03-01

    The aim of the study was to compare myoelectric manifestation in neck muscle endurance and fatigue characteristics during sub-maximal isometric endurance test in patients with cervical radiculopathy and asymptomatic subjects. An additional aim was to explore associations between primary neck muscle endurance, myoelectric fatigability, and self-rated levels of fatigue, pain and subjective health measurements in patients with cervical radiculopathy. Muscle fatigue in the ventral and dorsal neck muscles was assessed in patients with cervical radiculopathy and in an asymptomatic group during an isometric neck muscle endurance test in prone and supine. 46 patients and 34 asymptomatic subjects participated. Surface electromyography signals were recorded from the sternocleidomastoid, cervical paraspinal muscles and upper and middle trapezius bilaterally during the endurance test. Subjective health measurements were assessed with questionnaires. The results showed altered neck muscle endurance in several of the muscles investigated with greater negative median frequency slope, greater variability, side imbalance, lower endurance time and higher experience of fatigue among the cervical radiculopathy patients compared with healthy subjects. Endurance times were significantly lower in both prone and in supine positions between the patients compared to asymptomatic subjects. During the neck muscle endurance test, fatigues in the upper trapezius muscles during the prone test and in the sternocleidomastoid muscles during the supine test were of more importance than self-perceived pain, fatigue, disability and kinesiophobia in predicting neck muscle endurance (NME). NME testing in the primary neck muscles seems to be an important factor to take into consideration in rehabilitation.

  13. New developments in insulin delivery.

    Science.gov (United States)

    Khan Ghilzai, Naushad M

    2003-03-01

    A vigorous research effort has been undertaken worldwide to replace injectable insulin by a more comfortable and painless delivery method. Several routes have been explored for their suitability with respect to insulin degradation in the human body. Considerable progress has been made in achieving the common goal for a convenient and equally effective insulin delivery. This article reviews the different routes available for insulin administration and the many successful developments that have been made in recent years for improving that particular route for a much better insulin delivery.

  14. Adipokines and Hepatic Insulin Resistance

    Science.gov (United States)

    Hassan, Waseem

    2013-01-01

    Obesity is a major risk factor for insulin resistance and type 2 diabetes. Adipose tissue is now considered to be an active endocrine organ that secretes various adipokines such as adiponectin, leptin, resistin, tumour necrosis factor-α, and interleukin-6. Recent studies have shown that these factors might provide a molecular link between increased adiposity and impaired insulin sensitivity. Since hepatic insulin resistance plays the key role in the whole body insulin resistance, clarification of the regulatory processes about hepatic insulin resistance by adipokines in rodents and human would seem essential in order to understand the mechanism of type 2 diabetes and for developing novel therapeutic strategies to treat it. PMID:23762871

  15. Antihyperglycemic and Insulin Secretagogue Activities of Abrus precatorius Leaf Extract.

    Science.gov (United States)

    Umamahesh, Balekari; Veeresham, Ciddi

    2016-01-01

    Abrus precatorius leaves methanolic extract (APME) was evaluated for in vivo antihyperglycemic activity and in vitro insulinotropic effect. In vivo antihyperglycemic and insulin secretagogue activities were assessed in streptozotocin-induced diabetic rats by oral administration of APME (200 mg/kg body weight [bw]) for 28 days. In vitro insulin secretion mechanisms were studied using mouse insulinoma beta cells (MIN6-β). In vivo body weight and blood glucose and in vivo and in vitro insulin levels were estimated. In diabetic rats, APME treatment significantly restored body weight (26.39%), blood glucose (32.39%), and insulin levels (73.95%) in comparison to diabetic control rats. In MIN6-β cells, APME potentiated insulin secretion in a dependent manner of glucose (3-16.7 mM) and extract (5-500 μg/mL) concentration. Insulin secretagogue effect was demonstrated in the presence of 3-isobutyl-1-methyl xanthine, glibenclamide, elevated extracellular calcium, and K(+) depolarized media. Insulin release was reduced in the presence of nifedipine, ethylene glycol tetra acetic acid (calcium blocking agents), and diazoxide (potassium channel opener). The study suggests that APME antihyperglycemic activity might involve the insulin secretagogue effect by pancreatic beta cells physiological pathways via K(+)-ATP channel dependent and independently, along with an effect on Ca(2+) channels. Abrus precatorius leaves methanolic extract (APME) showed a significant anti hyperglycemic and insulin secretagogue activities in streptozotocin induced diabetic rats. Also demonstrated a potent In vitro insulin secretagogue effect in mouse insulinoma beta cells (MIN6-β)APME treatment significantly restored body weight (26.39%), reduced blood glucose (32.39%) and enhanced circulatory insulin levels (73.95%) in diabetic ratsAPME demonstrated glucose and extract dose dependent insulin secretionInsulin secretagogue effect was demonstrated in the presence of 3-isobutyl-1-methyl xanthine

  16. Selective Insulin Resistance in Adipocytes*

    Science.gov (United States)

    Tan, Shi-Xiong; Fisher-Wellman, Kelsey H.; Fazakerley, Daniel J.; Ng, Yvonne; Pant, Himani; Li, Jia; Meoli, Christopher C.; Coster, Adelle C. F.; Stöckli, Jacqueline; James, David E.

