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Sample records for normal insulin sensitivity

  1. Role of insulin in the hyperandrogenemia of lean women with polycystic ovary syndrome and normal insulin sensitivity.

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    Baillargeon, Jean-Patrice; Carpentier, André

    2007-10-01

    To determine the effect of reducing insulin secretion on hyperandrogenemia in lean normoinsulinemic women with polycystic ovary syndrome (PCOS) and normal metabolic insulin sensitivity. Transversal assessment at baseline and prospective follow-up of lean PCOS group after 8 days of diazoxide, which reduces insulin secretion, and 1 month of leuprolide, which suppresses LH. Clinical research center of an academic hospital. Nine lean women (body mass index PCOS and normal insulin levels, as well as 17 lean healthy women. Lean PCOS women were reassessed after 8 days of diazoxide and after 1 month of leuprolide, which suppresses LH. Androgen levels and insulin-stimulated glucose disposal (metabolic insulin sensitivity), determined by euglycemic-hyperinsulinemic clamp (M-value). Mean M-value of lean PCOS women (48.5 micromol/kg.min) was similar to lean control subjects (52.9 micromol/kg.min). They also had comparable anthropometric measures, lipids, fibrinogen, and plasminogen activator inhibitor 1. The LH did not change significantly after diazoxide, but was almost suppressed after leuprolide in the PCOS group. Androstenedione decreased significantly after diazoxide and even more after leuprolide. However, free T significantly decreased only after diazoxide in lean PCOS women. Diazoxide also increased SHBG significantly in this group. In women with typical PCOS and normal insulin levels and metabolic insulin sensitivity, reducing insulin secretion significantly decreased androgen and increased SHBG levels. These results suggest that insulin contributes to hyperandrogenemia even in PCOS women with normal metabolic insulin sensitivity, which might be due to increased sensitivity of their androgenic insulin pathway.

  2. Skeletal muscle phosphatidylcholine fatty acids and insulin sensitivity in normal humans.

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    Clore, J N; Li, J; Gill, R; Gupta, S; Spencer, R; Azzam, A; Zuelzer, W; Rizzo, W B; Blackard, W G

    1998-10-01

    The fatty acid composition of skeletal muscle membrane phospholipids (PL) is known to influence insulin responsiveness in humans. However, the contribution of the major PL of the outer (phosphatidylcholine, PC) and inner (phosphatidylethanolamine, PE) layers of the sarcolemma to insulin sensitivity is not known. Fatty acid composition of PC and PE from biopsies of vastus lateralis from 27 normal men and women were correlated with insulin sensitivity determined by the hyperinsulinemic euglycemic clamp technique at insulin infusion rates of 0.4, 1.0, and 10.0 mU . kg-1 . min-1. Significant variation in the half-maximal insulin concentration (ED50) was observed in the normal volunteers (range 24.0-146.0 microU/ml), which correlated directly with fasting plasma insulin (r = 0.75, P insulin sensitivity was observed in PE (NS). These studies suggest that the fatty acid composition of PC may be of particular importance in the relationship between fatty acids and insulin sensitivity in normal humans.

  3. Omentin, an adipokine with insulin-sensitizing properties, is negatively associated with insulin resistance in normal gestation.

    Science.gov (United States)

    Brandt, Benny; Mazaki-Tovi, Shali; Hemi, Rina; Yinon, Yoav; Schiff, Eyal; Mashiach, Roy; Kanety, Hannah; Sivan, Eyal

    2015-05-01

    Omentin, a newly identified adipokine, enhances insulin mediated glucose uptake in human adipocytes, thus, inducing systemic insulin-sensitizing effect. The aims of this study were to determine whether circulating maternal omentin levels are associated with insulin resistance indices and to assess which compartment, maternal, fetal, or placental, is the source of omentin in maternal circulation. Fasting serum glucose, insulin, and omentin were determined in 25 healthy pregnant women at the third trimester, before and 3 days after elective cesarean section. Cord blood omentin was measured in the 25 term neonates. Homeostasis model assessment (HOMA) was used to evaluate insulin sensitivity before and after delivery. Antepartum maternal omentin levels were negatively correlated with insulin levels (r=-0.41, P=0.04) and positively correlated with insulin sensitivity (HOMA%S; r=0.4, P=0.04). Postpartum omentin levels were negatively correlated with maternal body mass index (r=-0.44, P=0.02). Median maternal omentin levels was comparable before and after delivery (57.2, inter-quartile range: 38.2-76.2 ng/mL vs. 53.4, 39.8-69.4 ng/mL, respectively, P=0.25) and highly correlated (r=0.83, Pinsulin resistance indices, suggesting that this adipokine may play a role in metabolic adaptations of normal gestation. The strong correlation between anteparum and postpartum maternal omentin levels, as well as the lack of association between maternal and neonatal omentin levels, suggest that placental or fetal compartments are unlikely as the main source of circulating maternal omentin.

  4. 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...... AND METHODS: We investigated 1,415 healthy, nondiabetic participants (mean age 43.9 ± 8.3 years; 54.3% women) from the RISC (Relationship between Insulin Sensitivity and Cardiovascular Disease) study, of whom 852 participated in a follow-up examination after 3 years. At baseline, insulin sensitivity...... was assessed by hyperinsulinemic-euglycemic clamps, expressed as the M/I value. Oral glucose tolerance test-based insulin sensitivity (OGIS), homeostasis model assessment of insulin resistance (HOMA-IR), and urinary albumin-to-creatinine ratio (UACR) were determined at baseline and follow-up. RESULTS...

  5. Insulin's acute effects on glomerular filtration rate correlate with insulin sensitivity whereas insulin's acute effects on proximal tubular sodium reabsorption correlate with salt sensitivity in normal subjects

    NARCIS (Netherlands)

    ter Maaten, JC; Bakker, SJL; Serne, EH; ter Wee, PM; Gans, ROB

    1999-01-01

    Background. Insulin induces increasing distal tubular sodium reabsorption. Opposite effects of insulin to offset insulin-induced sodium retention are supposedly increases in glomerular filtration rate (GFR) and decreases in proximal tubular sodium reabsorption. Defects in these opposing effects

  6. PTP1B antisense oligonucleotide lowers PTP1B protein, normalizes blood glucose, and improves insulin sensitivity in diabetic mice

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    Zinker, Bradley A.; Rondinone, Cristina M.; Trevillyan, James M.; Gum, Rebecca J.; Clampit, Jill E.; Waring, Jeffrey F.; Xie, Nancy; Wilcox, Denise; Jacobson, Peer; Frost, Leigh; Kroeger, Paul E.; Reilly, Regina M.; Koterski, Sandra; Opgenorth, Terry J.; Ulrich, Roger G.; Crosby, Seth; Butler, Madeline; Murray, Susan F.; McKay, Robert A.; Bhanot, Sanjay; Monia, Brett P.; Jirousek, Michael R.

    2002-01-01

    The role of protein-tyrosine phosphatase 1B (PTP1B) in diabetes was investigated using an antisense oligonucleotide in ob/ob and db/db mice. PTP1B antisense oligonucleotide treatment normalized plasma glucose levels, postprandial glucose excursion, and HbA1C. Hyperinsulinemia was also reduced with improved insulin sensitivity. PTP1B protein and mRNA were reduced in liver and fat with no effect in skeletal muscle. Insulin signaling proteins, insulin receptor substrate 2 and phosphatidylinositol 3 (PI3)-kinase regulatory subunit p50α, were increased and PI3-kinase p85α expression was decreased in liver and fat. These changes in protein expression correlated with increased insulin-stimulated protein kinase B phosphorylation. The expression of liver gluconeogenic enzymes, phosphoenolpyruvate carboxykinase, and fructose-1,6-bisphosphatase was also down-regulated. These findings suggest that PTP1B modulates insulin signaling in liver and fat, and that therapeutic modalities targeting PTP1B inhibition may have clinical benefit in type 2 diabetes. PMID:12169659

  7. Natural history of insulin sensitivity and insulin secretion in the progression from normal glucose tolerance to impaired fasting glycemia and impaired glucose tolerance: the Inter99 study

    DEFF Research Database (Denmark)

    Faerch, Kristine; Vaag, Allan; Holst, Jens J

    2008-01-01

    of insulin sensitivity (HOMA-IS), early-phase insulin release (EPIR), and insulin secretion relative to insulin action (disposition index) were estimated. RESULTS: Five years before the pre-diabetes diagnoses (i-IFG, i-IGT, and IFG/IGT), ISI, HOMA-IS, EPIR, and disposition index were lower than...

  8. Glutamate Cysteine Ligase—Modulatory Subunit Knockout Mouse Shows Normal Insulin Sensitivity but Reduced Liver Glycogen Storage

    KAUST Repository

    Lavoie, Suzie

    2016-04-21

    Glutathione (GSH) deficits have been observed in several mental or degenerative illness, and so has the metabolic syndrome. The impact of a decreased glucose metabolism on the GSH system is well-known, but the effect of decreased GSH levels on the energy metabolism is unclear. The aim of the present study was to investigate the sensitivity to insulin in the mouse knockout (KO) for the modulatory subunit of the glutamate cysteine ligase (GCLM), the rate-limiting enzyme of GSH synthesis. Compared to wildtype (WT) mice, GCLM-KO mice presented with reduced basal plasma glucose and insulin levels. During an insulin tolerance test, GCLM-KO mice showed a normal fall in glycemia, indicating normal insulin secretion. However, during the recovery phase, plasma glucose levels remained lower for longer in KO mice despite normal plasma glucagon levels. This is consistent with a normal counterregulatory hormonal response but impaired mobilization of glucose from endogenous stores. Following a resident-intruder stress, during which stress hormones mobilize glucose from hepatic glycogen stores, KO mice showed a lower hyperglycemic level despite higher plasma cortisol levels when compared to WT mice. The lower hepatic glycogen levels observed in GCLM-KO mice could explain the impaired glycogen mobilization following induced hypoglycemia. Altogether, our results indicate that reduced liver glycogen availability, as observed in GCLM-KO mice, could be at the origin of their lower basal and challenged glycemia. Further studies will be necessary to understand how a GSH deficit, typically observed in GCLM-KO mice, leads to a deficit in liver glycogen storage.

  9. Glutamate Cysteine Ligase—Modulatory Subunit Knockout Mouse Shows Normal Insulin Sensitivity but Reduced Liver Glycogen Storage

    KAUST Repository

    Lavoie, Suzie; Steullet, Pascal; Kulak, Anita; Preitner, Frederic; Do, Kim Q.; Magistretti, Pierre J.

    2016-01-01

    Glutathione (GSH) deficits have been observed in several mental or degenerative illness, and so has the metabolic syndrome. The impact of a decreased glucose metabolism on the GSH system is well-known, but the effect of decreased GSH levels on the energy metabolism is unclear. The aim of the present study was to investigate the sensitivity to insulin in the mouse knockout (KO) for the modulatory subunit of the glutamate cysteine ligase (GCLM), the rate-limiting enzyme of GSH synthesis. Compared to wildtype (WT) mice, GCLM-KO mice presented with reduced basal plasma glucose and insulin levels. During an insulin tolerance test, GCLM-KO mice showed a normal fall in glycemia, indicating normal insulin secretion. However, during the recovery phase, plasma glucose levels remained lower for longer in KO mice despite normal plasma glucagon levels. This is consistent with a normal counterregulatory hormonal response but impaired mobilization of glucose from endogenous stores. Following a resident-intruder stress, during which stress hormones mobilize glucose from hepatic glycogen stores, KO mice showed a lower hyperglycemic level despite higher plasma cortisol levels when compared to WT mice. The lower hepatic glycogen levels observed in GCLM-KO mice could explain the impaired glycogen mobilization following induced hypoglycemia. Altogether, our results indicate that reduced liver glycogen availability, as observed in GCLM-KO mice, could be at the origin of their lower basal and challenged glycemia. Further studies will be necessary to understand how a GSH deficit, typically observed in GCLM-KO mice, leads to a deficit in liver glycogen storage.

  10. Insulin sensitivity is normalized in the third generation (F3 offspring of developmentally programmed insulin resistant (F2 rats fed an energy-restricted diet

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    Martin John F

    2008-10-01

    Full Text Available Abstract Background/Aims The offspring and grandoffspring of female rats fed low protein diets during pregnancy and lactation, but fed nutritionally adequate diets thereafter, have been shown to exhibit altered insulin sensitivity in adulthood. The current study investigates the insulin sensitivity of the offspring and grandoffspring of female rats fed low protein diets during pregnancy, and then maintained on energy-restricted diets post weaning over three generations. Methods Female Sprague Dawley rats (F0 were mated with control males and protein malnourished during pregnancy/lactation. F1 offspring were then weaned to adequate but energy-restricted diets into adulthood. F1 dams were fed energy-restricted diets throughout pregnancy/lactation. F2 offspring were also fed energy-restricted diets post weaning. F2 pregnant dams were maintained as described above. Their F3 offspring were split into two groups; one was maintained on the energy-restricted diet, the other was maintained on an adequate diet consumed ad libitum post weaning. Results F2 animals fed energy-restricted diets were insulin resistant (p ad libitum postweaning diets (p Conclusion Maternal energy-restriction did not consistently program reduced insulin sensitivity in offspring over three consecutive generations. The reasons for this remain unclear. It is possible that the intergenerational transmission of developmentally programmed insulin resistance is determined in part by the relative insulin sensitivity of the mother during pregnancy/lactation.

  11. Effects of ambient temperature on glucose tolerance and insulin sensitivity test outcomes in normal and obese C57 male mice.

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    Dudele, Anete; Rasmussen, Gitte Marie; Mayntz, David; Malte, Hans; Lund, Sten; Wang, Tobias

    2015-05-01

    Mice are commonly used as animal models to study human metabolic diseases, but experiments are typically performed at room temperature, which is far below their thermoneutral zone and is associated with elevated heart rate, food intake, and energy expenditure. We set out to study how ambient temperature affects glucose tolerance and insulin sensitivity in control and obese male mice. Adult male C57BL/6J mice were housed at room temperature (23°C) for 6 weeks and fed either control or high fat diet. They were then fasted for 6 h before glucose or insulin tolerance tests were performed at 15, 20, 25, or 30°C. To ensure that behavioral thermoregulation did not counterbalance the afflicted ambient temperatures, oxygen consumption was determined on mice with the same thermoregulatory opportunities as during the tests. Decreasing ambient temperatures increased oxygen consumption and body mass loss during fasting in both groups. Mice fed high fat diet had improved glucose tolerance at 30°C and increased levels of fasting insulin followed by successive decrease of fasting glucose. However, differences between control and high-fat diet mice were present at all temperatures. Ambient temperature did not affect glucose tolerance in control group and insulin tolerance in either of the groups. Ambient temperature affects glucose metabolism in mice and this effect is phenotype specific. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  12. IGF-1 levels across the spectrum of normal to elevated in acromegaly: relationship to insulin sensitivity, markers of cardiovascular risk and body composition.

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    Reid, Tirissa J; Jin, Zhezhen; Shen, Wei; Reyes-Vidal, Carlos M; Fernandez, Jean Carlos; Bruce, Jeffrey N; Kostadinov, Jane; Post, Kalmon D; Freda, Pamela U

    2015-12-01

    Activity of acromegaly is gauged by levels of GH and IGF-1 and epidemiological studies demonstrate that their normalization reduces acromegaly's excess mortality rate. However, few data are available linking IGF-1 levels to features of the disease that may relate to cardiovascular (CV) risk. Therefore, we tested the hypothesis that serum IGF-1 levels relative to the upper normal limit relate to insulin sensitivity, serum CV risk markers and body composition in acromegaly. In this prospective, cross-sectional study conducted at a pituitary tumor referral center we studied 138 adult acromegaly patients, newly diagnosed and previously treated surgically, with fasting and post-oral glucose levels of endocrine and CV risk markers and body composition assessed by DXA. Active acromegaly is associated with lower insulin sensitivity, body fat and CRP levels than acromegaly in remission. %ULN IGF-1 strongly predicts insulin sensitivity, better than GH and this persists after adjustment for body fat and lean tissue mass. %ULN IGF-1 also relates inversely to CRP levels and fat mass, positively to lean tissue and skeletal muscle estimated (SM(E)) by DXA, but not to blood pressure, lipids, BMI or waist circumference. Gender interacts with the IGF-1-lean tissue mass relationship. Active acromegaly presents a unique combination of features associated with CV risk, reduced insulin sensitivity yet lower body fat and lower levels of some serum CV risk markers, a pattern that is reversed in remission. %ULN IGF-1 levels strongly predict these features. Given the known increased CV risk of active acromegaly, these findings suggest that of these factors insulin resistance is most strongly related to disease activity and potentially to the increased CV risk of active acromegaly.

  13. Definitions of Normal Liver Fat and the Association of Insulin Sensitivity with Acquired and Genetic NAFLD—A Systematic Review

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    Elina M. Petäjä

    2016-04-01

    Full Text Available Non-alcoholic fatty liver disease (NAFLD covers a spectrum of disease ranging from simple steatosis (NAFL to non-alcoholic steatohepatitis (NASH and fibrosis. “Obese/Metabolic NAFLD” is closely associated with obesity and insulin resistance and therefore predisposes to type 2 diabetes and cardiovascular disease. NAFLD can also be caused by common genetic variants, the patatin-like phospholipase domain-containing 3 (PNPLA3 or the transmembrane 6 superfamily member 2 (TM6SF2. Since NAFL, irrespective of its cause, can progress to NASH and liver fibrosis, its definition is of interest. We reviewed the literature to identify data on definition of normal liver fat using liver histology and different imaging tools, and analyzed whether NAFLD caused by the gene variants is associated with insulin resistance. Histologically, normal liver fat content in liver biopsies is most commonly defined as macroscopic steatosis in less than 5% of hepatocytes. In the population-based Dallas Heart Study, the upper 95th percentile of liver fat measured by proton magnetic spectroscopy (1H-MRS in healthy subjects was 5.6%, which corresponds to approximately 15% histological liver fat. When measured by magnetic resonance imaging (MRI-based techniques such as the proton density fat fraction (PDFF, 5% macroscopic steatosis corresponds to a PDFF of 6% to 6.4%. In contrast to “Obese/metabolic NAFLD”, NAFLD caused by genetic variants is not associated with insulin resistance. This implies that NAFLD is heterogeneous and that “Obese/Metabolic NAFLD” but not NAFLD due to the PNPLA3 or TM6SF2 genetic variants predisposes to type 2 diabetes and cardiovascular disease.

  14. Mechanism of insulin resistance in normal pregnancy.

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    Hodson, K; Man, C Dalla; Smith, F E; Thelwall, P E; Cobelli, C; Robson, S C; Taylor, R

    2013-08-01

    Normal pregnancy is associated with insulin resistance although the mechanism is not understood. Increased intramyocellular lipid is closely associated with the insulin resistance of type 2 diabetes and obesity, and the aim of this study was to determine whether this was so for the physiological insulin resistance of pregnancy. Eleven primiparous healthy pregnant women (age: 27-39 years, body mass index 24.0±3.1 kg/m2) and no personal or family history of diabetes underwent magnetic resonance studies to quantify intramyocellular lipid, plasma lipid fractions, and insulin sensitivity. The meal-related insulin sensitivity index was considerably lower in pregnancy (45.6±9.9 vs. 193.0±26.1; 10(-4) dl/kg/min per pmol/l, p=0.0002). Fasting plasma triglyceride levels were elevated 3-fold during pregnancy (2.3±0.2 vs. 0.8±0.1 mmol/l, pinsulin resistance is distinct from that underlying type 2 diabetes. © Georg Thieme Verlag KG Stuttgart · New York.

  15. Left ventricular function impairment in patients with normal-weight obesity: contribution of abdominal fat deposition, profibrotic state, reduced insulin sensitivity, and proinflammatory activation.

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    Kosmala, Wojciech; Jedrzejuk, Diana; Derzhko, Roksolana; Przewlocka-Kosmala, Monika; Mysiak, Andrzej; Bednarek-Tupikowska, Grazyna

    2012-05-01

    Obesity predisposes to left ventricular (LV) dysfunction and heart failure; however, the risk of these complications has not been assessed in patients with a normal body mass index (BMI) but increased body fat content (normal-weight obesity, NWO). We hypothesized that LV performance in NWO may be impaired and sought to investigate potential contributors to cardiac functional abnormalities. One hundred sixty-eight subjects (age, 38±7 years) with BMI affecting the myocardium were classified on the basis of body fat content into 2 groups: with NWO and without NWO. Echocardiographic indices of LV systolic and diastolic function, including myocardial velocities and deformation, serological fibrosis markers, indicators of proinflammatory activation, and metabolic control, were evaluated. Subjects with NWO demonstrated impaired LV systolic and diastolic function, increased fibrosis intensity (assessed by procollagen type I carboxy-terminal propeptide [PICP]), impaired insulin sensitivity, and increased proinflammatory activation as compared with individuals with normal body fat. The independent correlates of LV systolic and diastolic function variables were as follows: for strain, IL-18 (β=-0.17, P<0.006), C-reactive protein (β=-0.20, P<0.002) and abdominal fat deposit (β=-0.20, P<0.003); for tissue S velocity, PICP (β=-0.21, P<0.002) and abdominal fat deposit (β=-0.43, P<0.0001); for tissue E velocity, abdominal fat deposit (β=-0.30, P<0.0001), PICP (β=-0.31, P<0.0001) and homeostasis model assessment of insulin resistance index (HOMA IR; β=-0.20, P<0.002); and for E/e'-PICP, IL-18 (both β=0.18, P<0.01) and HOMA IR (β=0.16, P<0.04). In patients with NWO, subclinical disturbances of LV function are independently associated with the extent of abdominal fat deposit, profibrotic state (as reflected by circulating PICP), reduced insulin sensitivity, and proinflammatory activation.

  16. Is serum zinc associated with pancreatic beta cell function and insulin sensitivity in pre-diabetic and normal individuals? Findings from the Hunter Community Study.

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    Khanrin P Vashum

    Full Text Available AIM: To determine if there is a difference in serum zinc concentration between normoglycaemic, pre-diabetic and type-2 diabetic groups and if this is associated with pancreatic beta cell function and insulin sensitivity in the former 2 groups. METHOD: Cross sectional study of a random sample of older community-dwelling men and women in Newcastle, New South Wales, Australia. Beta cell function, insulin sensitivity and insulin resistance were calculated for normoglycaemic and prediabetes participants using the Homeostasis Model Assessment (HOMA-2 calculator. RESULT: A total of 452 participants were recruited for this study. Approximately 33% (N = 149 had diabetes, 33% (N = 151 had prediabetes and 34% (N = 152 were normoglycaemic. Homeostasis Model Assessment (HOMA parameters were found to be significantly different between normoglycaemic and prediabetes groups (p<0.001. In adjusted linear regression, higher serum zinc concentration was associated with increased insulin sensitivity (p = 0.01 in the prediabetic group. There was also a significant association between smoking and worse insulin sensitivity. CONCLUSION: Higher serum zinc concentration is associated with increased insulin sensitivity. Longitudinal studies are required to determine if low serum zinc concentration plays a role in progression from pre-diabetes to diabetes.

  17. Insulin sensitivity : modulation by the brain

    NARCIS (Netherlands)

    Coomans, Claudia Pascalle

    2012-01-01

    The studies in this thesis contribute to the understanding of the role of the brain in insulin sensitivity. We demonstrate that disturbances in circadian rhythm resulting in alterations in SCN output, can contribute to the development of insulin resistance. We also shown that insulin-stimulated

  18. Insulin resistance, insulin sensitization and inflammation in polycystic ovarian syndrome

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    Dhindsa G

    2004-04-01

    Full Text Available It is estimated that 5-10% of women of reproductive age have polycystic ovarian syndrome (PCOS. While insulin resistance is not part of the diagnostic criteria for PCOS, its importance in the pathogenesis of PCOS cannot be denied. PCOS is associated with insulin resistance independent of total or fat-free body mass. Post-receptor defects in the action of insulin have been described in PCOS which are similar to those found in obesity and type 2 diabetes. Treatment with insulin sensitizers, metformin and thiazolidinediones, improve both metabolic and hormonal patterns and also improve ovulation in PCOS. Recent studies have shown that PCOS women have higher circulating levels of inflammatory mediators like C-reactive protein, tumour necrosis factor- , tissue plasminogen activator and plasminogen activator inhibitor-1 (PAI-1 . It is possible that the beneficial effect of insulin sensitizers in PCOS may be partly due to a decrease in inflammation.

  19. Increased skeletal muscle capillarization enhances insulin sensitivity

    DEFF Research Database (Denmark)

    Åkerström, Thorbjörn; Laub, Lasse; Vedel, Kenneth

    2014-01-01

    Increased skeletal muscle capillarization is associated with improved glucose tolerance and insulin sensitivity. However, a possible causal relationship has not previously been identified. We therefore investigated whether increased skeletal muscle capillarization increases insulin sensitivity....... Skeletal muscle specific angiogenesis was induced by adding the α1-adrenergic receptor antagonist Prazosin to the drinking water of Sprague Dawley rats (n=33) while 34 rats served as controls. Insulin sensitivity was measured ≥40 h after termination of the 3-week Prazosin treatment, which ensured...... that Prazosin was cleared from the blood stream. Whole-body insulin sensitivity was measured in conscious, unrestrained rats by hyperinsulinemic euglycemic clamp. Tissue specific insulin sensitivity was assessed by administration of 2-deoxy-[(3)H]-Glucose during the plateau phase of the clamp. Whole...

  20. Dimethylarginine Dimethylaminohydrolase Overexpression enhances Insulin Sensitivity

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    Sydow, Karsten; Mondon, Carl E.; Schrader, Joerg; Konishi, Hakuoh; Cooke, John P.

    2011-01-01

    Objective Previous studies suggest that nitric oxide (NO) may modulate insulin-induced uptake of glucose in insulin-sensitive tissues. Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NO synthase (NOS). We hypothesized that a reduction in endogenous ADMA would increase NO synthesis and thereby enhance insulin sensitivity. Methods and Results To test this hypothesis we employed a transgenic mouse in which we overexpressed human dimethylarginine dimethylaminohydrolase (DDAH-I). The DDAH-I mice had lower plasma ADMA at all ages (22–70 weeks) by comparison to wild-type (WT) littermates. With a glucose challenge, WT mice showed a prompt increase in ADMA, whereas DDAH-I mice had a blunted response. Furthermore, DDAH-I mice had a blunted increase in plasma insulin and glucose levels after glucose challenge, with a 50% reduction in the insulin resistence index, consistent with enhanced sensitivity to insulin. In liver, we observed an increased Akt phosphorylation in the DDAH-I mice after i.p. glucose challenge. Incubation of skeletal muscle from WT mice ex vivo with ADMA (2μM) markedly suppressed insulin-induced glycogen synthesis in fast-twitch but not slow-twitch muscle. Conclusions These findings suggest that the endogenous NOS inhibitor ADMA reduces insulin sensitivity, consistent with previous observations that NO plays a role in insulin sensitivity. PMID:18239148

  1. Mechanisms for greater insulin-stimulated glucose uptake in normal and insulin-resistant skeletal muscle after acute exercise

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    2015-01-01

    Enhanced skeletal muscle and whole body insulin sensitivity can persist for up to 24–48 h after one exercise session. This review focuses on potential mechanisms for greater postexercise and insulin-stimulated glucose uptake (ISGU) by muscle in individuals with normal or reduced insulin sensitivity. A model is proposed for the processes underlying this improvement; i.e., triggers initiate events that activate subsequent memory elements, which store information that is relayed to mediators, which translate memory into action by controlling an end effector that directly executes increased insulin-stimulated glucose transport. Several candidates are potential triggers or memory elements, but none have been conclusively verified. Regarding potential mediators in both normal and insulin-resistant individuals, elevated postexercise ISGU with a physiological insulin dose coincides with greater Akt substrate of 160 kDa (AS160) phosphorylation without improved proximal insulin signaling at steps from insulin receptor binding to Akt activity. Causality remains to be established between greater AS160 phosphorylation and improved ISGU. The end effector for normal individuals is increased GLUT4 translocation, but this remains untested for insulin-resistant individuals postexercise. Following exercise, insulin-resistant individuals can attain ISGU values similar to nonexercising healthy controls, but after a comparable exercise protocol performed by both groups, ISGU for the insulin-resistant group has been consistently reported to be below postexercise values for the healthy group. Further research is required to fully understand the mechanisms underlying the improved postexercise ISGU in individuals with normal or subnormal insulin sensitivity and to explain the disparity between these groups after similar exercise. PMID:26487009

  2. Insulin sensitivity in post-obese women

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    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 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...... 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)...

  3. Microbial Modulation of Insulin Sensitivity

    NARCIS (Netherlands)

    Khan, Muhammad Tanweer; Nieuwdorp, Max; Bäckhed, Fredrik

    2014-01-01

    The gut microbiota has emerged as an integral factor that impacts host metabolism and has been suggested to play a vital role in metabolic diseases such as obesity, insulin resistance, type 2 diabetes, and cardiovascular disease. In humans, cross-sectional studies have identified microbiota profiles

  4. Insulin and Insulin-Sensitizing Drugs in Neurodegeneration: Mitochondria as Therapeutic Targets

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    Paula I. Moreira

    2009-12-01

    Full Text Available Insulin, besides its glucose lowering effects, is involved in the modulation of lifespan, aging and memory and learning processes. As the population ages, neurodegenerative disorders become epidemic and a connection between insulin signaling dysregulation, cognitive decline and dementia has been established. Mitochondria are intracellular organelles that despite playing a critical role in cellular metabolism are also one of the major sources of reactive oxygen species. Mitochondrial dysfunction, oxidative stress and neuroinflammation, hallmarks of neurodegeneration, can result from impaired insulin signaling. Insulin-sensitizing drugs such as the thiazolidinediones are a new class of synthetic compounds that potentiate insulin action in the target tissues and act as specific agonists of the peroxisome proliferator-activated receptor gamma (PPAR-γ. Recently, several PPAR agonists have been proposed as novel and possible therapeutic agents for neurodegenerative disorders. Indeed, the literature shows that these agents are able to protect against mitochondrial dysfunction, oxidative damage, inflammation and apoptosis. This review discusses the role of mitochondria and insulin signaling in normal brain function and in neurodegeneration. Furthermore, the potential protective role of insulin and insulin sensitizers in Alzheimer´s, Parkinson´s and Huntington´s diseases and amyotrophic lateral sclerosis will be also discussed.

  5. Obese but not normal-weight women with polycystic ovary syndrome are characterized by metabolic and microvascular insulin resistance.

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    Ketel, Iris J G; Stehouwer, Coen D A; Serné, Erik H; Korsen, Ted J M; Hompes, Peter G A; Smulders, Yvo M; de Jongh, Renate T; Homburg, Roy; Lambalk, Cornelis B

    2008-09-01

    Polycystic ovary syndrome (PCOS) and obesity are associated with diabetes and cardiovascular disease, but it is unclear to what extent PCOS contributes independently of obesity. The objective of the study was to investigate whether insulin sensitivity and insulin's effects on the microcirculation are impaired in normal-weight and obese women with PCOS. Thirty-five women with PCOS (19 normal weight and 16 obese) and 27 age- and body mass index-matched controls (14 normal weight and 13 obese) were included. Metabolic Insulin sensitivity (isoglycemic-hyperinsulinemic clamp) and microvascular insulin sensitivity [endothelium dependent (acetylcholine [ACh])] and endothelium-independent [sodium nitroprusside (SNP)] vasodilation with laser Doppler flowmetry was assessed at baseline and during hyperinsulinemia. Metabolic insulin sensitivity (M/I value) and the area under the response curves to ACh and SNP curves were measured to assess microcirculatory function at baseline and during insulin infusion (microvascular insulin sensitivity). Obese women were more insulin resistant than normal-weight women (P PCOS women were more resistant than obese controls (P = 0.02). In contrast, normal-weight women with PCOS had similar insulin sensitivity, compared with normal-weight women without PCOS. Baseline responses to ACh showed no difference in the four groups. ACh responses during insulin infusion were significantly greater in normal-weight PCOS and controls than in obese PCOS and controls. PCOS per se had no significant influence on ACh responses during insulin infusion. During hyperinsulinemia, SNP-dependent vasodilatation did not significantly increase, compared with baseline in the four groups. PCOS per se was not associated with impaired metabolic insulin sensitivity in normal-weight women but aggravates impairment of metabolic insulin sensitivity in obese women. In obese but not normal-weight women, microvascular and metabolic insulin sensitivity are decreased, independent

  6. How can we measure insulin sensitivity?

    International Nuclear Information System (INIS)

    Hovorka, R.

    1999-01-01

    Insulin resistance is common in general population and prevalent in patients with obesity and Type 2 diabetes. Insulin sensitivity, reciprocal to insulin resistance, can be measured with a variety of experimental methods ranging from the 'gold' standard glucose clamp to the simple HOMA assessment. Each method has its merit and is applicable under different circumstances. Adoption of glucose tracers in the experimental protocols and more specifically in glucose clamp and minimal model allows hepatic vs. peripheral insulin sensitivity to be discriminated and estimated separately. The objective of this review is to give an account of the minimal modelling approach and provide summary information about other measurement methods together with information about reproducibility of the most popular methods, the minimal model and the glucose clamp techniques. (author)

  7. Insulin sensitivity deteriorates after short-term lifestyle intervention in the insulin sensitive phenotype of obesity.

    Science.gov (United States)

    Gilardini, Luisa; Vallone, Luciana; Cottafava, Raffaella; Redaelli, Gabriella; Croci, Marina; Conti, Antonio; Pasqualinotto, Lucia; Invitti, Cecilia

    2012-01-01

    To investigate the effects of a 3-month lifestyle intervention on insulin sensitivity and its related cardiometabolic factors in obese patients. Anthropometry, body composition, oral glucose tolerance test, lipids, alanine aminotransferase, insulin sensitivity (insulinogenic index (ISI), homeostasis model assessment, β-cell performance (disposition index)) were evaluated in 263 obese women and 93 obese men before and after 3 months of hypocaloric low fat/high protein diet associated with physical activity 30 min/day. Patients were divided into 3 groups according to the intervention-induced ISI changes: group 1 (decrease), group 2 (stability) and group 3 (increase). Insulin sensitivity and the disposition index were significantly higher before the intervention in group 1 than in group 3. BMI, waist circumference, and fat mass significantly decreased in groups 1 and 3 in both sexes. β-cell performance decreased in group 1 and increased in group 3. Metabolic variables improved in group 3, whereas glucose levels increased in women of group 1. The post-intervention insulin sensitivity was lower in group 1 than in group 3. Lifestyle intervention induces changes in insulin sensitivity and metabolic factors that depend on the pre-intervention degree of insulin sensitivity. Weight loss leads to metabolic benefits in insulin-resistant, obese patients, whereas it may paradoxically worsen the metabolic conditions in the insulin-sensitive phenotype of obesity. Copyright © 2012 S. Karger GmbH, Freiburg.

  8. Exercise, pregnancy, and insulin sensitivity--what is new?

    DEFF Research Database (Denmark)

    Damm, Peter; Breitowicz, Bettina; Hegaard, Hanne

    2007-01-01

    Pregnancy is characterized by a marked physiological insulin resistance. Overweight and obesity or lack of physical activity can aggravate this reduced insulin sensitivity further. Increased insulin resistance has been associated with serious pregnancy complications, such as gestational diabetes...

  9. Prediction of clamp-derived insulin sensitivity from the oral glucose insulin sensitivity index

    DEFF Research Database (Denmark)

    Tura, Andrea; Chemello, Gaetano; Szendroedi, Julia

    2018-01-01

    that underwent both a clamp and an OGTT or meal test, thereby allowing calculation of both the M value and OGIS. The population was divided into a training and a validation cohort (n = 359 and n = 154, respectively). After a stepwise selection approach, the best model for M value prediction was applied......AIMS/HYPOTHESIS: The euglycaemic-hyperinsulinaemic clamp is the gold-standard method for measuring insulin sensitivity, but is less suitable for large clinical trials. Thus, several indices have been developed for evaluating insulin sensitivity from the oral glucose tolerance test (OGTT). However......, most of them yield values different from those obtained by the clamp method. The aim of this study was to develop a new index to predict clamp-derived insulin sensitivity (M value) from the OGTT-derived oral glucose insulin sensitivity index (OGIS). METHODS: We analysed datasets of people...

  10. Insulin-Sensitizers, Polycystic Ovary Syndrome and Gynaecological Cancer Risk

    Science.gov (United States)

    Lauretta, Rosa; Lanzolla, Giulia; Vici, Patrizia; Mariani, Luciano; Moretti, Costanzo

    2016-01-01

    Preclinical, early phase clinical trials and epidemiological evidence support the potential role of insulin-sensitizers in cancer prevention and treatment. Insulin-sensitizers improve the metabolic and hormonal profile in PCOS patients and may also act as anticancer agents, especially in cancers associated with hyperinsulinemia and oestrogen dependent cancers. Several lines of evidence support the protection against cancer exerted by dietary inositol, in particular inositol hexaphosphate. Metformin, thiazolidinediones, and myoinositol postreceptor signaling may exhibit direct inhibitory effects on cancer cell growth. AMPK, the main molecular target of metformin, is emerging as a target for cancer prevention and treatment. PCOS may be correlated to an increased risk for developing ovarian and endometrial cancer (up to threefold). Several studies have demonstrated an increase in mortality rate from ovarian cancer among overweight/obese PCOS women compared with normal weight women. Long-term use of metformin has been associated with lower rates of ovarian cancer. Considering the evidence supporting a higher risk of gynaecological cancer in PCOS women, we discuss the potential use of insulin-sensitizers as a potential tool for chemoprevention, hypothesizing a possible rationale through which insulin-sensitizers may inhibit tumourigenesis. PMID:27725832

  11. The brain modulates insulin sensitivity in multiple tissues

    NARCIS (Netherlands)

    Parlevliet, Edwin T.; Coomans, Claudia P.; Rensen, Patrick C. N.; Romijn, Johannes A.

    2014-01-01

    Insulin sensitivity is determined by direct effects of circulating insulin on metabolically active tissues in combination with indirect effects of circulating insulin, i.e. via the central nervous system. The dose-response effects of insulin differ between the various physiological effects of

  12. Insulin sensitizers in adolescents with polycystic ovary syndrome.

    Science.gov (United States)

    LE, Trang N; Wickham, Edmond P; Nestler, John E

    2017-10-01

    Polycystic ovary syndrome (PCOS) is the most common disorder of androgen excess in women of reproductive age. The diagnosis of PCOS can be more challenging in adolescents than in adult women given significant overlap between normal puberty and the signs of PCOS, including acne, menstrual irregularity, and polycystic ovarian morphology. Optimal treatments for adult women with PCOS vary depending on patient risk factors and reproductive goals, but mainly include hormonal contraception and insulin sensitizers. There is continued interest in targeting the intrinsic insulin resistance that contributes to metabolic and hormonal derangements associated with PCOS. The vast majority of published data on insulin sensitizing PCOS treatments are reported in adult women; these have included weight loss, metformin, thiazolidinediones, and the inositols. Furthermore, there is also a small but growing body of evidence in support of the use of insulin sensitizers in adolescents, with or without oral contraceptives. Discussion of the available treatments, including benefits, potential side effects, and incorporation of patient and family preferences is critical in developing a plan of care aimed at achieving patient-important improvements in PCOS signs and symptoms while addressing the longer-term cardiometabolic risks associated with the syndrome.

  13. A model to estimate insulin sensitivity in dairy cows

    OpenAIRE

    Holtenius, Paul; Holtenius, Kjell

    2007-01-01

    Abstract Impairment of the insulin regulation of energy metabolism is considered to be an etiologic key component for metabolic disturbances. Methods for studies of insulin sensitivity thus are highly topical. There are clear indications that reduced insulin sensitivity contributes to the metabolic disturbances that occurs especially among obese lactating cows. Direct measurements of insulin sensitivity are laborious and not suitable for epidemiological studies. We have therefore adopted an i...

  14. Effects of menopause and high-intensity training on insulin sensitivity and muscle metabolism

    DEFF Research Database (Denmark)

    Mandrup, Camilla M; Egelund, Jon; Nyberg, Michael

    2018-01-01

    To investigate peripheral insulin sensitivity and skeletal muscle glucose metabolism in premenopausal and postmenopausal women, and evaluate whether exercise training benefits are maintained after menopause. Sedentary, healthy, normal-weight, late premenopausal (n = 21), and early postmenopausal (n...

  15. The relationship between bone turnover and insulin sensitivity and secretion

    DEFF Research Database (Denmark)

    Frost, Morten; Balkau, Beverley; Hatunic, Mensud

    2018-01-01

    Bone metabolism appears to influence insulin secretion and sensitivity, and insulin promotes bone formation in animals, but similar evidence in humans is limited. The objectives of this study are to explore if bone turnover markers were associated with insulin secretion and sensitivity and to det...