    2015-01-01

    Aside from glucose metabolism, insulin regulates a variety of pathways in peripheral tissues. Under insulin-resistant conditions, it is well known that insulin-stimulated glucose uptake is impaired, and many studies attribute this to a defect in Akt signaling. Here we make use of several insulin resistance models, including insulin-resistant 3T3-L1 adipocytes and fat explants prepared from high fat-fed C57BL/6J and ob/ob mice, to comprehensively distinguish defective from unaffected aspects of insulin signaling and its downstream consequences in adipocytes. Defective regulation of glucose uptake was observed in all models of insulin resistance, whereas other major actions of insulin such as protein synthesis and anti-lipolysis were normal. This defect corresponded to a reduction in the maximum response to insulin. The pattern of change observed for phosphorylation in the Akt pathway was inconsistent with a simple defect at the level of Akt. The only Akt substrate that showed consistently reduced phosphorylation was the RabGAP AS160 that regulates GLUT4 translocation. We conclude that insulin resistance in adipose tissue is highly selective for glucose metabolism and likely involves a defect in one of the components regulating GLUT4 translocation to the cell surface in response to insulin. PMID:25720492

  17. Insulin resistance and chronic inflammation

    Directory of Open Access Journals (Sweden)

    Natalia Matulewicz

    2016-12-01

    Full Text Available Insulin resistance is a condition of reduced biological response to insulin. Growing evidence indicates the role of the chronic low-grade inflammatory response in the pathogenesis of insulin resistance. Adipose tissue in obesity is characterized by increased lipolysis with the excessive release of free fatty acids, and is also a source of proinflammatory cytokines. Both these factors may inhibit insulin action. Proinflammatory cytokines exert their effect by stimulating major inflammatory NFκB and JNK pathways within the cells. Inflammatory processes in other insulin responsive tissues may also play a role in inducing insulin resistance. This paper is an overview of the chronic low-grade inflammation in adipose tissue, skeletal muscle, liver and endothelial cells during the development of insulin resistance.

  18. Influence of the dynamics of body weight on the risk factors of cardiovascular disease in patients with type 2 diabetes during the first year of insulin treatment

    Directory of Open Access Journals (Sweden)

    T S Dzhavakhishvili

    2013-03-01

    Full Text Available The aim of the present study was to investigate whether insulin treatment-induced weight gain had an adverse impact on cardiovascular risk factors in insulin-treated type 2 diabetic patients during the first year after initiating insulin therapy when insulin analogues or human insulins are used. A total of 157 patients with newly insulinized type 2 diabetes were included in the study. The patients were divided in two groups. First group consisted of subjects (mean age 57 [45; 73], duration of diabetes of 10 years [4; 16] who had received long-acting basal (glargine, detemir, premixed (biphasic insulin aspart 30, Humalog Mix 25 or short-acting (aspart, lispro insulin analogues. Patients from second group (mean age 59 [46; 75], duration of diabetes of 10 years [5; 15] were treated with intermediate-acting basal (Protophane, Humulin NPH insulin, premixed (biphasic human insulin 30, Humulin M3 and regular (Actrapid, Humulin R human insulins. Our study has shown that insulin-induced weight gain may not adversely affect cardiovascular risk factors, particularly, lipid profile, in insulin-treated type 2 diabetic patients during the first year after initiating insulin therapy. Use of insulin analogues for treatment of type 2 diabetes patients results in better glycaemic control, significant declines in blood lipid concentrations, less increase in waist circumference compared with human insulins during the first year after initiating insulin therapy.

  19. Glucose-induced insulin resistance of skeletal-muscle glucose transport and uptake

    DEFF Research Database (Denmark)

    Richter, Erik; Hansen, B F; Hansen, S A

    1988-01-01

    , impairment of insulin action on muscle glucose transport and uptake. Thus maximal insulin-stimulated glucose uptake at 12 mM-glucose decreased from 34.8 +/- 1.9 to 11.5 +/- 1.1 mumol/h per g (mean +/- S.E.M., n = 10) during 5 h perfusion. This decrease in glucose uptake was accompanied by a similar change...... in the presence of glucose and insulin. The data indicate that exposure to a moderately increased glucose concentration (12 mM) leads to rapidly developing resistance of skeletal-muscle glucose transport and uptake to maximal insulin stimulation. The effect of glucose is enhanced by simultaneous insulin exposure......, whereas exposure for 5 h to insulin itself does not cause measurable resistance to maximal insulin stimulation....

  20. The establishment of insulin resistance model in FL83B and L6 cell

    Science.gov (United States)

    Liu, Lanlan; Han, Jizhong; Li, Haoran; Liu, Mengmeng; Zeng, Bin

    2017-10-01

    The insulin resistance models of mouse liver epithelial and rat myoblasts cells were induced by three kinds of inducers: dexamethasone, high insulin and high glucose. The purpose is to select the optimal insulin resistance model, to provide a simple and reliable TR cell model for the study of the pathogenesis of TR and the improvement of TR drugs and functional foods. The MTT method is used for toxicity screening of three compounds, selecting security and suitable concentration. We performed a Glucose oxidase peroxidase (GOD-POD) method involving FL83B and L6 cell with dexamethasone, high insulin and high glucose-induced insulin resistance. Results suggested that FL83B cells with dexamethasone-induced (0.25uM) were established insulin resistance and L6 cells with high-glucose (30mM) and dexamethasone-induced (0.25uM) were established insulin resistance.

  1. Insulin sensitizers prevent fine particulate matter-induced vascular insulin resistance and changes in endothelial progenitor cell homeostasis.

    Science.gov (United States)

    Haberzettl, Petra; McCracken, James P; Bhatnagar, Aruni; Conklin, Daniel J

    2016-06-01

    Exposure to fine particular matter (PM2.5) increases the risk of developing cardiovascular disease and Type 2 diabetes. Because blood vessels are sensitive targets of air pollutant exposure, we examined the effects of concentrated ambient PM2.5 (CAP) on vascular insulin sensitivity and circulating levels of endothelial progenitor cells (EPCs), which reflect cardiovascular health. We found that CAP exposure for 9 days decreased insulin-stimulated Akt phosphorylation in the aorta of mice maintained on control diet. This change was accompanied by the induction of IL-1β and increases in the abundance of cleaved IL-18 and p10 subunit of Casp-1, consistent with the activation of the inflammasome pathway. CAP exposure also suppressed circulating levels of EPCs (Flk-1(+)/Sca-1(+) cells), while enhancing the bone marrow abundance of these cells. Although similar changes in vascular insulin signaling and EPC levels were observed in mice fed high-fat diet, CAP exposure did not exacerbate diet-induced changes in vascular insulin resistance or EPC homeostasis. Treatment with an insulin sensitizer, metformin or rosiglitazone, prevented CAP-induced vascular insulin resistance and NF-κB and inflammasome activation and restored peripheral blood and bone marrow EPC levels. These findings suggest that PM2.5 exposure induces diet-independent vascular insulin resistance and inflammation and prevents EPC mobilization, and that this EPC mobilization defect could be mediated by vascular insulin resistance. Impaired vascular insulin sensitivity may be an important mechanism underlying PM2.5-induced vascular injury, and pharmacological sensitization to insulin action could potentially prevent deficits in vascular repair and mitigate vascular inflammation due to exposure to elevated levels of ambient air pollution. Copyright © 2016 the American Physiological Society.

  2. Differential interferences of hemoglobin and hemolysis on insulin assay with the Abbott Architect-Ci8200 immunoassay.

    Science.gov (United States)

    Garinet, Simon; Fellahi, Soraya; Marlin, Ginette; Capeau, Jacqueline; Lefèvre, Guillaume; Bastard, Jean-Philippe

    2014-04-01

    This paper evaluates the effect of hemoglobin (Hb) and hemolysis on insulin measurements with the Architect-Ci8200 analyzer. Insulin concentrations were measured using the Architect-Ci8200. Interference studies were performed by spiking serum pools of defined insulin concentrations with increasing concentrations of either free Hb or hemolysate. A change of more than 10% was taken as evidence of significant interference. A significant negative bias in insulin results was observed only in samples spiked with hemolysate but not with free Hb. The bias was proportional to the degree of hemolysis and to the time elapsed before insulin assay. This interference was decreased when samples were kept at +4°C. For all insulin requests, hemolysis must be systematically checked before biological interpretation of insulin results. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  3. UV-light exposure of insulin: pharmaceutical implications upon covalent insulin dityrosine dimerization and disulphide bond photolysis.

    Directory of Open Access Journals (Sweden)

    Manuel Correia

    Full Text Available In this work we report the effects of continuous UV-light (276 nm, ~2.20 W.m(-2 excitation of human insulin on its absorption and fluorescence properties, structure and functionality. Continuous UV-excitation of the peptide hormone in solution leads to the progressive formation of tyrosine photo-product dityrosine, formed upon tyrosine radical cross-linkage. Absorbance, fluorescence emission and excitation data confirm dityrosine formation, leading to covalent insulin dimerization. Furthermore, UV-excitation of insulin induces disulphide bridge breakage. Near- and far-UV-CD spectroscopy shows that UV-excitation of insulin induces secondary and tertiary structure losses. In native insulin, the A and B chains are held together by two disulphide bridges. Disruption of either of these bonds is likely to affect insulin's structure. The UV-light induced structural changes impair its antibody binding capability and in vitro hormonal function. After 1.5 and 3.5 h of 276 nm excitation there is a 33.7% and 62.1% decrease in concentration of insulin recognized by guinea pig anti-insulin antibodies, respectively. Glucose uptake by human skeletal muscle cells decreases 61.7% when the cells are incubated with pre UV-illuminated insulin during 1.5 h. The observations presented in this work highlight the importance of protecting insulin and other drugs from UV-light exposure, which is of outmost relevance to the pharmaceutical industry. Several drug formulations containing insulin in hexameric, dimeric and monomeric forms can be exposed to natural and artificial UV-light during their production, packaging, storage or administration phases. We can estimate that direct long-term exposure of insulin to sunlight and common light sources for indoors lighting and UV-sterilization in industries can be sufficient to induce irreversible changes to human insulin structure. Routine fluorescence and absorption measurements in laboratory experiments may also induce changes

  4. Activation of Wnt/beta-catenin signaling increases insulin sensitivity through a reciprocal regulation of Wnt10b and SREBP-1c in skeletal muscle cells

    National Research Council Canada - National Science Library

    Abiola, Mounira; Favier, Maryline; Christodoulou-Vafeiadou, Eleni; Pichard, Anne-Lise; Martelly, Isabelle; Guillet-Deniau, Isabelle

    2009-01-01

    Intramyocellular lipid accumulation is strongly related to insulin resistance in humans, and we have shown that high glucose concentration induced de novo lipogenesis and insulin resistance in murin muscle cells...

  5. Bariatric surgery in morbidly obese insulin resistant humans normalises insulin signalling but not insulin-stimulated glucose disposal.