  16. 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...

  17. Recombinant DNA derived monomeric insulin analogue: comparison with soluble human insulin in normal subjects.

    Science.gov (United States)

    Vora, J P; Owens, D R; Dolben, J; Atiea, J A; Dean, J D; Kang, S; Burch, A; Brange, J

    1988-11-12

    To compare the rate of absorption from subcutaneous tissue and the resulting hypoglycaemic effect of iodine-125 labelled soluble human insulin and a monomeric insulin analogue derived by recombinant DNA technology. Single blind randomised comparison of equimolar doses of 125I labelled soluble human insulin and insulin analogue. Study in normal people at a diabetes research unit and a university department of medical physics. Seven healthy male volunteers aged 20-39 not receiving any other drugs. After an overnight fast and a basal period of one hour two doses (0.05 and 0.1 U/kg) of 125I labelled soluble human insulin and insulin analogue were injected subcutaneously into the anterior abdominal wall on four separate days. To find a fast acting insulin for meal related requirements in insulin dependent diabetics. MEASUREMENTS and main results--Residual radioactivity at the injection site was measured continuously for the first two hours after injection of the 125I labelled preparations and thereafter for five minutes simultaneously with blood sampling. Frequent venous blood samples were obtained over six hours for determination of plasma immunoreactive insulin, insulin analogue, glucose, and glucagon values. Time to 50% of initial radioactivity at the injection site for the insulin analogue compared with soluble insulin was 61 v 135 minutes (p less than 0.05) with 0.05 U/kg and 67 v 145 minutes (p less than 0.001) with 0.1 U/kg. Concentrations in plasma increased faster after the insulin analogue compared with soluble insulin, resulting in higher plasma concentrations between 10 and 150 minutes (0.001 less than p less than 0.05) after 0.05 U/kg and between 40 and 360 minutes (0.001 less than p less than 0.05) after 0.1 U/kg. The hypoglycaemic response to insulin analogue was a plasma glucose nadir at 60 minutes with both doses compared with 90 and 120 minutes with soluble insulin at 0.5 and 0.1 U/kg respectively. The response of glucagon substantiated the earlier and

  18. Brain GLP-1 and insulin sensitivity.

    Science.gov (United States)

    Sandoval, Darleen; Sisley, Stephanie R

    2015-12-15

    Type 2 diabetes is often treated with a class of drugs referred to as glucagon-like peptide-1 (GLP-1) analogs. GLP-1 is a peptide secreted by the gut that acts through only one known receptor, the GLP-1 receptor. The primary function of GLP-1 is thought to be lowering of postprandial glucose levels. Indeed, medications utilizing this system, including the long-acting GLP-1 analogs liraglutide and exenatide, are beneficial in reducing both blood sugars and body weight. GLP-1 analogs were long presumed to affect glucose control through their ability to increase insulin levels through peripheral action on beta cells. However, multiple lines of data point to the ability of GLP-1 to act within the brain to alter glucose regulation. In this review we will discuss the evidence for a central GLP-1 system and the effects of GLP-1 in the brain on regulating multiple facets of glucose homeostasis including glucose tolerance, insulin production, insulin sensitivity, hepatic glucose production, muscle glucose uptake, and connections of the central GLP-1 system to the gut. Although the evidence indicates that GLP-1 receptors in the brain are not necessary for physiologic control of glucose regulation, we discuss the research showing a strong effect of acute manipulation of the central GLP-1 system on glucose control and how it is relevant to type 2 diabetic patients. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Depressive symptoms, insulin sensitivity and insulin secretion in the RISC cohort study

    NARCIS (Netherlands)

    Bot, M.; Pouwer, F.; de Jonge, P.; Nolan, J.J.; Mari, A.; Højlund, K.; Golay, A.; Balkau, B.; Dekker, J.M.

    2013-01-01

    Aim This study explored the association of depressive symptoms with indices of insulin sensitivity and insulin secretion in a cohort of non-diabetic men and women aged 30 to 64 years. Methods The study population was derived from the 3-year follow-up of the Relationship between Insulin Sensitivity

  20. Depressive symptoms, insulin sensitivity and insulin secretion in the RISC cohort study

    NARCIS (Netherlands)

    Bot, M.; Pouwer, F.; De Jonge, P.; Nolan, J. J.; Mari, A.; Hojlund, K.; Golay, A.; Balkau, B.; Dekker, J. M.

    Aim. This study explored the association of depressive symptoms with indices of insulin sensitivity and insulin secretion in a cohort of non-diabetic men and women aged 30 to 64 years. Methods. The study population was derived from the 3-year follow-up of the Relationship between Insulin Sensitivity

  1. Depressive symptoms, insulin sensitivity and insulin secretion in the RISC cohort study

    DEFF Research Database (Denmark)

    Bot, M; Pouwer, F; De Jonge, P

    2013-01-01

    Sensitivity and Cardiovascular Disease Risk (RISC) study. Presence of significant depressive symptoms was defined as a Center for Epidemiologic Studies Depression Scale (CES-D) score ≥ 16. Standard oral glucose tolerance tests were performed. Insulin sensitivity was assessed with the oral glucose insulin......AIM: This study explored the association of depressive symptoms with indices of insulin sensitivity and insulin secretion in a cohort of non-diabetic men and women aged 30 to 64 years. METHODS: The study population was derived from the 3-year follow-up of the Relationship between Insulin...... sensitivity (OGIS) index. Insulin secretion was estimated using three model-based parameters of insulin secretion (beta-cell glucose sensitivity, the potentiation factor ratio, and beta-cell rate sensitivity). RESULTS: A total of 162 out of 1027 participants (16%) had significant depressive symptoms. Having...

  2. Insulin sensitivity and metabolic flexibility following exercise training among different obese insulin resistant phenotypes

    DEFF Research Database (Denmark)

    Malin, Steven K; Haus, Jacob M; Solomon, Thomas

    2013-01-01

    Impaired fasting glucose (IFG) blunts the reversal of impaired glucose tolerance (IGT) after exercise training. Metabolic inflexibility has been implicated in the etiology of insulin resistance, however, the efficacy of exercise on peripheral and hepatic insulin sensitivity or substrate utilizati...

  3. Relationship between Inflammation markers, Coagulation Activation and Impaired Insulin Sensitivity in Obese Healthy Women

    International Nuclear Information System (INIS)

    Soliman, S.Et; Shousha, M.A.

    2011-01-01

    Obesity, insulin resistance syndrome, and atherosclerosis are closely linked phenomena, often connected with a chronic low grade inflammatory state and pro thrombotic hypo fibrinolytic condition. This study investigated the relationship between impaired insulin sensitivity and selected markers of inflammation and thrombin generation in obese healthy women. The study included 36 healthy obese women (body mass index ≥ 30), with normal insulin sensitivity (NIS, n = 18) or impaired insulin sensitivity (IIS, n 18), and 10 non obese women (body mass index < 25).Impaired insulin sensitivity patients had significantly higher levels of high sensitivity C-reactive protein (hs-CRP), transforming growth factor -β1(TGF-β1), plasminogen activator inhibitor-1 (PAI-1), activated factor VII (VIIa), and prothrombin fragments 1 + 2 (F1 + 2) compared with either control subjects or normal insulin sensitivity patients. On the other hand, NIS patients had higher hs-CRP, TGF-β1, PAI-1, and factor VIIa, but not F1 + 2, levels than controls. Significant inverse correlations were observed between the insulin sensitivity index and TGF-β1, hs-CRP, PAI-1; factor VIIa, and F1 + 2 levels. Moreover, significant direct correlations were noted between TGF-β1 and CRP, PAI-1, factor VIIa, and F1 + 2 concentrations. Finally, multiple regressions revealed that TGF-β1 and the insulin sensitivity index were independently related to F1 + 2. These results document an in vivo relationship between insulin sensitivity and coagulation activation in obesity. Here we report that obesity is associated with higher TGF-β, PAI-1, prothrombin fragments 1 and 2 (F1 + 2), and activated factor VII (VIIa) plasma levels, and that insulin resistance exacerbates these alterations. The elevated TGF-β1 levels detected in the obese population may provide a biochemical link between insulin resistance and an increased risk for cardiovascular disease

  4. Heart Rate Variability, Insulin Resistance, and Insulin Sensitivity in Japanese Adults: The Toon Health Study

    Directory of Open Access Journals (Sweden)

    Isao Saito

    2015-09-01

    Full Text Available Background: Although impaired cardiac autonomic function is associated with an increased risk of type 2 diabetes in Caucasians, evidence in Asian populations with a lower body mass index is limited. Methods: Between 2009–2012, the Toon Health Study recruited 1899 individuals aged 30–79 years who were not taking medication for diabetes. A 75-g oral glucose tolerance test was used to diagnose type 2 diabetes, and fasting and 2-h-postload glucose and insulin concentrations were measured. We assessed the homeostasis model assessment index for insulin resistance (HOMA-IR and Gutt’s insulin sensitivity index (ISI. Pulse was recorded for 5 min, and time-domain heart rate variability (HRV indices were calculated: the standard deviation of normal-to-normal intervals (SDNN and the root mean square of successive difference (RMSSD. Power spectral analysis provided frequency domain measures of HRV: high frequency (HF power, low frequency (LF power, and the LF:HF ratio. Results: Multivariate-adjusted logistic regression models showed decreased SDNN, RMSSD, and HF, and increased LF:HF ratio were associated significantly with increased HOMA-IR and decreased ISI. When stratified by overweight status, the association of RMSSD, HF, and LF:HF ratio with decreased ISI was also apparent in non-overweight individuals. The interaction between LF:HF ratio and decreased ISI in overweight individuals was significant, with the odds ratio for decreased ISI in the highest quartile of LF:HF ratio in non-overweight individuals being 2.09 (95% confidence interval, 1.41–3.10. Conclusions: Reduced HRV was associated with insulin resistance and lower insulin sensitivity. Decreased ISI was linked with parasympathetic dysfunction, primarily in non-overweight individuals.

  5. Current understanding of increased insulin sensitivity after exercise - emerging candidates

    DEFF Research Database (Denmark)

    Maarbjerg, Stine Just; Sylow, Lykke; Richter, Erik

    2011-01-01

    signaling component in the insulin signaling pathway such as aPKC, Rac1, TBC1D4 and TBC1D1 have been described. These are all affected by both insulin and exercise which means that they are likely converging points in promoting GLUT4 translocation and therefore possible candidates for regulating insulin...... sensitivity after exercise. Whereas TBC1D1 does not appear to regulate insulin sensitivity after exercise, correlative evidence in contrast suggests TBC1D4 to be a relevant candidate. Little is known about aPKC and Rac1 in relation to insulin sensitivity after exercise. Besides mechanisms involved...

  6. Low fish oil intake improves insulin sensitivity, lipid profile and muscle metabolism on insulin resistant MSG-obese rats.

    Science.gov (United States)

    Yamazaki, Ricardo K; Brito, Gleisson A P; Coelho, Isabela; Pequitto, Danielle C T; Yamaguchi, Adriana A; Borghetti, Gina; Schiessel, Dalton Luiz; Kryczyk, Marcelo; Machado, Juliano; Rocha, Ricelli E R; Aikawa, Julia; Iagher, Fabiola; Naliwaiko, Katya; Tanhoffer, Ricardo A; Nunes, Everson A; Fernandes, Luiz Claudio

    2011-04-28

    Obesity is commonly associated with diabetes, cardiovascular diseases and cancer. The purpose of this study was to determinate the effect of a lower dose of fish oil supplementation on insulin sensitivity, lipid profile, and muscle metabolism in obese rats. Monosodium glutamate (MSG) (4 mg/g body weight) was injected in neonatal Wistar male rats. Three-month-old rats were divided in normal-weight control group (C), coconut fat-treated normal weight group (CO), fish oil-treated normal weight group (FO), obese control group (Ob), coconut fat-treated obese group (ObCO) and fish oil-treated obese group (ObFO). Obese insulin-resistant rats were supplemented with fish oil or coconut fat (1 g/kg/day) for 4 weeks. Insulin sensitivity, fasting blood biochemicals parameters, and skeletal muscle glucose metabolism were analyzed. Obese animals (Ob) presented higher Index Lee and 2.5 fold epididymal and retroperitoneal adipose tissue than C. Insulin sensitivity test (Kitt) showed that fish oil supplementation was able to maintain insulin sensitivity of obese rats (ObFO) similar to C. There were no changes in glucose and HDL-cholesterol levels amongst groups. Yet, ObFO revealed lower levels of total cholesterol (TC; 30%) and triacylglycerol (TG; 33%) compared to Ob. Finally, since exposed to insulin, ObFO skeletal muscle revealed an increase of 10% in lactate production, 38% in glycogen synthesis and 39% in oxidation of glucose compared to Ob. Low dose of fish oil supplementation (1 g/kg/day) was able to reduce TC and TG levels, in addition to improved systemic and muscle insulin sensitivity. These results lend credence to the benefits of n-3 fatty acids upon the deleterious effects of insulin resistance mechanisms.

  7. Low fish oil intake improves insulin sensitivity, lipid profile and muscle metabolism on insulin resistant MSG-obese rats

    Directory of Open Access Journals (Sweden)

    Iagher Fabiola

    2011-04-01

    Full Text Available Abstract Background Obesity is commonly associated with diabetes, cardiovascular diseases and cancer. The purpose of this study was to determinate the effect of a lower dose of fish oil supplementation on insulin sensitivity, lipid profile, and muscle metabolism in obese rats. Methods Monosodium glutamate (MSG (4 mg/g body weight was injected in neonatal Wistar male rats. Three-month-old rats were divided in normal-weight control group (C, coconut fat-treated normal weight group (CO, fish oil-treated normal weight group (FO, obese control group (Ob, coconut fat-treated obese group (ObCO and fish oil-treated obese group (ObFO. Obese insulin-resistant rats were supplemented with fish oil or coconut fat (1 g/kg/day for 4 weeks. Insulin sensitivity, fasting blood biochemicals parameters, and skeletal muscle glucose metabolism were analyzed. Results Obese animals (Ob presented higher Index Lee and 2.5 fold epididymal and retroperitoneal adipose tissue than C. Insulin sensitivity test (Kitt showed that fish oil supplementation was able to maintain insulin sensitivity of obese rats (ObFO similar to C. There were no changes in glucose and HDL-cholesterol levels amongst groups. Yet, ObFO revealed lower levels of total cholesterol (TC; 30% and triacylglycerol (TG; 33% compared to Ob. Finally, since exposed to insulin, ObFO skeletal muscle revealed an increase of 10% in lactate production, 38% in glycogen synthesis and 39% in oxidation of glucose compared to Ob. Conclusions Low dose of fish oil supplementation (1 g/kg/day was able to reduce TC and TG levels, in addition to improved systemic and muscle insulin sensitivity. These results lend credence to the benefits of n-3 fatty acids upon the deleterious effects of insulin resistance mechanisms.

  8. A novel insulin resistance index to monitor changes in insulin sensitivity and glucose tolerance: the ACT NOW study.

    Science.gov (United States)

    Tripathy, Devjit; Cobb, Jeff E; Gall, Walter; Adam, Klaus-Peter; George, Tabitha; Schwenke, Dawn C; Banerji, MaryAnn; Bray, George A; Buchanan, Thomas A; Clement, Stephen C; Henry, Robert R; Kitabchi, Abbas E; Mudaliar, Sunder; Ratner, Robert E; Stentz, Frankie B; Reaven, Peter D; Musi, Nicolas; Ferrannini, Ele; DeFronzo, Ralph A

    2015-05-01

    The objective was to test the clinical utility of Quantose M(Q) to monitor changes in insulin sensitivity after pioglitazone therapy in prediabetic subjects. Quantose M(Q) is derived from fasting measurements of insulin, α-hydroxybutyrate, linoleoyl-glycerophosphocholine, and oleate, three nonglucose metabolites shown to correlate with insulin-stimulated glucose disposal. Participants were 428 of the total of 602 ACT NOW impaired glucose tolerance (IGT) subjects randomized to pioglitazone (45 mg/d) or placebo and followed for 2.4 years. At baseline and study end, fasting plasma metabolites required for determination of Quantose, glycated hemoglobin, and oral glucose tolerance test with frequent plasma insulin and glucose measurements to calculate the Matsuda index of insulin sensitivity were obtained. Pioglitazone treatment lowered IGT conversion to diabetes (hazard ratio = 0.25; 95% confidence interval = 0.13-0.50; P < .0001). Although glycated hemoglobin did not track with insulin sensitivity, Quantose M(Q) increased in pioglitazone-treated subjects (by 1.45 [3.45] mg·min(-1)·kgwbm(-1)) (median [interquartile range]) (P < .001 vs placebo), as did the Matsuda index (by 3.05 [4.77] units; P < .0001). Quantose M(Q) correlated with the Matsuda index at baseline and change in the Matsuda index from baseline (rho, 0.85 and 0.79, respectively; P < .0001) and was progressively higher across closeout glucose tolerance status (diabetes, IGT, normal glucose tolerance). In logistic models including only anthropometric and fasting measurements, Quantose M(Q) outperformed both Matsuda and fasting insulin in predicting incident diabetes. In IGT subjects, Quantose M(Q) parallels changes in insulin sensitivity and glucose tolerance with pioglitazone therapy. Due to its strong correlation with improved insulin sensitivity and its ease of use, Quantose M(Q) may serve as a useful clinical test to identify and monitor therapy in insulin-resistant patients.

  9. Hormone-sensitive lipase null mice exhibit signs of impaired insulin sensitivity whereas insulin secretion is intact

    DEFF Research Database (Denmark)

    Mulder, Hindrik; Sörhede-Winzell, Maria; Contreras, Juan Antonio

    2003-01-01

    of increased amounts of insulin. Impaired insulin sensitivity was further indicated by retarded glucose disposal during an insulin tolerance test. A euglycemic hyperinsulinemic clamp revealed that hepatic glucose production was insufficiently blocked by insulin in HSL null mice. In vitro, insulin......-stimulated glucose uptake into soleus muscle, and lipogenesis in adipocytes were moderately reduced, suggesting additional sites of insulin resistance. Morphometric analysis of pancreatic islets revealed a doubling of beta-cell mass in HSL null mice, which is consistent with an adaptation to insulin resistance....... Insulin secretion in vitro, examined by perifusion of isolated islets, was not impacted by HSL deficiency. Thus, HSL deficiency results in a moderate impairment of insulin sensitivity in multiple target tissues of the hormone but is compensated by hyperinsulinemia....

  10. A model to estimate insulin sensitivity in dairy cows

    Directory of Open Access Journals (Sweden)

    Holtenius Kjell

    2007-10-01

    Full Text Available Abstract Impairment of the insulin regulation of energy metabolism is considered to be an etiologic key component for metabolic disturbances. Methods for studies of insulin sensitivity thus are highly topical. There are clear indications that reduced insulin sensitivity contributes to the metabolic disturbances that occurs especially among obese lactating cows. Direct measurements of insulin sensitivity are laborious and not suitable for epidemiological studies. We have therefore adopted an indirect method originally developed for humans to estimate insulin sensitivity in dairy cows. The method, "Revised Quantitative Insulin Sensitivity Check Index" (RQUICKI is based on plasma concentrations of glucose, insulin and free fatty acids (FFA and it generates good and linear correlations with different estimates of insulin sensitivity in human populations. We hypothesized that the RQUICKI method could be used as an index of insulin function in lactating dairy cows. We calculated RQUICKI in 237 apparently healthy dairy cows from 20 commercial herds. All cows included were in their first 15 weeks of lactation. RQUICKI was not affected by the homeorhetic adaptations in energy metabolism that occurred during the first 15 weeks of lactation. In a cohort of 24 experimental cows fed in order to obtain different body condition at parturition RQUICKI was lower in early lactation in cows with a high body condition score suggesting disturbed insulin function in obese cows. The results indicate that RQUICKI might be used to identify lactating cows with disturbed insulin function.

  11. Insulin sensitivity and secretion in Arab Americans with glucose intolerance.

    Science.gov (United States)

    Salinitri, Francine D; Pinelli, Nicole R; Martin, Emily T; Jaber, Linda A

    2013-12-01

    This study examined the pathophysiological abnormalities in Arab Americans with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT). Homeostasis model assessment of insulin resistance (HOMA-IR), homeostasis model assessment of insulin secretion (HOMA-%β), and the Matsuda Insulin Sensitivity Index composite (ISIcomposite) were calculated from the fasting and stimulated glucose and insulin concentrations measured during the oral glucose tolerance test in a population-based, representative, cross-sectional sample of randomly selected Arab Americans. In total, 497 individuals (42±14 years old; 40% males; body mass index [BMI], 29±6 kg/m(2)) were studied. Multivariate linear regression models were performed to compare HOMA-IR, HOMA-%β, and ISIcomposite among individuals with normal glucose tolerance (NGT) (n=191) versus isolated IFG (n=136), isolated IGT (n=22), combined IFG/IGT (n=43), and diabetes (n=105). Compared with individuals with NGT (2.9±1.6), HOMA-IR progressively increased in individuals with isolated IFG (4.8±2.7, Psex and BMI, these associations remained unchanged. Whole-body insulin sensitivity as measured by ISIcomposite was significantly lower in individuals with isolated IFG (3.9±2.3, Psex, and BMI, isolated IFG (146.6±80.2) was also significantly associated with a decline in HOMA-%β relative to NGT (P=0.005). This study suggests that differences in the underlying metabolic defects leading to diabetes in Arab Americans with IFG and/or IGT exist and may require different strategies for the prevention of diabetes.

  12. The Insulin-Sensitive Side of SHIP2

    Directory of Open Access Journals (Sweden)

    Stephane Schurmans

    2001-01-01

    Full Text Available A substantial and increasing proportion of death and disability in the EU (and elsewhere is attributable to diseases associated with insulin resistance (i.e., decreased insulin sensitivity. Beside type II diabetes, other diseases like obesity, hypertension, atherosclerosis, hyperlipidaemia, polycystic ovarian syndrome, and acromegaly are indeed associated with insulin resistance [1].

  13. Normal insulin-stimulated endothelial function and impaired insulin-stimulated muscle glucose uptake in young adults with low birth weight

    DEFF Research Database (Denmark)

    Hermann, T S; Rask-Madsen, C; Ihlemann, N

    2003-01-01

    of acetylcholine and sodium nitroprusside in the forearm of fourteen 21-yr-old men with low birth weight and 16 controls of normal birth weight. Glucose uptake was measured during intraarterial insulin infusion. Dose-response studies were repeated during insulin infusion. The maximal blood flow during......Low birth weight has been linked to insulin resistance and cardiovascular disease. We hypothesized that insulin sensitivity of both muscle and vascular tissues were impaired in young men with low birth weight. Blood flow was measured by venous occlusion plethysmography during dose-response studies...... acetylcholine infusion was 14.1 +/- 2.7 and 14.4 +/- 2.1 [ml x (100 ml forearm)(-1) x min(-1)] in low and normal birth weight subjects, respectively. Insulin coinfusion increased acetylcholine-stimulated flow in both groups: 18.0 +/- 3.1 vs. 17.9 +/- 3.1 [ml x (100 ml forearm)(-1) x min(-1)], NS. Insulin...

  14. Reduced Circulating Insulin Enhances Insulin Sensitivity in Old Mice and Extends Lifespan

    Directory of Open Access Journals (Sweden)

    Nicole M. Templeman

    2017-07-01

    Full Text Available The causal relationships between insulin levels, insulin resistance, and longevity are not fully elucidated. Genetic downregulation of insulin/insulin-like growth factor 1 (Igf1 signaling components can extend invertebrate and mammalian lifespan, but insulin resistance, a natural form of decreased insulin signaling, is associated with greater risk of age-related disease in mammals. We compared Ins2+/− mice to Ins2+/+ littermate controls, on a genetically stable Ins1 null background. Proteomic and transcriptomic analyses of livers from 25-week-old mice suggested potential for healthier aging and altered insulin sensitivity in Ins2+/− mice. Halving Ins2 lowered circulating insulin by 25%–34% in aged female mice, without altering Igf1 or circulating Igf1. Remarkably, decreased insulin led to lower fasting glucose and improved insulin sensitivity in aged mice. Moreover, lowered insulin caused significant lifespan extension, observed across two diverse diets. Our study indicates that elevated insulin contributes to age-dependent insulin resistance and that limiting basal insulin levels can extend lifespan.

  15. Reduced Circulating Insulin Enhances Insulin Sensitivity in Old Mice and Extends Lifespan.

    Science.gov (United States)

    Templeman, Nicole M; Flibotte, Stephane; Chik, Jenny H L; Sinha, Sunita; Lim, Gareth E; Foster, Leonard J; Nislow, Corey; Johnson, James D

    2017-07-11

    The causal relationships between insulin levels, insulin resistance, and longevity are not fully elucidated. Genetic downregulation of insulin/insulin-like growth factor 1 (Igf1) signaling components can extend invertebrate and mammalian lifespan, but insulin resistance, a natural form of decreased insulin signaling, is associated with greater risk of age-related disease in mammals. We compared Ins2 +/- mice to Ins2 +/+ littermate controls, on a genetically stable Ins1 null background. Proteomic and transcriptomic analyses of livers from 25-week-old mice suggested potential for healthier aging and altered insulin sensitivity in Ins2 +/- mice. Halving Ins2 lowered circulating insulin by 25%-34% in aged female mice, without altering Igf1 or circulating Igf1. Remarkably, decreased insulin led to lower fasting glucose and improved insulin sensitivity in aged mice. Moreover, lowered insulin caused significant lifespan extension, observed across two diverse diets. Our study indicates that elevated insulin contributes to age-dependent insulin resistance and that limiting basal insulin levels can extend lifespan. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  16. Monomeric tartrate resistant acid phosphatase induces insulin sensitive obesity.

    Directory of Open Access Journals (Sweden)

    Pernilla Lång

    2008-03-01

    Full Text Available Obesity is associated with macrophage infiltration of adipose tissue, which may link adipose inflammation to insulin resistance. However, the impact of inflammatory cells in the pathophysiology of obesity remains unclear. Tartrate resistant acid phosphatase (TRAP is an enzyme expressed by subsets of macrophages and osteoclasts that exists either as an enzymatically inactive monomer or as an active, proteolytically processed dimer.Using mice over expressing TRAP, we show that over-expression of monomeric, but not the dimeric form in adipose tissue leads to early onset spontaneous hyperplastic obesity i.e. many small fat cells. In vitro, recombinant monomeric, but not proteolytically processed TRAP induced proliferation and differentiation of mouse and human adipocyte precursor cells. In humans, monomeric TRAP was highly expressed in the adipose tissue of obese individuals. In both the mouse model and in the obese humans the source of TRAP in adipose tissue was macrophages. In addition, the obese TRAP over expressing mice exhibited signs of a low-grade inflammatory reaction in adipose tissue without evidence of abnormal adipocyte lipolysis, lipogenesis or insulin sensitivity.Monomeric TRAP, most likely secreted from adipose tissue macrophages, induces hyperplastic obesity with normal adipocyte lipid metabolism and insulin sensitivity.

  17. Higher intramuscular triacylglycerol in women does not impair insulin sensitivity and proximal insulin signaling

    DEFF Research Database (Denmark)

    Høeg, Louise; Roepstorff, Carsten; Thiele, Maja

    2009-01-01

    that despite 47% higher IMTG levels in women in the follicular phase whole body as well as leg insulin sensitivity are higher than in matched men. This was not explained by sex differences in proximal insulin signalling in women. In women it seems that a high capillary density and type 1 muscle fiber...... expression may be important for insulin action. Key words: Muscle Triglycerides, gender, insulin action, sex paradox....

  18. Variability of HOMA and QUICKI insulin sensitivity indices.

    Science.gov (United States)

    Žarković, Miloš; Ćirić, Jasmina; Beleslin, Biljana; Stojković, Mirjana; Savić, Slavica; Stojanović, Miloš; Lalić, Tijana

    2017-07-01

    Assessment of insulin sensitivity based on a single measurement of insulin and glucose, is both easy to understand and simple to perform. The tests most often used are HOMA and QUICKI. The aim of this study was to assess the biological variability of estimates of insulin sensitivity using HOMA and QUICKI indices. After a 12-h fast, blood was sampled for insulin and glucose determination. Sampling lasted for 90 min with an intersample interval of 2 min. A total of 56 subjects were included in the study, and in nine subjects sampling was done before and after weight reduction, so total number of analyzed series was 65. To compute the reference value of the insulin sensitivity index, averages of all 46 insulin and glucose samples were used. We also computed point estimates (single value estimates) of the insulin sensitivity index based on the different number of insulin/glucose samples (1-45 consecutive samples). To compute the variability of point estimates a bootstrapping procedure was used using 1000 resamples for each series and for each number of samples used to average insulin and glucose. Using a single insulin/glucose sample HOMA variability was 26.18 ± 4.31%, and QUICKI variability was 3.30 ± 0.54%. For 10 samples variability was 11.99 ± 2.22% and 1.62 ± 0.31% respectively. Biological variability of insulin sensitivity indices is significant, and it can be reduced by increasing the number of samples. Oscillations of insulin concentration in plasma are the major cause of variability of insulin sensitivity indices.

  19. Partial sleep restriction decreases insulin sensitivity in type 1 diabetes

    NARCIS (Netherlands)

    Donga, Esther; van Dijk, Marieke [Leiden Univ., LUMC; van Dijk, J. Gert; Biermasz, Nienke R.; Lammers, Gert-Jan; van Kralingen, Klaas; Hoogma, Roel P. L. M.; Corssmit, Eleonora P. M.; Romijn, Johannes A.

    2010-01-01

    Sleep restriction results in decreased insulin sensitivity and glucose tolerance in healthy subjects. We hypothesized that sleep duration is also a determinant of insulin sensitivity in patients with type 1 diabetes. We studied seven patients (three men, four women) with type 1 diabetes: mean age 44

  20. Increased insulin sensitivity in intrauterine growth retarded newborns--do thyroid hormones play a role?

    Science.gov (United States)

    Setia, Sajita; Sridhar, M G; Koner, B C; Bobby, Zachariah; Bhat, Vishnu; Chaturvedula, Lata

    2007-02-01

    Thyroid hormones are necessary for normal brain development. We studied thyroid hormone profile and insulin sensitivity in intrauterine growth retarded (IUGR) newborns to find correlation between insulin sensitivity and thyroid status in IUGR newborns. Fifty IUGR and fifty healthy control infants were studied at birth. Cord blood was collected for determination of T(3), T(4), TSH, glucose and insulin levels. IUGR newborns had significantly lower insulin, mean+/-S.D., 5.25+/-2.81 vs. 11.02+/-1.85microU/ml, but significantly higher insulin sensitivity measured as glucose to insulin ratio (G/I), 9.80+/-2.91 vs. 6.93+/-1.08 compared to healthy newborns. TSH was also significantly higher 6.0+/-2.70 vs. 2.99+/-1.05microU/ml with significantly lower T(4), 8.65+/-1.95 vs. 9.77+/-2.18microg/dl, but similar T(3) levels, 100.8+/-24.36 vs. 101.45+/-23.45ng/dl. On stepwise linear regression analysis in IUGR infants, insulin sensitivity was found to have a significant negative association with T(4) and significant positive association with TSH. Thyroid hormones may play a role in increased insulin sensitivity at birth in IUGR.

  1. Mechanical stress regulates insulin sensitivity through integrin-dependent control of insulin receptor localization.

    Science.gov (United States)

    Kim, Jung; Bilder, David; Neufeld, Thomas P

    2018-01-15

    Insulin resistance, the failure to activate insulin signaling in the presence of ligand, leads to metabolic diseases, including type 2 diabetes. Physical activity and mechanical stress have been shown to protect against insulin resistance, but the molecular mechanisms remain unclear. Here, we address this relationship in the Drosophila larval fat body, an insulin-sensitive organ analogous to vertebrate adipose tissue and livers. We found that insulin signaling in Drosophila fat body cells is abolished in the absence of physical activity and mechanical stress even when excess insulin is present. Physical movement is required for insulin sensitivity in both intact larvae and fat bodies cultured ex vivo. Interestingly, the insulin receptor and other downstream components are recruited to the plasma membrane in response to mechanical stress, and this membrane localization is rapidly lost upon disruption of larval or tissue movement. Sensing of mechanical stimuli is mediated in part by integrins, whose activation is necessary and sufficient for mechanical stress-dependent insulin signaling. Insulin resistance develops naturally during the transition from the active larval stage to the immotile pupal stage, suggesting that regulation of insulin sensitivity by mechanical stress may help coordinate developmental programming with metabolism. © 2018 Kim et al.; Published by Cold Spring Harbor Laboratory Press.

  2. Low fish oil intake improves insulin sensitivity, lipid profile and muscle metabolism on insulin resistant MSG-obese rats

    OpenAIRE

    Iagher Fabiola; Aikawa Julia; Rocha Ricelli ER; Machado Juliano; Kryczyk Marcelo; Schiessel Dalton; Borghetti Gina; Yamaguchi Adriana A; Pequitto Danielle CT; Coelho Isabela; Brito Gleisson AP; Yamazaki Ricardo K; Naliwaiko Katya; Tanhoffer Ricardo A; Nunes Everson A

    2011-01-01

    Abstract Background Obesity is commonly associated with diabetes, cardiovascular diseases and cancer. The purpose of this study was to determinate the effect of a lower dose of fish oil supplementation on insulin sensitivity, lipid profile, and muscle metabolism in obese rats. Methods Monosodium glutamate (MSG) (4 mg/g body weight) was injected in neonatal Wistar male rats. Three-month-old rats were divided in normal-weight control group (C), coconut fat-treated normal weight group (CO), fish...

  3. Role of AMPK in Regulating Muscle Insulin Sensitivity

    DEFF Research Database (Denmark)

    Kjøbsted, Rasmus

    The ability of insulin to stimulate skeletal muscle glucose uptake is instrumental for controlling whole-body glucose homeostasis. Decreased peripheral sensitivity to insulin increases the risk of developing type 2 diabetes. Insulin sensitivity can be defined as the concentration of insulin that ...... prevail in healthy lean subjects. In the present thesis, experimental results from the three studies as well as unpublished observations are placed in the context of existing literature in order to provide a general overview of the current understandings within this field of research....

  4. Nitric oxide is required for the insulin sensitizing effects of contraction in mouse skeletal muscle.

    Science.gov (United States)

    Zhang, Xinmei; Hiam, Danielle; Hong, Yet-Hoi; Zulli, Anthony; Hayes, Alan; Rattigan, Stephen; McConell, Glenn K

    2017-12-15

    People with insulin resistance or type 2 diabetes can substantially increase their skeletal muscle glucose uptake during exercise and insulin sensitivity after exercise. Skeletal muscle nitric oxide (NO) is important for glucose uptake during exercise, although how prior exercise increases insulin sensitivity is unclear. In the present study, we examined whether NO is necessary for normal increases in skeletal muscle insulin sensitivity after contraction ex vivo in mouse muscle. The present study uncovers, for the first time, a novel role for NO in the insulin sensitizing effects of ex vivo contraction, which is independent of blood flow. The factors regulating the increase in skeletal muscle insulin sensitivity after exercise are unclear. We examined whether nitric oxide (NO) is required for the increase in insulin sensitivity after ex vivo contractions. Isolated C57BL/6J mouse EDL muscles were contracted for 10 min or remained at rest (basal) with or without the NO synthase (NOS) inhibition (N G -monomethyl-l-arginine; l-NMMA; 100 μm). Then, 3.5 h post contraction/basal, muscles were exposed to saline or insulin (120 μU ml -1 ) with or without l-NMMA during the last 30 min. l-NMMA had no effect on basal skeletal muscle glucose uptake. The increase in muscle glucose uptake with insulin (57%) was significantly (P contraction (140% increase). NOS inhibition during the contractions had no effect on this insulin-sensitizing effect of contraction, whereas NOS inhibition during insulin prevented the increase in skeletal muscle insulin sensitivity post-contraction. Soluble guanylate cyclase inhibition, protein kinase G (PKG) inhibition or cyclic nucleotide phosphodiesterase inhibition each had no effect on the insulin-sensitizing effect of prior contraction. In conclusion, NO is required for increases in insulin sensitivity several hours after contraction of mouse skeletal muscle via a cGMP/PKG independent pathway. © 2017 The Authors. The Journal of Physiology

  5. Genetic Variants Associated With Glycine Metabolism and Their Role in Insulin Sensitivity and Type 2 Diabetes

    NARCIS (Netherlands)

    Xie, W.J.; Wood, A.R.; Lyssenko, V.; Weedon, M.N.; Knowles, J.W.; Alkayyali, S.; Assimes, T.L.; Quertermous, T.; Abbasi, F.; Paananen, J.; Haring, H.; Hansen, T.; Pedersen, O.; Smith, U.; Laakso, M.; Dekker, J.M.; Nolan, J.J.; Groop, L.; Ferrannini, E.; Adam, K.P.; Gall, W.E.; Frayling, T.M.; Walker, M.

    2013-01-01

    Circulating metabolites associated with insulin sensitivity may represent useful biomarkers, but their causal role in insulin sensitivity and diabetes is less certain. We previously identified novel metabolites correlated with insulin sensitivity measured by the hyperinsulinemic-euglycemic clamp.

  6. Exercise, pregnancy, and insulin sensitivity--what is new?

    DEFF Research Database (Denmark)

    Damm, Peter; Breitowicz, Bettina; Hegaard, Hanne Kristine

    2007-01-01

    Pregnancy is characterized by a marked physiological insulin resistance. Overweight and obesity or lack of physical activity can aggravate this reduced insulin sensitivity further. Increased insulin resistance has been associated with serious pregnancy complications, such as gestational diabetes...... mellitus (GDM) and pre-eclampsia. Recent studies clearly indicate that physical activity before and during pregnancy can reduce the risk of GDM and pre-eclampsia....

  7. Intranasal Insulin Restores Metabolic Parameters and Insulin Sensitivity in Rats with Metabolic Syndrome.

    Science.gov (United States)

    Derkach, K V; Ivantsov, A O; Chistyakova, O V; Sukhov, I B; Buzanakov, D M; Kulikova, A A; Shpakov, A O

    2017-06-01

    We studied the effect of 10-week treatment with intranasal insulin (0.5 IU/day) on glucose tolerance, glucose utilization, lipid metabolism, functions of pancreatic β cells, and insulin system in the liver of rats with cafeteria diet-induced metabolic syndrome. The therapy reduced body weight and blood levels of insulin, triglycerides, and atherogenic cholesterol that are typically increased in metabolic syndrome, normalized glucose tolerance and its utilization, and increased activity of insulin signaling system in the liver, thus reducing insulin resistance. The therapy did not affect the number of pancreatic islets and β cells. The study demonstrates prospects of using intranasal insulin for correction of metabolic parameters and reduction of insulin resistance in metabolic syndrome.

  8. Role of PKCδ in Insulin Sensitivity and Skeletal Muscle Metabolism

    DEFF Research Database (Denmark)

    Li, Mengyao; Vienberg, Sara G; Bezy, Olivier

    2015-01-01

    Protein kinase C (PKC)δ has been shown to be increased in liver in obesity and plays an important role in the development of hepatic insulin resistance in both mice and humans. In the current study, we explored the role of PKCδ in skeletal muscle in the control of insulin sensitivity and glucose......-body insulin sensitivity and muscle insulin resistance and by 15 months of age improved the age-related decline in whole-body glucose tolerance. At 15 months of age, M-PKCδKO mice also exhibited decreased metabolic rate and lower levels of some proteins of the OXPHOS complex suggesting a role for PKCδ...... in the regulation of mitochondrial mass at older age. These data indicate an important role of PKCδ in the regulation of insulin sensitivity and mitochondrial homeostasis in skeletal muscle with aging....

  9. Effect of Avocado Soybean Unsaponifiables on Insulin Secretion and Insulin Sensitivity in Patients with Obesity

    Directory of Open Access Journals (Sweden)

    Esperanza Martínez-Abundis

    2013-10-01

    Full Text Available Aim: To evaluate the effect of avocado soybean unsaponifiables (ASU on insulin secretion and insulin sensitivity in patients with obesity. Methods: A randomized, double-blind, placebo-controlled, clinical trial was carried out in 14 obese adult volunteers. After random allocation of the intervention, 7 patients received 300 mg of ASU or placebo during a fasting state for 3 months. A metabolic profile including IL-6 and high-sensitivity C-reactive protein (hs-CRP levels was carried out prior to the intervention. A hyperglycemic-hyperinsulinemic clamp technique was used to assess insulin secretion and insulin sensitivity phases. Mann-Whitney U test and Wilcoxon test were performed for statistical analyses. The study was approved by the local ethics committee of our institution. Results: At baseline, both groups were similar according to clinical and laboratory characteristics. There was no significant difference in insulin secretion and insulin sensitivity with ASU. Conclusions: ASU administration for 3 months did not modify insulin secretion and insulin sensitivity in patients with obesity.