    Science.gov (United States)

    Chen, Mimi Z; Hudson, Claire A; Vincent, Emma E; de Berker, David A R; May, Margaret T; Hers, Ingeborg; Dayan, Colin M; Andrews, Robert C; Tavaré, Jeremy M

    2015-01-01

    Weight-loss after bariatric surgery improves insulin sensitivity, but the underlying molecular mechanism is not clear. To ascertain the effect of bariatric surgery on insulin signalling, we examined glucose disposal and Akt activation in morbidly obese volunteers before and after Roux-en-Y gastric bypass surgery (RYGB), and compared this to lean volunteers. The hyperinsulinaemic euglycaemic clamp, at five infusion rates, was used to determine glucose disposal rates (GDR) in eight morbidly obese (body mass index, BMI=47.3 ± 2.2 kg/m(2)) patients, before and after RYGB, and in eight lean volunteers (BMI=20.7 ± 0.7 kg/m2). Biopsies of brachioradialis muscle, taken at fasting and insulin concentrations that induced half-maximal (GDR50) and maximal (GDR100) GDR in each subject, were used to examine the phosphorylation of Akt-Thr308, Akt-473, and pras40, in vivo biomarkers for Akt activity. Pre-operatively, insulin-stimulated GDR was lower in the obese compared to the lean individuals (PMANCOVA), and Akt activity towards the substrate PRAS40 (P=0.003, MANCOVA), and in contrast to GDR, were fully normalised after the surgery (obese vs lean, P=0.6, P=0.35, P=0.46, respectively). Our data show that although Akt activity substantially improved after surgery, it did not lead to a full restoration of insulin-stimulated glucose disposal. This suggests that a major defect downstream of, or parallel to, Akt signalling remains after significant weight-loss.

  6. Effects of the rate of insulin infusion during isoglycemic, hyperinsulinemic clamp procedures on measures of insulin action in healthy, mature thoroughbred mares.

    Science.gov (United States)

    Urschel, K L; Escobar, J; McCutcheon, L J; Geor, R J

    2014-04-01

    The objective of this study was to determine whether the rate of insulin infusion during isoglycemic hyperinsulinemic clamp procedures affected measures of insulin action, including glucose disposal and plasma non-esterified fatty acid, endothelin-1, and nitric oxide concentrations, in mature, healthy horses. Eight thoroughbred mares were studied during a 2-h hyperinsulinemic clamp procedure, conducted at each of 4 rates of insulin infusion: 0 (CON), 1.2 (LOWINS), 3 (MEDINS), and 6 (HIGHINS) mU · kg(-1) · min(-1). The infusion rate of a dextrose solution was adjusted throughout the clamp procedures to maintain blood glucose levels within 10% of baseline glucose concentrations. Plasma insulin concentrations were measured throughout the clamp procedures, and used with the rate of glucose infusion to calculate the plasma insulin concentration-to-rate of glucose infusion ratio, a measure of insulin action on glucose disposal. The rate of glucose infusion increased with rate of insulin infusion (P clamp procedures in the LOWINS, MEDINS, and HIGHINS treatments (P 0.05). The data indicate that it is important to standardize insulin infusion rate if data are to be compared between hyperinsulinemic clamp studies. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Insulin-mediated FFA suppression is associated with triglyceridemia and insulin sensitivity independent of adiposity.

    Science.gov (United States)

    Bush, Nikki C; Basu, Rita; Rizza, Robert A; Nair, K Sreekumaran; Khosla, Sundeep; Jensen, Michael D

    2012-11-01

    A central/visceral fat distribution and excess free fatty acid (FFA) availability are associated with dyslipidemia and insulin resistance. However, these two characteristics often coexist, making it difficult to detect the independent contributions of each. Whether FFA suppression is more closely linked to metabolic abnormalities is not clear. The aim of the study was to examine the relationship between FFA suppression, body fat distribution, and fitness as contributors toward insulin resistance and hypertriglyceridemia. We measured systemic palmitate turnover using an iv infusion of [9,10-(3)H]palmitate; upper body sc adipose tissue (UBSQ) and visceral adipose tissue (VAT) with dual-energy x-ray absorptiometry and a single-slice abdominal computed tomography scan; fitness with a graded exercise treadmill test; and insulin sensitivity with both the iv glucose tolerance test (IVGTT) (SI(IVGTT)) and mixed meal tolerance test (SI(Meal)). The study was conducted at a General Clinical Research Center. Baseline data were obtained from 140 elderly adults (age, 60-88 yr; 83 males) and 60 young adults (age, 18-31 yr; 31 males) who participated in a previously published trial assessing the effects of 2-yr supplementation of dehydroepiandrosterone or testosterone on body composition, glucose metabolism, and bone density. There were no interventions. We measured fasting plasma triglyceride (TG) concentrations, SI(IVGTT), and SI(Meal). Using multivariate regression analysis, the strongest combined predictors of TG concentrations were VAT, postmeal nadir FFA concentrations, sex, and age. The best predictors of SI(IVGTT) were IVGTT nadir palmitate concentration, VAT, UBSQ fat, fitness, and age, whereas the best predictors of SI(Meal) were meal nadir palmitate concentration, UBSQ fat, fitness, and sex. FFA suppression is associated with both fasting TG concentrations and insulin sensitivity, independent of measures of adiposity.

  8. Bariatric surgery in morbidly obese insulin resistant humans normalises insulin signalling but not insulin-stimulated glucose disposal.

    Directory of Open Access Journals (Sweden)

    Mimi Z Chen

    Full Text Available Weight-loss after bariatric surgery improves insulin sensitivity, but the underlying molecular mechanism is not clear. To ascertain the effect of bariatric surgery on insulin signalling, we examined glucose disposal and Akt activation in morbidly obese volunteers before and after Roux-en-Y gastric bypass surgery (RYGB, and compared this to lean volunteers.The hyperinsulinaemic euglycaemic clamp, at five infusion rates, was used to determine glucose disposal rates (GDR in eight morbidly obese (body mass index, BMI=47.3 ± 2.2 kg/m(2 patients, before and after RYGB, and in eight lean volunteers (BMI=20.7 ± 0.7 kg/m2. Biopsies of brachioradialis muscle, taken at fasting and insulin concentrations that induced half-maximal (GDR50 and maximal (GDR100 GDR in each subject, were used to examine the phosphorylation of Akt-Thr308, Akt-473, and pras40, in vivo biomarkers for Akt activity.Pre-operatively, insulin-stimulated GDR was lower in the obese compared to the lean individuals (P<0.001. Weight-loss of 29.9 ± 4 kg after surgery significantly improved GDR50 (P=0.004 but not GDR100 (P=0.3. These subjects still remained significantly more insulin resistant than the lean individuals (p<0.001. Weight loss increased insulin-stimulated skeletal muscle Akt-Thr308 and Akt-Ser473 phosphorylation, P=0.02 and P=0.03 respectively (MANCOVA, and Akt activity towards the substrate PRAS40 (P=0.003, MANCOVA, and in contrast to GDR, were fully normalised after the surgery (obese vs lean, P=0.6, P=0.35, P=0.46, respectively.Our data show that although Akt activity substantially improved after surgery, it did not lead to a full restoration of insulin-stimulated glucose disposal. This suggests that a major defect downstream of, or parallel to, Akt signalling remains after significant weight-loss.

  9. Insulin and Glucagon

    DEFF Research Database (Denmark)

    Holst, Jens Juul; Holland, William; Gromada, Jesper

    2017-01-01

    In August 2016, several leaders in glucagon biology gathered for the European Association for the Study of Diabetes Hagedorn Workshop in Oxford, England. A key point of discussion focused on the need for basal insulin to allow for the therapeutic benefit of glucagon blockade in the treatment...... of diabetes. Among the most enlightening experimental results presented were findings from studies in which glucagon receptor-deficient mice were administered streptozotocin to destroy pancreatic β cells or had undergone diphtheria toxin-induced β cell ablation. This article summarizes key features...... of the discussion as a consensus was reached. Agents that antagonize glucagon may be of great benefit for the treatment of diabetes; however, sufficient levels of basal insulin are required for their therapeutic efficacy....

  10. Insulin resistance: Is it time for primary prevention?

    Science.gov (United States)

    Mercurio, Valentina; Carlomagno, Guido; Fazio, Valeria; Fazio, Serafino

    2012-01-01

    Insulin resistance is a clinical condition characterized by a decrease in sensitivity and responsiveness to the metabolic actions of insulin, so that a given concentration of insulin produces a less-than-expected biological effect. As a result, higher levels of insulin are needed to maintain normal glucose tolerance. Hyperinsulinemia, indeed, is one of the principal characteristics of insulin resistance states. This feature is common in several pathologic conditions, such as type 2 diabetes, obesity, and dyslipidemia, and it is also a prominent component of hypertension, coronary heart disease, and atherosclerosis. The presence of endothelial dysfunction, related to insulin resistance, plays a key role in the development and progression of atherosclerosis in all of these disorders. Insulin resistance represents the earliest detectable abnormality in type 2 diabetes, and is one of the major underlying mechanisms of hypertension and cardiovascular diseases. Its early detection could be of great importance, in order to set a therapeutic attack and to counteract the higher risk of diabetes and cardiovascular diseases. PMID:22279598

  11. [Insulin-requiring diabetes].

    Science.gov (United States)

    Leutenegger, M; Gross, A; Ostermann, G; Grulet, H; Pasqual, C; Dijoux, B

    1988-01-01

    The insulinorequiring diabetes is a notion which deserves a clear definition, essentially clinical, because it covers a wide range of physiopathological situations. The progressive degradation of Diabetes type II means a progressive discrepancy of insulinosecretion and above all an increase of insulinoresistance. The noxious part of chronical hyperglycemia is at present well known. The present therapeutical prospects tend to delay or limit insulinotherapy, by trying to obtain remission of insulinorequiring and some attempt to give a combined treatment associating insulin and hypoglycemic drugs.

  12. Decreased insulin clearance in individuals with elevated 1-h post-load plasma glucose levels.

    Directory of Open Access Journals (Sweden)

    Maria Adelaide Marini

    Full Text Available Reduced insulin clearance has been shown to predict the development of type 2 diabetes. Recently, it has been suggested that plasma glucose concentrations ≥ 8.6 mmol/l (155 mg/dl at 1 h during an oral glucose tolerance test (OGTT can identify individuals at high risk for type 2 diabetes among those who have normal glucose tolerance (NGT 1 h-high. The aim of this study was to examine whether NGT 1 h-high have a decrease in insulin clearance, as compared with NGT individuals with 1-h post-load glucose <8.6 mmol/l (l (155 mg/dl, NGT 1 h-low. To this end, 438 non-diabetic White individuals were subjected to OGTT and euglycemic-hyperinsulinemic clamp to evaluate insulin clearance and insulin sensitivity. As compared with NGT 1 h-low individuals, NGT 1 h-high had significantly higher 1-h and 2-h post-load plasma glucose and 2-h insulin levels as well as higher fasting glucose and insulin levels. NGT 1 h-high exhibited also a significant decrease in both insulin sensitivity (P<0.0001 and insulin clearance (P = 0.006 after adjusting for age, gender, adiposity measures, and insulin sensitivity. The differences in insulin clearance remained significant after adjustment for fasting glucose (P = 0.02 in addition to gender, age, and BMI. In univariate analyses adjusted for gender and age, insulin clearance was inversely correlated with body weight, body mass index, waist, fat mass, 1-h and 2-h post-load glucose levels, fasting, 1-h and 2-h post-load insulin levels, and insulin-stimulated glucose disposal. In conclusion, our data show that NGT 1 h-high have a reduction in insulin clearance as compared with NGT 1 h-low individuals; this suggests that impaired insulin clearance may contribute to sustained fasting and post-meal hyperinsulinemia.