  10. Dietary Fat – Insulin Sensitivity and Molecular Substrate Metabolism

    DEFF Research Database (Denmark)

    Lundsgaard, Annemarie

    metabolism in skeletal muscle. The high-fat diet was primarily comprised of unsaturated FA. We demonstrated in lean, healthy and moderately trained men that three days’ intake of 78 E% dietary fat coupled with 75% energy excess was sufficient to reduce whole-body insulin sensitivity by 17% and insulin...

  11. Euglycemic clamp insulin sensitivity and longitudinal systolic blood pressure

    DEFF Research Database (Denmark)

    Petrie, John R; Malik, Muhammad Omar; Balkau, Beverley

    2013-01-01

    and Cardiovascular disease (RISC) study, we measured insulin sensitivity (M/I) using the euglycemic clamp technique in 1073 healthy European adults (587 women, 486 men) aged 30 to 60 years followed up 3 years later. Systolic BP (SBP) at baseline was higher in insulin-resistant women (ie, those in the low sex...

  12. Normocaloric Diet Restores Weight Gain and Insulin Sensitivity in Obese Mice

    Directory of Open Access Journals (Sweden)

    Giovanni Enrico Lombardo

    2016-05-01

    Full Text Available An increased incidence of obesity is registered worldwide, and its association with insulin resistance and type 2 diabetes is closely related with increased morbidity and mortality for cardiovascular diseases. A major clinical problem in the management of obesity is the non-adherence or low adherence of patients to a hypo-caloric dietetic restriction. In this study we evaluated in obese mice the effects on insulin sensitivity of shifting from high-calorie foods to normal diet. Male C57BL/6JolaHsd mice (n=20 were fed with high fat diet for a 24 weeks period. Afterwards, body weight, energy and food intake were measured in all animals, together with parameters of insulin sensitivity by homeostatic model assessment of insulin resistance and plasma glucose levels in response to insulin administration. Moreover, in half of these mice, Glut4 mRNA levels were measured in muscle at the end of the high fat treatment, whereas the rest of the animals (n=10 were shifted to normocaloric diet for 10 weeks, after which the same analyses were carried out. A significant reduction of body weight was found after the transition from high to normal fat diet, and this decrease correlated well with an improvement in insulin sensitivity. In fact, we found a reduction in serum insulin levels and the recovery of insulin responsiveness in terms of glucose disposal measured by insulin tolerance test and Glut4 mRNA and protein expression. These results indicate that obesity related insulin resistance may be rescued by shifting from high fat diet to normocaloric diet.

  13. The Relationship between 25-hydroxyvitamin D Levels, Insulin Sensitivity and Insulin Secretion in Women 3 Years after Delivery.

    Science.gov (United States)

    Tänczer, Tímea; Magenheim, Rita; Fürst, Ágnes; Domján, Beatrix; Janicsek, Zsófia; Szabó, Eszter; Ferencz, Viktória; Tabák, Ádám G

    2017-12-01

    There is a direct correlation between 25-hydroxyvitamin D (25[OH]D) levels and insulin sensitivity. Furthermore, women with gestational diabetes (GDM) may have lower levels of 25(OH)D compared to controls. The present study intended to investigate 25(OH)D levels and their association with insulin sensitivity and insulin secretion in women with prior GDM and in controls 3.2 years after delivery. A total of 87 patients with prior GDM and 45 randomly selected controls (age range, 22 to 44 years) with normal glucose tolerance during pregnancy nested within a cohort of all deliveries at Saint Margit Hospital, Budapest, between January 1 2005, and December 31 2006, were examined. Their 25(OH) D levels were measured by radioimmunoassay. Insulin sensitivity and fasting insulin secretion were estimated using the homeostasis model asssessment (HOMA) calculator and early insulin secretion by the insulinogenic index based on a 75 g oral glucose tolerance test. There was no significant difference in 25(OH)D levels between cases and controls (27.2±13.1 [±SD] vs. 26.9±9.8 ng/L). There was a positive association between HOMA insulin sensitivity and 25(OH)D levels (beta = 0.017; 95% CI 0.001 to 0.034/1 ng/mL) that was robust to adjustment for age and body mass index. There was a nonsignificant association between HOMA insulin secretion and 25(OH)D (p=0.099), while no association was found with the insulinogenic index. Prior GDM status was not associated with 25(OH)D levels; however, 25(OH) D levels were associated with HOMA insulin sensitivity. It is hypothesized that the association between HOMA insulin secretion and 25(OH)D levels is related to the autoregulation of fasting glucose levels because no association between 25(OH)D and insulinogenic index was found. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

  14. High normal fasting glucose level in obese youth: a marker for insulin resistance and beta cell dysregulation.

    LENUS (Irish Health Repository)

    O'Malley, G

    2010-06-01

    A high but normal fasting plasma glucose level in adults is a risk factor for future development of type 2 diabetes mellitus and cardiovascular disease. We investigated whether normal fasting plasma glucose levels (<5.60 mmol\\/l) are associated with decreases in insulin sensitivity and beta cell function, as well as an adverse cardiovascular profile in obese youth.

  15. Skeletal muscle phosphatidylcholine and phosphatidylethanolamine respond to exercise and influence insulin sensitivity in men.

    Science.gov (United States)

    Lee, Sindre; Norheim, Frode; Gulseth, Hanne L; Langleite, Torgrim M; Aker, Andreas; Gundersen, Thomas E; Holen, Torgeir; Birkeland, Kåre I; Drevon, Christian A

    2018-04-25

    Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) composition in skeletal muscle have been linked to insulin sensitivity. We evaluated the relationships between skeletal muscle PC:PE, physical exercise and insulin sensitivity. We performed lipidomics and measured PC and PE in m. vastus lateralis biopsies obtained from 13 normoglycemic normal weight men and 13 dysglycemic overweight men at rest, immediately after 45 min of cycling at 70% maximum oxygen uptake, and 2 h post-exercise, before as well as after 12 weeks of combined endurance- and strength-exercise intervention. Insulin sensitivity was monitored by euglycemic-hyperinsulinemic clamp. RNA-sequencing was performed on biopsies, and mitochondria and lipid droplets were quantified on electron microscopic images. Exercise intervention for 12 w enhanced insulin sensitivity by 33%, skeletal muscle levels of PC by 21%, PE by 42%, and reduced PC:PE by 16%. One bicycle session reduced PC:PE by 5%. PC:PE correlated negatively with insulin sensitivity (β = -1.6, P insulin sensitivity.

  16. Skeletal Muscle Angiogenesis and Its Relation to Insulin Sensitivity

    DEFF Research Database (Denmark)

    Lindqvist, Anna Maria Charlotte K

    mediator of angiogenesis) are reduced in insulin resistant individuals. Exercise training can improve skeletal muscle capillarization and the angiogenic potential and physical activity has also been proven to enhance muscle insulin sensitivity. Increased skeletal muscle capillarization is associated......) or by overexpression of VEGF-A in the tibialis anterior muscle (transfection; study II) and the effect of the increased muscle capillarization on muscle insulin sensitivity was examined. In study I skeletal muscle specific angiogenesis was induced by administering an α1-adrenergic antagonist (prazosin) to healthy...

  17. Insulin Sensitivity Determines Effects of Insulin and Meal Ingestion on Systemic Vascular Resistance in Healthy Subjects.

    Science.gov (United States)

    Woerdeman, Jorn; Meijer, Rick I; Eringa, Etto C; Hoekstra, Trynke; Smulders, Yvo M; Serné, Erik H

    2016-01-01

    In addition to insulin's metabolic actions, insulin can dilate arterioles which increase blood flow to metabolically active tissues. This effect is blunted in insulin-resistant subjects. Insulin's effect on SVR, determined by resistance arterioles, has, however, rarely been examined directly. We determined the effects of both hyperinsulinemia and a mixed meal on SVR and its relationship with insulin sensitivity. Thirty-seven lean and obese women underwent a hyperinsulinemic-euglycemic clamp, and 24 obese volunteers underwent a mixed-meal test. SVR was assessed using CPP before and during hyperinsulinemia as well as before and 60 and 120 minutes after a meal. SVR decreased significantly during hyperinsulinemia (-13%; p Insulin decreased SVR more strongly in insulin-sensitive individuals (standardized β: -0.44; p = 0.01). In addition, SVR at 60 minutes after meal ingestion was inversely related to the Matsuda index (β: -0.39; p = 0.04) and the change in postprandial SVR was directly related to postprandial glycemia (β: 0.53; p insulin resistance. This suggests that resistance to insulin-induced vasodilatation contributes to regulation of vascular resistance. © 2015 John Wiley & Sons Ltd.

  18. Influence of insulin on beta-endorphin plasma levels in obese and normal weight subjects.

    Science.gov (United States)

    Brunani, A; Pincelli, A I; Pasqualinotto, L; Tibaldi, A; Baldi, G; Scacchi, M; Fatti, L M; Cavagnini, F

    1996-08-01

    To establish the possible role of hyperinsulinemia in the elevation of plasma beta-endorphin (beta-EP) levels observed in obese patients after an oral glucose load. Oral glucose tolerance test (OGTT) and euglycemic-hyperinsulinemic clamp. Two groups of six (age: 22-39 y, BMI: 30-48 kg/m2) and eight obese men (age: 18-37 y, BMI: 35-45 kg/m2), respectively, and five normal weight healthy men (age: 22-30 y, BMI 22-23 kg/m2). Glucose, insulin and beta-EP levels at baseline and every 30 min until 180 min during the OGTT; glucose, insulin, C-peptide and beta-EP concentrations at baseline and in steady state condition (i.e. during the last 30 min of insulin infusion) in the euglycemic-hyperinsulinemic clamp studies. In the six obese patients undergoing the OGTT a significant elevation of beta-EP plasma levels was observed between 60 and 90 min after glucose ingestion. In the clamp studies no significant differences in beta-EP plasma levels, blood glucose and serum insulin were observed between obese and normal weight subjects both at baseline and at steady state. A markedly diminished insulin sensitivity along with a lower inhibition of C-peptide during insulin infusion was observed in obese patients compared to control subjects. A rise in serum insulin levels unaccompanied by a concomitant increase in blood glucose concentration is unable to elicit a beta-EP response in obese patients.

  19. Bromocriptine and insulin sensitivity in lean and obese subjects

    Directory of Open Access Journals (Sweden)

    L Bahler

    2016-11-01

    Full Text Available Bromocriptine is a glucose-lowering drug, which was shown to be effective in obese subjects with insulin resistance. It is usually administered in the morning. The exact working mechanism of bromocriptine still has to be elucidated. Therefore, in this open-label randomized prospective cross-over mechanistic study, we assessed whether the timing of bromocriptine administration (morning vs evening results in different effects and whether these effects differ between lean and obese subjects. We studied the effect of bromocriptine on insulin sensitivity in 8 lean and 8 overweight subjects using an oral glucose tolerance test. The subjects used bromocriptine in randomized cross-over order for 2 weeks in the morning and 2 weeks in the evening. We found that in lean subjects, bromocriptine administration in the evening resulted in a significantly higher post-prandial insulin sensitivity as compared with the pre-exposure visit (glucose area under the curve (AUC 742 mmol/L * 120 min (695–818 vs 641 (504–750, P = 0.036, AUC for insulin did not change, P = 0.575. In obese subjects, both morning and evening administration of bromocriptine resulted in a significantly higher insulin sensitivity: morning administration in obese: insulin AUC (55,900 mmol/L * 120 min (43,236–96,831 vs 36,448 (25,213–57,711, P = 0.012 and glucose AUC P = 0.069; evening administration in obese: glucose AUC (735 mmol/L * 120 min (614–988 vs 644 (568–829, P = 0.017 and insulin AUC, P = 0.208. In conclusion, bromocriptine increases insulin sensitivity in both lean and obese subjects. In lean subjects, this effect only occurred when bromocriptine was administrated in the evening, whereas in the obese, insulin sensitivity increased independent of the timing of bromocriptine administration.

  20. The adipose transcriptional response to insulin is determined by obesity, not insulin sensitivity

    DEFF Research Database (Denmark)

    Rydén, Mikael; Hrydziuszko, Olga; Mileti, Enrichetta

    2016-01-01

    Metabolically healthy obese subjects display preserved insulin sensitivity and a beneficial white adipose tissue gene expression pattern. However, this observation stems from fasting studies when insulin levels are low. We investigated adipose gene expression by 5'Cap-mRNA sequencing in 17 healthy...... non-obese (NO), 21 insulin-sensitive severely obese (ISO), and 30 insulin-resistant severely obese (IRO) subjects, before and 2 hr into a hyperinsulinemic euglycemic clamp. ISO and IRO subjects displayed a clear but globally similar transcriptional response to insulin, which differed from the small...... effects observed in NO subjects. In the obese, 231 genes were altered; 71 were enriched in ISO subjects (e.g., phosphorylation processes), and 52 were enriched in IRO subjects (e.g., cellular stimuli). Common cardio-metabolic risk factors and gender do not influence these findings. This study demonstrates...

  1. Characterization of the insulin sensitivity of ghrelin receptor KO mice using glycemic clamps

    Directory of Open Access Journals (Sweden)

    Morgan Kristen

    2011-01-01

    characterized by robust improvements of glucose disposal in both normal and metabolically challenged states, relative to WT controls. GhrR KO mice have an intact 1st phase insulin response but require significantly less insulin for glucose disposal. Our experiments reveal that the insulin sensitivity of GhrR KO mice is due to both BW independent and dependent factors. We also provide several lines of evidence that a key feature of the GhrR KO mouse is maintenance of hepatic insulin sensitivity during metabolic challenge.

  2. Intensive insulin therapy improves insulin sensitivity and mitochondrial function in severely burned children.

    Science.gov (United States)

    Fram, Ricki Y; Cree, Melanie G; Wolfe, Robert R; Mlcak, Ronald P; Qian, Ting; Chinkes, David L; Herndon, David N

    2010-06-01

    To institute intensive insulin therapy protocol in an acute pediatric burn unit and study the mechanisms underlying its benefits. Prospective, randomized study. An acute pediatric burn unit in a tertiary teaching hospital. Children, 4-18 yrs old, with total body surface area burned > or =40% and who arrived within 1 wk after injury were enrolled in the study. Patients were randomized to one of two groups. Intensive insulin therapy maintained blood glucose levels between 80 and 110 mg/dL. Conventional insulin therapy maintained blood glucose patients were included in the data analysis consisting of resting energy expenditure, whole body and liver insulin sensitivity, and skeletal muscle mitochondrial function. Studies were performed at 7 days postburn (pretreatment) and at 21 days postburn (posttreatment). Resting energy expenditure significantly increased posttreatment (1476 +/- 124 to 1925 +/- 291 kcal/m(2) x day; p = .02) in conventional insulin therapy as compared with a decline in intensive insulin therapy. Glucose infusion rate was identical between groups before treatment (6.0 +/- 0.8 conventional insulin therapy vs. 6.8 +/- 0.9 mg/kg x min intensive insulin therapy; p = .5). Intensive insulin therapy displayed a significantly higher glucose clamp infusion rate posttreatment (9.1 +/- 1.3 intensive insulin therapy versus 4.8 +/- 0.6 mg/kg x min conventional insulin therapy, p = .005). Suppression of hepatic glucose release was significantly greater in the intensive insulin therapy after treatment compared with conventional insulin therapy (5.0 +/- 0.9 vs. 2.5 +/- 0.6 mg/kg x min; intensive insulin therapy vs. conventional insulin therapy; p = .03). States 3 and 4 mitochondrial oxidation of palmitate significantly improved in intensive insulin therapy (0.9 +/- 0.1 to 1.7 +/- 0.1 microm O(2)/CS/mg protein/min for state 3, p = .004; and 0.7 +/- 0.1 to 1.3 +/- 0.1 microm O(2)/CS/mg protein/min for state 4, p protocol improves insulin sensitivity and mitochondrial

  3. Insulin sensitivity : modulation by neuropeptides and hormones

    NARCIS (Netherlands)

    Hoek, Anita van den

    2006-01-01

    Nowadays, obesity has reached epidemic proportions globally. It can lead to several chronic diseases, including insulin resistance/type 2 diabetes mellitus. Feeding behaviour is regulated in the hypothalamus of the brain by two opposing pathways: NPY/AgRP neurons vs. POMC/CART neurons. In addition,

  4. Lipid-anthropometric index optimization for insulin sensitivity estimation

    Science.gov (United States)

    Velásquez, J.; Wong, S.; Encalada, L.; Herrera, H.; Severeyn, E.

    2015-12-01

    Insulin sensitivity (IS) is the ability of cells to react due to insulińs presence; when this ability is diminished, low insulin sensitivity or insulin resistance (IR) is considered. IR had been related to other metabolic disorders as metabolic syndrome (MS), obesity, dyslipidemia and diabetes. IS can be determined using direct or indirect methods. The indirect methods are less accurate and invasive than direct and they use glucose and insulin values from oral glucose tolerance test (OGTT). The accuracy is established by comparison using spearman rank correlation coefficient between direct and indirect method. This paper aims to propose a lipid-anthropometric index which offers acceptable correlation to insulin sensitivity index for different populations (DB1=MS subjects, DB2=sedentary without MS subjects and DB3=marathoners subjects) without to use OGTT glucose and insulin values. The proposed method is parametrically optimized through a random cross-validation, using the spearman rank correlation as comparator with CAUMO method. CAUMO is an indirect method designed from a simplification of the minimal model intravenous glucose tolerance test direct method (MINMOD-IGTT) and with acceptable correlation (0.89). The results show that the proposed optimized method got a better correlation with CAUMO in all populations compared to non-optimized. On the other hand, it was observed that the optimized method has better correlation with CAUMO in DB2 and DB3 groups than HOMA-IR method, which is the most widely used for diagnosing insulin resistance. The optimized propose method could detect incipient insulin resistance, when classify as insulin resistant subjects that present impaired postprandial insulin and glucose values.

  5. Effects of body weight and alcohol consumption on insulin sensitivity

    Directory of Open Access Journals (Sweden)

    Holcomb Valerie B

    2010-03-01

    Full Text Available Abstract Background Obesity is a risk factor for the development of insulin resistance, which can eventually lead to type-2 diabetes. Alcohol consumption is a protective factor against insulin resistance, and thus protects against the development of type-2 diabetes. The mechanism by which alcohol protects against the development of type-2 diabetes is not well known. To determine the mechanism by which alcohol improves insulin sensitivity, we fed water or alcohol to lean, control, and obese mice. The aim of this study was to determine whether alcohol consumption and body weights affect overlapping metabolic pathways and to identify specific target genes that are regulated in these pathways. Method Adipose tissue dysfunction has been associated with the development of type-2 diabetes. We assessed possible gene expression alterations in epididymal white adipose tissue (WAT. We obtained WAT from mice fed a calorie restricted (CR, low fat (LF Control or high fat (HF diets and either water or 20% ethanol in the drinking water. We screened the expression of genes related to the regulation of energy homeostasis and insulin regulation using a gene array composed of 384 genes. Results Obesity induced insulin resistance and calorie restriction and alcohol improved insulin sensitivity. The insulin resistance in obese mice was associated with the increased expression of inflammatory markers Cd68, Il-6 and Il-1α; in contrast, most of these genes were down-regulated in CR mice. Anti-inflammatory factors such as Il-10 and adrenergic beta receptor kinase 1 (Adrbk1 were decreased in obese mice and increased by CR and alcohol. Also, we report a direct correlation between body weight and the expression of the following genes: Kcnj11 (potassium inwardly-rectifying channel, subfamily J, member 11, Lpin2 (lipin2, and Dusp9 (dual-specificity MAP kinase phosphatase 9. Conclusion We show that alcohol consumption increased insulin sensitivity. Additionally, alterations

  6. Calcineurin inhibitors acutely improve insulin sensitivity without affecting insulin secretion in healthy human volunteers

    DEFF Research Database (Denmark)

    Øzbay, Aygen; Møller, Niels; Juhl, Claus

    2012-01-01

    and tacrolimus has been attributed to both beta cell dysfunction and impaired insulin sensitivity. WHAT THIS STUDY ADDS: This is the first trial to investigate beta cell function and insulin sensitivity using gold standard methodology in healthy human volunteers treated with clinically relevant doses...... of ciclosporin and tacrolimus. We document that both drugs acutely increase insulin sensitivity, while first phase and pulsatile insulin secretion remain unaffected. This study demonstrates that ciclosporin and tacrolimus have similar acute effects on glucose metabolism in healthy humans. AIM The introduction...... of calcineurin inhibitors (CNIs) ciclosporin (CsA) and tacrolimus (Tac) has improved the outcome of organ transplants, but complications such as new onset diabetes mellitus after transplantation (NODAT) cause impairment of survival rates. The relative contribution of each CNI to the pathogenesis and development...

  7. 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 PEDO group compared with the CNO group. Maternal periodontal disease may induce insulin resistance and reduce IST in adult offspring, but such alterations are not attributable to low birth weight.

  8. Maternal Rat Diabetes Mellitus Deleteriously Affects Insulin Sensitivity and Beta-Cell Function in the Offspring

    Directory of Open Access Journals (Sweden)

    Abdel-Baset M. Aref

    2013-01-01

    Full Text Available This study was designed to assess the effect of maternal diabetes in rats on serum glucose and insulin concentrations, insulin resistance, histological architecture of pancreas and glycogen content in liver of offspring. The pregnant rat females were allocated into two main groups: normal control group and streptozotocin-induced diabetic group. After birth, the surviving offspring were subjected to biochemical and histological examination immediately after delivery and at the end of the 1st and 2nd postnatal weeks. In comparison with the offspring of normal control dams, the fasting serum glucose level of offspring of diabetic mothers was significantly increased at the end of the 1st and 2nd postnatal weeks. Serum insulin level of offspring of diabetic dams was significantly higher at birth and decreased significantly during the following 2 postnatal weeks, while in normal rat offspring, it was significantly increased with progress of time. HOMA Insulin Resistance (HOMA-IR was significantly increased in the offspring of diabetic dams at birth and after 1 week than in normal rat offspring, while HOMA insulin sensitivity (HOMA-IS was significantly decreased. HOMA beta-cell function was significantly decreased at all-time intervals in offspring of diabetic dams. At birth, islets of Langerhans as well as beta cells in offspring of diabetic dams were hypertrophied. The cells constituting islets seemed to have a high division rate. However, beta-cells were degenerated during the following 2 post-natal weeks and smaller insulin secreting cells predominated. Vacuolation and necrosis of the islets of Langerhans were also observed throughout the experimental period. The carbohydrate content in liver of offspring of diabetic dams was at all-time intervals lower than that in control. The granule distribution was more random. Overall, the preexisting maternal diabetes leads to glucose intolerance, insulin resistance, and impaired insulin sensitivity and

  9. Insulin sensitivity and insulin secretion at birth in intrauterine growth retarded infants.

    Science.gov (United States)

    Setia, Sajita; Sridhar, M G; Bhat, Vishnu; Chaturvedula, Lata; Vinayagamoorti, R; John, Mathew

    2006-06-01

    To study insulin sensitivity, secretion and relation of insulin levels with birth weight and ponderal index in intrauterine growth retarded (IUGR) infants at birth. We studied 30 IUGR and 30 healthy newborns born at term by vaginal delivery in Jipmer, Pondicherry, India. Cord blood was collected at the time of delivery for measurement of plasma glucose and insulin. When compared with healthy newborns, IUGR newborns had lower plasma glucose levels (mean 2.3+/-0.98 versus 4.1+/-0.51 mmol/L, p<0.001); lower plasma insulin levels (mean 4.5+/-2.64 versus 11.03+/-1.68 microU/L, p<0.001); higher insulin sensitivity calculated using G/I ratio (mean 11.6+/-5.1 versus 6.7+/-0.31, p<0.001), HOMA IS (mean 5.5+/-6.0 versus 0.53+/-0.15, p<0.001), and QUICKI (mean 0.47+/-0.12 versus 0.34+/-0.02, p<0.001); and decreased pancreatic beta-cell function test measured as I/G (mean 0.10+/-0.037 versus 0.15+/-0.006, p<0.001). A positive correlation was identified between insulin levels and birth weight in both the healthy control group (r2 = 0.17, p = 0.024) and IUGR group (r2 = 0.13, p = 0.048). However correlation of insulin levels with ponderal index was much more confident in both healthy control (r2 = 0.90, p<0.001) and IUGR groups (r2 = 0.28, p = 0.003). Insulin status correlated both with birth weight and ponderal index more confidently in control group than in IUGR group. At birth, IUGR infants are hypoglycaemic, hypoinsulinaemic and display increased insulin sensitivity and decreased pancreatic beta-cell function. Insulin levels correlate with ponderal index much more confidently than with birth weight.

  10. Human skeletal muscle perilipin 2 and 3 expression varies with insulin sensitivity

    DEFF Research Database (Denmark)

    Vigelsø Hansen, Andreas; Prats Gavalda, Clara; Ploug, Thorkil

    2013-01-01

    Background: Impaired insulin sensitivity may partly arise from a dysregulated lipid metabolism in human skeletal muscle. This study investigates the expression levels of perilipin 2, 3, and 5, and four key lipases in human skeletal muscle from the subjects that exhibit a range from normal to very...

  11. Circulating docosahexaenoic acid levels are associated with fetal insulin sensitivity.

    Directory of Open Access Journals (Sweden)

    Jin-Ping Zhao

    Full Text Available Arachidonic acid (AA; C20∶4 n-6 and docosahexaenoic acid (DHA; C22∶6 n-3 are important long-chain polyunsaturated fatty acids (LC-PUFA in maintaining pancreatic beta-cell structure and function. Newborns of gestational diabetic mothers are more susceptible to the development of type 2 diabetes in adulthood. It is not known whether low circulating AA or DHA is involved in perinatally "programming" this susceptibility. This study aimed to assess whether circulating concentrations of AA, DHA and other fatty acids are associated with fetal insulin sensitivity or beta-cell function, and whether low circulating concentrations of AA or DHA are involved in compromised fetal insulin sensitivity in gestational diabetic pregnancies.In a prospective singleton pregnancy cohort, maternal (32-35 weeks gestation and cord plasma fatty acids were assessed in relation to surrogate indicators of fetal insulin sensitivity (cord plasma glucose-to-insulin ratio, proinsulin concentration and beta-cell function (proinsulin-to-insulin ratio in 108 mother-newborn pairs. Cord plasma DHA levels (in percentage of total fatty acids were lower comparing newborns of gestational diabetic (n = 24 vs. non-diabetic pregnancies (2.9% vs. 3.5%, P = 0.01. Adjusting for gestational age at blood sampling, lower cord plasma DHA levels were associated with lower fetal insulin sensitivity (lower glucose-to-insulin ratio, r = 0.20, P = 0.036; higher proinsulin concentration, r = -0.37, P <0.0001. The associations remained after adjustment for maternal and newborn characteristics. Cord plasma saturated fatty acids C18∶0 and C20∶0 were negatively correlated with fetal insulin sensitivity, but their levels were not different between gestational diabetic and non-diabetic pregnancies. Cord plasma AA levels were not correlated with fetal insulin sensitivity.Low circulating DHA levels are associated with compromised fetal insulin sensitivity, and may be involved in

  12. Insulin sensitivity and metabolic flexibility following exercise training among different obese insulin-resistant phenotypes.

    Science.gov (United States)

    Malin, Steven K; Haus, Jacob M; Solomon, Thomas P J; Blaszczak, Alecia; Kashyap, Sangeeta R; Kirwan, John P

    2013-11-15

    Impaired fasting glucose (IFG) blunts the reversal of impaired glucose tolerance (IGT) after exercise training. Metabolic inflexibility has been implicated in the etiology of insulin resistance; however, the efficacy of exercise on peripheral and hepatic insulin sensitivity or substrate utilization in adults with IFG, IGT, or IFG + IGT is unknown. Twenty-four older (66.7 ± 0.8 yr) obese (34.2 ± 0.9 kg/m(2)) adults were categorized as IFG (n = 8), IGT (n = 8), or IFG + IGT (n = 8) according to a 75-g oral glucose tolerance test (OGTT). Subjects underwent 12-wk of exercise (60 min/day for 5 days/wk at ∼85% HRmax) and were instructed to maintain a eucaloric diet. A euglycemic hyperinsulinemic clamp (40 mU·m(2)·min(-1)) with [6,6-(2)H]glucose was used to determine peripheral and hepatic insulin sensitivity. Nonoxidative glucose disposal and metabolic flexibility [insulin-stimulated respiratory quotient (RQ) minus fasting RQ] were also assessed. Glucose incremental area under the curve (iAUCOGTT) was calculated from the OGTT. Exercise increased clamp-derived peripheral and hepatic insulin sensitivity more in adults with IFG or IGT alone than with IFG + IGT (P work is required to assess the molecular mechanism(s) by which chronic hyperglycemia modifies insulin sensitivity following exercise training.

  13. Nasal insulin changes peripheral insulin sensitivity simultaneously with altered activity in homeostatic and reward-related human brain regions.

    Science.gov (United States)

    Heni, M; Kullmann, S; Ketterer, C; Guthoff, M; Linder, K; Wagner, R; Stingl, K T; Veit, R; Staiger, H; Häring, H-U; Preissl, H; Fritsche, A

    2012-06-01

    Impaired insulin sensitivity is a major factor leading to type 2 diabetes. Animal studies suggest that the brain is involved in the regulation of insulin sensitivity. We investigated whether insulin action in the human brain regulates peripheral insulin sensitivity and examined which brain areas are involved. Insulin and placebo were given intranasally. Plasma glucose, insulin and C-peptide were measured in 103 participants at 0, 30 and 60 min. A subgroup (n = 12) was also studied with functional MRI, and blood sampling at 0, 30 and 120 min. For each time-point, the HOMA of insulin resistance (HOMA-IR) was calculated as an inverse estimate of peripheral insulin sensitivity. Plasma insulin increased and subsequently decreased. This excursion was accompanied by slightly decreased plasma glucose, resulting in an initially increased HOMA-IR. At 1 h after insulin spray, the HOMA-IR subsequently decreased and remained lower up to 120 min. An increase in hypothalamic activity was observed, which correlated with the increased HOMA-IR at 30 min post-spray. Activity in the putamen, right insula and orbitofrontal cortex correlated with the decreased HOMA-IR at 120 min post-spray. Central insulin action in specific brain areas, including the hypothalamus, may time-dependently regulate peripheral insulin sensitivity. This introduces a potential novel mechanism for the regulation of peripheral insulin sensitivity and underlines the importance of cerebral insulin action for the whole organism.

  14. Increased abundance of insulin/insulin-like growth factor-I hybrid receptors in skeletal muscle of obese subjects is correlated with in vivo insulin sensitivity.

    Science.gov (United States)

    Federici, M; Porzio, O; Lauro, D; Borboni, P; Giovannone, B; Zucaro, L; Hribal, M L; Sesti, G

    1998-08-01

    We reported that in noninsulin-dependent diabetes melitus (NIDDM) patients expression of insulin/insulin-like growth factor I (IGF-I) hybrid receptors is increased in insulin target tissues. Whether this is a defect associated with NIDDM or represents a generalized abnormality associated with insulin resistant states is still unsettled. To address this, we applied a microwell-based immunoassay to measure abundance of insulin receptors, type 1 IGF receptors, and hybrid receptors in muscle of eight normal and eight obese subjects. Maximal insulin binding to insulin receptors was lower in obese than in control subjects (B/T = 1.8 +/- 0.20 and 2.6 +/- 0.30; P < 0.03, respectively) and was negatively correlated with insulinemia (r = -0.60; P < 0.01). Maximal IGF-I binding to type 1 IGF receptors was higher in obese than in controls (B/T = 1.9 +/- 0.20 and 0.86 +/- 0.10; P < 0.0001, respectively) and was negatively correlated with plasma IGF-I levels (r = -0.69; P < 0.003). Hybrid receptor abundance was higher in obese than in normal subjects (B/T = 1.21 +/- 0.14 and 0.44 +/- 0.06; P < 0.0003, respectively) and was negatively correlated with insulin binding (r = -0.60; P < 0.01) and positively correlated with IGF-I binding (r = 0.92; P < 0.0001). Increased abundance of hybrids was correlated with insulinemia (r = 0.70; P < 0.002) and body mass index (r = 0.71; P < 0.0019), whereas it was negatively correlated with in vivo insulin sensitivity measured by ITT (r = -0.67; P < 0.016). These results indicate that downregulation of insulin receptors or upregulation of type 1 IGF receptors because of changes in plasma insulin and IGF-I levels may result in modifications in hybrid receptor abundance.

  15. A comparison between the minimal model and the glucose clamp in the assessment of insulin sensitivity across the spectrum of glucose tolerance. Insulin Resistance Atherosclerosis Study.

    Science.gov (United States)

    Saad, M F; Anderson, R L; Laws, A; Watanabe, R M; Kades, W W; Chen, Y D; Sands, R E; Pei, D; Savage, P J; Bergman, R N

    1994-09-01

    An insulin-modified frequently sampled intravenous glucose tolerance test (FSIGTT) with minimal model analysis was compared with the glucose clamp in 11 subjects with normal glucose tolerance (NGT), 20 with impaired glucose tolerance (IGT), and 24 with non-insulin-dependent diabetes mellitus (NIDDM). The insulin sensitivity index (SI) was calculated from FSIGTT using 22- and 12-sample protocols (SI(22) and SI(12), respectively). Insulin sensitivity from the clamp was expressed as SI(clamp) and SIP(clamp). Minimal model parameters were similar when calculated with SI(22) and SI(12). SI could not be distinguished from 0 in approximately 50% of diabetic patients with either protocol. SI(22) correlated significantly with SI(clamp) in the whole group (r = 0.62), and in the NGT (r = 0.53), IGT (r = 0.48), and NIDDM (r = 0.41) groups (P SIP(clamp) were expressed in the same units, SI(22) was 66 +/- 5% (mean +/- SE) and 50 +/- 8% lower than SI(clamp) and SIP(clamp), respectively. Thus, minimal model analysis of the insulin-modified FSIGTT provides estimates of insulin sensitivity that correlate significantly with those from the glucose clamp. The correlation was weaker, however, in NIDDM. The insulin-modified FSIGTT can be used as a simple test for assessment of insulin sensitivity in population studies involving nondiabetic subjects. Additional studies are needed before using this test routinely in patients with NIDDM.

  16. Adiponectin and osteocalcin: relation to insulin sensitivity.

    Science.gov (United States)

    Zhang, Yanjun; Zhou, Peng; Kimondo, Julia Wanjiru

    2012-10-01

    Obesity and osteoporosis have grave consequences for human health, quality of life, and even the efficiency of the labor force. Interestingly, these diseases share several features including a genetic predisposition and a common progenitor cell. Recent findings show that high adipocyte count in bone marrow is directly related to bone loss, as fat cells replace osteoblasts resulting in reduced bone mineral density and increased propensity towards osteoporosis. This close relationship has a positive aspect, whereby higher osteocalcin levels results in increased adiponectin production while the presence of adiponectin influences osteoblast proliferation and differentiation in a positive way. We focus on how osteoblasts and adipocytes affect each other and ultimately insulin resistance through the hormones they produce. This approach to whole animal physiology is the main stay of Alternative Medicine. It is assumed that the body is linked together intricately, and treating one is equal to treating the whole body. As we go further into bone and adipocytes physiology, it is evident that these organs affect each other. Therefore, elucidation on the actions of fat on bone and vice versa will unravel the complex mechanism of insulin resistance.

  17. Endocrine determinants of changes in insulin sensitivity and insulin secretion during a weight cycle in healthy men.

    Directory of Open Access Journals (Sweden)

    Judith Karschin

    Full Text Available Changes in insulin sensitivity (IS and insulin secretion occur with perturbations in energy balance and glycemic load (GL of the diet that may precede the development of insulin resistance and hyperinsulinemia. Determinants of changes in IS and insulin secretion with weight cycling in non-obese healthy subjects remain unclear.In a 6wk controlled 2-stage randomized dietary intervention 32 healthy men (26±4y, BMI: 24±2kg/m2 followed 1wk of overfeeding (OF, 3wks of caloric restriction (CR containing either 50% or 65% carbohydrate (CHO and 2wks of refeeding (RF with the same amount of CHO but either low or high glycaemic index at ±50% energy requirement. Measures of IS (basal: HOMA-index, postprandial: Matsuda-ISI, insulin secretion (early: Stumvoll-index, total: tAUC-insulin/tAUC-glucose and potential endocrine determinants (ghrelin, leptin, adiponectin, thyroid hormone levels, 24h-urinary catecholamine excretion were assessed.IS improved and insulin secretion decreased due to CR and normalized upon RF. Weight loss-induced improvements in basal and postprandial IS were associated with decreases in leptin and increases in ghrelin levels, respectively (r = 0.36 and r = 0.62, p<0.05. Weight regain-induced decrease in postprandial IS correlated with increases in adiponectin, fT3, TSH, GL of the diet and a decrease in ghrelin levels (r-values between -0.40 and 0.83, p<0.05 whereas increases in early and total insulin secretion were associated with a decrease in leptin/adiponectin-ratio (r = -0.52 and r = -0.46, p<0.05 and a decrease in fT4 (r = -0.38, p<0.05 for total insulin secretion only. After controlling for GL associations between RF-induced decrease in postprandial IS and increases in fT3 and TSH levels were no longer significant.Weight cycling induced changes in IS and insulin secretion were associated with changes in all measured hormones, except for catecholamine excretion. While leptin, adiponectin and ghrelin seem to be the major

  18. Effect of chloroquine on insulin and glucose homoeostasis in normal subjects and patients with non-insulin-dependent diabetes mellitus.

    OpenAIRE

    Smith, G D; Amos, T A; Mahler, R; Peters, T J

    1987-01-01

    Plasma glucose, insulin, and C peptide concentrations were determined after an oral glucose load in normal subjects and in a group of patients with non-insulin-dependent diabetes mellitus before and during a short course of treatment with chloroquine. In the control group there was a small but significant reduction in fasting blood glucose concentration but overall glucose tolerance and hormone concentrations were unaffected. In contrast, the patients with non-insulin-dependent diabetes melli...

  19. Relationship between red cell membrane fatty acids and adipokines in individuals with varying insulin sensitivity.

    Science.gov (United States)

    Min, Y; Lowy, C; Islam, S; Khan, F S; Swaminathan, R

    2011-06-01

    Plasma leptin and adiponectin, and membrane phospholipid fatty acid composition are implicated into the mechanism of insulin resistance but no clear pattern has emerged. Hence, this study examined these variables in subjects presenting to the diabetic clinic for a diagnostic glucose tolerance test. Body composition, glucose, glycated hemoglobin, insulin, leptin, adiponectin, and red cell and plasma phospholipid fatty acids were assessed from 42 normal and 28 impaired glucose tolerant subjects. Insulin sensitivity was determined by homeostatic model assessment. The plasma phosphatidylcholine fatty acid composition of the impaired glucose tolerant subjects was similar to that of normal subjects. However, the impaired glucose tolerant subjects had significantly lower linoleic (Pphosphatidylcholine and phosphatidylethanolamine compared with the normal subjects. Moreover, red cell phosphatidylcholine docosahexaenoic acid correlated positively with adiponectin (r=0.290, Pinsulin (r=-0.335, Pinsulin resistance (r=-0.322, Pinsulin level whereas insulin was the only component that predicted the membrane fatty acids. We postulate that membrane phospholipids fatty acids have an indirect role in determining insulin concentration but insulin has a major role in determining membrane fatty acid composition.

  20. Insulin sensitivity affects corticolimbic brain responses to visual food cues in polycystic ovary syndrome patients.

    Science.gov (United States)

    Alsaadi, Hanin M; Van Vugt, Dean A

    2015-11-01

    This study examined the effect of insulin sensitivity on the responsiveness of appetite regulatory brain regions to visual food cues. Nineteen participants diagnosed with polycystic ovary syndrome (PCOS) were divided into insulin-sensitive (n=8) and insulin-resistant (n=11) groups based on the homeostatic model assessment of insulin resistance (HOMA2-IR). Subjects underwent functional magnetic resonance imaging (fMRI) while viewing food pictures following water or dextrose consumption. The corticolimbic blood oxygen level dependent (BOLD) responses to high-calorie (HC) or low-calorie (LC) food pictures were compared within and between groups. BOLD responses to food pictures were reduced during a glucose challenge in numerous corticolimbic brain regions in insulin-sensitive but not insulin-resistant subjects. Furthermore, the degree of insulin resistance positively correlated with the corticolimbic BOLD response in the medial prefrontal cortex (mPFC), orbitofrontal cortex (OFC), anterior cingulate and ventral tegmental area (VTA) in response to HC pictures, and in the dorsolateral prefrontal cortex (DLPFC), mPFC, anterior cingulate, and insula in response to LC pictures following a glucose challenge. BOLD signal in the OFC, midbrain, hippocampus, and amygdala following a glucose challenge correlated with HOMA2-IR in response to HC-LC pictures. We conclude that the normal inhibition of corticolimbic brain responses to food pictures during a glucose challenge is compromised in insulin-resistant subjects. The increase in brain responsiveness to food pictures during postprandial hyperinsulinemia may lead to greater non-homeostatic eating and perpetuate obesity in insulin-resistant subjects.