  13. Losartan reduces insulin resistance by inhibiting oxidative stress and enhancing insulin signaling transduction.

    Science.gov (United States)

    Pan, Y; Qiao, Q Y; Pan, L H; Zhou, D C; Hu, C; Gu, H F; Fu, S K; Liu, X L; Jin, H M

    2015-03-01

    Inhibition of the rennin-angiotensin system (RAS) could reduce insulin resistance in patients with hypertension and diabetic kidney disease (DKD), but whether the effect of losartan on insulin resistance is associated with reduction of oxidative stress and enhancement of insulin signaling transduction has not been fully elucidated. 130 patients with type 2 DKD were randomly assigned into 2 groups, the losartan group (n=65, 100 mg orally daily for 12 months) and the amlodipine group (n=65, 10 mg orally daily for 12 months). Oxidative stress markers in plasma, urine concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and nitrotyrosine (NT) as well as SOD activity were measured by ELISA. After in vitro treatment with different doses of losartan (10, 100 μmol/L) or amlodipine for 48 h, the size of H2O2-induced adipocytes and glucose consumption were measured. Western blot was performed to investigate IRS-1 serine phosphorylation level as well as the protein expressions of phosphorylated insulin receptor (pIR), phosphatidylinositol 3- kinase (PI3K) and insulin receptor substrate 1 (IRS-1) in 3T3-L1 adipocytes. After 12-month treatment, there were no significant differences in systolic and diastolic blood pressures decreases, plasma fasting blood glucose and HbA1c between the 2 groups. Compared with amlodipine group, fasting blood insulin levels and insulin resistance index (HOMA-IR) were significantly decreased in losartan group, and in addition, the circulating levels of 8-OHdG and NT were significantly decreased in losartan group, while the serum SOD activity was enhanced. There were significant positively correlations of HOMA-IR with inflammatory oxidative stress markers. In vitro study showed that losartan could increase glucose uptake in 3T3-L1 adipocytes (Padipocyte size (Preduction of oxidative stress and inflammation in patients with type 2 DKD as well as the activation of insulin signal pathway in insulin-resistance 3T3-L1 adipocytes through

  14. Variations in leptin and insulin levels within one swimming season in non-obese female cold water swimmers.

    Science.gov (United States)

    Gibas-Dorna, Magdalena; Checinska, Zuzanna; Korek, Emilia; Kupsz, Justyna; Sowinska, Anna; Wojciechowska, Malgorzata; Krauss, Hanna; Piątek, Jacek

    2016-10-01

    We examined whether cold water swimming for seven consecutive months changes basal leptin and insulin concentrations and insulin sensitivity in healthy non-obese women. Fourteen recreational female swimmers aged 45 ± 8.7 years, regularly swimming outdoors during winter months were exposed to cold water at least twice a week. Fasting blood samples were collected in October, January and April. Serum leptin, insulin and glucose concentrations were tested and insulin sensitivity was calculated using updated model HOMA2. Repeated cold water baths significantly increased insulin sensitivity and decreased insulin and leptin concentrations (p = 0.006, p = 0.032, p = 0.042, respectively). Leptin concentration positively correlated with body-mass index (BMI) and insulin level (r = 0.412, r = 0.868, respectively). Insulin level inversely correlated with insulin sensitivity and positively with glucose (r = -0.893, r = 0.166, respectively). No associations between leptin and insulin sensitivity were found. Regular cold water swimming may stimulate metabolic changes suggesting that leptin and insulin participate in adaptive metabolic mechanisms triggered by repeated cold exposure accompanied by mild exercise in healthy non-obese women.

  15. Waist circumference, ghrelin and selected adipose tissue-derived adipokines as predictors of insulin resistance in obese patients: preliminary results.

    Science.gov (United States)

    Stepien, Mariusz; Rosniak-Bak, Kinga; Paradowski, Marek; Misztal, Malgorzata; Kujawski, Krzysztof; Banach, Maciej; Rysz, Jacek

    2011-11-01

    The aim of the study was to estimate the association between anthropometric obesity parameters, serum concentrations of ghrelin, resistin, leptin, adiponectin and homeostasis model assessment (HOMA-IR) in obese non-diabetic insulin-sensitive and insulin-resistant patients. Study subjects included 37 obese (body mass index [BMI] ≥ 30 kg/m2) out-clinic patients aged 25 to 66 years. Insulin resistance was evaluated by HOMA-IR. Serum fasting concentrations of glucose, insulin, ghrelin, adiponectin, resistin and leptin were measured by using the ELISA method. Body weight, waist and hip circumferences were measured to calculate BMI and waist-to-hip ratio (WHR) values for all the patients. According to HOMA-IR, patients were divided into two groups: A, insulin sensitive (n=19); and B, insulin resistant (n=18). Patients with insulin resistance have greater mean waist circumference (WC) higher mean serum insulin level and leptin concentration, but lower concentrations of adiponectin and ghrelin. In the insulin-sensitive patient group we observed positive correlations between BMI and HOMA-IR, WC and HOMA-IR, and adiponectin and leptin, and negative correlations between ghrelin and HOMA-IR, WC and adiponectin, and WHR and adiponectin. In the insulin-resistant group, there was a positive correlation between resistin and ghrelin and a negative correlation between WHR and leptin. Waist circumference, adiponectin, leptin and ghrelin are associated with insulin resistance and may be predictors of this pathology.

  16. Effects of divergent selection for serum insulin-like growth factor-I concentration on performance, feed efficiency, and ultrasound measures of carcass composition traits in Angus bulls and heifers.

    Science.gov (United States)

    Lancaster, P A; Carstens, G E; Ribeiro, F R B; Davis, M E; Lyons, J G; Welsh, T H

    2008-11-01

    Angus bulls and heifers from lines divergently selected for serum IGF-I concentration were used to evaluate the effects of IGF-I selection line on growth performance and feed efficiency in 2 studies. In study 1, bulls (low line, n = 9; high line, n = 8; initial BW = 367.1 +/- 22.9 kg) and heifers (low line, n = 9; high line, n = 13; initial BW = 286.4 +/- 28.6 kg) were adapted to a roughage-based diet (ME = 1.95 Mcal/kg of DM) for 24 d and fed individually for 77 d by using Calan gate feeders. In study 2, bulls (low line, n = 15; high line, n = 12; initial BW = 297.5 +/- 34.4 kg) and heifers (low line, n = 9; high line, n = 20; initial BW = 256.0 +/- 25.1 kg) were adapted to a grain-based diet (ME = 2.85 Mcal/kg of DM) for 32 d and fed individually for 70 d by using Calan gate feeders. Blood samples were collected at weaning and at the start and end of each study, and serum IGF-I concentration was determined. Residual feed intake (RFI) was calculated, within study, as the residual from the linear regression of DMI on midtest BW(0.75), ADG, sex, sex by midtest BW(0.75) and sex by ADG. In study 1, calves from the low IGF-I selection line had similar initial and final BW and ADG, compared with calves from the high IGF-I selection line. In addition, DMI and feed conversion ratio were similar between IGF-I selection lines; however, calves from the low IGF-I selection line tended (P calves from the high IGF-I selection line (-0.26 vs. 0.24 +/- 0.31 kg/d). In study 2, IGF-I selection line had no influence on performance or feed efficiency traits. However, there was a tendency (P = 0.15) for an IGF-I selection line x sex interaction for RFI. Bulls from the low IGF-I selection line had numerically lesser RFI than those from the high IGF-I selection line, whereas in heifers, the IGF-I selection line had no effect on RFI. In studies 1 and 2, weaning and initial IGF-I concentrations were not correlated with either feed conversion ratio or RFI. However, regression analysis

  17. Hyperinsulinemia is associated with increased soluble insulin receptors release from hepatocytes

    Directory of Open Access Journals (Sweden)

    Marcia eHiriart

    2014-06-01

    Full Text Available It has been generally assumed that insulin circulates freely in blood. However it can also interact with plasma proteins. Insulin receptors are located in the membrane of target cells and consist of an alpha and beta subunits with a tyrosine kinase cytoplasmic domain. The ectodomain, called soluble insulin receptor (SIR has been found elevated in patients with diabetes mellitus. We explored if insulin binds to SIRs in circulation under physiological conditions and hypothesize that this SIR may be released by hepatocytes in response to high insulin concentrations. The presence of SIR in rat and human plasmas and the culture medium of hepatocytes was explored using Western blot analysis. A purification protocol was performed to isolated SIR using affinity, gel filtration and ion exchange chromatographies. A modified reverse hemolytic plaque assay was used to measure SIR release from cultured hepatocytes. Incubation with 1 nmol l-1 insulin induces the release of the insulin receptor ectodomains from normal rat hepatocytes. This effect can be partially prevented by blocking protease activity. Furthermore, plasma levels of SIR were higher in a model of metabolic syndrome, where rats are hyperinsulinemic. We also found increased SIR levels in hyperinsulinemic humans. SIR may be an important regulator of the amount of free insulin in circulation. In hyperinsulinemia the amount of this soluble receptor increases, this could lead to higher amounts of insulin bound to this receptor, rather than free insulin, which is the biologically active form of the hormone. This observation could enlighten the mechanisms of insulin resistance.

  18. Insulin regulates its own delivery to skeletal muscle by feed-forward actions on the vasculature

    Science.gov (United States)

    Wang, Hong; Upchurch, Charles T.; Liu, Zhenqi

    2011-01-01

    Insulin, at physiological concentrations, regulates the volume of microvasculature perfused within skeletal and cardiac muscle. It can also, by relaxing the larger resistance vessels, increase total muscle blood flow. Both of these effects require endothelial cell nitric oxide generation and smooth muscle cell relaxation, and each could increase delivery of insulin and nutrients to muscle. The capillary microvasculature possesses the greatest endothelial surface area of the body. Yet, whether insulin acts on the capillary endothelial cell is not known. Here, we review insulin's actions at each of three levels of the arterial vasculature as well as recent data suggesting that insulin can regulate a vesicular transport system within the endothelial cell. This latter action, if it occurs at the capillary level, could enhance insulin delivery to muscle interstitium and thereby complement insulin's actions on arteriolar endothelium to increase insulin delivery. We also review work that suggests that this action of insulin on vesicle transport depends on endothelial cell nitric oxide generation and that insulin's ability to regulate this vesicular transport system is impaired by inflammatory cytokines that provoke insulin resistance. PMID:21610226

  19. High-frequency submaximal stimulation over muscle evokes centrally generated forces in human upper limb skeletal muscles.