  1. Changes in phosphatidylcholine fatty acid composition are associated with altered skeletal muscle insulin responsiveness in normal man.

    Science.gov (United States)

    Clore, J N; Harris, P A; Li, J; Azzam, A; Gill, R; Zuelzer, W; Rizzo, W B; Blackard, W G

    2000-02-01

    The fatty acid composition of skeletal muscle cell membrane phospholipids (PLs) is known to influence insulin responsiveness in man. We have recently shown that the fatty acid composition of phosphatidylcholine (PC), and not phosphatidylethanolamine (PE), from skeletal muscle membranes is of particular importance in this relationship. Efforts to alter the PL fatty acid composition in animal models have demonstrated induction of insulin resistance. However, it has been more difficult to determine if changes in insulin sensitivity are associated with changes in the skeletal muscle membrane fatty acid composition of PL in man. Using nicotinic acid (NA), an agent known to induce insulin resistance in man, 9 normal subjects were studied before and after treatment for 1 month. Skeletal muscle membrane fatty acid composition of PC and PE from biopsies of vastus lateralis was correlated with insulin responsiveness using a 3-step hyperinsulinemic-euglycemic clamp. Treatment with NA was associated with a 25% increase in the half-maximal insulin concentration ([ED50] 52.0 +/- 7.5 to 64.6 +/- 9.0 microU/mL, P insulin sensitivity. Significant changes in the fatty acid composition of PC, but not PE, were also observed after NA administration. An increase in the percentage of 16:0 (21% +/- 0.3% to 21.7% +/- 0.4%, P insulin resistance with NA is associated with changes in the fatty acid composition of PC in man.

  2. [Insulin-sensitizing agents: metformin and thiazolidinedione derivatives].

    Science.gov (United States)

    Satoh, Jo

    2003-07-01

    Both metformin and thiazolidinedione derivatives(TZDs) improve insulin resistance, a major pathogenesis of type 2 diabetes, and decrease blood glucose levels without stimulating insulin secretion. Metformin inhibits glucose output from the liver, while TZDs increase glucose utilization in the peripheral tissues. In addition, there has been indicated that these agents ameliorate metabolic syndrome beyond glucose-level lowering. Molecular targets of these agents have recently been revealed; AMP-activated protein kinase (AMPK) for metformin and adiponectin, while PPAR gamma for TZDs which induce gene expression of adipocyte glycerol kinase and adiponectin. Insulin-sensitizing agents are clinically useful for obese diabetic patients with insulin resistance. However, periodical examinations are necessary to avoid serious adverse effects such as lactic acidosis, although rare, by metformin and liver injury by TZDs.

  3. Dietary Sodium Restriction Decreases Insulin Secretion Without Affecting Insulin Sensitivity in Humans

    Science.gov (United States)

    Byrne, Loretta M.; Yu, Chang; Wang, Thomas J.; Brown, Nancy J.

    2014-01-01

    Context: Interruption of the renin-angiotensin-aldosterone system prevents incident diabetes in high-risk individuals, although the mechanism remains unclear. Objective: To test the hypothesis that activation of the endogenous renin-angiotensin-aldosterone system or exogenous aldosterone impairs insulin secretion in humans. Design: We conducted a randomized, blinded crossover study of aldosterone vs vehicle and compared the effects of a low-sodium versus a high-sodium diet. Setting: Academic clinical research center. Participants: Healthy, nondiabetic, normotensive volunteers. Interventions: Infusion of exogenous aldosterone (0.7 μg/kg/h for 12.5 h) or vehicle during low or high sodium intake. Low sodium (20 mmol/d; n = 12) vs high sodium (160 mmol/d; n = 17) intake for 5–7 days. Main Outcome Measures: Change in acute insulin secretory response assessed during hyperglycemic clamps while in sodium balance during a low-sodium vs high-sodium diet during aldosterone vs vehicle. Results: A low-sodium diet increased endogenous aldosterone and plasma renin activity, and acute glucose-stimulated insulin (−16.0 ± 5.6%; P = .007) and C-peptide responses (−21.8 ± 8.4%; P = .014) were decreased, whereas the insulin sensitivity index was unchanged (−1.0 ± 10.7%; P = .98). Aldosterone infusion did not affect the acute insulin response (+1.8 ± 4.8%; P = .72) or insulin sensitivity index (+2.0 ± 8.8%; P = .78). Systolic blood pressure and serum potassium were similar during low and high sodium intake and during aldosterone infusion. Conclusions: Low dietary sodium intake reduces insulin secretion in humans, independent of insulin sensitivity. PMID:25029426

  4. Insulin sensitivity is reduced in children with high body-fat regardless of BMI

    DEFF Research Database (Denmark)

    Fairchild, Timothy J; Klakk, Heidi; Heidemann, Malene

    2018-01-01

    BF% was measured by dual-energy X-ray absorptiometry (DXA). Fasting plasma glucose and insulin concentrations were measured and the homoeostatic model assessment of insulin resistance (HOMA-IR) used to assess insulin sensitivity. RESULTS: Approximately 8% of children classified as normal weight...... by BMI had high BF% (NW + Adipose). Children with high BF% had significantly higher insulin (NW + adipose: 32.3%; OW/OB + Adipose: 52.2%) and HOMA-IR scores (NW + Adipose: 32.3%; OW/OB + Adipose: 55.3%) than children classified as NW without high BF% (reference group; NW + NonAdipose). Adjusting for CRF...

  5. Correlations between insulin sensitivity and bone mineral density in non-diabetic men

    DEFF Research Database (Denmark)

    Abrahamsen, B.; Rohold, A.; Henriksen, Jan Erik

    2000-01-01

    AIMS: To investigate relationships between bone mineral density (BMD), insulin secretion and insulin sensitivity, controlling for body composition, in view of data suggesting that hyperglycaemia [corrected] leads to decreased osteoblast proliferation and a negative calcium balance and that insulin...

  6. Detection of Independent Associations of Plasma Lipidomic Parameters with Insulin Sensitivity Indices Using Data Mining Methodology.

    Directory of Open Access Journals (Sweden)

    Steffi Kopprasch

    Full Text Available Glucolipotoxicity is a major pathophysiological mechanism in the development of insulin resistance and type 2 diabetes mellitus (T2D. We aimed to detect subtle changes in the circulating lipid profile by shotgun lipidomics analyses and to associate them with four different insulin sensitivity indices.The cross-sectional study comprised 90 men with a broad range of insulin sensitivity including normal glucose tolerance (NGT, n = 33, impaired glucose tolerance (IGT, n = 32 and newly detected T2D (n = 25. Prior to oral glucose challenge plasma was obtained and quantitatively analyzed for 198 lipid molecular species from 13 different lipid classes including triacylglycerls (TAGs, phosphatidylcholine plasmalogen/ether (PC O-s, sphingomyelins (SMs, and lysophosphatidylcholines (LPCs. To identify a lipidomic signature of individual insulin sensitivity we applied three data mining approaches, namely least absolute shrinkage and selection operator (LASSO, Support Vector Regression (SVR and Random Forests (RF for the following insulin sensitivity indices: homeostasis model of insulin resistance (HOMA-IR, glucose insulin sensitivity index (GSI, insulin sensitivity index (ISI, and disposition index (DI. The LASSO procedure offers a high prediction accuracy and and an easier interpretability than SVR and RF.After LASSO selection, the plasma lipidome explained 3% (DI to maximal 53% (HOMA-IR variability of the sensitivity indexes. Among the lipid species with the highest positive LASSO regression coefficient were TAG 54:2 (HOMA-IR, PC O- 32:0 (GSI, and SM 40:3:1 (ISI. The highest negative regression coefficient was obtained for LPC 22:5 (HOMA-IR, TAG 51:1 (GSI, and TAG 58:6 (ISI.Although a substantial part of lipid molecular species showed a significant correlation with insulin sensitivity indices we were able to identify a limited number of lipid metabolites of particular importance based on the LASSO approach. These few selected lipids with the closest

  7. Low whole-body insulin sensitivity in patients with ischaemic heart disease is associated with impaired myocardial glucose uptake predictive of poor outcome after revascularisation

    DEFF Research Database (Denmark)

    Kofoed, Klaus F; Carstensen, Steen; Hove, Jens D

    2002-01-01

    patients with ischaemic heart disease and impaired LV ejection fraction (EF) and age-matched healthy volunteers ( n = 30). As assessed by euglycaemic glucose-insulin clamp, 15 patients had a low and 14 a normal whole-body insulin sensitivity. Using positron emission tomography, patterns of fluorine-18......We tested the hypothesis that low whole-body insulin sensitivity in patients with ischaemic heart disease and impaired left ventricular (LV) function is associated with abnormalities of insulin-mediated myocardial glucose uptake affecting outcome after coronary bypass surgery (CABG). We studied 29......-normal myocardium was found to be higher in patients with normal whole-body insulin sensitivity ( P body insulin sensitivity more segments displayed a pattern of reduced glucose uptake in normoperfused myocardium (PET-reverse mismatch) ( P

  8. Estrogen restores brain insulin sensitivity in ovariectomized non-obese rats, but not in ovariectomized obese rats.

    Science.gov (United States)

    Pratchayasakul, Wasana; Chattipakorn, Nipon; Chattipakorn, Siriporn C

    2014-06-01

    We previously demonstrated that obesity caused the reduction of peripheral and brain insulin sensitivity and that estrogen therapy improved these defects. However, the beneficial effect of estrogen on brain insulin sensitivity and oxidative stress in either ovariectomy alone or ovariectomy with obesity models has not been determined. We hypothesized that ovariectomy alone or ovariectomy with obesity reduces brain insulin sensitivity and increases brain oxidative stress, which are reversed by estrogen treatment. Thirty female rats were assigned as either sham-operated or ovariectomized. After the surgery, each group was fed either a normal diet or high-fat diet for 12 weeks. At week 13, rats in each group received either the vehicle or estradiol for 30 days. At week 16, blood and brain were collected for determining the peripheral and brain insulin sensitivity as well as brain oxidative stress. We found that ovariectomized rats and high-fat diet fed rats incurred obesity, reduced peripheral and brain insulin sensitivity, and increased brain oxidative stress. Estrogen ameliorated peripheral insulin sensitivity in these rats. However, the beneficial effect of estrogen on brain insulin sensitivity and brain oxidative stress was observed only in ovariectomized normal diet-fed rats, but not in ovariectomized high fat diet-fed rats. Our results suggested that reduced brain insulin sensitivity and increased brain oxidative stress occurred after either ovariectomy or obesity. However, the reduced brain insulin sensitivity and the increased brain oxidative stress in ovariectomy with obesity could not be ameliorated by estrogen treatment. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. The impact of pegvisomant treatment on substrate metabolism and insulin sensitivity in patients with acromegaly

    DEFF Research Database (Denmark)

    Lindberg-Larsen, Rune; Møller, Niels; Schmitz, Ole

    2007-01-01

    CONTEXT: Pegvisomant is a specific GH receptor antagonist that is able to normalize serum IGF-I concentrations in most patients with acromegaly. The impact of pegvisomant on insulin sensitivity and substrate metabolism is less well described. PATIENTS AND METHODS: We assessed basal and insulin......-stimulated (euglycemic clamp) substrate metabolism in seven patients with active acromegaly before and after 4-wk pegvisomant treatment (15 mg/d) in an open design. RESULTS: After pegvisomant, IGF-I decreased, whereas GH increased (IGF-I, 621 +/- 82 vs. 247 +/- 33 microg/liter, P = 0.02; GH, 5.3 +/- 1.5 vs. 10.8 +/- 3...... vs. 1563 +/- 101 kcal/24 h, P = 0.03), but the rate of lipid oxidation did not change significantly. CONCLUSIONS: 1) Pegvisomant treatment for 4 wk improves peripheral and hepatic insulin sensitivity in acromegaly. 2) This is associated with a decrease in resting energy expenditure, whereas free...

  10. Insulin secretion and sensitivity in space flight: diabetogenic effects

    Science.gov (United States)

    Tobin, Brian W.; Uchakin, Peter N.; Leeper-Woodford, Sandra K.

    2002-01-01

    Nearly three decades of space flight research have suggested that there are subclinical diabetogenic changes that occur in microgravity. Alterations in insulin secretion, insulin sensitivity, glucose tolerance, and metabolism of protein and amino acids support the hypothesis that insulin plays an essential role in the maintenance of muscle mass in extended-duration space flight. Experiments in flight and after flight and ground-based bedrest studies have associated microgravity and its experimental paradigms with manifestations similar to those of diabetes, physical inactivity, and aging. We propose that these manifestations are characterized best by an etiology that falls into the clinical category of "other" causes of diabetes, including, but not restricted to, genetic beta-cell defects, insulin action defects, diseases of the endocrine pancreas, endocrinopathies, drug or chemically induced diabetes, infections, immune-mediated metabolic alteration, and a host of genetic related diseases. We present data showing alterations in tumor necrosis factor-alpha production, insulin secretion, and amino acid metabolism in pancreatic islets of Langerhans cultured in a ground-based cell culture bioreactor that mimics some of the effects of microgravity. Taken together, space flight research, ground-based studies, and bioreactor studies of pancreatic islets of Langerhans support the hypothesis that the pancreas is unable to overcome peripheral insulin resistance and amino acid dysregulation during space flight. We propose that measures of insulin secretion and insulin action will be necessary to design effective countermeasures against muscle loss, and we advance the "disposition index" as an essential model to be used in the clinical management of space flight-induced muscle loss.

  11. 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

    (insulin-stimulated glucose disposal, hyperinsulinemic clamp), and glucose tolerance (75-g oral glucose tolerance test) were measured in 55 Pima Indians (47 men and 8 women, aged 31 +/- 8 years, body fat 29 +/- 8% [mean +/- SD]; 50 with normal glucose tolerance, 3 with impaired glucose tolerance, and 2......Adiponectin, the most abundant adipose-specific protein, has been found to be negatively associated with degree of adiposity and positively associated with insulin sensitivity in Pima Indians and other populations. Moreover, adiponectin administration to rodents has been shown to increase insulin...

  12. Normocaloric Diet Restores Weight Gain and Insulin Sensitivity in Obese Mice

    OpenAIRE

    Lombardo, Giovanni Enrico; Arcidiacono, Biagio; De Rose, Roberta Francesca; Lepore, Saverio Massimo; Costa, Nicola; Montalcini, Tiziana; Brunetti, Antonio; Russo, Diego; De Sarro, Giovambattista; Celano, Marilena

    2016-01-01

    An increased incidence of obesity is registered worldwide, and its association with insulin resistance and type 2 diabetes is closely related with increased morbidity and mortality for cardiovascular diseases. A major clinical problem in the management of obesity is the non-adherence or low adherence of patients to a hypo-caloric dietetic restriction. In this study we evaluated in obese mice the effects on insulin sensitivity of shifting from high-calorie foods to normal diet. Male C57BL/6Jol...

  13. Insulin sensitivity and carotid intima-media thickness

    DEFF Research Database (Denmark)

    Kozakova, Michaela; Natali, Andrea; Dekker, Jacqueline

    2013-01-01

    Despite a wealth of experimental data in animal models, the independent association of insulin resistance with early carotid atherosclerosis in man has not been demonstrated. APPROACH AND RESULTS: We studied a European cohort of 525 men and 655 women (mean age, 44±8 years) free of conditions known...... to affect carotid wall (diabetes mellitus, hypertension, and dyslipidemia). All subjects received an oral glucose tolerance test, a euglycemic hyperinsulinemic clamp (M/I as a measure of insulin sensitivity), and B-mode carotid ultrasound. In 833 participants (380 men), the carotid ultrasound was repeated...

  14. Effects of turtle oil on insulin sensitivity and glucose metabolism in insulin resistant cell model

    International Nuclear Information System (INIS)

    Bai Jing; Tian Yaping; Guo Duo

    2007-01-01

    To evaluate the effects of turtle oil on insulin sensitivity and glucose metabolism in an insulin-resistant (IR) cell model which was established by the way of high concentration of insulin induction with HepG 2 cell in vitro culture. The IR cells were treated by turtle oil, the glucose consumption and 3 H-D-glucose incorporation rate in IR cells were detected by the way of glucose oxidase and 3 H-D-glucose incorporation assay respectively. The state of cell proliferation was tested by MTT method. The results showed that the incorporation rate of 3 H-D-glucose in IR cells was significantly lower than that in the control cells(P 3 H-D-glucose incorporation rate in either IR cells or control cells was increased with the increase of insulin concentration. Moreover, the 3 H-D-glucose incorporation rate of IR cells increased slower than that of control cells. The MTT assay showed that turtle oil can promote the proliferation of IR cell and control cell. The glucose uptake and glucose consumption in IR cell which treated with turtle oil was significantly increase than that in the control cells (P<0.05). Turtle oil can improve the insulin sensitivity and glucose metabolism in the IR cell model. (authors)

  15. Insulin-mediated increases in renal plasma flow are impaired in insulin-resistant normal subjects

    NARCIS (Netherlands)

    ter Maaten, JC; Bakker, SJL; Serne, EH; Moshage, HJ; Gans, ROB

    2000-01-01

    Background Impaired vasodilatation in skeletal muscle is a possible mechanism linking insulin resistance to blood pressure regulation. Increased renal vascular resistance has been demonstrated in the offspring of essential hypertensives. We assessed whether insulin-mediated renal vasodilatation is

  16. Insulin sensitivity in relation to fat distribution and plasma adipocytokines among abusers of anabolic androgenic steroids

    DEFF Research Database (Denmark)

    Rasmussen, Jon Jarløv; Schou, Morten; Selmer, Christian

    2017-01-01

    Objective: Abuse of anabolic androgenic steroids (AAS) is prevalent among young men, but information regarding effects on insulin sensitivity and fat distribution is limited. The objective was to investigate insulin sensitivity in relation to fat distribution and adipocytokines among current...

  17. Insulin binding properties of normal and transformed human epidermal cultured keratinocytes

    International Nuclear Information System (INIS)

    Verrando, P.; Ortonne, J.P.

    1985-01-01

    Insulin binding to its receptors was studied in cultured normal and transformed (A431 line) human epidermal keratinocytes. The specific binding was a temperature-dependent, saturable process. Normal keratinocytes possess a mean value of about 80,000 receptors per cell. Fifteen hours exposure of the cells to insulin lowered their receptor number (about 65% loss in available sites); these reappeared when the hormone was removed from the culture medium. In the A431 epidermoid carcinoma cell line, there is a net decrease in insulin binding (84% of the initial bound/free hormone ratio in comparison with normal cells) essentially related to a loss in receptor affinity for insulin. Thus, cultured human keratinocytes which express insulin receptors may be a useful tool in understanding skin pathology related to insulin disorders

  18. [Mechanism of action of insulin sensitizer agents in the treatment of polycystic ovarian syndrome].

    Science.gov (United States)

    Galindo García, Carlos G; Vega Arias, Maria de Jesús; Hernández Marín, Imelda; Ayala, Aquiles R

    2007-03-01

    Polycystic ovarian disease (PCOD) is the most important endocrine abnormality that affects women in reproductive age. It is characterized by chronic anovulation and hyperandrogenemia probably secondary to insulin resistance. Hence insulin sensitizers agents had been used in PCOD. Metformin is a biguanide used in the treatment of PCOD via decrease of hepatic gluconeogenesis and insulinemia; improvement peripheral glucose utilization, oxidative glucose metabolism, nonoxidative glucose metabolism and intracellular glucose transport. Such effects, when this drug is administered alone during 3 to 6 months, increase sex hormone binding globulin (SHBG), reduce free androgens index and hirsutism, decrease insulin resistance, and regulate menses in 60 to 70% of cases. Thiazolidinodiones are drugs that decrease insulin resistance in the liver with hepatic glucose production. Their mechanism of action is through the peroxisome proliferator-activated receptors gamma (PPAR-gamma), that help to decrease plasmatic concentrations of free fatty acids, pre and postprandial glucose, insulin, triglycerides, increased HDL cholesterol and decreased LDL, menses return to normality, with improvement of ovulation and decreased hirsutism. It seems that by modulation and attenuation of insulin resistance, hypoglucemic agents such as metfomin and thiazolidinodiones can be used effectively to treat anovulation, infertility and hyperandrogenemia.

  19. Leptin rapidly improves glucose homeostasis in obese mice by increasing hypothalamic insulin sensitivity.

    Science.gov (United States)

    Koch, Christiane; Augustine, Rachael A; Steger, Juliane; Ganjam, Goutham K; Benzler, Jonas; Pracht, Corinna; Lowe, Chrishanthi; Schwartz, Michael W; Shepherd, Peter R; Anderson, Greg M; Grattan, David R; Tups, Alexander

    2010-12-01

    Obesity is associated with resistance to the actions of both leptin and insulin via mechanisms that remain incompletely understood. To investigate whether leptin resistance per se contributes to insulin resistance and impaired glucose homeostasis, we investigated the effect of acute leptin administration on glucose homeostasis in normal as well as leptin- or leptin receptor-deficient mice. In hyperglycemic, leptin-deficient Lep(ob/ob) mice, leptin acutely and potently improved glucose metabolism, before any change of body fat mass, via a mechanism involving the p110α and β isoforms of phosphatidylinositol-3-kinase (PI3K). Unlike insulin, however, the anti-diabetic effect of leptin occurred independently of phospho-AKT, a major downstream target of PI3K, and instead involved enhanced sensitivity of the hypothalamus to insulin action upstream of PI3K, through modulation of IRS1 (insulin receptor substrate 1) phosphorylation. These data suggest that leptin resistance, as occurs in obesity, reduces the hypothalamic response to insulin and thereby impairs peripheral glucose homeostasis, contributing to the development of type 2 diabetes.

  20. Changes in erythrocyte insulin receptors in normal dogs and keeshond dogs with inheritable, early onset, insulin dependent diabetes mellitus

    International Nuclear Information System (INIS)

    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 ( 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

  1. Proximity to Delivery Alters Insulin Sensitivity and Glucose Metabolism in Pregnant Mice.

    Science.gov (United States)

    Musial, Barbara; Fernandez-Twinn, Denise S; Vaughan, Owen R; Ozanne, Susan E; Voshol, Peter; Sferruzzi-Perri, Amanda N; Fowden, Abigail L

    2016-04-01

    In late pregnancy, maternal insulin resistance occurs to support fetal growth, but little is known about insulin-glucose dynamics close to delivery. This study measured insulin sensitivity in mice in late pregnancy at day 16 (D16) and near term at D19. Nonpregnant (NP) and pregnant mice were assessed for metabolite and hormone concentrations, body composition by DEXA, tissue insulin signaling protein abundance by Western blotting, glucose tolerance and utilization, and insulin sensitivity using acute insulin administration and hyperinsulinemic-euglycemic clamps with [(3)H]glucose infusion. Whole-body insulin resistance occurred in D16 pregnant dams in association with basal hyperinsulinemia, insulin-resistant endogenous glucose production, and downregulation of several proteins in hepatic and skeletal muscle insulin signaling pathways relative to NP and D19 values. Insulin resistance was less pronounced at D19, with restoration of NP insulin concentrations, improved hepatic insulin sensitivity, and increased abundance of hepatic insulin signaling proteins. At D16, insulin resistance at whole-body, tissue, and molecular levels will favor fetal glucose acquisition, while improved D19 hepatic insulin sensitivity will conserve glucose for maternal use in anticipation of lactation. Tissue sensitivity to insulin, therefore, alters differentially with proximity to delivery in pregnant mice, with implications for human and other species. © 2016 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.

  2. Grizzly bears exhibit augmented insulin sensitivity while obese prior to a reversible insulin resistance during hibernation.

    Science.gov (United States)

    Nelson, O Lynne; Jansen, Heiko T; Galbreath, Elizabeth; Morgenstern, Kurt; Gehring, Jamie Lauren; Rigano, Kimberly Scott; Lee, Jae; Gong, Jianhua; Shaywitz, Adam J; Vella, Chantal A; Robbins, Charles T; Corbit, Kevin C

    2014-08-05

    The confluence of obesity and diabetes as a worldwide epidemic necessitates the discovery of new therapies. Success in this endeavor requires translatable preclinical studies, which traditionally employ rodent models. As an alternative approach, we explored hibernation where obesity is a natural adaptation to survive months of fasting. Here we report that grizzly bears exhibit seasonal tripartite insulin responsiveness such that obese animals augment insulin sensitivity but only weeks later enter hibernation-specific insulin resistance (IR) and subsequently reinitiate responsiveness upon awakening. Preparation for hibernation is characterized by adiposity coupled to increased insulin sensitivity via modified PTEN/AKT signaling specifically in adipose tissue, suggesting a state of "healthy" obesity analogous to humans with PTEN haploinsufficiency. Collectively, we show that bears reversibly cope with homeostatic perturbations considered detrimental to humans and describe a mechanism whereby IR functions not as a late-stage metabolic adaptation to obesity, but rather a gatekeeper of the fed-fasting transition. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Insulin production rate in normal man as an estimate for calibration of continuous intravenous insulin infusion in insulin-dependent diabetic patients.

    Science.gov (United States)

    Waldhäusl, W K; Bratusch-Marrain, P R; Francesconi, M; Nowotny, P; Kiss, A

    1982-01-01

    This study examines the feasibility of deriving the 24-h insulin requirement of insulin-dependent diabetic patients who were devoid of any endogenous insulin release (IDD) from the insulin-production rate (IPR) of healthy man (basal, 17 mU/min; stimulated 1.35 U/12.5 g glucose). To this end, continuous intravenous insulin infusion (CIVII) was initiated at a precalculated rate of 41.2 +/- 4.6 (SD) U/24 h in IDD (N - 12). Blood glucose profiles were compared with those obtained during intermittent subcutaneous (s.c.) insulin therapy (IIT) and those of healthy controls (N = 7). Regular insulin (Hoechst CS) was infused with an adapted Mill Hill Infuser at a basal infusion rate of 1.6 U/h (6:00 a.m. to 8:00 p.m.), and of 0.8 U/h from 8:00 p.m. to 6:00 a.m. Preprandial insulin (3.2-6.4 U) was added for breakfast, lunch, and dinner. Daily individual food intake totaled 7688 +/- 784 kJ (1836 +/- 187 kcal)/24 h including 184 +/- 37 g of glucose. Proper control of blood glucose (BG) (mean BG 105 +/- 10 mg/dl; mean amplitude of glycemic excursions 54 +/- 18 mg/dl; and 1 h postprandial BG levels not exceeding 160 mg/dl) and of plasma concentrations of beta-hydroxybutyrate and lactate was maintained by 41.4 +/- 4.4 U insulin/24 h. Although BG values only approximated the upper normal range as seen in healthy controls, they were well within the range reported by others during CIVII. Therefore, we conclude that in adult IDD completely devoid of endogenous insulin (1) the IPR of normal man can be used during CIVII as an estimate for the patient's minimal insulin requirement per 24 h, and (2) this approach allows for a blood glucose profile close to the upper range of a normal control group. Thus, deriving a patient's daily insulin dose from the insulin production rate of healthy man may add an additional experimental protocol which aids in making general calculations of a necessary insulin dose instead of using trial and error or a closed-loop insulin infusion system.

  4. Environmental factors and dam characteristics associated with insulin sensitivity and insulin secretion in newborn Holstein calves

    International Nuclear Information System (INIS)

    Kamal, M.M.; Van Eetvelde, M.; Bogaert, H.; Hostens, M.; Vandaele, L.; Shamsuddin, M.; Opsomer, G.

    2016-01-01

    Full text: The objective of the present retrospective cohort study was to evaluate potential associations between environmental factors and dam characteristics, including level of milk production during gestation, and insulin traits in newborn Holstein calves. Birth weight and gestational age of the calves at delivery were determined. On the next day, heart girth, wither height and diagonal length of both the calves and their dams were measured. Parity, body condition score and age at calving were recorded for all dams. For the cows, days open before last gestation, lactation length (LL), lenght of dry period (DP) and calving interval were also calculated. The magnitude and shape of the lactation curve both quantified using the MilkBot model based on monthly milk weights, were used to calculate the amount of milk produced during gestation. Using the same procedure, cumulative milk production from conception to drying off (MGEST) was calculated. A blood sample was collected from all calves (n=481; 169 born to heifers and 312 born to cows) at least 5 h after a milk meal on day 3 of life to measure basal glucose and insulin levels. In addition, an intravenous glucose-stimulated insulin secretion test was performed in a subset of the calves (n=316). After descriptive analysis, generalized linear mixed models were used to identify factors that were significantly associated with the major insulin traits (Insb, basal insulin level; QUICKI, quantitative insulin sensitivity check index; AIR, acute insulin response; DI, disposition index) of the newborn calves. The overall average birth weight of the calves was 42.7 ± 5.92 kg. The insulin traits were significantly associated with MGEST (P=0.076) and longer DP (P=0.034). The QUICKI was estimated to be lower in calves born to the cows having passed a higher MGEST (P=0.030) and longer DP (P=0.058). Moreover, the AIR (P=0.009) and DI (P=0.049) were estimated to be lower in male compared with female calves. Furthermore, the AIR

  5. [Primary study on characteristics of insulin secretion rate, metabolic clearance rate and sensitivity in non-insulin-dependent diabetic subjects from multiplex diabetic pedigrees].

    Science.gov (United States)

    Ran, J; Cheng, H; Li, F

    2000-01-01

    To investigate the characteristics of insulin secretion rate (ISR), metabolic clearance rate (MCR-I) and sensitivity and to explore their relationship with obesity in non-insulin-dependent diabetic subjects from multiplex diabetic pedigrees (MDP). Fifteen subjects with normal glucose tolerance and 11 non-insulin-dependent diabetic patients from MDP were included in the study. Frequently sampled intravenous glucose tolerance test (FSIVGTT) was performed. Glucose, insulin (INS) and connecting-peptide (C-P) concentrations were measured. A computer procedure devised by our laboratory was used to calculate the value of ISR at each time point, then MCR-I was acquired. Insulin sensitivity index (SI) was calculated according to minimal model technique about glucose in FSIVGTT. The ISR curve in control group was biphasic, while in non-insulin. In non-insulin-dependent diabetic group, areas under the curves of C-P (AUCC) and ISR level (AUCS) measured during 0 approximately 16 min were 7.9 nmol.min(-1).L(-1) +/- 2.8 nmol.min(-1).L(-1), and 6.1 nmol +/- 2.2 nmol, respectively, which were significantly lower than those in control group 17.7 nmol.min(-1).L(-1) +/- 4.92 nmol.min(-1).L(-1) and 12.3 nmol +/- 3.9 nmol (P < 0.01). The two parameters were slightly higher than those in control group 155 nmol.min(-1).L(-1) +/- 44 nmol.min(-1).L(-1) vs 101 nmol.min(-1).L(-1) +/- 30 nmol.min(-1).L(-1) and 76 nmol +/- 26 nmol vs 54 nmol +/- 20.0 nmol (P < 0.05)measured during 16 approximately 180 min. There was no significant difference, between the two groups about the amount of insulin secretion during 3 hours (82 nmol +/- 28nmol vs 68 nmol +/- 21 nmol, P = 0.2). In control group, there were significant positive correlation, between AUCS, waist-hip ratio (WHR), and body surface area, (BSA) and significant negative correlation between MCR-I, SI and WHR, BSA (P < 0.01), and also between MCR-I and SI. In non-insulin-dependent diabetic group, AUCS were significantly correlated with body mass

  6. Lipid metabolism disturbances contribute to insulin resistance and decrease insulin sensitivity by malathion exposure in Wistar rat.

    Science.gov (United States)

    Lasram, Mohamed Montassar; Bouzid, Kahena; Douib, Ines Bini; Annabi, Alya; El Elj, Naziha; El Fazaa, Saloua; Abdelmoula, Jaouida; Gharbi, Najoua

    2015-04-01

    Several studies showed that organophosphorus pesticides disturb glucose homeostasis and can increase incidence of metabolic disorders and diabetes via insulin resistance. The current study investigates the influence of malathion on glucose metabolism regulation, in vivo, during subchronic exposure. Malathion was administered orally (200 mg/kg), once a day for 28 consecutive days. Plasma glucose, insulin and Glycated hemoglobin levels were significantly increased while hepatic glycogen content was decreased in intoxicated animals compared with the control group. Furthermore, there was a significant disturbance of lipid content in subchronic treated and post-treated rats deprived of malathion for one month. In addition, we used the homeostasis model assessment (HOMA) to assess insulin resistance (HOMA-IR) and pancreatic β-cell function (HOMA-β). Our results show that malathion increases insulin resistance biomarkers and decreases insulin sensitivity indices. Statistical analysis demonstrates that there was a positive and strong significant correlation between insulin level and insulin resistance indices, HOMA-IR, HOMA-β. Similarly, a negative and significant correlation was also found between insulin level and insulin sensitivity indices. For the first time, we demonstrate that malathion induces insulin resistance in vivo using homeostasis model assessment and these changes were detectable one month after the end of exposure. To explain insulin resistance induced by malathion we focus on lipid metabolism disturbances and their interaction with many proteins involved in insulin signaling pathways.

  7. Diabetes mellitus and insulin in an aspirin sensitive asthmatic.

    Science.gov (United States)

    Caplin, I

    1976-03-01

    The infrequency of diabetes mellitus and asthma in the same individual is re-examined. The antagonism between epinephrine and insulin, as suggested by Konig in 1935, is indeed accurate. The assays done by the Eli Lilly Research Department revealed no in vitro effect of insulin on the CAMP and GMP level of mast cells as occurs in liver cells. It is felt that this effect is probably an in vivo effect produced via the vagus nerve and alpha-adrenergic receptor system stimulation. This would explain the mechanism of aggravation of asthma by excess insulin. Dr. Petersen's studies, the negative intradermal skin tests to insulin and the absence of change on either beef or pork insulin usage by our patient all point to a nonatopic factor in the aggravation of the asthma of this patient. In the uncommon occurrence of asthma and diabetes in the same patient, insulin dosage should be considered as a factor in all such asthmatics who do not respond well to conventional therapy. Two additional asthmatics who also have diabetes did improve with cessation of nocturnal asthma by a reduction of their evening dose of insulin. A high fat, low carbohydrate diet, as suggested by Abrahamson to avoid dietary hyperinsulinism, is certainly worth considering in patients with nocturnal asthma. If patients cannot be made to follow a diet requiring frequent feedings high in protein and fats and low in carbohydrates, another approach suggests itself. Abrahamson was able to relieve the patients who developed nocturnal asthma with hypoglycemia by having them drink a glass of milk. Assuming other causes have been eliminated and a patient awakens each day at 3:00 a.m., an alarm clock could be set at 2:00 a.m. Milk or a milk substitute in milk sensitive patients could be taken at 2:00 a.m. to raise the blood sugar and hopefully prevent the asthma associated with hypoglycemia. Also to be noted is the ubiquitous use of tartrazine in so many drugs, including those used to relieve asthmatic symptoms

  8. Trajectories of glycaemia, insulin sensitivity and insulin secretion in South Asian and white individuals before diagnosis of type 2 diabetes

    DEFF Research Database (Denmark)

    Hulman, Adam; Simmons, Rebecca K; Brunner, Eric J

    2017-01-01

    AIMS/HYPOTHESIS: South Asian individuals have reduced insulin sensitivity and increased risk of type 2 diabetes compared with white individuals. Temporal changes in glycaemic traits during middle age suggest that impaired insulin secretion is a particular feature of diabetes development among South...... Asians. We therefore aimed to examine ethnic differences in early changes in glucose metabolism prior to incident type 2 diabetes. METHODS: In a prospective British occupational cohort, subject to 5 yearly clinical examinations, we examined ethnic differences in trajectories of fasting plasma glucose...... (FPG), 2 h post-load plasma glucose (2hPG), fasting serum insulin (FSI), 2 h post-load serum insulin (2hSI), HOMA of insulin sensitivity (HOMA2-S) and secretion (HOMA2-B), and the Gutt insulin sensitivity index (ISI0,120) among 120 South Asian and 867 white participants who developed diabetes during...

  9. New measure of insulin sensitivity predicts cardiovascular disease better than HOMA estimated insulin resistance.

    Directory of Open Access Journals (Sweden)

    Kavita Venkataraman

    Full Text Available CONTEXT: Accurate assessment of insulin sensitivity may better identify individuals at increased risk of cardio-metabolic diseases. OBJECTIVES: To examine whether a combination of anthropometric, biochemical and imaging measures can better estimate insulin sensitivity index (ISI and provide improved prediction of cardio-metabolic risk, in comparison to HOMA-IR. DESIGN AND PARTICIPANTS: Healthy male volunteers (96 Chinese, 80 Malay, 77 Indian, 21 to 40 years, body mass index 18-30 kg/m(2. Predicted ISI (ISI-cal was generated using 45 randomly selected Chinese through stepwise multiple linear regression, and validated in the rest using non-parametric correlation (Kendall's tau τ. In an independent longitudinal cohort, ISI-cal and HOMA-IR were compared for prediction of diabetes and cardiovascular disease (CVD, using ROC curves. SETTING: The study was conducted in a university academic medical centre. OUTCOME MEASURES: ISI measured by hyperinsulinemic euglycemic glucose clamp, along with anthropometric measurements, biochemical assessment and imaging; incident diabetes and CVD. RESULTS: A combination of fasting insulin, serum triglycerides and waist-to-hip ratio (WHR provided the best estimate of clamp-derived ISI (adjusted R(2 0.58 versus 0.32 HOMA-IR. In an independent cohort, ROC areas under the curve were 0.77±0.02 ISI-cal versus 0.76±0.02 HOMA-IR (p>0.05 for incident diabetes, and 0.74±0.03 ISI-cal versus 0.61±0.03 HOMA-IR (p<0.001 for incident CVD. ISI-cal also had greater sensitivity than defined metabolic syndrome in predicting CVD, with a four-fold increase in the risk of CVD independent of metabolic syndrome. CONCLUSIONS: Triglycerides and WHR, combined with fasting insulin levels, provide a better estimate of current insulin resistance state and improved identification of individuals with future risk of CVD, compared to HOMA-IR. This may be useful for estimating insulin sensitivity and cardio-metabolic risk in clinical and

  10. Effect of chloroquine on insulin and glucose homoeostasis in normal subjects and patients with non-insulin-dependent diabetes mellitus.

    Science.gov (United States)

    Smith, G D; Amos, T A; Mahler, R; Peters, T J

    1987-01-01

    Plasma glucose, insulin, and C peptide concentrations were determined after an oral glucose load in normal subjects and in a group of patients with non-insulin-dependent diabetes mellitus before and during a short course of treatment with chloroquine. In the control group there was a small but significant reduction in fasting blood glucose concentration but overall glucose tolerance and hormone concentrations were unaffected. In contrast, the patients with non-insulin-dependent diabetes mellitus showed a significant improvement in their glucose tolerance, which paralleled the severity of their diabetes. This response seems to reflect decreased degradation of insulin rather than increased pancreatic output. These observations suggest that treatment with chloroquine or suitable analogues may be a new approach to the management of diabetes. PMID:3103729

  11. APPL1 potentiates insulin sensitivity by facilitating the binding of IRS1/2 to the insulin receptor.

    Science.gov (United States)

    Ryu, Jiyoon; Galan, Amanda K; Xin, Xiaoban; Dong, Feng; Abdul-Ghani, Muhammad A; Zhou, Lijun; Wang, Changhua; Li, Cuiling; Holmes, Bekke M; Sloane, Lauren B; Austad, Steven N; Guo, Shaodong; Musi, Nicolas; DeFronzo, Ralph A; Deng, Chuxia; White, Morris F; Liu, Feng; Dong, Lily Q

    2014-05-22

    Binding of insulin receptor substrate proteins 1 and 2 (IRS1/2) to the insulin receptor (IR) is essential for the regulation of insulin sensitivity and energy homeostasis. However, the mechanism of IRS1/2 recruitment to the IR remains elusive. Here, we identify adaptor protein APPL1 as a critical molecule that promotes IRS1/2-IR interaction. APPL1 forms a complex with IRS1/2 under basal conditions, and this complex is then recruited to the IR in response to insulin or adiponectin stimulation. The interaction between APPL1 and IR depends on insulin- or adiponectin-stimulated APPL1 phosphorylation, which is greatly reduced in insulin target tissues in obese mice. appl1 deletion in mice consistently leads to systemic insulin resistance and a significant reduction in insulin-stimulated IRS1/2, but not IR, tyrosine phosphorylation, indicating that APPL1 sensitizes insulin signaling by acting at a site downstream of the IR. Our study uncovers a mechanism regulating insulin signaling and crosstalk between the insulin and adiponectin pathways. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  12. New measure of insulin sensitivity predicts cardiovascular disease better than HOMA estimated insulin resistance.