    Science.gov (United States)

    Blouin, Jean-Sébastien; Walsh, Lee D; Nickolls, Peter; Gandevia, Simon C

    2009-02-01

    Control of posture and movement requires control of the output from motoneurons. Motoneurons of human lower limb muscles exhibit sustained, submaximal activity to high-frequency electrical trains, which has been hypothesized to be partly triggered by monosynaptic Ia afferents. The possibility to trigger such behavior in upper limb motoneurons and the potential unique role of Ia afferents to trigger such behavior remain unclear. Subjects (n = 9) received high-frequency trains of electrical stimuli over biceps brachii and flexor pollicis longus (FPL). We chose to study the FPL muscle because it has weak monosynaptic Ia afferent connectivity and it is involved in fine motor control of the thumb. Two types of stimulus trains (100-Hz bursts and triangular ramps) were tested at five intensities below painful levels. All subjects exhibited enhanced torque in biceps and FPL muscles after both types of high-frequency train. Torques also persisted after stimulation, particularly for the highest stimulus intensity. To separate the evoked torques that resulted from a peripheral mechanism (e.g., muscle potentiation) and that which resulted from a central origin, we studied FPL responses to high-frequency trains after complete combined nerve blocks of the median and radial nerves (n = 2). During the blocks, high-frequency trains over the FPL did not yield torque enhancements or persisting torques. These results suggest that enhanced contractions of central origin can be elicited in motoneurons innervating the upper limb, despite weak monosynaptic Ia connections for FPL. Their presence in a recently evolved human muscle (FPL) indicates that these enhanced contractions may have a broad role in controlling tonic postural outputs of hand muscles and that they may be available even for fine motor activities involving the thumb.

  20. Effect of strength training with blood flow restriction on muscle power and submaximal strength in eumenorrheic women.

    Science.gov (United States)

    Gil, Ana L S; Neto, Gabriel R; Sousa, Maria S C; Dias, Ingrid; Vianna, Jeferson; Nunes, Rodolfo A M; Novaes, Jefferson S

    2017-03-01

    Blood flow restriction (BFR) training stimulates muscle size and strength by increasing muscle activation, accumulation of metabolites and muscle swelling. This method has been used in different populations, but no studies have evaluated the effects of training on muscle power and submaximal strength (SS) in accounted for the menstrual cycle. The aim of this study was to analyse the effect of strength training (ST) with BFR on the muscle power and SS of upper and lower limbs in eumenorrheic women. Forty untrained women (18-40 years) were divided randomly and proportionally into four groups: (i) high-intensity ST at 80% of 1RM (HI), (ii) low-intensity ST at 20% of 1RM combined with partial blood flow restriction (LI + BFR), (iii) low-intensity ST at 20% of 1RM (LI) and d) control group (CG). Each training group performed eight training sessions. Tests with a medicine ball (MB), horizontal jump (HJ), vertical jump (VJ), biceps curls (BC) and knee extension (KE) were performed during the 1st day follicular phase (FP), 14th day (ovulatory phase) and 26-28th days (luteal phase) of the menstrual cycle. There was no significant difference among groups in terms of the MB, HJ, VJ or BC results at any time point (P>0·05). SS in the KE exercise was significantly greater in the LI + BFR group compared to the CG group (P = 0·014) during the LP. Therefore, ST with BFR does not appear to improve the power of upper and lower limbs and may be an alternative to improve the SS of lower limbs of eumenorrheic women. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  1. Muscle coordination, activation and kinematics of world-class and elite breaststroke swimmers during submaximal and maximal efforts.

    Science.gov (United States)

    Olstad, Bjørn Harald; Vaz, João Rocha; Zinner, Christoph; Cabri, Jan M H; Kjendlie, Per-Ludvik

    2017-06-01

    The aims of this study were to describe muscular activation patterns and kinematic variables during the complete stroke cycle (SC) and the different phases of breaststroke swimming at submaximal and maximal efforts. Surface electromyography (sEMG) was collected from eight muscles in nine elite swimmers; five females (age 20.3 ± 5.4 years; Fédération Internationale de Natation [FINA] points 815 ± 160) and four males (27.7 ± 7.1 years; FINA points 879 ± 151). Underwater cameras were used for 3D kinematic analysis with automatic motion tracking. The participants swam 25 m of breaststroke at 60%, 80% and 100% effort and each SC was divided into three phases: knee extension, knee extended and knee flexion. With increasing effort, the swimmers decreased their SC distance and increased their velocity and stroke rate. A decrease during the different phases was found for duration during knee extended and knee flexion, distance during knee extended and knee angle at the beginning of knee extension with increasing effort. Velocity increased for all phases. The mean activation pattern remained similar across the different effort levels, but the muscles showed longer activation periods relative to the SC and increased integrated sEMG (except trapezius) with increasing effort. The muscle activation patterns, muscular participation and kinematics assessed in this study with elite breaststroke swimmers contribute to a better understanding of the stroke and what occurs at different effort levels. This could be used as a reference for optimising breaststroke training to improve performance.

  2. Influence of PAMAM dendrimers on the human insulin

    Science.gov (United States)

    Nowacka, Olga; Miłowska, Katarzyna; Ionov, Maksim; Bryszewska, Maria

    2015-12-01

    Dendrimers are specific class of polymeric macromolecules with wide spectrum of properties. One of the promising activities of dendrimers involves inhibition of protein fibril formation. Aggregation and fibrillation of insulin occurs in insulin-dependent diabetic patients after repeated administration, due to these processes being very easily triggered by the conditions of drug administration. The aim of this work was to study the influence of various generations PAMAM dendrimers on human insulin zeta potential, secondary structure and dithiotreitol (DTT)-induced aggregation. We observed the dependence between the number of positive charges on the surface of the PAMAM dendrimer and the values of zeta potential. Addition of dendrimers to insulin caused insignificant changes in the secondary structure. There was a small decrease in ellipticity, but it did not result in alterations in the circular dichroism (CD) spectrum shape. Dendrimers neither induced protein aggregation nor inhibited the aggregation process induced by DTT, except for 0.01 µmol/l concentration.

  3. I