    Science.gov (United States)

    Venkataraman, Kavita; Khoo, Chin Meng; Leow, Melvin K S; Khoo, Eric Y H; Isaac, Anburaj V; Zagorodnov, Vitali; Sadananthan, Suresh A; Velan, Sendhil S; Chong, Yap Seng; Gluckman, Peter; Lee, Jeannette; Salim, Agus; Tai, E Shyong; Lee, Yung Seng

    2013-01-01

    Accurate assessment of insulin sensitivity may better identify individuals at increased risk of cardio-metabolic diseases. To examine whether a combination of anthropometric, biochemical and imaging measures can better estimate insulin sensitivity index (ISI) and provide improved prediction of cardio-metabolic risk, in comparison to HOMA-IR. Healthy male volunteers (96 Chinese, 80 Malay, 77 Indian), 21 to 40 years, body mass index 18-30 kg/m(2). Predicted ISI (ISI-cal) was generated using 45 randomly selected Chinese through stepwise multiple linear regression, and validated in the rest using non-parametric correlation (Kendall's tau τ). In an independent longitudinal cohort, ISI-cal and HOMA-IR were compared for prediction of diabetes and cardiovascular disease (CVD), using ROC curves. The study was conducted in a university academic medical centre. ISI measured by hyperinsulinemic euglycemic glucose clamp, along with anthropometric measurements, biochemical assessment and imaging; incident diabetes and CVD. A combination of fasting insulin, serum triglycerides and waist-to-hip ratio (WHR) provided the best estimate of clamp-derived ISI (adjusted R(2) 0.58 versus 0.32 HOMA-IR). In an independent cohort, ROC areas under the curve were 0.77±0.02 ISI-cal versus 0.76±0.02 HOMA-IR (p>0.05) for incident diabetes, and 0.74±0.03 ISI-cal versus 0.61±0.03 HOMA-IR (pHOMA-IR. This may be useful for estimating insulin sensitivity and cardio-metabolic risk in clinical and epidemiological settings.

  13. Adipocyte-specific blockade of gamma-secretase, but not inhibition of Notch activity, reduces adipose insulin sensitivity

    Directory of Open Access Journals (Sweden)

    David P. Sparling

    2016-02-01

    Full Text Available Objective: As the obesity pandemic continues to expand, novel molecular targets to reduce obesity-related insulin resistance and Type 2 Diabetes (T2D continue to be needed. We have recently shown that obesity is associated with reactivated liver Notch signaling, which, in turn, increases hepatic insulin resistance, opening up therapeutic avenues for Notch inhibitors to be repurposed for T2D. Herein, we tested the systemic effects of γ-secretase inhibitors (GSIs, which prevent endogenous Notch activation, and confirmed these effects through creation and characterization of two different adipocyte-specific Notch loss-of-function mouse models through genetic ablation of the Notch transcriptional effector Rbp-Jk (A-Rbpj and the obligate γ-secretase component Nicastrin (A-Nicastrin. Methods: Glucose homeostasis and both local adipose and systemic insulin sensitivity were examined in GSI-treated, A-Rbpj and A-Nicastrin mice, as well as vehicle-treated or control littermates, with complementary in vitro studies in primary hepatocytes and 3T3-L1 adipocytes. Results: GSI-treatment increases hepatic insulin sensitivity in obese mice but leads to reciprocal lowering of adipose glucose disposal. While A-Rbpj mice show normal body weight, adipose development and mass and unchanged adipose insulin sensitivity as control littermates, A-Nicastrin mice are relatively insulin-resistant, mirroring the GSI effect on adipose insulin action. Conclusions: Notch signaling is dispensable for normal adipocyte function, but adipocyte-specific γ-secretase blockade reduces adipose insulin sensitivity, suggesting that specific Notch inhibitors would be preferable to GSIs for application in T2D. Keywords: Notch, γ-secretase complex, Insulin resistance

  14. Synergistic effects of metformin, resveratrol, and hydroxymethylbutyrate on insulin sensitivity

    Directory of Open Access Journals (Sweden)

    Bruckbauer A

    2013-02-01

    Full Text Available Antje Bruckbauer,1 Michael B Zemel1,21NuSirt Sciences Inc, 2Department of Nutrition, University of Tennessee, Knoxville, TN, USABackground: The purpose of this study was to determine whether a mixture of the polyphenol, resveratrol, and the leucine metabolite, hydroxymethylbutyrate (HMB, acts synergistically with low doses of metformin to impact insulin sensitivity and AMP-activated protein kinase-dependent outcomes in cell culture and in diabetic mice.Methods: C2C12 skeletal myotubes and 3T3-L1 adipocytes were treated with resveratrol 0.2 µM, HMB 5 µM, and metformin 0.1 mM alone or in combination. db/db mice were treated for 2 weeks with high (1.5 g/kg diet, low (0.75 g/kg diet, or very low (0.25 g/kg diet doses of metformin alone or in combination with a diet containing resveratrol 12.5 mg and CaHMB 2 g/kg.Results: The combination of metformin-resveratrol-HMB significantly increased fat oxidation, AMP-activated protein kinase, and Sirt1 activity in muscle cells compared with metformin or resveratrol-HMB alone. A similar trend was found in 3T3L1 adipocytes. In mice, the two lower doses of metformin exerted no independent effect but, when combined with resveratrol-HMB, both low-dose and very low-dose metformin improved insulin sensitivity (HOMAIR, plasma insulin levels, and insulin tolerance test response to a level comparable with that found for high-dose metformin. In addition, the metformin-resveratrol-HMB combination decreased visceral fat and liver weight in mice.Conclusion: Resveratrol-HMB combined with metformin may act synergistically on AMP-activated protein kinase-dependent pathways, leading to increased insulin sensitivity, which may reduce the therapeutic doses of metformin necessary in the treatment of diabetes.Keywords: diabetes, AMP-activated protein kinase, Sirt1, fat oxidation

  15. Phospholipid environment alters hormone-sensitivity of the purified insulin receptor kinase.

    OpenAIRE

    Lewis, R E; Czech, M P

    1987-01-01

    Insulin receptor kinase, affinity-purified by adsorption and elution from immobilized insulin, is stimulated 2-3-fold by insulin in detergent solution. Reconstitution of the receptor kinase into leaky vesicles containing phosphatidylcholine and phosphatidylethanolamine (1:1, w/w) by detergent removal on Sephadex G-50 results in the complete loss of receptor kinase sensitivity to activation by insulin. Insulin receptors in these vesicles also exhibit an increase in their apparent affinity for ...

  16. Altered Fetal Skeletal Muscle Nutrient Metabolism Following an Adverse In Utero Environment and the Modulation of Later Life Insulin Sensitivity

    Directory of Open Access Journals (Sweden)

    Kristyn Dunlop

    2015-02-01

    Full Text Available The importance of the in utero environment as a contributor to later life metabolic disease has been demonstrated in both human and animal studies. In this review, we consider how disruption of normal fetal growth may impact skeletal muscle metabolic development, ultimately leading to insulin resistance and decreased insulin sensitivity, a key precursor to later life metabolic disease. In cases of intrauterine growth restriction (IUGR associated with hypoxia, where the fetus fails to reach its full growth potential, low birth weight (LBW is often the outcome, and early in postnatal life, LBW individuals display modifications in the insulin-signaling pathway, a critical precursor to insulin resistance. In this review, we will present literature detailing the classical development of insulin resistance in IUGR, but also discuss how this impaired development, when challenged with a postnatal Western diet, may potentially contribute to the development of later life insulin resistance. Considering the important role of the skeletal muscle in insulin resistance pathogenesis, understanding the in utero programmed origins of skeletal muscle deficiencies in insulin sensitivity and how they may interact with an adverse postnatal environment, is an important step in highlighting potential therapeutic options for LBW offspring born of pregnancies characterized by placental insufficiency.

  17. Altered fetal skeletal muscle nutrient metabolism following an adverse in utero environment and the modulation of later life insulin sensitivity.

    Science.gov (United States)

    Dunlop, Kristyn; Cedrone, Megan; Staples, James F; Regnault, Timothy R H

    2015-02-12

    The importance of the in utero environment as a contributor to later life metabolic disease has been demonstrated in both human and animal studies. In this review, we consider how disruption of normal fetal growth may impact skeletal muscle metabolic development, ultimately leading to insulin resistance and decreased insulin sensitivity, a key precursor to later life metabolic disease. In cases of intrauterine growth restriction (IUGR) associated with hypoxia, where the fetus fails to reach its full growth potential, low birth weight (LBW) is often the outcome, and early in postnatal life, LBW individuals display modifications in the insulin-signaling pathway, a critical precursor to insulin resistance. In this review, we will present literature detailing the classical development of insulin resistance in IUGR, but also discuss how this impaired development, when challenged with a postnatal Western diet, may potentially contribute to the development of later life insulin resistance. Considering the important role of the skeletal muscle in insulin resistance pathogenesis, understanding the in utero programmed origins of skeletal muscle deficiencies in insulin sensitivity and how they may interact with an adverse postnatal environment, is an important step in highlighting potential therapeutic options for LBW offspring born of pregnancies characterized by placental insufficiency.

  18. Stevioside from Stevia rebaudiana Bertoni Increases Insulin Sensitivity in 3T3-L1 Adipocytes

    Directory of Open Access Journals (Sweden)

    Nabilatul Hani Mohd-Radzman

    2013-01-01

    Full Text Available Stevioside from Stevia rebaudiana has been reported to exert antihyperglycemic effects in both rat and human subjects. There have been few studies on these effects in vitro. In this paper, radioactive glucose uptake assay was implemented in order to assess improvements in insulin sensitivity in 3T3-L1 cells by elevation of glucose uptake following treatment with stevioside. Oil Red-O staining and MTT assay were utilized to confirm adipocyte differentiation and cell viability, respectively. Findings from this research showed a significant increase in absorbance values in mature adipocytes following Oil Red-O staining, confirming the differentiation process. Stevioside was noncytotoxic to 3T3-L1 cells as cell viability was reduced by a maximum of 17%, making it impossible to determine its IC50. Stevioside increased glucose uptake activities by 2.1 times (p<0.001 in normal conditions and up to 4.4 times (p<0.001 in insulin-resistant states. At times, this increase was higher than that seen in positive control group treated with rosiglitazone maleate, an antidiabetic agent. Expressions of pY20 and p-IRS1 which were measured via Western blot were improved by stevioside treatment. In conclusion, stevioside has direct effects on 3T3-L1 insulin sensitivity via increase in glucose uptake and enhanced expression of proteins involved in insulin-signalling pathway.

  19. Effect of Artemisia dracunculus Administration on Glycemic Control, Insulin Sensitivity, and Insulin Secretion in Patients with Impaired Glucose Tolerance.

    Science.gov (United States)

    Méndez-Del Villar, Miriam; Puebla-Pérez, Ana M; Sánchez-Peña, María J; González-Ortiz, Luis J; Martínez-Abundis, Esperanza; González-Ortiz, Manuel

    2016-05-01

    To evaluate the effect of Artemisia dracunculus on glycemic control, insulin sensitivity, and insulin secretion in patients with impaired glucose tolerance (IGT). A randomized, double blind, placebo-controlled clinical trial was performed in 24 patients with diagnosis of IGT. Before and after the intervention, glucose and insulin levels were measured every 30 min for 2 h after a 75-g dextrose load, along with glycated hemoglobin A1c (A1C) and lipid profile. Twelve patients received A. dracunculus (1000 mg) before breakfast and dinner for 90 days; the remaining 12 patients received placebo. Area under the curve (AUC) of glucose and insulin, total insulin secretion, first phase of insulin secretion, and insulin sensitivity were calculated. Wilcoxon signed-rank, Mann-Whitney U, and chi-square tests were used for statistical analyses. The institutional ethics committee approved the protocol. After A. dracunculus administration, there were significant decreases in systolic blood pressure (SBP; 120.0 ± 11.3 vs. 113.0 ± 11.2 mmHg, P AUC of insulin (56,136.0 ± 27,426.0 vs. 44,472.0 ± 23,370.0 pmol/L, P AUC of insulin, and total insulin secretion with a significant increase in HDL-C levels.

  20. Intralipid decreases apolipoprotein M levels and insulin sensitivity in rats.

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    Lu Zheng

    Full Text Available BACKGROUND: Apolipoprotein M (ApoM is a constituent of high-density lipoproteins (HDL. It plays a crucial role in HDL-mediated reverse cholesterol transport. Insulin resistance is associated with decreased ApoM levels. AIMS: To assess the effects of increased free fatty acids (FFAs levels after short-term Intralipid infusion on insulin sensitivity and hepatic ApoM gene expression. METHODS: Adult male Sprague-Dawley (SD rats infused with 20% Intralipid solution for 6 h. Glucose infusion rates (GIR were determined by hyperinsulinemic-euglycemic clamp during Intralipid infusion and plasma FFA levels were measured by colorimetry. Rats were sacrificed after Intralipid treatment and livers were sampled. Human embryonic kidney 293T cells were transfected with a lentivirus mediated human apoM overexpression system. Goto-Kakizaki (GK rats were injected with the lentiviral vector and insulin tolerance was assessed. Gene expression was assessed by real-time RT-PCR and PCR array. RESULTS: Intralipid increased FFAs by 17.6 folds and GIR was decreased by 27.1% compared to the control group. ApoM gene expression was decreased by 40.4% after Intralipid infusion. PPARβ/δ expression was not changed by Intralipid. Whereas the mRNA levels of Acaca, Acox1, Akt1, V-raf murine sarcoma 3611 viral oncogene homolog, G6pc, Irs2, Ldlr, Map2k1, pyruvate kinase and RBC were significantly increased in rat liver after Intralipid infusion. The Mitogen-activated protein kinase 8 (MAPK8 was significantly down-regulated in 293T cells overexpressing ApoM. Overexpression of human ApoM in GK rats could enhance the glucose-lowering effect of exogenous insulin. CONCLUSION: These results suggest that Intralipid could decrease hepatic ApoM levels. ApoM overexpression may have a potential role in improving insulin resistance in vivo and modulating apoM expression might be a future therapeutic strategy against insulin resistance in type 2 diabetes.

  1. Clustering effects on postprandial insulin secretion and sensitivity in response to meals with different fatty acid compositions.

    Science.gov (United States)

    Bermudez, Beatriz; Ortega-Gomez, Almudena; Varela, Lourdes M; Villar, Jose; Abia, Rocio; Muriana, Francisco J G; Lopez, Sergio

    2014-07-25

    Dietary fatty acids play a role in glucose homeostasis. The aim of this study was to assess the individual relationship between dietary saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids with postprandial β-cell function and insulin sensitivity in subjects with normal and high fasting triglycerides. We assessed postprandial β-cell function (by the insulinogenic index and the ratio of the insulin to glucose areas under the time-concentration curve) and insulin sensitivity (by the oral glucose and the minimal model insulin sensitivity indices) over four nonconsecutive, randomly assigned, high-fat meals containing a panel of SFA (palmitic and stearic acids), MUFA (palmitoleic and oleic acids) and PUFA (linoleic and α-linolenic acids) in 14 subjects with normal and in 14 subjects with high fasting triglycerides. The proportions of each fatty acid in the meals and the values for surrogate measures of postprandial β-cell function and insulin sensitivity were subjected to a Pearson correlation and hierarchical cluster analysis, which revealed two classes of dietary fatty acids for regulating postprandial glucose homeostasis. We successfully discriminated the adverse effects of SFA palmitic acid from the beneficial effects of MUFA oleic acid on postprandial β-cell function (r ≥ 0.84 for SFA palmitic acid and r ≥ -0.71 for MUFA oleic acid; P < 0.05) and insulin sensitivity (r ≥ -0.92 for SFA palmitic acid and r ≥ 0.89 for MUFA oleic acid; P < 0.001) both in subjects with normal and high fasting triglycerides. In conclusion, dietary MUFA oleic acid, in contrast to SFA palmitic acid, favours the tuning towards better postprandial glycaemic control in subjects with normal and high fasting triglycerides.

  2. FENOFIBRATE ADMINISTRATION DOES NOT AFFECT MUSCLE TRIGLYCERIDE CONCENTRATION OR INSULIN SENSITIVITY IN HUMANS

    Science.gov (United States)

    Perreault, Leigh; Bergman, Bryan C.; Hunerdosse, Devon M.; Howard, David J.; Eckel, Robert H.

    2010-01-01

    Objective Animal data suggest that males, in particular, rely on PPAR-α activity to maintain normal muscle triglyceride metabolism. We sought to examine whether this was also true in men vs. women and its relationship to insulin sensitivity. Materials/Methods Normolipidemic obese men (n=9) and women (n=9) underwent an assessment of insulin sensitivity (IVGTT) and intramuscular triglyceride metabolism (GC/MS and GC/C/IRMS from plasma and muscle biopsies taken after infusion of [U-13C]palmitate) before and after 12 weeks of fenofibrate treatment. Results Women were more insulin sensitive (Si; 5.2(0.7 vs. 2.4(0.4 ×10−4/uU/ml, W vs. M, ptriglyceride (IMTG) concentration (41.9(15.5 vs. 30.8(5.1 ug/mg dry weight, W vs. M, p=0.43), and IMTG fractional synthesis rate (FSR; 0.27(0.07 vs. 0.35(0.06/hr, W vs. M, p=0.41) as men. Fenofibrate enhanced FSR in men (0.35(0.06 to 0.54(0.06, p=0.05), with no such change seen in women (0.27(0.07 to 0.32(0.13, p=0.73), and no change in IMTG concentration in either group (23.0(3.9 in M, p=0.26 vs. baseline; 36.3(12.0 in W, p=0.79 vs. baseline). Insulin sensitivity was unaffected by fenofibrate (p>0.68). Lower percent saturation of IMTG in women vs. men before (29.1(2.3 vs. 35.2(1.7%, p=0.06) and after (27.3(2.8 vs. 35.1(1.9%, p=0.04) fenofibrate most closely related to their greater insulin sensitivity (R2=0.34, p=0.10), and was largely unchanged by the drug. Conclusions PPAR-α agonist therapy had little effect on IMTG metabolism in men or women. IMTG saturation, rather than IMTG concentration or FSR, most closely (but not significantly) related to insulin sensitivity and was unchanged by fenofibrate administration. PMID:21306746

  3. 2-deoxyglucose tissue levels and insulin levels following tolazamide dosing in normal and obese mice

    International Nuclear Information System (INIS)

    Skillman, C.A.; Fletcher, H.P.

    1986-01-01

    The effect of tolazamide (TZ), a sulfonylurea, on 14 C-2-deoxyglucose ( 14 C-2DG) tissue distribution and insulin levels of normal and obese mice was investigated using an in vivo physiological method. Acute doses of TZ (50 mg/kg ip) increased 14 C-2DG levels in gastrocnemius muscle and retroperitoneal fat and produced a transient elevation of insulin which most likely accounts for the increased 14 C-2DG levels in muscle and fat. The results demonstrate that the in vivo 14 C-2DG method produced results consistent with known actions of sulfonylureas on in vitro hexose assimilation in muscle and fat. Subchronic treatment (7 days) with TZ 50 mg/kg ip twice daily did not result in increased insulin-stimulated 14 C-2DG tissue levels in normal mice when compared to saline treated controls. However, insulin levels were lower in mice treated subchronically with TZ compared to saline controls suggesting an enhancement of insulin action. Viable yellow obese mice represent a model of maturity onset obesity presenting with insulin resistance. The insulin resistance of this obese strain appears to reside in the fat tissue as assessed by comparing 14 C-2DG tissue levels of obese mice with lean littermate controls. Subchronic TZ treatment had no effect on 14 C-2DG uptake in fat or muscle tissue of viable yellow obese mice and did not alter their plasma insulin levels. It appears that genetically obese viable mice may be resistant to subchronic treatment with TZ. (author)

  4. Acute insulin resistance stimulates and insulin sensitization attenuates vascular smooth muscle cell migration and proliferation.

    Science.gov (United States)

    Cersosimo, Eugenio; Xu, Xiaojing; Upala, Sikarin; Triplitt, Curtis; Musi, Nicolas

    2014-08-01

    Differential activation/deactivation of insulin signaling, PI-3K and MAP-K pathways by high glucose and palmitate, with/out the insulin sensitizer pioglitazone (PIO), have been previously shown in vascular smooth muscle cells (VSMCs). To determine the biological impact of these molecular changes, we examined VSMC migration and proliferation ("M"&"P") patterns in similar conditions. VSMCs from healthy human coronary arteries were incubated in growth medium and "M"&"P" were analyzed after exposure to high glucose (25 mmol/L) ± palmitate (200 μmol/L) and ± PIO (8 μmol/L) for 5 h. "M"&"P" were assessed by: (1) polycarbonate membrane barrier with chemo-attractants and extended cell protrusions quantified by optical density (OD595 nm); (2) % change in radius area (2D Assay) using inverted microscopy images; and (3) cell viability assay expressed as cell absorbance (ABS) in media. "M" in 25 mmol/L glucose media increased by ~25% from baseline and % change in radius area rose from ~20% to ~30%. The addition of PIO was accompanied by a significant decrease in "M" from 0.25 ± 0.02 to 0.19 ± 0.02; a comparable decline from 0.25 ± 0.02 to 0.18 ± 0.02 was also seen with 25 mmol/L of glucose +200 μmol/L of palmitate. When PIO was coincubated with high glucose plus palmitate there was a 50% reduction in % change in radius. A ~10% increase in ABS, reflecting augmented "P" in media with 25 mmol/L glucose versus control was documented. The addition of PIO reduced ABS from 0.208 ± 0.03 to 0.183 ± 0.06. Both high glucose and palmitate showed ABS of ~0.140 ± 0.02, which decreased with PIO to ~0.120 ± 0.02, indicating "P" was reduced. These results confirm that high glucose and palmitate stimulate VSMCs migration and proliferation in vitro, which is attenuated by coincubation with the insulin sensitizer PIO. Although, we cannot ascertain whether these functional changes are coincident with the activation/deactivation of signal molecules, our findings are consistent with the

  5. Stimulatory effect of insulin on glucose uptake by muscle involves the central nervous system in insulin-sensitive mice.

    Science.gov (United States)

    Coomans, Claudia P; Biermasz, Nienke R; Geerling, Janine J; Guigas, Bruno; Rensen, Patrick C N; Havekes, Louis M; Romijn, Johannes A

    2011-12-01

    Insulin inhibits endogenous glucose production (EGP) and stimulates glucose uptake in peripheral tissues. Hypothalamic insulin signaling is required for the inhibitory effects of insulin on EGP. We examined the contribution of central insulin signaling on circulating insulin-stimulated tissue-specific glucose uptake. Tolbutamide, an inhibitor of ATP-sensitive K(+) channels (K(ATP) channels), or vehicle was infused into the lateral ventricle in the basal state and during hyperinsulinemic-euglycemic conditions in postabsorptive, chow-fed C57Bl/6J mice and in postabsorptive C57Bl/6J mice with diet-induced obesity. Whole-body glucose uptake was measured by d-[(14)C]glucose kinetics and tissue-specific glucose uptake by 2-deoxy-d-[(3)H]glucose uptake. During clamp conditions, intracerebroventricular administration of tolbutamide impaired the ability of insulin to inhibit EGP by ∼20%. In addition, intracerebroventricular tolbutamide diminished insulin-stimulated glucose uptake in muscle (by ∼59%) but not in heart or adipose tissue. In contrast, in insulin-resistant mice with diet-induced obesity, intracerebroventricular tolbutamide did not alter the effects of insulin during clamp conditions on EGP or glucose uptake by muscle. Insulin stimulates glucose uptake in muscle in part through effects via K(ATP) channels in the central nervous system, in analogy with the inhibitory effects of insulin on EGP. High-fat diet-induced obesity abolished the central effects of insulin on liver and muscle. These observations stress the role of central insulin resistance in the pathophysiology of diet-induced insulin resistance.

  6. 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.

  7. Plerocercoid growth factor (PGF), a human growth hormone (hGH) analogue produced by the tapeworm Spirometra mansonoides, has direct insulin-like action in adipose tissue of normal rats in vitro

    International Nuclear Information System (INIS)

    Salem, M.A.M.; Phares, C.K.

    1986-01-01

    The metabolic actions of GH can be divided into acute (insulin-like) and chronic (lipolytic/anti-insulin). The insulin-like actions of GH are most readily elicited in GH-deficient animals as GH induces resistance to its own insulin-like action. Like GH, PGF stimulates growth and cross-reacts with anti-hGH antibodies. Independent experiments were conducted comparing the direct actions of PGF to insulin or hGH in vitro. Insulin-like effects were determined by the ability of PGF, insulin or hGH to stimulate [U- 14 C]glucose metabolism in epidydimal fat pads from normal rats and by inhibition of epinephrine-stimulated lipolysis. Direct stimulation of lipolysis was used as anti-insulin activity. To determine if PGF competes for insulin or GH receptors, adipocytes (3 x 10 5 cells/ml) were incubated with either [ 125 I]insulin or [ 125 I]hGH +/- PGF, +/- insulin or +/- hGH. PGF stimulated glucose oxidation and 14 C-incorporation into lipids. Insulin, hGH and PGF inhibited lipolysis (33%, 29% and 34%, respectively). Adipose tissue was very sensitive to the lipolytic effect of hGH but PGF was neither lipolytic nor did it confer refractoriness to its insulin-like action. PGF bound to GH but not to insulin receptors. Therefore, PGF had direct insulin-like effects but did not stimulate lipolysis in tissue from normal rats in vitro

  8. Effects of glucose, insulin, and insulin resistance on cerebral 18F-FDG distribution in cognitively normal older subjects

    Science.gov (United States)

    Onishi, Airin; Fujiwara, Yoshinori; Ishiwata, Kiichi; Ishii, Kenji

    2017-01-01

    Background Increasing plasma glucose levels and insulin resistance can alter the distribution pattern of fluorine-18-labeled fluorodeoxyglucose (18F-FDG) in the brain and relatively reduce 18F-FDG uptake in Alzheimer's disease (AD)-related hypometabolic regions, leading to the appearance of an AD-like pattern. However, its relationship with plasma insulin levels is unclear. We aimed to compare the effects of plasma glucose levels, plasma insulin levels and insulin resistance on the appearance of the AD-like pattern in 18F-FDG images. Methods Fifty-nine cognitively normal older subjects (age = 75.7 ± 6.4 years) underwent 18F-FDG positron emission tomography along with measurement of plasma glucose and insulin levels. As an index of insulin resistance, the Homeostasis model assessment of Insulin Resistance (HOMA-IR) was calculated. Results Plasma glucose levels, plasma insulin levels, and HOMA-IR were 102.2 ± 8.1 mg/dL, 4.1 ± 1.9 μU/mL, and 1.0 ± 0.5, respectively. Whole-brain voxelwise analysis showed a negative correlation of 18F-FDG uptake with plasma glucose levels in the precuneus and lateral parietotemporal regions (cluster-corrected p < 0.05), and no correlation with plasma insulin levels or HOMA-IR. In the significant cluster, 18F-FDG uptake decreased by approximately 4–5% when plasma glucose levels increased by 20 mg/dL. In the precuneus region, volume-of-interest analysis confirmed a negative correlation of 18F-FDG uptake with plasma glucose levels (r = -0.376, p = 0.002), and no correlation with plasma insulin levels (r = 0.156, p = 0.12) or HOMA-IR (r = 0.096, p = 0.24). Conclusion This study suggests that, of the three parameters, plasma glucose levels have the greatest effect on the appearance of the AD-like pattern in 18F-FDG images. PMID:28715453

  9. Effects of glucose, insulin, and insulin resistance on cerebral 18F-FDG distribution in cognitively normal older subjects.

    Directory of Open Access Journals (Sweden)

    Kenji Ishibashi

    Full Text Available Increasing plasma glucose levels and insulin resistance can alter the distribution pattern of fluorine-18-labeled fluorodeoxyglucose (18F-FDG in the brain and relatively reduce 18F-FDG uptake in Alzheimer's disease (AD-related hypometabolic regions, leading to the appearance of an AD-like pattern. However, its relationship with plasma insulin levels is unclear. We aimed to compare the effects of plasma glucose levels, plasma insulin levels and insulin resistance on the appearance of the AD-like pattern in 18F-FDG images.Fifty-nine cognitively normal older subjects (age = 75.7 ± 6.4 years underwent 18F-FDG positron emission tomography along with measurement of plasma glucose and insulin levels. As an index of insulin resistance, the Homeostasis model assessment of Insulin Resistance (HOMA-IR was calculated.Plasma glucose levels, plasma insulin levels, and HOMA-IR were 102.2 ± 8.1 mg/dL, 4.1 ± 1.9 μU/mL, and 1.0 ± 0.5, respectively. Whole-brain voxelwise analysis showed a negative correlation of 18F-FDG uptake with plasma glucose levels in the precuneus and lateral parietotemporal regions (cluster-corrected p < 0.05, and no correlation with plasma insulin levels or HOMA-IR. In the significant cluster, 18F-FDG uptake decreased by approximately 4-5% when plasma glucose levels increased by 20 mg/dL. In the precuneus region, volume-of-interest analysis confirmed a negative correlation of 18F-FDG uptake with plasma glucose levels (r = -0.376, p = 0.002, and no correlation with plasma insulin levels (r = 0.156, p = 0.12 or HOMA-IR (r = 0.096, p = 0.24.This study suggests that, of the three parameters, plasma glucose levels have the greatest effect on the appearance of the AD-like pattern in 18F-FDG images.

  10. The Effect of a Diet Moderately High in Protein and Fiber on Insulin Sensitivity Measured Using the Dynamic Insulin Sensitivity and Secretion Test (DISST

    Directory of Open Access Journals (Sweden)

    Lisa Te Morenga

    2017-11-01

    Full Text Available Evidence shows that weight loss improves insulin sensitivity but few studies have examined the effect of macronutrient composition independently of weight loss on direct measures of insulin sensitivity. We randomised 89 overweight or obese women to either a standard diet (StdD, that was intended to be low in fat and relatively high in carbohydrate (n = 42 or to a relatively high protein (up to 30% of energy, relatively high fibre (>30 g/day diet (HPHFib (n = 47 for 10 weeks. Advice regarding strict adherence to energy intake goals was not given. Insulin sensitivity and secretion was assessed by a novel method—the Dynamic Insulin Sensitivity and Secretion Test (DISST. Although there were significant improvements in body composition and most cardiometabolic risk factors on HPHFib, insulin sensitivity was reduced by 19.3% (95% CI: 31.8%, 4.5%; p = 0.013 in comparison with StdD. We conclude that the reduction in insulin sensitivity after a diet relatively high in both protein and fibre, despite cardiometabolic improvements, suggests insulin sensitivity may reflect metabolic adaptations to dietary composition for maintenance of glucose homeostasis, rather than impaired metabolism.

  11. Insulin resistance in dairy cows.

    Science.gov (United States)

    De Koster, Jenne D; Opsomer, Geert

    2013-07-01

    Glucose is the molecule that drives milk production, and insulin plays a pivotal role in the glucose metabolism of dairy cows. The effect of insulin on the glucose metabolism is regulated by the secretion of insulin by the pancreas and the insulin sensitivity of the skeletal muscles, the adipose tissue, and the liver. Insulin resistance may develop as part of physiologic (pregnancy and lactation) and pathologic processes, which may manifest as decreased insulin sensitivity or decreased insulin responsiveness. A good knowledge of the normal physiology of insulin is needed to measure the in vivo insulin resistance of dairy cows. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Determining pancreatic β-cell compensation for changing insulin sensitivity using an oral glucose tolerance test

    DEFF Research Database (Denmark)

    Solomon, Thomas; Malin, Steven K; Karstoft, Kristian

    2014-01-01

    Plasma glucose, insulin, and C-peptide responses during an OGTT are informative for both research and clinical practice in type 2 diabetes. The aim of this study was to use such information to determine insulin sensitivity and insulin secretion so as to calculate an oral glucose disposition index...

  13. Lipid droplet size and location in human skeletal muscle fibers are associated with insulin sensitivity

    DEFF Research Database (Denmark)

    Nielsen, Joachim; Christensen, Anders E; Nellemann, Birgitte

    2017-01-01

    In skeletal muscle, an accumulation of lipid droplets (LDs) in the subsarcolemmal space is associated with insulin resistance, but the underlying mechanism is not clear. We aimed to investigate how the size, number and location of LDs are associated with insulin sensitivity and muscle fiber types...... are associated with insulin resistance in skeletal muscle....

  14. Influence of apolipoproteins on the association between lipids and insulin sensitivity

    DEFF Research Database (Denmark)

    Baldi, Simona; Bonnet, Fabrice; Laville, Martine

    2013-01-01

    We evaluated whether the association of insulin sensitivity with HDL cholesterol (HDL) and triglycerides is influenced by major plasma apolipoproteins, as suggested by recent experimental evidence....

  15. Systemic insulin sensitivity is regulated by GPS2 inhibition of AKT ubiquitination and activation in adipose tissue.

    Science.gov (United States)

    Cederquist, Carly T; Lentucci, Claudia; Martinez-Calejman, Camila; Hayashi, Vanessa; Orofino, Joseph; Guertin, David; Fried, Susan K; Lee, Mi-Jeong; Cardamone, M Dafne; Perissi, Valentina

    2017-01-01

    Insulin signaling plays a unique role in the regulation of energy homeostasis and the impairment of insulin action is associated with altered lipid metabolism, obesity, and Type 2 Diabetes. The main aim of this study was to provide further insight into the regulatory mechanisms governing the insulin signaling pathway by investigating the role of non-proteolytic ubiquitination in insulin-mediated activation of AKT. The molecular mechanism of AKT regulation through ubiquitination is first dissected in vitro in 3T3-L1 preadipocytes and then validated in vivo using mice with adipo-specific deletion of GPS2, an endogenous inhibitor of Ubc13 activity (GPS2-AKO mice). Our results indicate that K63 ubiquitination is a critical component of AKT activation in the insulin signaling pathway and that counter-regulation of this step is provided by GPS2 preventing AKT ubiquitination through inhibition of Ubc13 enzymatic activity. Removal of this negative checkpoint, through GPS2 downregulation or genetic deletion, results in sustained activation of insulin signaling both in vitro and in vivo . As a result, the balance between lipid accumulation and utilization is shifted toward storage in the adipose tissue and GPS2-AKO mice become obese under normal laboratory chow diet. However, the adipose tissue of GPS2-AKO mice is not inflamed, the levels of circulating adiponectin are elevated, and systemic insulin sensitivity is overall improved. Our findings characterize a novel layer of regulation of the insulin signaling pathway based on non-proteolytic ubiquitination of AKT and define GPS2 as a previously unrecognized component of the insulin signaling cascade. In accordance with this role, we have shown that GPS2 presence in adipocytes modulates systemic metabolism by restricting the activation of insulin signaling during the fasted state, whereas in absence of GPS2, the adipose tissue is more efficient at lipid storage, and obesity becomes uncoupled from inflammation and insulin

  16. Association of Tumor Growth Factor-? and Interferon-? Serum Levels with Insulin Resistance in Normal Pregnancy

    OpenAIRE

    Jahromi, Abdolreza Sotoodeh; Sanie, Mohammad Sadegh; Yusefi, Alireza; Zabetian, Hassan; Zareian, Parvin; Hakimelahi, Hossein; Madani, Abdolhossien; Hojjat-Farsangi, Mohammad

    2015-01-01

    Pregnancy is related to change in glucose metabolism and insulin production. The aim of our study was to determine the association of serum IFN-? and TGF-? levels with insulin resistance during normal pregnancy. This cross sectional study was carried out on 97 healthy pregnant (in different trimesters) and 28 healthy non-pregnant women. Serum TGF-? and IFN-? level were measured by ELISA method. Pregnant women had high level TGF-? and low level IFN-? as compared non-pregnant women. Maternal se...

  17. Genome-wide association study of the modified Stumvoll Insulin Sensitivity Index identifies BCL2 and FAM19A2 as novel insulin sensitivity loci

    DEFF Research Database (Denmark)

    Walford, Geoffrey A; Gustafsson, Stefan; Rybin, Denis

    2016-01-01

    of the modified Stumvoll Insulin Sensitivity Index (ISI) within the Meta-Analyses of Glucose and Insulin-related traits Consortium. Discovery was performed in 16,753 individuals, and replication was attempted for the 23 most significant novel loci in 13,354 independent individuals. Association with ISI was tested...

  18. Effect of body weight gain on insulin sensitivity after retirement from exercise training

    Science.gov (United States)

    Dolkas, Constantine B.; Rodnick, Kenneth J.; Mondon, Carl E.

    1990-01-01

    The effect of the body-weight gain after retirement from an exercise-training program on the retained increase in insulin sensitivity elicited by the training was investigated in exercise-trained (ET) rats. Insulin sensitivity was assessed by oral glucose tolerance and insulin suppression tests immediately after training and during retirement. Results show that, compared with sedentary controls, exercise training enhanced insulin-induced glucose uptake, but the enhanced sensitivity was gradually lost with the end of running activity until after seven days of retirement, when it became equal to that of controls. This loss of enhanced sensitivity to insulin was associated with an accelerated gain in body weight beginning one day after the start of retirement. However, those animals that gained weight only at rates similar to those of control rats, retained their enhanced sensitivity to insulin.

  19. Chronic insulin treatment of diabetes does not fully normalize alterations in the retinal transcriptome

    Directory of Open Access Journals (Sweden)

    Kimball Scot R

    2011-05-01

    Full Text Available Abstract Background Diabetic retinopathy (DR is a leading cause of blindness in working age adults. Approximately 95% of patients with Type 1 diabetes develop some degree of retinopathy within 25 years of diagnosis despite normalization of blood glucose by insulin therapy. The goal of this study was to identify molecular changes in the rodent retina induced by diabetes that are not normalized by insulin replacement and restoration of euglycemia. Methods The retina transcriptome (22,523 genes and transcript variants was examined after three months of streptozotocin-induced diabetes in male Sprague Dawley rats with and without insulin replacement for the later one and a half months of diabetes. Selected gene expression changes were confirmed by qPCR, and also examined in independent control and diabetic rats at a one month time-point. Results Transcriptomic alterations in response to diabetes (1376 probes were clustered according to insulin responsiveness. More than half (57% of diabetes-induced mRNA changes (789 probes observed at three months were fully normalized to control levels with insulin therapy, while 37% of probes (514 were only partially normalized. A small set of genes (5%, 65 probes was significantly dysregulated in the insulin-treated diabetic rats. qPCR confirmation of findings and examination of a one month time point allowed genes to be further categorized as prevented or rescued with insulin therapy. A subset of genes (Ccr5, Jak3, Litaf was confirmed at the level of protein expression, with protein levels recapitulating changes in mRNA expression. Conclusions These results provide the first genome-wide examination of the effects of insulin therapy on retinal gene expression changes with diabetes. While insulin clearly normalizes the majority of genes dysregulated in response to diabetes, a number of genes related to inflammatory processes, microvascular integrity, and neuronal function are still altered in expression in

  20. Stimuli sensitive polymethacrylic acid microparticles (PMAA)--oral insulin delivery.

    Science.gov (United States)

    Victor, Sunita Prem; Sharma, Chandra P

    2002-10-01

    This study investigated polymethacrylic acid (PMAA) microparticles for controlled release of Insulin in oral administration. The microparticles were characterised by scanning electron microscopy (SEM) for morphological studies. The swelling behaviour and drug release profile in various pH media were studied. The % swelling of gels was found to be inversely related to the amount of crosslinker added. Inclusion complex of betaCD and Insulin was studied using polyacrylamide gel electrophoresis (PAGE). Optimum complexation was obtained in the ratio 100 mg betaCD: 200 IU Insulin. The release pattern of Insulin from Insulin-betaCD complex encapsulated PMAA microparticles showed release of Insulin for more than seven hours.

  1. PROXIMITY TO DELIVERY ALTERS INSULIN SENSITIVITY AND GLUCOSE METABOLISM IN PREGNANT MICE

    OpenAIRE

    Musial, Barbara; Fernandez-Twinn, Denise S.; Vaughan, Owen R.; Ozanne, Susan E.; Voshol, Peter; Sferruzzi-Perri, Amanda N.; Fowden, Abigail L.

    2016-01-01

    In late pregnancy, maternal insulin resistance occurs to support fetal growth but little is known about insulin-glucose dynamics close to delivery. This study measured insulin sensitivity in mice in late pregnancy, day (D) 16, and near term, D19, (term 20.5D). Non-pregnant (NP) and pregnant mice were assessed for metabolite and hormone concentrations, body composition by dual energy X-ray absorptiometry, tissue insulin signalling protein abundance by Western blotting, glucose tolerance and ut...

  2. Effects of menopause and high-intensity training on insulin sensitivity and muscle metabolism.

    Science.gov (United States)

    Mandrup, Camilla M; Egelund, Jon; Nyberg, Michael; Enevoldsen, Lotte Hahn; Kjær, Andreas; Clemmensen, Andreas E; Christensen, Anders Nymark; Suetta, Charlotte; Frikke-Schmidt, Ruth; Steenberg, Dorte Enggaard; Wojtaszewski, Jørgen F P; Hellsten, Ylva; Stallknecht, Bente M

    2018-02-01

    To investigate peripheral insulin sensitivity and skeletal muscle glucose metabolism in premenopausal and postmenopausal women, and evaluate whether exercise training benefits are maintained after menopause. Sedentary, healthy, normal-weight, late premenopausal (n = 21), and early postmenopausal (n = 20) women were included in a 3-month high-intensity exercise training intervention. Body composition was assessed by magnetic resonance imaging and dual-energy x-ray absorptiometry, whole body glucose disposal rate (GDR) by hyperinsulinemic euglycemic clamp (40 mU/m/min), and femoral muscle glucose uptake by positron emission tomography/computed tomography, using the glucose analog fluorodeoxyglucose, expressed as estimated metabolic rate (eMR). Insulin signaling was investigated in muscle biopsies. Age difference between groups was 4.5 years, and no difference was observed in body composition. Training increased lean body mass (estimate [95% confidence interval] 0.5 [0.2-0.9] kg, P training (eMR vastus lateralis muscle: 27.8 [19.6-36.0] μmol/min/kg, P training-induced increases in insulin sensitivity included increased expression of hexokinase (19.2 [5.0-24.7] AU, P = 0.02) and glycogen synthase (32.4 [15.0-49.8] AU, P high-intensity exercise training.

  3. Enhanced insulin sensitivity in prepubertal children with constitutional delay of growth and development.

    Science.gov (United States)

    Wilson, Dyanne A; Hofman, Paul L; Miles, Harriet L; Sato, Tim A; Billett, Nathalie E; Robinson, Elizabeth M; Cutfield, Wayne S

    2010-02-01

    To test the hypothesis that prepubertal children with presumed constitutional delay of growth and development (CDGD) have enhanced insulin sensitivity and, therefore, insulin sensitivity is associated with later onset of puberty. Twenty-one prepubertal children with presumed CDGD and 23 prepubertal control children, underwent a frequently sampled intravenous glucose tolerance test to evaluate insulin sensitivity and other markers of insulin, glucose, and growth regulation. Children in the CDGD group were shorter and leaner than control subjects. Children with presumed CDGD were 40% more insulin sensitive (17.0 x 10(-4) min(-1)/[mU/L] versus 12.1 x 10(-4) min(-1)/[mU/L]; P = .0006) and had reduced acute insulin response, thus maintaining euglycemia (216 mU/L versus 330 mU/L; P = .02) compared with control subjects. In addition, the CDGD group had lower serum insulin-like growth factor binding protein 3 levels (3333 ng/mL versus 3775 ng/mL; P = .0004) and a trend toward lower serum insulin-like growth factor-II levels (794 ng/mL versus 911 ng/mL; P = .06). Prepubertal children with presumed CDGD have enhanced insulin sensitivity, supporting the hypothesis that insulin sensitivity is associated with timing of puberty. It may signify long-term biological advantages with lower risk of metabolic syndrome and malignancy. Copyright 2010 Mosby, Inc. All rights reserved.

  4. [Metabolic profile in obese patients with obstructive sleep apnea. A comparison between patients with insulin resistance and with insulin sensitivity].

    Science.gov (United States)

    Dumitrache-Rujinski, Stefan; Dinu, Ioana; Călcăianu, George; Erhan, Ionela; Cocieru, Alexandru; Zaharia, Dragoş; Toma, Claudia Lucia; Bogdan, Miron Alexandru

    2014-01-01

    Obstructive sleep apnea syndrome (OSAS) may induce metabolic abnormalities through intermittent hypoxemia and simpathetic activation. It is difficult to demonstrate an independent role of OSAS in the occurrence of metabolic abnormalities, as obesity represents an important risk factor for both OSAS and metabolic abnormalities. to assess the relations between insulin resistance (IR), insulin sensitivity (IS), OSAS severity and nocturnal oxyhaemoglobin levels in obese, nondiabetic patients with daytime sleepiness. We evaluated 99 consecutive, obese, nondiabetic patients (fasting glycemia 5/hour and daytime sleepiness) by an ambulatory six channel cardio-respiratory polygraphy. Hight, weight serum triglycerides (TG), high density lipoprotein-cholesterol (HDL-C) levels were evaluated. Correlations between Apneea Hypopnea Index (AHI), Oxygen Desaturation Index (ODI), average and lowest oxyhaemoglobin saturation (SaO), body mass index (BMI) and insulin resistance or sensitivity were assesed. IR was defined as a TG/ HDL-Cratio > 3, and insulin sensitivity (IS) as a TG/HDL-C ratio obese nondiabetic patients. Preserving insulin sensitivity is more likely when oxyhaemoglobin levels are higher and ODI is lower. Mean lowest nocturnal SaO2 levels seems to be independently involved in the development of insulin resistance as no statistically significant differences were found for BMI between the two groups.

  5. [Normal plasma insulin and HOMA values among Chilean children and adolescents].

    Science.gov (United States)

    Barja, Salesa; Arnaiz, Pilar; Domínguez, Angélica; Villarroel, Luis; Cassis, Berta; Castillo, Oscar; Salomó, Gianina; Farías, Marcelo; Goycoolea, Manuela; Quiroga, Teresa; Mardones, Francisco

    2011-11-01

    Plasma insulin and HOMA (homeostasis model assessment) index, used to determine insulin resistance, do not have local standard values for children and adolescents in Chile. To establish the normal reference intervals for insulin and HOMA in children and adolescents aged 10-15 years, according to sex and puberal maturation. A cross-sectional study of 2,153 children and adolescents from Puente Alto County was performed, during 2009 and 2010. Anthropometry and self-report of puberal maturation were assessed. Fasting glucose (hexoquinase) and insulin blood levels (chemiluminiscence), were determined and HOMA index was calculated. Percentile distributions of these variables were calculated. The reference group included only subjects with normal body mass index and fasting blood glucose (n = 1,192). Girls had higher insulin and HOMA values than boys (12.5 ± 6.0 and 9.1 ± 4.9 μϋ/mL (p HOMA mean values than subjects with Tanner III and IV (9.0 ± 4.3 and 12.5 ± 6.2μϋ/ml (p HOMA distributions according to sex and maturation, was selected as the upper cut-off point to identify individuals with insulin resistance. HOMA cutoff point for Tanner I and II boys was 3.2, for Tanner I and II girls was 4.1, for Tanner III and IV boys was 4.2 and for Tanner III and IV girls was 5.0.

  6. Voluntary exercise improves insulin sensitivity and adipose tissue inflammation in diet-induced obese mice

    OpenAIRE

    Bradley, Richard L.; Jeon, Justin Y.; Liu, Fen-Fen; Maratos-Flier, Eleftheria

    2008-01-01

    Exercise promotes weight loss and improves insulin sensitivity. However, the molecular mechanisms mediating its beneficial effects are not fully understood. Obesity correlates with increased production of inflammatory cytokines, which in turn, contributes to systemic insulin resistance. To test the hypothesis that exercise mitigates this inflammatory response, thereby improving insulin sensitivity, we developed a model of voluntary exercise in mice made obese by feeding of a high fat/high suc...

  7. Lack of effect of long-term amlodipine on insulin sensitivity and plasma insulin in obese patients with essential hypertension

    DEFF Research Database (Denmark)

    de Courten, Maximilian; Ferrari, P; Schneider, M

    1993-01-01

    Method of Bergman, fasting plasma insulin and glucose concentrations, serum total triglyceride and lipoprotein cholesterol fractions, and blood pressure in 20 obese, non-diabetic patients with essential hypertension before and after 6 weeks of placebo and again after 6 months of amlodipine. Ten patients......To evaluate the effects of long-term treatment antihypertensive with the dihydropyridine calcium antagonist amlodipine on insulin sensitivity, plasma insulin, and lipoprotein metabolism in obese hypertensive patients. We measured the insulin sensitivity index (SI), determined by the Minimal Model...... [mean body mass index (BMI) 30.2 kg.m-2] had been on prior treatment with a thiazide diuretic in low dosage and/or a beta-adrenoceptor blocker (group A), and 10 matched patients [BMI 31.8 kg.m-2] had been previously untreated (group B). Amlodipine was started in a dose of 5 mg and was increased to 10 mg...

  8. Drosophila Insulin receptor regulates the persistence of injury-induced nociceptive sensitization

    Science.gov (United States)

    Patel, Atit A.

    2018-01-01

    ABSTRACT Diabetes-associated nociceptive hypersensitivity affects diabetic patients with hard-to-treat chronic pain. Because multiple tissues are affected by systemic alterations in insulin signaling, the functional locus of insulin signaling in diabetes-associated hypersensitivity remains obscure. Here, we used Drosophila nociception/nociceptive sensitization assays to investigate the role of Insulin receptor (Insulin-like receptor, InR) in nociceptive hypersensitivity. InR mutant larvae exhibited mostly normal baseline thermal nociception (absence of injury) and normal acute thermal hypersensitivity following UV-induced injury. However, their acute thermal hypersensitivity persists and fails to return to baseline, unlike in controls. Remarkably, injury-induced persistent hypersensitivity is also observed in larvae that exhibit either type 1 or type 2 diabetes. Cell type-specific genetic analysis indicates that InR function is required in multidendritic sensory neurons including nociceptive class IV neurons. In these same nociceptive sensory neurons, only modest changes in dendritic morphology were observed in the InRRNAi-expressing and diabetic larvae. At the cellular level, InR-deficient nociceptive sensory neurons show elevated calcium responses after injury. Sensory neuron-specific expression of InR rescues the persistent thermal hypersensitivity of InR mutants and constitutive activation of InR in sensory neurons ameliorates the hypersensitivity observed with a type 2-like diabetic state. Our results suggest that a sensory neuron-specific function of InR regulates the persistence of injury-associated hypersensitivity. It is likely that this new system will be an informative genetically tractable model of diabetes-associated hypersensitivity. PMID:29752280

  9. The insulin sensitizing effect of topiramate involves KATP channel activation in the central nervous system

    NARCIS (Netherlands)

    Coomans, C.P.; Geerling, J.J.; Berg, S.A.A. van den; Diepen, H.C. van; Garcia-Tardõn, N.; Thomas, A.; Schröder-Van Der Elst, J.P.; Ouwens, D.M.; Pijl, H.; Rensen, P.C.N.; Havekes, L.M.; Guigas, B.; Romijn, J.A.

    2013-01-01

    Background and Purpose Topiramate improves insulin sensitivity, in addition to its antiepileptic action. However, the underlying mechanism is unknown. Therefore, the present study was aimed at investigating the mechanism of the insulin-sensitizing effect of topiramate both in vivo and in vitro.

  10. The insulin sensitizing effect of topiramate involves KATP channel activation in the central nervous system

    NARCIS (Netherlands)

    Coomans, C. P.; Geerling, J. J.; van den Berg, S. A. A.; van Diepen, H. C.; Garcia-Tardón, N.; Thomas, A.; Schröder-van der Elst, J. P.; Ouwens, D. M.; Pijl, H.; Rensen, P. C. N.; Havekes, L. M.; Guigas, B.; Romijn, J. A.

    2013-01-01

    Topiramate improves insulin sensitivity, in addition to its antiepileptic action. However, the underlying mechanism is unknown. Therefore, the present study was aimed at investigating the mechanism of the insulin-sensitizing effect of topiramate both in vivo and in vitro. Male C57Bl/6J mice were fed

  11. Central GLP-2 enhances hepatic insulin sensitivity via activating PI3K signaling in POMC neurons

    Science.gov (United States)

    Glucagon-like peptides (GLP-1/GLP-2) are coproduced and highlighted as key modulators to improve glucose homeostasis and insulin sensitivity after bariatric surgery. However, it is unknown if CNS GLP-2 plays any physiological role in the control of glucose homeostasis and insulin sensitivity. We sho...

  12. Acute activation of GLP-1-expressing neurons promotes glucose homeostasis and insulin sensitivity

    Directory of Open Access Journals (Sweden)

    Xuemei Shi

    2017-11-01

    Conclusions: We conclude that acute activation of PPG neurons in the brainstem reduces basal glucose production, enhances intraperitoneal glucose tolerance, and augments hepatic insulin sensitivity, suggesting an important physiological role of PPG neurons-mediated circuitry in promoting glycemic control and insulin sensitivity.

  13. Dissociation of in vitro sensitivities of glucose transport and antilipolysis to insulin in NIDDM

    International Nuclear Information System (INIS)

    Yki-Jaervinen, H.; Kubo, K.; Zawadzki, J.; Lillioja, S.; Young, A.; Abbott, W.; Foley, J.E.

    1987-01-01

    It is unclear from previous studies whether qualitative or only quantitative differences exist in insulin action in adipocytes obtained from obese subjects with non-insulin-dependent diabetes mellitus (NIDDM) when compared with equally obese nondiabetic subjects. In addition, the role of changes in insulin binding as a cause of insulin resistance in NIDDM is still controversial. The authors compared the sensitivities of [ 14 C]-glucose transport and antilipolysis to insulin and measured [ 125 I]-insulin binding in abdominal adipocytes obtained from 45 obese nondiabetic, obese diabetic, and 15 nonobese female southwestern American Indians. Compared with the nonobese group, the sensitivities of glucose transport antilipolysis were reduced in both the obese nondiabetic and obese diabetic groups. Compared with the obese nondiabetic subjects, the ED 50 for stimulation of glucose transport was higher in the obese patients with NIDDM. In contrast, the ED 50 S for antilipolysis were similar in obese diabetic patients and obese nondiabetic subjects. No differences was found in insulin binding in patients with NIDDM when compared with the equally obese nondiabetic subjects. These data indicate 1) the mechanism of insulin resistance differs in NIDDM and obesity, and 2) the selective loss of insulin sensitivity in NIDDM precludes changes in insulin binding as a cause of insulin resistance in this disorder

  14. Adipose tissue (P)RR regulates insulin sensitivity, fat mass and body weight.

    Science.gov (United States)

    Shamansurova, Zulaykho; Tan, Paul; Ahmed, Basma; Pepin, Emilie; Seda, Ondrej; Lavoie, Julie L

    2016-10-01

    We previously demonstrated that the handle-region peptide, a prorenin/renin receptor [(P)RR] blocker, reduces body weight and fat mass and may improve insulin sensitivity in high-fat fed mice. We hypothesized that knocking out the adipose tissue (P)RR gene would prevent weight gain and insulin resistance. An adipose tissue-specific (P)RR knockout (KO) mouse was created by Cre-loxP technology using AP2-Cre recombinase mice. Because the (P)RR gene is located on the X chromosome, hemizygous males were complete KO and had a more pronounced phenotype on a normal diet (ND) diet compared to heterozygous KO females. Therefore, we challenged the female mice with a high-fat diet (HFD) to uncover certain phenotypes. Mice were maintained on either diet for 9 weeks. KO mice had lower body weights compared to wild-types (WT). Only hemizygous male KO mice presented with lower total fat mass, higher total lean mass as well as smaller adipocytes compared to WT mice. Although food intake was similar between genotypes, locomotor activity during the active period was increased in both male and female KO mice. Interestingly, only male KO mice had increased O2 consumption and CO2 production during the entire 24-hour period, suggesting an increased basal metabolic rate. Although glycemia during a glucose tolerance test was similar, KO males as well as HFD-fed females had lower plasma insulin and C-peptide levels compared to WT mice, suggesting improved insulin sensitivity. Remarkably, all KO animals exhibited higher circulating adiponectin levels, suggesting that this phenotype can occur even in the absence of a significant reduction in adipose tissue weight, as observed in females and, thus, may be a specific effect related to the (P)RR. (P)RR may be an important therapeutic target for the treatment of obesity and its associated complications such as type 2 diabetes.

  15. Enhanced muscle insulin sensitivity after contraction/exercise is mediated by AMPK

    DEFF Research Database (Denmark)

    Kjøbsted, Rasmus; Munk-Hansen, Nanna; Birk, Jesper Bratz

    2017-01-01

    muscle and whole body insulin sensitivity in wild type (WT) mice, respectively. These effects were not found in AMPKα1α2 muscle-specific knockout mice. Prior in situ contraction did not increase insulin sensitivity in m. soleus from either genotype. Improvement in muscle insulin sensitivity....... Collectively, our data suggest that the AMPK-TBC1D4 signaling axis is likely mediating the improved muscle insulin sensitivity after contraction/exercise and illuminates an important and physiological relevant role of AMPK in skeletal muscle.......Earlier studies have demonstrated that muscle insulin sensitivity to stimulate glucose uptake is enhanced several hours after an acute bout of exercise. Using 5-aminoimidazole-4-carboxamide-ribonucleotide (AICAR), we recently demonstrated that prior activation of AMPK is sufficient to increase...

  16. Human gut microbes impact host serum metabolome and insulin sensitivity

    DEFF Research Database (Denmark)

    Pedersen, Helle Krogh; Gudmundsdottir, Valborg; Nielsen, Henrik Bjørn

    2016-01-01

    Insulin resistance is a forerunner state of ischaemic cardiovascular disease and type 2 diabetes. Here we show how the human gut microbiome impacts the serum metabolome and associates with insulin resistance in 277 non-diabetic Danish individuals. The serum metabolome of insulin-resistant individ......Insulin resistance is a forerunner state of ischaemic cardiovascular disease and type 2 diabetes. Here we show how the human gut microbiome impacts the serum metabolome and associates with insulin resistance in 277 non-diabetic Danish individuals. The serum metabolome of insulin......-resistant individuals is characterized by increased levels of branched-chain amino acids (BCAAs), which correlate with a gut microbiome that has an enriched biosynthetic potential for BCAAs and is deprived of genes encoding bacterial inward transporters for these amino acids. Prevotella copri and Bacteroides vulgatus...

  17. Sensitivity determination of CR-39 from Normal and inclined incidence

    International Nuclear Information System (INIS)

    Abou, A.A.; El-Kheir, A.A.; Daas, A.F.; Awwad, Z.; Reda, A.M.

    2000-01-01

    An experimental study have been carried out on alpha- particle track opening (Major and minor axes) using alpha-particles of different energies incident with different angels in addition to the normal incidence. The sensitivity of CR-39 in present work is determined for each of normal and inclined incidence. The results indicated a difference in the sensitivity according to angle of incidence. The variation of alpha- particle tracks (major and minor axes) are calculated and compared with our measured values. Also, it is found that the sensitivity of CR-39 detector is change due to the storage time at room temperature

  18. [Effects of total glucosides of paeony on enhancing insulin sensitivity and antagonizing nonalcoholic fatty liver in rats].

    Science.gov (United States)

    Zheng, Lin-Ying; Pan, Jing-Qiang; Lv, Jun-Hua

    2008-10-01

    To study the pathological changes of blood glucose, serum lipid, insulin resistance, liver function, liver cell denaturalization of total glucosides of paeony on nonalcoholic fatty liver rats caused by insulin resistance and discuss the acting mechanism. Adult SD rats were maintained on high-fat-sugar-salt diet for 56 days. In the 57th day, their fasting blood glucose (FBG) and 2-hours blood glucose after oral glucose tolerance test (OGTT-2 hBG) were mensurated, according to which and the weight the rats were divided randomly into nonalcoholic fatty liver model group, metformin group (0.2 g x kg(-1)) and total glucosides of paeony group (high dosage 0.15 g x kg(-1), low dosage 0.05 g x kg(-1)). All the rats were still administered the same diet and given different drugs by intragastric administration for 28 days. In the 29th day, all of them were killed and the blood was sampled to measure the levels of blood glucose [FBG, OGTT-2 hBG, fasting insulin (Fins)] and serum lipid [free fatty acids (FFA), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C)], then the HOMA insulin resistance index (HOMA-IRI, fasting glucosexinsulin) and insulin sensitivity index (ISI) were counted. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholinesterase (ChE), superoxide dismutase (SOD) and the contents of malondialdehyde (MDA) were measured also. Livers were weighed and collected to be observed the pathological changes. Compared with normal group, in nonalcoholic fatty liver model group the levels of Fins and IRI were increased obviously (P insulin resistence were resisted (P insulin resistance, and its action mechanism may be concerned with enhancing insulin sensitivity and antioxidative ability, decreasing serum lipid.

  19. The insulin sensitizing effect of topiramate involves KATP channel activation in the central nervous system.

    Science.gov (United States)

    Coomans, C P; Geerling, J J; van den Berg, S A A; van Diepen, H C; Garcia-Tardón, N; Thomas, A; Schröder-van der Elst, J P; Ouwens, D M; Pijl, H; Rensen, P C N; Havekes, L M; Guigas, B; Romijn, J A

    2013-10-01

    Topiramate improves insulin sensitivity, in addition to its antiepileptic action. However, the underlying mechanism is unknown. Therefore, the present study was aimed at investigating the mechanism of the insulin-sensitizing effect of topiramate both in vivo and in vitro. Male C57Bl/6J mice were fed a run-in high-fat diet for 6 weeks, before receiving topiramate or vehicle mixed in high-fat diet for an additional 6 weeks. Insulin sensitivity was assessed by hyperinsulinaemic-euglycaemic clamp. The extent to which the insulin sensitizing effects of topiramate were mediated through the CNS were determined by concomitant i.c.v. infusion of vehicle or tolbutamide, an inhibitor of ATP-sensitive potassium channels in neurons. The direct effects of topiramate on insulin signalling and glucose uptake were assessed in vivo and in cultured muscle cells. In hyperinsulinaemic-euglycaemic clamp conditions, therapeutic plasma concentrations of topiramate (∼4 μg·mL(-1) ) improved insulin sensitivity (glucose infusion rate + 58%). Using 2-deoxy-D-[(3) H]glucose, we established that topiramate improved the insulin-mediated glucose uptake by heart (+92%), muscle (+116%) and adipose tissue (+586%). Upon i.c.v. tolbutamide, the insulin-sensitizing effect of topiramate was completely abrogated. Topiramate did not directly affect glucose uptake or insulin signalling neither in vivo nor in cultured muscle cells. In conclusion, topiramate stimulates insulin-mediated glucose uptake in vivo through the CNS. These observations illustrate the possibility of pharmacological modulation of peripheral insulin resistance through a target in the CNS. © 2013 The British Pharmacological Society.

  20. Insulin resistance and serum levels of interleukin-17 and interleukin-18 in normal pregnancy.

    Science.gov (United States)

    Jahromi, Abdolreza Sotoodeh; Shojaei, Mohammad; Ghobadifar, Mohamed Amin

    2014-06-01

    We performed this study to evaluate the role of Interleukin-17 (IL-17) and Interleukin-18 (IL-18) in insulin resistance during normal pregnancy. This descriptive cross sectional study was carried out on 97 healthy pregnant women including 32, 25, and 40 individuals in the first, second, and third trimesters, respectively, and on 28 healthy non pregnant women between the autumn of 2012 and the spring of 2013. We analyzed the serum concentrations of IL-17 and IL-18 by using the enzyme linked immunosorbent assay (ELISA). Insulin resistance was measured by homeostasis model assessment of insulin resistance equation. No significant differences between the demographic data of the pregnant and non pregnant groups were observed. Insulin resistant in pregnant women was significantly higher than the controls (p=0.006). Serum IL-17 concentration was significantly different in non pregnant women and pregnant women in all gestational ages (ppregnant women (pinsulin resistance (r=0.08, p=0.34 vs. r=0.01, p=0.91, respectively). Our data suggested that IL-17 and IL-18 do not appear to attribute greatly to pregnancy deduced insulin resistance during normal pregnancy.

  1. Statin Intake Is Associated With Decreased Insulin Sensitivity During Cardiac Surgery

    Science.gov (United States)

    Sato, Hiroaki; Carvalho, George; Sato, Tamaki; Hatzakorzian, Roupen; Lattermann, Ralph; Codere-Maruyama, Takumi; Matsukawa, Takashi; Schricker, Thomas

    2012-01-01

    OBJECTIVE Surgical trauma impairs intraoperative insulin sensitivity and is associated with postoperative adverse events. Recently, preprocedural statin therapy is recommended for patients with coronary artery disease. However, statin therapy is reported to increase insulin resistance and the risk of new-onset diabetes. Thus, we investigated the association between preoperative statin therapy and intraoperative insulin sensitivity in nondiabetic, dyslipidemic patients undergoing coronary artery bypass grafting. RESEARCH DESIGN AND METHODS In this prospective, nonrandomized trial, patients taking lipophilic statins were assigned to the statin group and hypercholesterolemic patients not receiving any statins were allocated to the control group. Insulin sensitivity was assessed by the hyperinsulinemic-normoglycemic clamp technique during surgery. The mean, SD of blood glucose, and the coefficient of variation (CV) after surgery were calculated for each patient. The association between statin use and intraoperative insulin sensitivity was tested by multiple regression analysis. RESULTS We studied 120 patients. In both groups, insulin sensitivity gradually decreased during surgery with values being on average ∼20% lower in the statin than in the control group. In the statin group, the mean blood glucose in the intensive care unit was higher than in the control group (153 ± 20 vs. 140 ± 20 mg/dL; P statin group (SD, P statin use was independently associated with intraoperative insulin sensitivity (β = −0.16; P = 0.03). CONCLUSIONS Preoperative use of lipophilic statins is associated with increased insulin resistance during cardiac surgery in nondiabetic, dyslipidemic patients. PMID:22829524

  2. Adipokine zinc-α2-glycoprotein regulated by growth hormone and linked to insulin sensitivity.

    Science.gov (United States)

    Balaz, Miroslav; Ukropcova, Barbara; Kurdiova, Timea; Gajdosechova, Lucia; Vlcek, Miroslav; Janakova, Zuzana; Fedeles, Jozef; Pura, Mikulas; Gasperikova, Daniela; Smith, Steven R; Tkacova, Ruzena; Klimes, Iwar; Payer, Juraj; Wolfrum, Christian; Ukropec, Jozef

    2015-02-01

    Hypertrophic obesity is associated with impaired insulin sensitivity and lipid-mobilizing activity of zinc-α2-glycoprotein. Adipose tissue (AT) of growth hormone (GH) -deficient patients is characterized by extreme adipocyte hypertrophy due to defects in AT lipid metabolism. It was hypothesized that zinc-α2-glycoprotein is regulated by GH and mediates some of its beneficial effects in AT. AT from patients with GH deficiency and individuals with obesity-related GH deficit was obtained before and after 5-year and 24-month GH supplementation therapy. GH action was tested in primary human adipocytes. Relationships of GH and zinc-α2-glycoprotein with adipocyte size and insulin sensitivity were evaluated in nondiabetic patients with noncancerous cachexia and hypertrophic obesity. AT in GH-deficient adults displayed a substantial reduction of zinc-α2-glycoprotein. GH therapy normalized AT zinc-α2-glycoprotein. Obesity-related relative GH deficit was associated with almost 80% reduction of zinc-α2-glycoprotein mRNA in AT. GH increased zinc-α2-glycoprotein mRNA in both AT of obese men and primary human adipocytes. Interdependence of GH and zinc-α2-glycoprotein in regulating AT morphology and metabolic phenotype was evident from their relationship with adipocyte size and AT-specific and whole-body insulin sensitivity. The results demonstrate that GH is involved in regulation of AT zinc-α2-glycoprotein; however, the molecular mechanism linking GH and zinc-α2-glycoprotein in AT is yet unknown. © 2014 The Obesity Society.

  3. Ghrelin differentially affects hepatic and peripheral insulin sensitivity in mice

    NARCIS (Netherlands)

    Heijboer, A. C.; van den Hoek, A. M.; Parlevliet, E. T.; Havekes, L. M.; Romijn, J. A.; Pijl, H.; Corssmit, E. P. M.

    2006-01-01

    This study was conducted to evaluate the effects of ghrelin on insulin's capacity to suppress endogenous glucose production and promote glucose disposal in mice. To establish whether the growth hormone secretagogue (GHS) receptor can mediate the putative effect of ghrelin on the action of insulin,

  4. Exercise increases human skeletal muscle insulin sensitivity via coordinated increases in microvascular perfusion and molecular signaling

    DEFF Research Database (Denmark)

    Sjøberg, Kim Anker; Frøsig, Christian; Kjøbsted, Rasmus

    2017-01-01

    and increased similarly in both legs during the clamp and L-NMMA had no effect on these insulin-stimulated signaling pathways. Therefore, acute exercise increases insulin sensitivity of muscle by a coordinated increase in insulin-stimulated microvascular perfusion and molecular signaling at the level of TBC1D4...... and glycogen synthase in muscle. This secures improved glucose delivery on the one hand and increased ability to take up and dispose of the delivered glucose on the other hand....

  5. Disruption of growth hormone receptor gene causes diminished pancreatic islet size and increased insulin sensitivity in mice.

    Science.gov (United States)

    Liu, Jun-Li; Coschigano, Karen T; Robertson, Katie; Lipsett, Mark; Guo, Yubin; Kopchick, John J; Kumar, Ujendra; Liu, Ye Lauren

    2004-09-01

    Growth hormone, acting through its receptor (GHR), plays an important role in carbohydrate metabolism and in promoting postnatal growth. GHR gene-deficient (GHR(-/-)) mice exhibit severe growth retardation and proportionate dwarfism. To assess the physiological relevance of growth hormone actions, GHR(-/-) mice were used to investigate their phenotype in glucose metabolism and pancreatic islet function. Adult GHR(-/-) mice exhibited significant reductions in the levels of blood glucose and insulin, as well as insulin mRNA accumulation. Immunohistochemical analysis of pancreatic sections revealed normal distribution of the islets despite a significantly smaller size. The average size of the islets found in GHR(-/-) mice was only one-third of that in wild-type littermates. Total beta-cell mass was reduced 4.5-fold in GHR(-/-) mice, significantly more than their body size reduction. This reduction in pancreatic islet mass appears to be related to decreases in proliferation and cell growth. GHR(-/-) mice were different from the human Laron syndrome in serum insulin level, insulin responsiveness, and obesity. We conclude that growth hormone signaling is essential for maintaining pancreatic islet size, stimulating islet hormone production, and maintaining normal insulin sensitivity and glucose homeostasis.

  6. Pterocarpan-Enriched Soy Leaf Extract Ameliorates Insulin Sensitivity and Pancreatic β-Cell Proliferation in Type 2 Diabetic Mice

    Directory of Open Access Journals (Sweden)

    Un-Hee Kim

    2014-11-01

    Full Text Available In Korea, soy (Glycine max (L. Merr. leaves are eaten as a seasonal vegetable or pickled in soy sauce. Ethyl acetate extracts of soy leaves (EASL are enriched in pterocarpans and have potent α-glucosidase inhibitory activity. This study investigated the molecular mechanisms underlying the anti-diabetic effect of EASL in C57BL/6J mice with high-fat diet (HFD-induced type 2 diabetes. Mice were randomly divided into normal diet (ND, HFD (60 kcal% fat diet, EASL (HFD with 0.56% (wt/wt EASL, and Pinitol (HFD with 0.15% (wt/wt pinitol groups. Weight gain and abdominal fat accumulation were significantly suppressed by EASL. Levels of plasma glucose, HbA1c, and insulin in the EASL group were significantly lower than those of the HFD group, and the pancreatic islet of the EASL group had greater size than those of the HFD group. EASL group up-regulated neurogenin 3 (Ngn3, paired box 4 (Pax4, and v-maf musculoaponeurotic fibrosarcoma oncogene homolog A (MafA, which are markers of pancreatic cell development, as well as insulin receptor substrate 1 (IRS1, IRS2, and glucose transporter 4 (GLUT4, which are related to insulin sensitivity. Furthermore, EASL suppressed genes involved in hepatic gluconeogenesis and steatosis. These results suggest that EASL improves plasma glucose and insulin levels in mice with HDF-induced type 2 diabetes by regulating β-cell proliferation and insulin sensitivity.

  7. Adipose tissue inflammation and reduced insulin sensitivity in ovariectomized mice occurs in the absence of increased adiposity.

    Science.gov (United States)

    Vieira Potter, Victoria J; Strissel, Katherine J; Xie, Chen; Chang, Eugene; Bennett, Grace; Defuria, Jason; Obin, Martin S; Greenberg, Andrew S

    2012-09-01

    Menopause promotes central obesity, adipose tissue (AT) inflammation, and insulin resistance (IR). Both obesity and the loss of estrogen can activate innate and adaptive immune cells (macrophages, T cells). The respective impacts of weight gain and loss of ovarian hormones on AT inflammation and IR are poorly understood. Here we determined the temporal kinetics of fat accretion, AT inflammation, and IR over a 26-wk time course in ovariectomized (OVX) mice, a model of menopause. OVX and sham-operated (SHM) C57BL6 mice were fed a normal chow diet. Weight, body composition (magnetic resonance imaging), total and regional adiposity, activity, food intake, AT crown-like structures, biohumoral measures, and insulin sensitivity (insulin tolerance testing and homeostatic model assessment) were determined at wk 12, 20, and 26. Macrophages and T cells from perigonadal AT were immunophenotyped by fluorescence-associated cell sorting, and perigonadal adipose tissue (PGAT) gene expression was quantified by quantitative PCR. OVX mice (≈ 31 g) became fatter than SHM mice (≈ 26 g) by wk 12, but mice were equally insulin sensitive. PGAT of OVX mice contained more T cells but expressed higher levels of M2-MΦ (arginase-1) and T cell-regulatory (cytotoxic T-lymphocyte antigen 4) genes. At wk 20, both OVX and SHM mice weighed approximately 35 g and were equally insulin sensitive with comparable amounts of PGAT and total body fat. OVX mice became less insulin sensitive than SHM mice by wk 26, coincident with the down-regulation of PGAT arginase-1 (-20-fold) and cytotoxic T-lymphocyte antigen 4 (2-fold) and up-regulation of M1/Th1 genes CD11c (+2-fold), IL12p40 (+2-fold), and interferon-γ (+78-fold). Ovarian hormone loss in mice induces PGAT inflammation and IR by mechanisms that can be uncoupled from OVX-induced obesity.

  8. Role of AMP-activated protein kinase for regulating post-exercise insulin sensitivity

    DEFF Research Database (Denmark)

    Kjøbsted, Rasmus; Wojtaszewski, Jørgen; Treebak, Jonas Thue

    2016-01-01

    Skeletal muscle insulin resistance precedes development of type 2 diabetes (T2D). As skeletal muscle is a major sink for glucose disposal, understanding the molecular mechanisms involved in maintaining insulin sensitivity of this tissue could potentially benefit millions of people that are diagno......Skeletal muscle insulin resistance precedes development of type 2 diabetes (T2D). As skeletal muscle is a major sink for glucose disposal, understanding the molecular mechanisms involved in maintaining insulin sensitivity of this tissue could potentially benefit millions of people...... that are diagnosed with insulin resistance. Regular physical activity in both healthy and insulin-resistant individuals is recognized as the single most effective intervention to increase whole-body insulin sensitivity and thereby positively affect glucose homeostasis. A single bout of exercise has long been known...... to increase glucose disposal in skeletal muscle in response to physiological insulin concentrations. While this effect is identified to be restricted to the previously exercised muscle, the molecular basis for an apparent convergence between exercise- and insulin-induced signaling pathways is incompletely...

  9. Sudden improvement of insulin sensitivity related to an endodontic treatment.

    Science.gov (United States)

    Schulze, A; Schönauer, M; Busse, M

    2007-12-01

    Inflammation contributes to the pathogenesis of diabetes. A reciprocal relationship exists between diabetes and chronic periodontitis. This report describes the effects of an acute focal dental inflammation and subsequent endodontic treatment on the required insulin dosage of a 70-year-old man who had moderately controlled diabetes. Following an exacerbation of a combined endodontic-periodontic (endo-perio) lesion of tooth #3, the patient noticed a sudden increase in his insulin demand. After 3 weeks, the required dosage was approximately 100% greater. In association with hyperglycemic incidents, he reported a prickling sensation in this tooth. The radiograph showed circular bone loss around the tooth. Just 1 day after the root-canal preparation, the insulin need decreased to approximately 50% of that required prior to treatment. Subsequently, an incision and systemic antibiotics were necessary because of the formation of a periodontal abscess. The insulin demand remained low despite this complication. Forty days after endodontic treatment, the insulin dosage was at a level comparable to that taken 4 weeks before the root-canal preparation. This clinical case revealed a highly relevant correlation between insulin resistance and a local dental inflammation. To avoid an increase in insulin resistance, it seems important to attend to radically non-vital teeth as well as any other dental inflammation in diabetic patients.

  10. Adipose tissue (PRR regulates insulin sensitivity, fat mass and body weight

    Directory of Open Access Journals (Sweden)

    Zulaykho Shamansurova

    2016-10-01

    Full Text Available Objective: We previously demonstrated that the handle-region peptide, a prorenin/renin receptor [(PRR] blocker, reduces body weight and fat mass and may improve insulin sensitivity in high-fat fed mice. We hypothesized that knocking out the adipose tissue (PRR gene would prevent weight gain and insulin resistance. Methods: An adipose tissue-specific (PRR knockout (KO mouse was created by Cre-loxP technology using AP2-Cre recombinase mice. Because the (PRR gene is located on the X chromosome, hemizygous males were complete KO and had a more pronounced phenotype on a normal diet (ND diet compared to heterozygous KO females. Therefore, we challenged the female mice with a high-fat diet (HFD to uncover certain phenotypes. Mice were maintained on either diet for 9 weeks. Results: KO mice had lower body weights compared to wild-types (WT. Only hemizygous male KO mice presented with lower total fat mass, higher total lean mass as well as smaller adipocytes compared to WT mice. Although food intake was similar between genotypes, locomotor activity during the active period was increased in both male and female KO mice. Interestingly, only male KO mice had increased O2 consumption and CO2 production during the entire 24-hour period, suggesting an increased basal metabolic rate. Although glycemia during a glucose tolerance test was similar, KO males as well as HFD-fed females had lower plasma insulin and C-peptide levels compared to WT mice, suggesting improved insulin sensitivity. Remarkably, all KO animals exhibited higher circulating adiponectin levels, suggesting that this phenotype can occur even in the absence of a significant reduction in adipose tissue weight, as observed in females and, thus, may be a specific effect related to the (PRR. Conclusions: (PRR may be an important therapeutic target for the treatment of obesity and its associated complications such as type 2 diabetes. Keywords: (Prorenin receptor, Renin-angiotensin system, Adipose

  11. In vivo kinetics of 123I-labelled insulin: studies in normal subjects and patients with diabetes mellitus

    International Nuclear Information System (INIS)

    Sinclair, A.J.; Signore, A.; Bomanji, J.; Britton, K.E.; Pozzilli, P.; Gale, E.A.M.

    1987-01-01

    Radioactive tracer techniques using 131 I- and 125 I-insulin have been applied to study insulin metabolism. A simple method to label human insulin with 123 I to a high specific activity is described. We have used this radiotracer to study insulin kinetics in vivo in normal subjects and in two groups of diabetic patients. The rate of decline in plasma radioactivity was shown to be significantly reduced in patients with diabetes. There were no significant differences in the time -activity profiles of liver and kidneys between the groups studied. This technique may provide insight into the mechanism of some forms of insulin resistance. (author)

  12. Associations of objective physical activity with insulin sensitivity and circulating adipokine profile

    DEFF Research Database (Denmark)

    Spartano, N L; Stevenson, M D; Xanthakis, V

    2017-01-01

    The purpose of this study was to explore the relation of physical activity (PA) and sedentary time (SED) to insulin sensitivity and adipokines. We assessed PA and SED using Actical accelerometers and insulin resistance (HOMA-IR) in 2109 participants (free of type 1 and 2 diabetes mellitus) from...

  13. Prior AICAR stimulation increases insulin sensitivity in mouse skeletal muscle in an AMPK-dependent manner

    DEFF Research Database (Denmark)

    Kjøbsted, Rasmus; Treebak, Jonas Thue; Fentz, Joachim

    2015-01-01

    Acute exercise increases glucose uptake in skeletal muscle by an insulin-independent mechanism. In the period after exercise insulin sensitivity to increase glucose uptake is enhanced. The molecular mechanisms underpinning this phenomenon are poorly understood, but appear to involve an increased ...

  14. Partial disruption of lipolysis increases postexercise insulin sensitivity in skeletal muscle despite accumulation of DAG

    DEFF Research Database (Denmark)

    Serup, Annette Karen Lundbeck; Alsted, Thomas Junker; Jordy, Andreas Børsting

    2016-01-01

    reactivity in vitro, we investigated if the described function of DAGs as mediators of lipid-induced insulin resistance was depending on the different DAG-isomers. We measured insulin stimulated glucose uptake in hormone sensitive lipase (HSL) knock out (KO) mice after treadmill exercise to stimulate...

  15. Effect of Moderate Alcohol Consumption on Adiponectin, Tumor Necrosis Factor-α, and Insulin Sensitivity

    NARCIS (Netherlands)

    Sierksma, A.; Patel, H.; Ouchi, N.; Kihara, S.; Funahashi, T.; Heine, R.J.; Grobbee, D.E.; Kluft, C.; Hendriks, H.F.J.

    2004-01-01

    OBJECTIVE - Epidemiological studies suggest that moderate alcohol consumers have enhanced insulin sensitivity and a reduced risk of type 2 diabetes. Adiponectin, an adipocyte-derived plasma protein, has been found to be negatively associated with adiposity and positively associated with insulin

  16. Sexual dimorphism in hepatic, adipose tissue and peripheral tissue insulin sensitivity in obese humans

    Directory of Open Access Journals (Sweden)

    Kasper W. ter Horst

    2015-11-01

    Full Text Available Glucose and lipid metabolism differ between men and women, and women tend to have better whole-body or muscle insulin sensitivity. This may be explained, in part, by differences in sex hormones and adipose tissue distribution. Few studies have investigated gender differences in hepatic, adipose tissue and whole-body insulin sensitivity between severely obese men and women. In this study, we aimed to determine the differences in glucose metabolism between severely obese men and women using tissue-specific measurements of insulin sensitivity. Insulin sensitivity was compared between age and body mass index (BMI-matched obese men and women by a two-step euglycemic hyperinsulinemic clamp with infusion of [6,6-2H2]glucose. Basal endogenous glucose production and insulin sensitivity of the liver, adipose tissue and peripheral tissues were assessed. Liver fat content was assessed by proton magnetic resonance spectroscopy in a subset of included subjects. We included 46 obese men and women (age, 48±2 vs 46±2 years, p=0.591; BMI, 41±1 vs 41±1 kg/m2, p=0.832. There was no difference in basal endogenous glucose production (14.4±1.0 vs 15.3±0.5 µmol•kg fat-free mass-1•min-1, p=0.410, adipose tissue insulin sensitivity (insulin-mediated suppression of free fatty acids, 71.6±3.6 vs 76.1±2.6%, p=0.314 or peripheral insulin sensitivity (insulin-stimulated rate of disappearance of glucose, 26.2±2.1 vs 22.7±1.7 µmol•kg-1•min-1, p=0.211. Obese men were characterized by lower hepatic insulin sensitivity (insulin-mediated suppression of endogenous glucose production, 61.7±4.1 vs 72.8±2.5% in men vs women, resp., p=0.028. Finally, these observations could not be explained by differences in liver fat content (men vs women, 16.5±3.1 vs 16.0±2.5%, p=0.913, n=27.We conclude that obese men have lower hepatic, but comparable adipose tissue and peripheral tissue, insulin sensitivity compared to similarly obese women. Hepatic insulin resistance may

  17. Insulin Sensitivity and Mortality Risk Estimation in Patients with Type ...

    African Journals Online (AJOL)

    2016-07-15

    Jul 15, 2016 ... density lipoprotein cholesterol (LDL), triglycerides (TG), high‑density lipoprotein cholesterol (HDL), urinary albumin‑to‑creatinine ratio ... the mortality risk scores in patients with T2DM and its relationship with insulin resistance.

  18. Study on the insulin resistance and β-cell function in individuals with normal and those with abnormal glucose metabolism

    International Nuclear Information System (INIS)

    Wei Zikun

    2006-01-01

    Objective: To study the insulin resistance and β-cell function in individuals with normal glucose tolerance (NGT) and those with glucose metabolism dysfunction. Methods: Insulin resistance and β-cell function were studied with oral glucose tolerance test and the following parameters: 2h insulin/2h plasma glucose (2hIns/2hPG), insulin resistance index (IRI), insulin sensitivity index (ISI) and 30 min net increment of insulin/30min net increment of glucose (AI 30 /AG 30 ) were examined in 44 individuals with NGT, 45 subjects with impaired glucose tolerance (IGT), 66 recently diagnosed diabetics and 175 well-established diabetics. Results: The insulin resistance index (IRI) increased progressively from that in NGT individuals to that in recently diabetics (20 ± 1. 5→3.1 ± 1.6→4.1 ± 1.8), while the 2hIns/2hPG, ΔI 30 /ΔG 30 and ISI decreased progressively with significant differences between those in successive groups (P 30 /ΔG 30 and ISI kept decreasing (values in patients with disease history less than 3 yrs vs those in patients with disease over 3yrs: 2.9 ± 3.2 vs 2.4 + 2.3, 30.2 + 1.1 vs 23.4 ± 2.3, P 30 /ΔG 30 were significantly correlated with ISI (F =96.3, 58.4 and 47.5 respectively). For principal component analysis display, the cumulative contribution rate of four parameters (2hIns/2hPG, ISI, ΔI 30 /ΔG 30 and 2h C-peptide) exceeded 85% (86.5%). Conclusion: As the dysfunction of glucose metabolism proceeded from IGT to well established diabetes, the IR increased first with decrease of β-cell secretion followed. The parameters 2hIns/2hPG, ISI, 2h C-peptide ΔI 30 /ΔG 30 were especially useful for the investigation . (authors)

  19. Effects of High Fat Diet and Physical Exercise on Glucose Tolelance and Insulin Sensitivity in Rats

    OpenAIRE

    福田,哲也

    1987-01-01

    To investigate the interrelationships between the westernized diet and physical exercise as they affect the development of non-insulin-dependent diabetes mellitus (NIDDM), adiposity, glucose tolerance and insulin response to an intraperitoneal glucose load (1.5g/kg bw) and insulin sensitivity to exogenous insulin (0.2U/kg bw) were studied in spontaneously exercised and sedentary rats fed either a high fat diet (40% fat, modern western type) or a low fat diet (10% fat, traditional Japanese typ...

  20. Endurance training improves insulin sensitivity and body composition in prostate cancer patients treated with androgen deprivation therapy.

    Science.gov (United States)

    Hvid, Thine; Winding, Kamilla; Rinnov, Anders; Dejgaard, Thomas; Thomsen, Carsten; Iversen, Peter; Brasso, Klaus; Mikines, Kari J; van Hall, Gerrit; Lindegaard, Birgitte; Solomon, Thomas P J; Pedersen, Bente K

    2013-10-01

    Insulin resistance and changes in body composition are side effects of androgen deprivation therapy (ADT) given to prostate cancer patients. The present study investigated whether endurance training improves insulin sensitivity and body composition in ADT-treated prostate cancer patients. Nine men undergoing ADT for prostate cancer and ten healthy men with normal testosterone levels underwent 12 weeks of endurance training. Primary endpoints were insulin sensitivity (euglycemic-hyperinsulinemic clamps with concomitant glucose-tracer infusion) and body composition (dual-energy X-ray absorptiometry and magnetic resonance imaging). The secondary endpoint was systemic inflammation. Statistical analysis was carried out using two-way ANOVA. Endurance training increased VO2max (ml(O2)/min per kg) by 11 and 13% in the patients and controls respectively (PBody weight (Pbody fat mass (FM) (Pbody mass (P=0.99) was unchanged. Additionally, reductions were observed in abdominal (Pcancer patients exhibited improved insulin sensitivity and body composition to a similar degree as eugonadal men.

  1. Assessment of insulin sensitivity/resistance and their relations with leptin concentrations and anthropometric measures in a pregnant population with and without gestational diabetes mellitus.

    Science.gov (United States)

    Yilmaz, Ozgur; Kucuk, Mert; Ilgin, Aydin; Dagdelen, Muride

    2010-01-01

    Fifty-six pregnant women with gestational diabetes mellitus (GDM) and 42 normal glucose tolerant (NGT) pregnant women between 26 and 36 gestational weeks were included in the study prospectively. The body fat percentage (BFP) was calculated using the Siri formula from skinfold thickness (SFT) measurements. Both groups were comparable for gestational age, height, weight, and body mass index (P>.05). Insulin resistance assessed by homeostasis model assessment for insulin resistance (HOMA-IR) method was significantly higher in GDM patients compared to their NGT weight-matched control group. In contrast, the insulin sensitivity calculated from quantitative insulin sensitivity check index (QUICKI-IS) equation was significantly lower in GDM group. Calculated lean body mass was found to be similar in between both groups. Body fat percentage derived from SFT parameters was significantly higher in women with GDM. Women with GDM had significantly higher levels of serum insulin and leptin concentrations when compared with the NGT group. All SFT measurements were higher in GDM group when compared to those in NGT women. We did not find any correlation between leptin levels and insulin resistance; we found negative correlation between leptin levels and insulin sensitivity. Thus, we observed that leptin may contribute development of GDM by decreasing insulin sensitivity but not increasing insulin resistance. Also, we observed that the BFP estimated by the Siri formula from SFT measurements correlated significantly with HOMA-IR and QUICKI-IS and leptin concentrations in pregnant women. We suggest that by simply evaluating SFT, we may hold a view about BFP and leptin concentrations and insulin sensitivity in pregnant women.

  2. Similar weight-adjusted insulin secretion and insulin sensitivity in short-duration late autoimmune diabetes of adulthood (LADA) and Type 2 diabetes

    DEFF Research Database (Denmark)

    Juhl, C B; Bradley, U; Holst, Jens Juul

    2014-01-01

    AIMS: To explore insulin sensitivity and insulin secretion in people with latent autoimmune diabetes in adulthood (LADA) compared with that in people with Type 2 diabetes. METHODS: A total of 12 people with LADA, defined as glutamic acid decarboxylase (GAD) antibody positivity and > 1 year...... of insulin independency (group A) were age-matched pairwise to people with Type 2 diabetes (group B) and to six people with Type 2 diabetes of similar age and BMI (group C). β-cell function (first-phase insulin secretion and assessment of insulin pulsatility), insulin sensitivity (hyperinsulinemic......-euglycemic clamp) and metabolic response during a mixed meal were studied. RESULTS: Both first-phase insulin secretion and insulin release during the meal were greater (P = 0.05 and P = 0.009, respectively) in Type 2 diabetes as compared with LADA; these differences were lost on adjustment for BMI (group C...

  3. P21-activated kinase 2 (PAK2) regulates glucose uptake and insulin sensitivity in neuronal cells.

    Science.gov (United States)

    Varshney, Pallavi; Dey, Chinmoy Sankar

    2016-07-05

    P21-activated kinases (PAKs) are recently reported as important players of insulin signaling and glucose homeostasis in tissues like muscle, pancreas and liver. However, their role in neuronal insulin signaling is still unknown. Present study reports the involvement of PAK2 in neuronal insulin signaling, glucose uptake and insulin resistance. Irrespective of insulin sensitivity, insulin stimulation decreased PAK2 activity. PAK2 downregulation displayed marked enhancement of GLUT4 translocation with increase in glucose uptake whereas PAK2 over-expression showed its reduction. Treatment with Akti-1/2 and wortmannin suggested that Akt and PI3K are mediators of insulin effect on PAK2 and glucose uptake. Rac1 inhibition demonstrated decreased PAK2 activity while inhibition of PP2A resulted in increased PAK2 activity, with corresponding changes in glucose uptake. Taken together, present study demonstrates an inhibitory role of insulin signaling (via PI3K-Akt) and PP2A on PAK2 activity and establishes PAK2 as a Rac1-dependent negative regulator of neuronal glucose uptake and insulin sensitivity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. Stimulatory effect of insulin on glucose uptake by muscle involves the central nervous system in insulin-sensitive mice

    NARCIS (Netherlands)

    Coomans, Claudia P.; Biermasz, Nienke R.; Geerling, Janine J.; Guigas, Bruno; Rensen, Patrick C. N.; Havekes, Louis M.; Romijn, Johannes A.

    2011-01-01

    Insulin inhibits endogenous glucose production (EGP) and stimulates glucose uptake in peripheral tissues. Hypothalamic insulin signaling is required for the inhibitory effects of insulin on EGP. We examined the contribution of central insulin signaling on circulating insulin-stimulated

  5. Stimulatory effect of insulin on glucose uptake by muscle involves the central nervous system in insulin-sensitive mice

    NARCIS (Netherlands)

    Coomans, C.P.; Biermasz, N.R.; Geerling, J.J.; Guigas, B.; Rensen, P.C.N.; Havekes, L.M.; Romijn, J.A.

    2011-01-01

    OBJECTIVE - Insulin inhibits endogenous glucose production (EGP) and stimulates glucose uptake in peripheral tissues. Hypothalamic insulin signaling is required for the inhibitory effects of insulin on EGP. We examined the contribution of central insulin signaling on circulating insulin-stimulated

  6. mTORC2 Regulation of Muscle Metabolism and Insulin Sensitivity

    DEFF Research Database (Denmark)

    Kleinert, Maximilian

    and skeletal muscle to take up blood glucose, ultimately lowering blood glucose levels. A hallmark of T2D is decreased organ sensitivity to the effects of the insulin. Therefore, an early event in the pathogenesis of T2D is an increase in insulin secretion in response to eating a meal, as more insulin....... In the absence of insulin, the majority of GLUT4 resides within the muscle. Conversely, insulin stimulation increases the muscle’s permeability to glucose, by triggering GLUT4 translocation to the plasma membrane. The effect of insulin on GLUT4 translocation is mediated by a chain of molecular signaling events...... that mTORC2 controls skeletal muscle glycolysis and lipid storage. In agreement, Ric mKO mice exhibited reduced muscle glycolytic flux, greater reliance on fat as an energy substrate, re-partitioning of lean to fat mass and higher intramyocellular triacylglycerol (IMTG) levels compared to Ric WT mice...

  7. Aerobic Exercise Increases Peripheral and Hepatic Insulin Sensitivity in Sedentary Adolescents

    NARCIS (Netherlands)

    van der Heijden, Gert-Jan; Toffolo, Gianna; Manesso, Erica; Sauer, Pieter J. J.; Sunehag, Agneta L.

    2009-01-01

    Context: Data are limited on the effects of controlled aerobic exercise programs (without weight loss) on insulin sensitivity and glucose metabolism in children and adolescents. Objective: To determine whether a controlled aerobic exercise program (without weight loss) improves peripheral and

  8. Effect of training on insulin sensitivity of glucose uptake and lipolysis in human adipose tissue

    DEFF Research Database (Denmark)

    Stallknecht, B; Larsen, J J; Mikines, K J

    2000-01-01

    Training increases insulin sensitivity of both whole body and muscle in humans. To investigate whether training also increases insulin sensitivity of adipose tissue, we performed a three-step hyperinsulinemic, euglycemic clamp in eight endurance-trained (T) and eight sedentary (S) young men...... (glucose only). Adipose tissue blood flow was measured by (133)Xe washout. In the basal state, adipose tissue blood flow tended to be higher in T compared with S subjects, and in both groups blood flow was constant during the clamp. The change from basal in arterial-interstitial glucose concentration......-time: T, 44 +/- 9 min (n = 7); S, 102 +/- 23 min (n = 5); P training enhances insulin sensitivity of glucose uptake in subcutaneous adipose tissue and in skeletal muscle. Furthermore, interstitial glycerol data suggest that training also increases insulin sensitivity of lipolysis...

  9. High intensity interval training improves liver and adipose tissue insulin sensitivity

    Directory of Open Access Journals (Sweden)

    Katarina Marcinko

    2015-12-01

    Conclusions: These data indicate that HIIT lowers blood glucose levels by improving adipose and liver insulin sensitivity independently of changes in adiposity, adipose tissue inflammation, liver lipid content or AMPK phosphorylation of ACC.

  10. Effects of Lactobacillus acidophilus NCFM on insulin sensitivity and the systemic inflammatory response in human subjects

    DEFF Research Database (Denmark)

    Andreasen, Anne Sofie; Larsen, Nadja; Pedersen-Skovsgaard, Theis

    2010-01-01

    According to animal studies, intake of probiotic bacteria may improve glucose homeostasis. We hypothesised that probiotic bacteria improve insulin sensitivity by attenuating systemic inflammation. Therefore, the effects of oral supplementation with the probiotic bacterium Lactobacillus acidophilus...

  11. Peri and Postparturient Concentrations of Lipid Lipoprotein Insulin and Glucose in Normal Dairy Cows

    OpenAIRE

    BAŞOĞLU, Abdullah; SEVİNÇ, Mutlu; OK, Mahmut

    1998-01-01

    In order to provide uniqe insight into the metabolic disturbences seen after calving cholesterol, triglycerid, high density lipoprotein, low density lipoprotein, very low density lipoprotein, glucose and insulin levels in serum were studied before calving (group I), in aerly (group II) and late (group III) lactation in 24 normal cows. Serum lipoproteins were separeted into various density classes by repeated ultracentrifugation. The results indicate that there was a rise in glucose, trygl...

  12. Environmental factors and dam characteristics associated with insulin sensitivity and insulin secretion in newborn Holstein calves

    International Nuclear Information System (INIS)

    Kamal, M.M.; Van Eetvelde, M.; Bogaert, H.; Hostens, M.; Vandaele, L.; Shamsuddin, M.; Opsomer, G.

    2015-01-01

    The objective of the present retrospective cohort study was to evaluate potential associations between environmental factors and dam characteristics, including level of milk production during gestation, and insulin traits in newborn Holstein calves

  13. A two-week reduction of ambulatory activity attenuates peripheral insulin sensitivity

    DEFF Research Database (Denmark)

    Krogh-Madsen, Rikke; Thyfault, John P; Broholm, Christa

    2009-01-01

    after step reduction, with a post hoc analysis revealing the most pronounced effect after 4 h of insulin infusion. In addition, the two-week period induced a 7% decline in VO2max (ml/min; cardiovascular fitness). Lean mass of legs, but not arms and truck, decreased concurrently. Taken together, one...... possible biological cause for the public health problem of type 2 diabetes has been identified. Reduced ambulatory activity for two weeks in healthy, non-exercising young men significantly reduced peripheral insulin sensitivity, cardiovascular fitness, and lean leg mass. Key words: Inactivity, Insulin...... number of daily steps induced a significant reduction of 17% in the glucose infusion rate (GIR) during the clamp. This reduction was due to a decline in peripheral insulin sensitivity with no effect on hepatic endogenous glucose production. The insulin-stimulated ratio of pAkt(thr308)/total Akt decreased...

  14. Metabolic and fibrinolytic response to changed insulin sensitivity in users of oral contraceptives

    DEFF Research Database (Denmark)

    Petersen, Kresten R.; Christiansen, Erik; Madsbad, Sten

    1999-01-01

    systems, are relevant in the evaluation of the risk of developing vascular disorders or diabetes in OC users. We studied insulin sensitivity index (S(I)), glucose effectiveness (S(g)), and insulin response in young, healthy women by frequently sampled intravenous glucose tolerance tests before and after...... randomization to 6 months of treatment with ethinyl estradiol in triphasic combination with norgestimate (n = 17) or gestodene (n = 20). Measurements of fasting triglycerides and antigen concentrations of tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1) were also...... included. Both compounds increased fasting plasma insulin and reduced S(i) but did not affect S(g). The relationships between S(i) and insulin response were unchanged. No consistent correlation between insulin sensitivity and triglycerides, t-PA, or PAI-1 were demonstrated before or during treatment. We...

  15. A low-fat diet improves peripheral insulin sensitivity in patients with Type 1 diabetes

    DEFF Research Database (Denmark)

    Rosenfalck, A M; Almdal, T; Viggers, L

    2006-01-01

    To compare the effects on insulin sensitivity, body composition and glycaemic control of the recommended standard weight-maintaining diabetes diet and an isocaloric low-fat diabetes diet during two, 3-month periods in patients with Type 1 diabetes.......To compare the effects on insulin sensitivity, body composition and glycaemic control of the recommended standard weight-maintaining diabetes diet and an isocaloric low-fat diabetes diet during two, 3-month periods in patients with Type 1 diabetes....

  16. Adenoviral gene transfer of PLD1-D4 enhances insulin sensitivity in mice by disrupting phospholipase D1 interaction with PED/PEA-15.

    Directory of Open Access Journals (Sweden)

    Angela Cassese

    Full Text Available Over-expression of phosphoprotein enriched in diabetes/phosphoprotein enriched in astrocytes (PED/PEA-15 causes insulin resistance by interacting with the D4 domain of phospholipase D1 (PLD1. Indeed, the disruption of this association restores insulin sensitivity in cultured cells over-expressing PED/PEA-15. Whether the displacement of PLD1 from PED/PEA-15 improves insulin sensitivity in vivo has not been explored yet. In this work we show that treatment with a recombinant adenoviral vector containing the human D4 cDNA (Ad-D4 restores normal glucose homeostasis in transgenic mice overexpressing PED/PEA-15 (Tg ped/pea-15 by improving both insulin sensitivity and secretion. In skeletal muscle of these mice, D4 over-expression inhibited PED/PEA-15-PLD1 interaction, decreased Protein Kinase C alpha activation and restored insulin induced Protein Kinase C zeta activation, leading to amelioration of insulin-dependent glucose uptake. Interestingly, Ad-D4 administration improved insulin sensitivity also in high-fat diet treated obese C57Bl/6 mice. We conclude that PED/PEA-15-PLD1 interaction may represent a novel target for interventions aiming at improving glucose tolerance.

  17. Aging and insulin signaling differentially control normal and tumorous germline stem cells.

    Science.gov (United States)

    Kao, Shih-Han; Tseng, Chen-Yuan; Wan, Chih-Ling; Su, Yu-Han; Hsieh, Chang-Che; Pi, Haiwei; Hsu, Hwei-Jan

    2015-02-01

    Aging influences stem cells, but the processes involved remain unclear. Insulin signaling, which controls cellular nutrient sensing and organismal aging, regulates the G2 phase of Drosophila female germ line stem cell (GSC) division cycle in response to diet; furthermore, this signaling pathway is attenuated with age. The role of insulin signaling in GSCs as organisms age, however, is also unclear. Here, we report that aging results in the accumulation of tumorous GSCs, accompanied by a decline in GSC number and proliferation rate. Intriguingly, GSC loss with age is hastened by either accelerating (through eliminating expression of Myt1, a cell cycle inhibitory regulator) or delaying (through mutation of insulin receptor (dinR) GSC division, implying that disrupted cell cycle progression and insulin signaling contribute to age-dependent GSC loss. As flies age, DNA damage accumulates in GSCs, and the S phase of the GSC cell cycle is prolonged. In addition, GSC tumors (which escape the normal stem cell regulatory microenvironment, known as the niche) still respond to aging in a similar manner to normal GSCs, suggesting that niche signals are not required for GSCs to sense or respond to aging. Finally, we show that GSCs from mated and unmated females behave similarly, indicating that female GSC-male communication does not affect GSCs with age. Our results indicate the differential effects of aging and diet mediated by insulin signaling on the stem cell division cycle, highlight the complexity of the regulation of stem cell aging, and describe a link between ovarian cancer and aging. © 2014 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  18. Glutathione depletion prevents diet-induced obesity and enhances insulin sensitivity.

    Science.gov (United States)

    Findeisen, Hannes M; Gizard, Florence; Zhao, Yue; Qing, Hua; Jones, Karrie L; Cohn, Dianne; Heywood, Elizabeth B; Bruemmer, Dennis

    2011-12-01

    Excessive accumulation of reactive oxygen species (ROS) in adipose tissue has been implicated in the development of insulin resistance and type 2 diabetes. However, emerging evidence suggests a physiologic role of ROS in cellular signaling and insulin sensitivity. In this study, we demonstrate that pharmacologic depletion of the antioxidant glutathione in mice prevents diet-induced obesity, increases energy expenditure and locomotor activity, and enhances insulin sensitivity. These observations support a beneficial role of ROS in glucose homeostasis and warrant further research to define the regulation of metabolism and energy balance by ROS.

  19. AgRP Neurons Control Systemic Insulin Sensitivity via Myostatin Expression in Brown Adipose Tissue.

    Science.gov (United States)

    Steculorum, Sophie M; Ruud, Johan; Karakasilioti, Ismene; Backes, Heiko; Engström Ruud, Linda; Timper, Katharina; Hess, Martin E; Tsaousidou, Eva; Mauer, Jan; Vogt, Merly C; Paeger, Lars; Bremser, Stephan; Klein, Andreas C; Morgan, Donald A; Frommolt, Peter; Brinkkötter, Paul T; Hammerschmidt, Philipp; Benzing, Thomas; Rahmouni, Kamal; Wunderlich, F Thomas; Kloppenburg, Peter; Brüning, Jens C

    2016-03-24

    Activation of Agouti-related peptide (AgRP) neurons potently promotes feeding, and chronically altering their activity also affects peripheral glucose homeostasis. We demonstrate that acute activation of AgRP neurons causes insulin resistance through impairment of insulin-stimulated glucose uptake into brown adipose tissue (BAT). AgRP neuron activation acutely reprograms gene expression in BAT toward a myogenic signature, including increased expression of myostatin. Interference with myostatin activity improves insulin sensitivity that was impaired by AgRP neurons activation. Optogenetic circuitry mapping reveals that feeding and insulin sensitivity are controlled by both distinct and overlapping projections. Stimulation of AgRP → LHA projections impairs insulin sensitivity and promotes feeding while activation of AgRP → anterior bed nucleus of the stria terminalis (aBNST)vl projections, distinct from AgRP → aBNSTdm projections controlling feeding, mediate the effect of AgRP neuron activation on BAT-myostatin expression and insulin sensitivity. Collectively, our results suggest that AgRP neurons in mice induce not only eating, but also insulin resistance by stimulating expression of muscle-related genes in BAT, revealing a mechanism by which these neurons rapidly coordinate hunger states with glucose homeostasis. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Liraglutide increases FGF-21 activity and insulin sensitivity in high fat diet and adiponectin knockdown induced insulin resistance.

    Directory of Open Access Journals (Sweden)

    Mengliu Yang

    Full Text Available BACKGROUND: Liraglutide is a glucagon-like peptide-1 analogue that stimulates insulin secretion and improves β-cell function. However, it is not clear whether liraglutide achieves its glucose lowering effect only by its known effects or whether other as yet unknown mechanisms are involved. The aim of this study was to examine the effects of liraglutide on Fibroblast growth factor-21 (FGF-21 activity in High-fat diet (HFD fed ApoE(-/- mice with adiponectin (Acrp30 knockdown. METHOD: HFD-fed ApoE(-/- mice were treated with adenovirus vectors expressing shAcrp30 to produce insulin resistance. Hyperinsulinemic-euglycemic clamp studies were performed to evaluate insulin sensitivity of the mouse model. QRT-PCR and Western blot were used to measure the mRNA and protein expression of the target genes. RESULTS: The combination of HFD, ApoE deficiency, and hypoadiponectinemia resulted in an additive effect on insulin resistance. FGF-21 mRNA expressions in both liver and adipose tissues were significantly increased while FGF-21 receptor 1 (FGFR-1 and β-Klotho mRNA levels in adipose tissue, as well as FGFR-1-3 and β-Klotho mRNA levels in liver were significantly decreased in this model. Liraglutide treatment markedly improved insulin resistance and increased FGF-21 expression in liver and FGFR-3 in adipose tissue, restored β-Klotho mRNA expression in adipose tissue as well as FGFR-1-3, β-Klotho levels and phosphorylation of FGFR1 up to the levels observed in control mice in liver. Liraglutide treatment also further increased FGF-21 proteins in liver and plasma. In addition, as shown by hyperinsulinemic-euglycemic clamp, liraglutide treatment also markedly improved glucose metabolism and insulin sensitivity in these animals. CONCLUSION: These findings demonstrate an additive effect of HFD, ApoE deficiency, and adiponectin knockdown on insulin resistance and unveil that the regulation of glucose metabolism and insulin sensitivity by liraglutide may be

  1. 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.

  2. Polyunsaturated fatty acids acutely affect triacylglycerol-derived skeletal muscle fatty acid uptake and increases postprandial insulin sensitivity

    NARCIS (Netherlands)

    Jans, Anneke; Konings, Ellen; Goossens, Gijs H.; Bouwman, Freek G.; Moors, Chantalle C.; Boekschoten, Mark; Afman, Lydia; Muller, Michael; Mariman, Edwin C.; Blaak, Ellen E.

    2012-01-01

    Dietary fat quality may influence skeletal muscle lipid handling and fat accumulation, thereby modulating insulin sensitivity. Objective: To examine acute effects of meals with various fatty acid (FA) compositions on skeletal muscle FA handling and postprandial insulin sensitivity in obese insulin

  3. Maternal insulin sensitivity is associated with oral glucose-induced changes in fetal brain activity.

    Science.gov (United States)

    Linder, Katarzyna; Schleger, Franziska; Ketterer, Caroline; Fritsche, Louise; Kiefer-Schmidt, Isabelle; Hennige, Anita; Häring, Hans-Ulrich; Preissl, Hubert; Fritsche, Andreas

    2014-06-01

    Fetal programming plays an important role in the pathogenesis of type 2 diabetes. The aim of the present study was to investigate whether maternal metabolic changes during OGTT influence fetal brain activity. Thirteen healthy pregnant women underwent an OGTT (75 g). Insulin sensitivity was determined by glucose and insulin measurements at 0, 60 and 120 min. At each time point, fetal auditory evoked fields were recorded with a fetal magnetoencephalographic device and response latencies were determined. Maternal insulin increased from a fasting level of 67 ± 25 pmol/l (mean ± SD) to 918 ± 492 pmol/l 60 min after glucose ingestion and glucose levels increased from 4.4 ± 0.3 to 7.4 ± 1.1 mmol/l. Over the same time period, fetal response latencies decreased from 297 ± 99 to 235 ± 84 ms (p = 0.01) and then remained stable until 120 min (235 ± 84 vs 251 ± 91 ms, p = 0.39). There was a negative correlation between maternal insulin sensitivity and fetal response latencies 60 min after glucose ingestion (r = 0.68, p = 0.02). After a median split of the group based on maternal insulin sensitivity, fetuses of insulin-resistant mothers showed a slower response to auditory stimuli (283 ± 79 ms) than those of insulin-sensitive mothers (178 ± 46 ms, p = 0.03). Lower maternal insulin sensitivity is associated with slower fetal brain responses. These findings provide the first evidence of a direct effect of maternal metabolism on fetal brain activity and suggest that central insulin resistance may be programmed during fetal development.

  4. Sustained NFκB inhibition improves insulin sensitivity but is detrimental to muscle health.

    Science.gov (United States)

    Zhang, Ning; Valentine, Joseph M; Zhou, You; Li, Mengyao E; Zhang, Yiqiang; Bhattacharya, Arunabh; Walsh, Michael E; Fischer, Katherine E; Austad, Steven N; Osmulski, Pawel; Gaczynska, Maria; Shoelson, Steven E; Van Remmen, Holly; Chen, Hung I; Chen, Yidong; Liang, Hanyu; Musi, Nicolas

    2017-08-01

    Older adults universally suffer from sarcopenia and approximately 60-70% are diabetic or prediabetic. Nonetheless, the mechanisms underlying these aging-related metabolic disorders are unknown. NFκB has been implicated in the pathogenesis of several aging-related pathologies including sarcopenia and type 2 diabetes and has been proposed as a target against them. NFκB also is thought to mediate muscle wasting seen with disuse, denervation, and some systemic diseases (e.g., cancer, sepsis). We tested the hypothesis that lifelong inhibition of the classical NFκB pathway would protect against aging-related sarcopenia and insulin resistance. Aged mice with muscle-specific overexpression of a super-repressor IκBα mutant (MISR) were protected from insulin resistance. However, MISR mice were not protected from sarcopenia; to the contrary, these mice had decreases in muscle mass and strength compared to wild-type mice. In MISR mice, NFκB suppression also led to an increase in proteasome activity and alterations in several genes and pathways involved in muscle growth and atrophy (e.g., myostatin). We conclude that the mechanism behind aging-induced sarcopenia is NFκB independent and differs from muscle wasting due to pathologic conditions. Our findings also indicate that, while suppressing NFκB improves insulin sensitivity in aged mice, this transcription factor is important for normal muscle mass maintenance and its sustained inhibition is detrimental to muscle function. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  5. Effects of exercise training on glucose control, lipid metabolism, and insulin sensitivity in hypertriglyceridemia and non-insulin dependent diabetes mellitus.

    Science.gov (United States)

    Lampman, R M; Schteingart, D E

    1991-06-01

    Exercise training has potential benefits for patients with hyperlipidemia and/or non-insulin dependent diabetes mellitus. In nondiabetic, nonobese subjects with hypertriglyceridemia, exercise training alone increased insulin sensitivity, improved glucose tolerance, and lowered serum triglyceride and cholesterol levels. These improvements did not occur when exercise training alone was given to similar patients with impaired glucose tolerance. In severely obese (X = 125 kg) subjects without diabetes melitus, a 600 calorie diet alone decreased glucose and insulin concentrations and improved glucose tolerance but did not increase insulin sensitivity. The addition of exercise training improved insulin sensitivity. Obese, non-insulin dependent diabetes mellitus subjects on sulfonylurea therapy alone increased insulin levels but failed to improve insulin sensitivity or glucose levels. In contrast, the addition of exercise training to this medication resulted in improved insulin sensitivity and lowered glucose levels. We conclude that exercise training has major effects on lowering triglyceride levels in hyperlipidemic subjects and can potentiate the effect of diet or drug therapy on glucose metabolism in patients with non-insulin dependent diabetes mellitus.

  6. Effects of Substituting Palm Olein with Carbohydrates on Insulin Sensitivity: A Review

    International Nuclear Information System (INIS)

    Kim-Tiu, T.; Faun, C.L.

    2016-01-01

    The role of palm olein on insulin resistance, which predisposes to disease progression of type 2 diabetes, is unclear. This article summarises the effects of substituting palm olein with carbohydrates on insulin sensitivity. Two intervention studies have reported conflicting findings. The RISCK (Reading, Imperial, Surreys, Cambridge and King's) study suggested that saturated fat-enriched diet consisting of mainly palm oil and milk fat did not differ from both high and low glycemic carbohydrates on insulin sensitivity in subjects at risk of developing metabolic syndrome. However, another study reported reduced insulin sensitivity after a diet enriched with palm olein and butter compared with high carbohydrate intake. No epidemiological data exists in this context. More clinical trials using solely palm olein in this area are needed. Further well-controlled large scale studies are needed to furnish the information on palm olein replacement with carbohydrates in diabetes prevention. (author)

  7. Insulin sensitivity : modulation by the gut-brain axis

    NARCIS (Netherlands)

    Heijboer, Annemieke Corine

    2006-01-01

    Er zijn steeds meer aanwijzingen dat neuropeptiden in de hypothalamus en maagdarmhormonen die hun werking hebben op de hypothalamus en betrokken zijn bij de regulatie van voedselinname, ook betrokken zouden kunnen zijn bij de regulatie van insuline gevoeligheid. Daarom hebben we eerst de effecten

  8. Ghrelin differentially affects hepatic and peripheral insulin sensitivity in mice

    NARCIS (Netherlands)

    Heijboer, A.C.; Hoek, A.M. van den; Parlevliet, E.T.; Havekes, L.M.; Romijn, J.A.; Pijl, H.; Corssmit, E.P.M.

    2006-01-01

    Aims/hypothesis: This study was conducted to evaluate the effects of ghrelin on insulin's capacity to suppress endogenous glucose production and promote glucose disposal in mice. To establish whether the growth hormone secretagogue (GHS) receptor can mediate the putative effect of ghrelin on the

  9. [Rosuvastatin improves insulin sensitivity in overweight rats induced by high fat diet. Role of SIRT1 in adipose tissue].

    Science.gov (United States)

    Valero-Muñoz, María; Martín-Fernández, Beatriz; Ballesteros, Sandra; Cachofeiro, Victoria; Lahera, Vicente; de Las Heras, Natalia

    2014-01-01

    To study the effects of rosuvastatin on insulin resistance in overweight rats induced by high fat diet, as well as potential mediators. We used male Wistar rats fed with a standard diet (CT) or high fat diet (33.5% fat) (HFD); half of the animals HFD were treated with rosuvastatin (15mg/kg/day) (HFD+Rosu) for 7 weeks. HFD rats showed increased body, epididymal and lumbar adipose tissue weights. Treatment with Rosu did not modify body weight or the weight of the adipose packages in HFD rat. Plasma glucose and insulin levels and HOMA index were higher in HFD rats, and rosuvastatin treatment reduced them. Leptin/adiponectin ratio in plasma and lumbar adipose tissue were higher in HDF rats, and were reduced by rosuvastatin. SIRT-1, PPAR-γ and GLUT-4 protein expression in lumbar adipose tissue were lower in HFD rats and Rosu normalized expression of the three mediators. Rosuvastatin ameliorates insulin sensitivity induced by HFD in rats. This effect is mediated by several mechanisms including reduction of leptin and enhancement of SIRT-1, PPAR-γ and GLUT-4 expression in white adipose tissue. SIRT1 could be considered a major mediator of the beneficial effects of rosuvastatin on insulin sensitivity in overweight rats induced by diet. Copyright © 2013 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

  10. Sensitivity of Raman spectroscopy to normal patient variability

    Science.gov (United States)

    Vargis, Elizabeth; Byrd, Teresa; Logan, Quinisha; Khabele, Dineo; Mahadevan-Jansen, Anita

    2011-11-01

    Many groups have used Raman spectroscopy for diagnosing cervical dysplasia; however, there have been few studies looking at the effect of normal physiological variations on Raman spectra. We assess four patient variables that may affect normal Raman spectra: Race/ethnicity, body mass index (BMI), parity, and socioeconomic status. Raman spectra were acquired from a diverse population of 75 patients undergoing routine screening for cervical dysplasia. Classification of Raman spectra from patients with a normal cervix is performed using sparse multinomial logistic regression (SMLR) to determine if any of these variables has a significant effect. Results suggest that BMI and parity have the greatest impact, whereas race/ethnicity and socioeconomic status have a limited effect. Incorporating BMI and obstetric history into classification algorithms may increase sensitivity and specificity rates of disease classification using Raman spectroscopy. Studies are underway to assess the effect of these variables on disease.

  11. "Symptom-based insulin adjustment for glucose normalization" (SIGN) algorithm: a pilot study.

    Science.gov (United States)

    Lee, Joyce Yu-Chia; Tsou, Keith; Lim, Jiahui; Koh, Feaizen; Ong, Sooim; Wong, Sabrina

    2012-12-01

    Lack of self-monitoring of blood glucose (SMBG) records in actual practice settings continues to create therapeutic challenges for clinicians, especially in adjusting insulin therapy. In order to overcome this clinical obstacle, a "Symptom-based Insulin adjustment for Glucose Normalization" (SIGN) algorithm was developed to guide clinicians in caring for patients with uncontrolled type 2 diabetes who have few to no SMBG records. This study examined the clinical outcome and safety of the SIGN algorithm. Glycated hemoglobin (HbA1c), insulin usage, and insulin-related adverse effects of a total of 114 patients with uncontrolled type 2 diabetes who refused to use SMBG or performed SMBG once a day for less than three times per week were studied 3 months prior to the implementation of the algorithm and prospectively at every 3-month interval for a total of 6 months after the algorithm implementation. Patients with type 1 diabetes, nonadherence to diabetes medications, or who were not on insulin therapy at any time during the study period were excluded from this study. Mean HbA1c improved by 0.29% at 3 months (P = 0.015) and 0.41% at 6 months (P = 0.006) after algorithm implementation. A slight increase in HbA1c was observed when the algorithm was not implemented. There were no major hypoglycemic episodes. The number of minor hypoglycemic episodes was minimal with the majority of the cases due to irregular meal habits. The SIGN algorithm appeared to offer a viable and safe approach when managing uncontrolled patients with type 2 diabetes who have few to no SMBG records.

  12. Site-specific differences of insulin action in adipose tissue derived from normal prepubertal children

    International Nuclear Information System (INIS)

    Grohmann, Malcolm; Stewart, Claire; Welsh, Gavin; Hunt, Linda; Tavare, Jeremy; Holly, Jeff; Shield, Julian; Sabin, Matt; Crowne, Elizabeth

    2005-01-01

    Body fat distribution determines obesity-related morbidity in adults but little is known of the aetiology or pathophysiology in children. This study investigates differences in insulin-mediated metabolism in primary cell cultures of subcutaneous and visceral preadipocytes derived from prepubertal children. The impact of differentiation and responses to TNFα exposure was also investigated. Proliferation rates were greater in subcutaneous versus visceral preadipocytes (41 h(3) versus 69 h(4); P = 0.008). Insulin caused a dose-dependent increase in GSK-3 phosphorylation and an increase in MAPK phosphorylation over time, with increased sensitivity in subcutaneous preadipocytes. Post-differentiation, dose-dependent increases in GSK-3 phosphorylation were maintained, while MAPK phosphorylation was identical in both subtypes. No changes were observed in insulin receptor abundance pre-/post-differentiation. GLUT4 abundance was significantly increased in visceral versus subcutaneous adipocytes by 76(4)%; P = 0.03), coincidental with increased insulin-stimulated 2-deoxy-glucose transport (+150(26)% versus +79(10)%; P = 0.014) and further elevated by acute exposure to TNFα (+230(52)%; P = 0.019 versus +123(24)%; P = 0.025, respectively). TNFα also significantly increased basal glucose transport rates (+44(14)%; P = 0.006 versus +34(11)%; P = 0.007) and GLUT1 localisation to the plasma membrane. These data establish site-specific differences in subcutaneous and visceral fat cells from children. Responses to insulin varied with differentiation and TNFα exposure in the two depots, consistent with parallel changes in GLUT1/4 abundance and localisation

  13. The product of triglycerides and glucose, a simple measure of insulin sensitivity. Comparison with the euglycemic-hyperinsulinemic clamp.

    Science.gov (United States)

    Guerrero-Romero, Fernando; Simental-Mendía, Luis E; González-Ortiz, Manuel; Martínez-Abundis, Esperanza; Ramos-Zavala, María G; Hernández-González, Sandra O; Jacques-Camarena, Omar; Rodríguez-Morán, Martha

    2010-07-01

    To meet the worldwide challenge of emerging diabetes, accessible and inexpensive tests to identify insulin resistance are needed. To evaluate the sensitivity and specificity of the product of fasting, we compared the triglycerides and glucose (TyG) index, a simple measure of insulin resistance, with the euglycemic-hyperinsulinemic clamp test. We conducted a cross-sectional study of the general population and outpatients of the Internal Medicine Department at the Medical Unit of High Specialty of the Specialty Hospital at the West National Medical Center in Guadalajara, Mexico. Eleven nonobese healthy subjects, 34 obese normal glucose tolerance individuals, 22 subjects with prediabetes, and 32 diabetic patients participated in the study. We performed a euglycemic-hyperinsulinemic clamp test. Sensitivity and specificity of the TyG index [Ln(fasting triglycerides) (mg/dl) x fasting glucose (mg/dl)/2] were measured, as well as the area under the curve of the receiver operating characteristic scatter plot and the correlation between the TyG index and the total glucose metabolism (M) rates. Pearson's correlation coefficient between the TyG index and M rates was -0.681 (P index and M rates was similar between men (-0.740) and women (-0.730), nonobese (-0.705) and obese (-0.710), and nondiabetic (-0.670) and diabetic (-0.690) individuals. The best value of the TyG index for diagnosis of insulin resistance was 4.68, which showed the highest sensitivity (96.5%) and specificity (85.0%; area under the curve + 0.858). The TyG index has high sensitivity and specificity, suggesting that it could be useful for identification of subjects with decreased insulin sensitivity.

  14. Resistance training, insulin sensitivity and muscle function in the elderly

    DEFF Research Database (Denmark)

    Dela, Flemming; Kjaer, Michael

    2006-01-01

    Ageing is associated with a loss in both muscle mass and in the metabolic quality of skeletal muscle. This leads to sarcopenia and reduced daily function, as well as to an increased risk for development of insulin resistance and type 2 diabetes. A major part, but not all, of these changes......, and likewise to improve muscle strength in both elderly healthy individuals and in elderly individuals with chronic disease. The increased strength is coupled to improved function and a decreased risk for fall injuries and fractures. Elderly individuals have preserved the capacity to improve muscle strength...... are associated with an age-related decrease in the physical activity level and can be counteracted by increased physical activity of a resistive nature. Strength training has been shown to improve insulin-stimulated glucose uptake in both healthy elderly individuals and patients with manifest diabetes...

  15. Insulin secretion enhancing activity of roselle calyx extract in normal and streptozotocin-induced diabetic rats

    Science.gov (United States)

    Wisetmuen, Eamruthai; Pannangpetch, Patchareewan; Kongyingyoes, Bunkerd; Kukongviriyapan, Upa; Yutanawiboonchai, Wiboonchai; Itharat, Arunporn

    2013-01-01

    Background and Objective: Our recent study revealed the antihyperglycemic activity of an ethanolic extract of roselle calyxes (Hibiscus sabdariffa) in diabetic rats. The present study had, therefore, an objective to investigate the mechanism underlying this activity. Materials and Methods: Male Sprague Dawley rats were induced to be diabetes by intraperitoneal injection of 45 mg/kg streptozotocin (STZ). Normal rats as well as diabetic rats were administered with the ethanolic extract of H. sabdariffa calyxes (HS-EE) at 0.1 and 1.0 g/kg/day, respectively, for 6 weeks. Then, blood glucose and insulin levels, at basal and glucose-stimulated secretions, were measured. The pancreas was dissected to examine histologically. Results: HS-EE 1.0 g/kg/day significantly decreased the blood glucose level by 38 ± 12% in diabetic rats but not in normal rats. In normal rats, treatment with 1.0 g/kg HS-EE increased the basal insulin level significantly as compared with control normal rats (1.28 ± 0.25 and 0.55 ± 0.05 ng/ml, respectively). Interestingly, diabetic rats treated with 1.0 g/kg HS-EE also showed a significant increase in basal insulin level as compared with the control diabetic rats (0.30 ± 0.05 and 0.15 ± 0.01 ng/ml, respectively). Concerning microscopic histological examination, HS-EE 1.0 g/kg significantly increased the number of islets of Langerhans in both normal rats (1.2 ± 0.1 and 2.0 ± 0.1 islet number/10 low-power fields (LPF) for control and HS-EE treated group, respectively) and diabetic rats (1.0 ± 0.3 and 3.9 ± 0.6 islet number/10 LPF for control and HS-EE treated group, respectively). Conclusion: The antidiabetic activity of HS-EE may be partially mediated via the stimulating effect on insulin secretion. PMID:23798879

  16. Temporal changes in sphingolipids and systemic insulin sensitivity during the transition from gestation to lactation.

    Directory of Open Access Journals (Sweden)

    J Eduardo Rico

    Full Text Available Reduced insulin action develops naturally during the peripartum to ensure maternal nutrient delivery to the fetus and neonate. However, increased insulin resistance can facilitate excessive lipolysis which in turn promotes metabolic disease in overweight dairy cattle. Increased fatty acid availability favors the accumulation of the sphingolipid ceramide and is implicated in the pathogenesis of insulin resistance, however, the relationship between sphingolipid metabolism and insulin resistance during the peripartum remains largely unknown. Our objectives were to characterize temporal responses in plasma and tissue sphingolipids in lean and overweight peripartal cows and to establish the relationships between sphingolipid supply and lipolysis, hepatic lipid deposition, and systemic insulin action. Twenty-one multiparous lean and overweight Holstein cows were enrolled in a longitudinal study spanning the transition from gestation to lactation (d -21 to 21, relative to parturition. Plasma, liver, and skeletal muscle samples were obtained, and sphingolipids were profiled using LC/MS/MS. Insulin sensitivity was assessed utilizing intravenous insulin and glucose challenges. Our results demonstrated the following: first, insulin resistance develops postpartum concurrently with increased lipolysis and hepatic lipid accumulation; second, ceramides and glycosylated ceramides accumulate during the transition from gestation to lactation and are further elevated in overweight cows; third, ceramide accrual is associated with lipolysis and liver lipid accumulation, and C16:0- and C24:0-ceramide are inversely associated with systemic insulin sensitivity postpartum; fourth, plasma sphingomyelin, a potential source of ceramides reaches a nadir at parturition and is closely associated with feed intake; fifth, select sphingomyelins are lower in the plasma of overweight cows during the peripartal period. Our results demonstrate that dynamic changes occur in

  17. Temporal changes in sphingolipids and systemic insulin sensitivity during the transition from gestation to lactation

    Science.gov (United States)

    Rico, J. Eduardo; Saed Samii, Sina; Mathews, Alice T.; Lovett, Jacqueline; Haughey, Norman J.; McFadden, Joseph W.

    2017-01-01

    Reduced insulin action develops naturally during the peripartum to ensure maternal nutrient delivery to the fetus and neonate. However, increased insulin resistance can facilitate excessive lipolysis which in turn promotes metabolic disease in overweight dairy cattle. Increased fatty acid availability favors the accumulation of the sphingolipid ceramide and is implicated in the pathogenesis of insulin resistance, however, the relationship between sphingolipid metabolism and insulin resistance during the peripartum remains largely unknown. Our objectives were to characterize temporal responses in plasma and tissue sphingolipids in lean and overweight peripartal cows and to establish the relationships between sphingolipid supply and lipolysis, hepatic lipid deposition, and systemic insulin action. Twenty-one multiparous lean and overweight Holstein cows were enrolled in a longitudinal study spanning the transition from gestation to lactation (d -21 to 21, relative to parturition). Plasma, liver, and skeletal muscle samples were obtained, and sphingolipids were profiled using LC/MS/MS. Insulin sensitivity was assessed utilizing intravenous insulin and glucose challenges. Our results demonstrated the following: first, insulin resistance develops postpartum concurrently with increased lipolysis and hepatic lipid accumulation; second, ceramides and glycosylated ceramides accumulate during the transition from gestation to lactation and are further elevated in overweight cows; third, ceramide accrual is associated with lipolysis and liver lipid accumulation, and C16:0- and C24:0-ceramide are inversely associated with systemic insulin sensitivity postpartum; fourth, plasma sphingomyelin, a potential source of ceramides reaches a nadir at parturition and is closely associated with feed intake; fifth, select sphingomyelins are lower in the plasma of overweight cows during the peripartal period. Our results demonstrate that dynamic changes occur in peripartal sphingolipids

  18. Pre-gravid physical activity and reduced risk of glucose intolerance in pregnancy: the role of insulin sensitivity.

    Science.gov (United States)

    Retnakaran, Ravi; Qi, Ying; Sermer, Mathew; Connelly, Philip W; Zinman, Bernard; Hanley, Anthony J G

    2009-04-01

    Pre-gravid physical activity has been associated with a reduced risk of gestational diabetes mellitus (GDM), although neither the types of exercise nor the physiologic mechanisms underlying this protective effect have been well-studied. Thus, we sought to study the relationships between types of pre-gravid physical activity and metabolic parameters in pregnancy, including glucose tolerance, insulin sensitivity and beta-cell function. A total of 851 women underwent a glucose challenge test (GCT) and a 3-h oral glucose tolerance test (OGTT) in late pregnancy, yielding four glucose tolerance groups: (i) GDM; (ii) gestational impaired glucose tolerance (GIGT); (iii) abnormal GCT with normal glucose tolerance on OGTT (abnormal GCT NGT); and (iv) normal GCT with NGT on OGTT (normal GCT NGT). Pre-gravid physical activity was assessed using the Baecke questionnaire, which measures (i) total physical activity and (ii) its three component domains: work, nonsport leisure-time, and vigorous/sports activity. Glucose tolerance status improved across increasing quartiles of pre-gravid total physical activity (P = 0.0244). Whereas neither work nor nonsport leisure-time activity differed between glucose tolerance groups, pre-gravid vigorous/sports activity was significantly higher in women with normal GCT NGT compared to women with (i) abnormal GCT NGT (P = 0.0018) (ii) GIGT (P = 0.0025), and (iii) GDM (P = 0.0044). In particular, vigorous/sports activity correlated with insulin sensitivity (measured by IS(OGTT)) (r = 0.21, P sports activity emerged as a significant independent predictor of IS(OGTT) in pregnancy (t = 4.97, P sports activity is associated with a reduced risk of glucose intolerance in pregnancy, an effect likely mediated by enhanced insulin sensitivity.

  19. ACSL1 Is Associated With Fetal Programming of Insulin Sensitivity and Cellular Lipid Content.

    Science.gov (United States)

    Joseph, Roy; Poschmann, Jeremie; Sukarieh, Rami; Too, Peh Gek; Julien, Sofi G; Xu, Feng; Teh, Ai Ling; Holbrook, Joanna D; Ng, Kai Lyn; Chong, Yap Seng; Gluckman, Peter D; Prabhakar, Shyam; Stünkel, Walter

    2015-06-01

    Individuals who are born small for gestational age (SGA) have a risk to develop various metabolic diseases during their life course. The biological memory of the prenatal state of growth restricted individuals may be reflected in epigenetic alterations in stem cell populations. Mesenchymal stem cells (MSCs) from the Wharton's jelly of umbilical cord tissue are multipotent, and we generated primary umbilical cord MSC isolates from SGA and normal neonates, which were subsequently differentiated into adipocytes. We established chromatin state maps for histone marks H3K27 acetylation and H3K27 trimethylation and tested whether enrichment of these marks was associated with gene expression changes. After validating gene expression levels for 10 significant chromatin immunoprecipitation sequencing candidate genes, we selected acyl-coenzyme A synthetase 1 (ACSL1) for further investigations due to its key roles in lipid metabolism. The ACSL1 gene was found to be highly associated with histone acetylation in adipocytes differentiated from MSCs with SGA background. In SGA-derived adipocytes, the ACSL1 expression level was also found to be associated with increased lipid loading as well as higher insulin sensitivity. ACSL1 depletion led to changes in expression of candidate genes such as proinflammatory chemokines and down-regulated both, the amount of cellular lipids and glucose uptake. Increased ACSL1, as well as modulated downstream candidate gene expression, may reflect the obese state, as detected in mice fed a high-fat diet. In summary, we believe that ACSL1 is a programmable mediator of insulin sensitivity and cellular lipid content and adipocytes differentiated from Wharton's jelly MSCs recapitulate important physiological characteristics of SGA individuals.

  20. One week treatment with the IL-1 receptor antagonist anakinra leads to a sustained improvement in insulin sensitivity in insulin resistant patients with type 1 diabetes mellitus.

    Science.gov (United States)

    van Asseldonk, Edwin J P; van Poppel, Pleun C M; Ballak, Dov B; Stienstra, Rinke; Netea, Mihai G; Tack, Cees J

    2015-10-01

    Inflammation associated with obesity is involved in the development of insulin resistance. We hypothesized that anti-inflammatory treatment with the Interleukin-1 receptor antagonist anakinra would improve insulin sensitivity. In an open label proof-of-concept study, we included overweight patients diagnosed with type 1 diabetes with an HbA1c level over 7.5%. Selecting insulin resistant patients with longstanding type 1 diabetes allowed us to study the effects of anakinra on insulin sensitivity. Patients were treated with 100mg anakinra daily for one week. Insulin sensitivity, insulin need and blood glucose profiles were measured before, after one week and after four weeks of follow-up. Fourteen patients completed the study. One week of anakinra treatment led to an improvement of insulin sensitivity, an effect that was sustained for four weeks. Similarly, glucose profiles, HbA1c levels and insulin needs improved. In conclusion, one week of treatment with anakinra improves insulin sensitivity in patients with type 1 diabetes. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Insulin sensitivity, fat distribution, and adipocytokine response to different diets in lean and obese cats before and after weight loss.

    Science.gov (United States)

    Hoenig, M; Thomaseth, K; Waldron, M; Ferguson, D C

    2007-01-01

    Obesity is a major health problem in cats and a risk factor for diabetes. It has been postulated that cats are always gluconeogenic and that the rise in obesity might be related to high dietary carbohydrates. We examined the effect of a high-carbohydrate/low-protein (HC) and a high-protein/low-carbohydrate (HP) diet on glucose and fat metabolism during euglycemic hyperinsulinemic clamp, adipocytokines, and fat distribution in 12 lean and 16 obese cats before and after weight loss. Feeding diet HP led to greater heat production in lean but not in obese cats. Regardless of diet, obese cats had markedly decreased glucose effectiveness and insulin resistance, but greater suppression of nonesterified fatty acids during the euglycemic hyperinsulinemic clamp was seen in obese cats on diet HC compared with lean cats on either diet or obese cats on diet HP. In contrast to humans, obese cats had abdominal fat equally distributed subcutaneously and intra-abdominally. Weight loss normalized insulin sensitivity; however, increased nonesterified fatty acid suppression was maintained and fat loss was less in cats on diet HC. Adiponectin was negatively and leptin positively correlated with fat mass. Lean cats and cats during weight loss, but not obese cats, adapted to the varying dietary carbohydrate/protein content with changes in substrate oxidation. We conclude that diet HP is beneficial through maintenance of normal insulin sensitivity of fat metabolism in obese cats, facilitating the loss of fat during weight loss, and increasing heat production in lean cats. These data also show that insulin sensitivity of glucose and fat metabolism can be differentially regulated in cats.

  2. A 2-wk reduction of ambulatory activity attenuates peripheral insulin sensitivity

    DEFF Research Database (Denmark)

    Krogh-Madsen, Rikke; Thyfault, John P; Broholm, Christa

    2010-01-01

    decreased after step reduction, with a post hoc analysis revealing the most pronounced effect after 4 h of insulin infusion. In addition, the 2-wk period induced a 7% decline in VO2 max (ml/min; cardiovascular fitness). Lean mass of legs, but not arms and trunk, decreased concurrently. Taken together, one...... possible biological cause for the public health problem of Type 2 diabetes has been identified. Reduced ambulatory activity for 2 wk in healthy, nonexercising young men significantly reduced peripheral insulin sensitivity, cardiovascular fitness, and lean leg mass........ A reduced number of daily steps induced a significant reduction of 17% in the glucose infusion rate (GIR) during the clamp. This reduction was due to a decline in peripheral insulin sensitivity with no effect on hepatic endogenous glucose production. The insulin-stimulated ratio of pAktthr308/total Akt...

  3. The effects of insulin sensitizers on the cardiovascular risk factors in women with polycystic ovary syndrome.

    Science.gov (United States)

    Kassi, E; Diamanti-Kandarakis, E

    2008-12-01

    Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in pre-menopausal women characterized by menstrual cycle disturbances, chronic anovulation, and clinical and/or biochemical hyperandrogenism. Although, the primary etiology of PCOS remains unknown, insulin resistance/hyperinsulinemia plays a pivotal role in the pathogenesis of the syndrome. A growing body of recent data support that women with PCOS have displayed an increased prevelance of cardiovascular disease (CVD) risk factors putting potentially at a hight risk for heart disease. Most of these CVD risk factors are etiologically correlated with insulin resistance/hyperinsulinemia, highlighting the role of insulin sensitizers in the therapeutic quiver for the chronic treatment of PCOS. In this review, we discuss the current literature on the CVD risk factors in PCOS and the influence of insulin sensitizers upon these risk factors.

  4. Impact of oral vancomycin on gut microbiota, bile acid metabolism, and insulin sensitivity

    DEFF Research Database (Denmark)

    Vrieze, Anne; Out, Carolien; Fuentes, Susana

    2014-01-01

    .i.d. At baseline and after 1 week of therapy, fecal microbiota composition (Human Intestinal Tract Chip phylogenetic microarray), fecal and plasma bile acid concentrations as well as insulin sensitivity (hyperinsulinemic euglycemic clamp using [6,6-(2)H2]-glucose tracer) were measured. RESULTS: Vancomycin reduced...... (pinsulin sensitivity (p... of vancomycin significantly impacts host physiology by decreasing intestinal microbiota diversity, bile acid dehydroxylation and peripheral insulin sensitivity in subjects with metabolic syndrome. These data show that intestinal microbiota, particularly of the Firmicutes phylum contributes to bile acid...

  5. Dietary fat and carbohydrates differentially alter insulin sensitivity during caloric restriction.

    Science.gov (United States)

    Kirk, Erik; Reeds, Dominic N; Finck, Brian N; Mayurranjan, S Mitra; Mayurranjan, Mitra S; Patterson, Bruce W; Klein, Samuel

    2009-05-01

    We determined the effects of acute and chronic calorie restriction with either a low-fat, high-carbohydrate (HC) diet or a low-carbohydrate (LC) diet on hepatic and skeletal muscle insulin sensitivity. Twenty-two obese subjects (body mass index, 36.5 +/- 0.8 kg/m2) were randomized to an HC (>180 g/day) or LC (vs 8.9% +/- 1.4%; P vs 7.2% +/- 1.4%; P vs 7.9% +/- 1.2%; P < .05). Insulin-mediated glucose uptake did not change at 48 hours but increased similarly in both groups after 7% weight loss (48.4% +/- 14.3%; P < .05). In both groups, insulin-stimulated phosphorylation of c-Jun-N-terminal kinase decreased by 29% +/- 13% and phosphorylation of Akt and insulin receptor substrate 1 increased by 35% +/- 9% and 36% +/- 9%, respectively, after 7% weight loss (all P < .05). Moderate calorie restriction causes temporal changes in liver and skeletal muscle metabolism; 48 hours of calorie restriction affects the liver (IHTG content, hepatic insulin sensitivity, and glucose production), whereas moderate weight loss affects muscle (insulin-mediated glucose uptake and insulin signaling).

  6. Bilirubin Increases Insulin Sensitivity by Regulating Cholesterol Metabolism, Adipokines and PPARγ Levels

    Science.gov (United States)

    Liu, Jinfeng; Dong, Huansheng; Zhang, Yong; Cao, Mingjun; Song, Lili; Pan, Qingjie; Bulmer, Andrew; Adams, David B.; Dong, Xiao; Wang, Hongjun

    2015-01-01

    Obesity can cause insulin resistance and type 2 diabetes. Moderate elevations in bilirubin levels have anti-diabetic effects. This study is aimed at determining the mechanisms by which bilirubin treatment reduces obesity and insulin resistance in a diet-induced obesity (DIO) mouse model. DIO mice were treated with bilirubin or vehicle for 14 days. Body weights, plasma glucose, and insulin tolerance tests were performed prior to, immediately, and 7 weeks post-treatment. Serum lipid, leptin, adiponectin, insulin, total and direct bilirubin levels were measured. Expression of factors involved in adipose metabolism including sterol regulatory element-binding protein (SREBP-1), insulin receptor (IR), and PPARγ in liver were measured by RT-PCR and Western blot. Compared to controls, bilirubin-treated mice exhibited reductions in body weight, blood glucose levels, total cholesterol (TC), leptin, total and direct bilirubin, and increases in adiponectin and expression of SREBP-1, IR, and PPARγ mRNA. The improved metabolic control achieved by bilirubin-treated mice was persistent: at two months after treatment termination, bilirubin-treated DIO mice remained insulin sensitive with lower leptin and higher adiponectin levels, together with increased PPARγ expression. These results indicate that bilirubin regulates cholesterol metabolism, adipokines and PPARγ levels, which likely contribute to increased insulin sensitivity and glucose tolerance in DIO mice. PMID:26017184

  7. Glucose tolerance, insulin sensitivity and insulin release in European non-diabetic carriers of a polymorphism upstream of CDKN2A and CDKN2B

    DEFF Research Database (Denmark)

    Hribal, M L; Presta, I; Procopio, T

    2011-01-01

    The aim of this study was to investigate the association of the rs10811661 polymorphism near the CDKN2B/CDKN2A genes with glucose tolerance, insulin sensitivity and insulin release in three samples of white people with European ancestry.......The aim of this study was to investigate the association of the rs10811661 polymorphism near the CDKN2B/CDKN2A genes with glucose tolerance, insulin sensitivity and insulin release in three samples of white people with European ancestry....

  8. Valsartan Improves β-Cell Function and Insulin Sensitivity in Subjects With Impaired Glucose Metabolism

    Science.gov (United States)

    van der Zijl, Nynke J.; Moors, Chantalle C.M.; Goossens, Gijs H.; Hermans, Marc M.H.; Blaak, Ellen E.; Diamant, Michaela

    2011-01-01

    OBJECTIVE Recently, the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research Trial demonstrated that treatment with the angiotensin receptor blocker (ARB) valsartan for 5 years resulted in a relative reduction of 14% in the incidence of type 2 diabetes in subjects with impaired glucose metabolism (IGM). We investigated whether improvements in β-cell function and/or insulin sensitivity underlie these preventive effects of the ARB valsartan in the onset of type 2 diabetes. RESEARCH DESIGN AND METHODS In this randomized controlled, double-blind, two-center study, the effects of 26 weeks of valsartan (320 mg daily; n = 40) or placebo (n = 39) on β-cell function and insulin sensitivity were assessed in subjects with impaired fasting glucose and/or impaired glucose tolerance, using a combined hyperinsulinemic-euglycemic and hyperglycemic clamp with subsequent arginine stimulation and a 2-h 75-g oral glucose tolerance test (OGTT). Treatment effects were analyzed using ANCOVA, adjusting for center, glucometabolic status, and sex. RESULTS Valsartan increased first-phase (P = 0.028) and second-phase (P = 0.002) glucose-stimulated insulin secretion compared with placebo, whereas the enhanced arginine-stimulated insulin secretion was comparable between groups (P = 0.25). In addition, valsartan increased the OGTT-derived insulinogenic index (representing first-phase insulin secretion after an oral glucose load; P = 0.027). Clamp-derived insulin sensitivity was significantly increased with valsartan compared with placebo (P = 0.049). Valsartan treatment significantly decreased systolic and diastolic blood pressure compared with placebo (P valsartan treatment increased glucose-stimulated insulin release and insulin sensitivity in normotensive subjects with IGM. These findings may partly explain the beneficial effects of valsartan in the reduced incidence of type 2 diabetes. PMID:21330640

  9. Effects of febuxostat on insulin resistance and expression of high-sensitivity C-reactive protein in patients with primary gout.

    Science.gov (United States)

    Meng, Juan; Li, Yanchun; Yuan, Xiaoxu; Lu, Yuewu

    2017-02-01

    We aimed to investigate the effects of febuxostat on IR and the expression of high-sensitivity C-reactive protein (hs-CRP) in patients with primary gout. Forty-two cases of primary gout patients without uric acid-lowering therapy were included in this study. After a physical examination, 20 age- and sex-matched patients were included as normal controls. The levels of fasting insulin (INS), fasting blood glucose (FBG), and hs-CRP were determined. IR was assessed using the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). Gout patients had higher levels of UA, INS, HOMA-IR, and hs-CRP than normal controls (P gout patients and implicate that febuxostat can effectively control the level of serum UA and increase insulin sensitivity in primary gout patients.

  10. Insulin Resistance and Serum Levels of Interleukin-17 and Interleukin-18 in Normal Pregnancy

    OpenAIRE

    Jahromi, Abdolreza Sotoodeh; Shojaei, Mohammad; Ghobadifar, Mohamed Amin

    2014-01-01

    We performed this study to evaluate the role of Interleukin-17 (IL-17) and Interleukin-18 (IL-18) in insulin resistance during normal pregnancy. This descriptive cross sectional study was carried out on 97 healthy pregnant women including 32, 25, and 40 individuals in the first, second, and third trimesters, respectively, and on 28 healthy non pregnant women between the autumn of 2012 and the spring of 2013. We analyzed the serum concentrations of IL-17 and IL-18 by using the enzyme linked im...

  11. MiR-155 Enhances Insulin Sensitivity by Coordinated Regulation of Multiple Genes in Mice

    Science.gov (United States)

    Lin, Taoyan; Lin, Xia; Chen, Li; Zeng, Hui; Han, Yanjiang; Wu, Lihong; Huang, Shun; Wang, Meng; Huang, Shenhao; Xie, Raoying; Liang, Liqi; Liu, Yu; Liu, Ruiyu; Zhang, Tingting; Li, Jing; Wang, Shengchun; Sun, Penghui; Huang, Wenhua; Yao, Kaitai; Xu, Kang; Du, Tao; Xiao, Dong

    2016-01-01

    miR-155 plays critical roles in numerous physiological and pathological processes, however, its function in the regulation of blood glucose homeostasis and insulin sensitivity and underlying mechanisms remain unknown. Here, we reveal that miR-155 levels are downregulated in serum from type 2 diabetes (T2D) patients, suggesting that miR-155 might be involved in blood glucose control and diabetes. Gain-of-function and loss-of-function studies in mice demonstrate that miR-155 has no effects on the pancreatic β-cell proliferation and function. Global transgenic overexpression of miR-155 in mice leads to hypoglycaemia, improved glucose tolerance and insulin sensitivity. Conversely, miR-155 deficiency in mice causes hyperglycemia, impaired glucose tolerance and insulin resistance. In addition, consistent with a positive regulatory role of miR-155 in glucose metabolism, miR-155 positively modulates glucose uptake in all cell types examined, while mice overexpressing miR-155 transgene show enhanced glycolysis, and insulin-stimulated AKT and IRS-1 phosphorylation in liver, adipose tissue or skeletal muscle. Furthermore, we reveal these aforementioned phenomena occur, at least partially, through miR-155-mediated repression of important negative regulators (i.e. C/EBPβ, HDAC4 and SOCS1) of insulin signaling. Taken together, these findings demonstrate, for the first time, that miR-155 is a positive regulator of insulin sensitivity with potential applications for diabetes treatment. PMID:27711113

  12. Increased insulin sensitivity and changes in the expression profile of key insulin regulatory genes and beta cell transcription factors in diabetic KKAy-mice after feeding with a soy bean protein rich diet high in isoflavone content.

    Science.gov (United States)

    Nordentoft, I; Jeppesen, P B; Hong, J; Abudula, R; Hermansen, K

    2008-06-25

    High content isoflavone soy protein (SBP) (Abalon) has been found in animal studies to possess beneficial effects on a number of the characteristic features of the insulin resistance syndrome. The aim of this study was to investigate whether SBP exerts beneficial effects on metabolism in the diabetic KKAy-mouse. Furthermore, we investigated the long-term in vivo effect of SBP on the expression profile in islets of key insulin regulatory genes. Twenty KKAy-mice, aged 5 weeks, were divided into 2 groups and treated for 9 weeks with either (A) standard chow diet (control) or (B) chow + 50% SBP. Twenty normal C57BL-mice fed with standard chow diet served as nondiabetic controls (C). Blood samples were collected and analyzed before and after intervention. Gene expression was determined in islets by quantitative real-time RT-PCR and Affymetrix microarray. It was demonstrated that long-term treatment with SBP improves glucose homeostasis, increases insulin sensitivity, and lowers plasma triglycerides in diabetic KKAy-mice. SBP reduces fasting plasma glucose, insulin, triglycerides, and total cholesterol. Furthermore, SBP markedly changes the gene expression profile of key insulin regulatory genes GLUT2, GLUT3, Ins1, Ins2, IGF1, Beta2/Neurod1, cholecystokinin, and LDLr, and proliferative genes in islets isolated from KKAy-mice. After 9 weeks of treatment with SBP, plasma glucose and insulin homeostasis was normalized compared to start levels. The results indicate that SBP improves glucose and insulin sensitivity and up-regulates the expression of key insulin regulatory genes.

  13. Vitamin D intake is associated with insulin sensitivity in African American, but not European American, women

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    Oster Robert A

    2010-04-01

    Full Text Available Abstract Background The prevalence of type 2 diabetes is higher among African Americans (AA vs European Americans (EA, independent of obesity and other known confounders. Although the reason for this disparity is not known, it is possible that relatively low levels of vitamin D among AA may contribute, as vitamin D has been positively associated with insulin sensitivity in some studies. The objective of this study was to test the hypothesis that dietary vitamin D would be associated with a robust measure of insulin sensitivity in AA and EA women. Methods Subjects were 115 African American (AA and 137 European American (EA healthy, premenopausal women. Dietary intake was determined with 4-day food records; the insulin sensitivity index (SI with a frequently-sampled intravenous glucose tolerance test and minimal modeling; the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR with fasting insulin and glucose; and body composition with dual-energy X-ray absorptiometry. Results Vitamin D intake was positively associated with SI (standardized β = 0.18, P = 0.05 and inversely associated with HOMA-IR (standardized β = -0.26, P = 0.007 in AA, and the relationships were independent of age, total body fat, energy intake, and % kcal from fat. Vitamin D intake was not significantly associated with indices of insulin sensitivity/resistance in EA (standardized β = 0.03, P = 0.74 and standardized β = 0.02, P = 0.85 for SI and HOMA-IR, respectively. Similar to vitamin D, dietary calcium was associated with SI and HOMA-IR among AA but not EA. Conclusions This study provides novel findings that dietary vitamin D and calcium were independently associated with insulin sensitivity in AA, but not EA. Promotion of these nutrients in the diet may reduce health disparities in type 2 diabetes risk among AA, although longitudinal and intervention studies are required.

  14. The Proton-Activated Receptor GPR4 Modulates Glucose Homeostasis by Increasing Insulin Sensitivity

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    Luca Giudici

    2013-11-01

    Full Text Available Background: The proton-activated G protein-coupled receptor GPR4 is expressed in many tissues including white adipose tissue. GPR4 is activated by extracellular protons in the physiological pH range (i.e. pH 7.7 - 6.8 and is coupled to the production of cAMP. Methods: We examined mice lacking GPR4 and examined glucose tolerance and insulin sensitivity in young and aged mice as well as in mice fed with a high fat diet. Expression profiles of pro- and anti-inflammatory cytokines in white adipose tissue, liver and skeletal muscle was assessed. Results: Here we show that mice lacking GPR4 have an improved intraperitoneal glucose tolerance test and increased insulin sensitivity. Insulin levels were comparable but leptin levels were increased in GPR4 KO mice. Gpr4-/- showed altered expression of PPARα, IL-6, IL-10, TNFα, and TGF-1β in skeletal muscle, white adipose tissue, and liver. High fat diet abolished the differences in glucose tolerance and insulin sensitivity between Gpr4+/+ and Gpr4-/- mice. In contrast, in aged mice (12 months old, the positive effect of GPR4 deficiency on glucose tolerance and insulin sensitivity was maintained. Liver and adipose tissue showed no major differences in the mRNA expression of pro- and anti-inflammatory factors between aged mice of both genotypes. Conclusion: Thus, GPR4 deficiency improves glucose tolerance and insulin sensitivity. The effect may involve an altered balance between pro- and anti-inflammatory factors in insulin target tissues.

  15. Acute activation of GLP-1-expressing neurons promotes glucose homeostasis and insulin sensitivity.

    Science.gov (United States)

    Shi, Xuemei; Chacko, Shaji; Li, Feng; Li, Depei; Burrin, Douglas; Chan, Lawrence; Guan, Xinfu

    2017-11-01

    Glucagon-like peptides are co-released from enteroendocrine L cells in the gut and preproglucagon (PPG) neurons in the brainstem. PPG-derived GLP-1/2 are probably key neuroendocrine signals for the control of energy balance and glucose homeostasis. The objective of this study was to determine whether activation of PPG neurons per se modulates glucose homeostasis and insulin sensitivity in vivo. We generated glucagon (Gcg) promoter-driven Cre transgenic mice and injected excitatory hM3Dq-mCherry AAV into their brainstem NTS. We characterized the metabolic impact of PPG neuron activation on glucose homeostasis and insulin sensitivity using stable isotopic tracers coupled with hyperinsulinemic euglycemic clamp. We showed that after ip injection of clozapine N-oxide, Gcg-Cre lean mice transduced with hM3Dq in the brainstem NTS downregulated basal endogenous glucose production and enhanced glucose tolerance following ip glucose tolerance test. Moreover, acute activation of PPG neurons NTS enhanced whole-body insulin sensitivity as indicated by increased glucose infusion rate as well as augmented insulin-suppression of endogenous glucose production and gluconeogenesis. In contrast, insulin-stimulation of glucose disposal was not altered significantly. We conclude that acute activation of PPG neurons in the brainstem reduces basal glucose production, enhances intraperitoneal glucose tolerance, and augments hepatic insulin sensitivity, suggesting an important physiological role of PPG neurons-mediated circuitry in promoting glycemic control and insulin sensitivity. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

  16. Diurnal Variations in Serum Glucose, Insulin and C-Peptide of Normal Korean Adults

    International Nuclear Information System (INIS)

    Choi, Du Hyok; Chung, June Key; Lee, Hong Kyu; Koh, Chang Soon; Hong, Kee Suk

    1983-01-01

    It is already well known that many factors are involved in maintaining normal blood glucose level. The amount and components of meal are also thought to be some of the factors which affect the blood glucose and insulin levels. It is reported that as for Koreans sugar takes up over 75% out of 2,098 kcal, the average daily calorie intake per adult. It implies that Koreans take a high-sugar diet compared with Westerners who take 40-50% of sugar out of their total average daily calorie. For the purpose of studying diurnal variations in serum glucose, insulin and C-peptide of normal Koreans adults based on ordinary Korean diet, we selected 13 normal Korean male adults and divided them into two groups, Group I (7 persons) and Group II (6 persons). We put Group I on 3,100 kcal and 75% sugar diet, and Group II on 2,100 kcal and 69% sugar diet per day for over 4 days. Serum glucose, insulin and C-peptide were checked every 30 minutes or every hour throughout 2 hour. Results are as follows: 1. As for serum glucose level, in the preprandial fasting state in the morning, mean±S.D. of Group I was 91.1±3.2 mg%, while that of Group II is 82.5±4.4 mg%. Both groups showed peaks of increased glucose level t postprandial 1 hour after each meal. The peak returned to the level shown during the fasting state at postprandial 1 hour after breakfast while the relatively high glucose levels were maintained respectively even for 2 or 3 hours after lunch and dinner. 2. As for serum insults level, Group I showed mean±S.D. of 14.7±3.0 μU/ml while Group II shows that of 7.0±2.6 μU/ml in the fasting state. Group I particularly showed the largest peak from preprandial a half or one and half an hour to postprandial one hour of lunch, and made relatively small peaks (47.7±10.8 μU/ml) at postprandial 1 hour after breakfast and dinner. No such large peak was marked in Group II, though it showed relatively similar patterns of peak after each meal. 3. As for C-peptide, in the fasting state

  17. Diurnal Variations in Serum Glucose, Insulin and C-Peptide of Normal Korean Adults

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Du Hyok; Chung, June Key; Lee, Hong Kyu; Koh, Chang Soon [Seoul National University College of Medicine, Seoul (Korea, Republic of); Hong, Kee Suk [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    1983-03-15

    It is already well known that many factors are involved in maintaining normal blood glucose level. The amount and components of meal are also thought to be some of the factors which affect the blood glucose and insulin levels. It is reported that as for Koreans sugar takes up over 75% out of 2,098 kcal, the average daily calorie intake per adult. It implies that Koreans take a high-sugar diet compared with Westerners who take 40-50% of sugar out of their total average daily calorie. For the purpose of studying diurnal variations in serum glucose, insulin and C-peptide of normal Koreans adults based on ordinary Korean diet, we selected 13 normal Korean male adults and divided them into two groups, Group I (7 persons) and Group II (6 persons). We put Group I on 3,100 kcal and 75% sugar diet, and Group II on 2,100 kcal and 69% sugar diet per day for over 4 days. Serum glucose, insulin and C-peptide were checked every 30 minutes or every hour throughout 2 hour. Results are as follows: 1. As for serum glucose level, in the preprandial fasting state in the morning, mean+-S.D. of Group I was 91.1+-3.2 mg%, while that of Group II is 82.5+-4.4 mg%. Both groups showed peaks of increased glucose level t postprandial 1 hour after each meal. The peak returned to the level shown during the fasting state at postprandial 1 hour after breakfast while the relatively high glucose levels were maintained respectively even for 2 or 3 hours after lunch and dinner. 2. As for serum insults level, Group I showed mean+-S.D. of 14.7+-3.0 muU/ml while Group II shows that of 7.0+-2.6 muU/ml in the fasting state. Group I particularly showed the largest peak from preprandial a half or one and half an hour to postprandial one hour of lunch, and made relatively small peaks (47.7+-10.8 muU/ml) at postprandial 1 hour after breakfast and dinner. No such large peak was marked in Group II, though it showed relatively similar patterns of peak after each meal. 3. As for C-peptide, in the fasting state

  18. Effects of short-term metformin treatment on insulin sensitivity of blood glucose and free fatty acids.

    Science.gov (United States)

    Iannello, S; Camuto, M; Cavaleri, A; Milazzo, P; Pisano, M G; Bellomia, D; Belfiore, F

    2004-01-01

    Based on the known effect of metformin (MET) in improving insulin sensitivity in type 2 diabetes, with the scope to focus the effects on glycaemic and free fatty acids (FFA) levels, we studied the effects of a short-term treatment with this drug in obese subjects and obese patients with diabetes or family history of diabetes (FHD). We used a method to allow us to evaluate the possible difference of insulin sensibility with regard to the insulin action on glycaemia and blood FFA, both in the basal state and during oral glucose tolerance test (OGTT). Insulin sensitivity was investigated before and after MET treatment (850 mg bid for 10 days) in seven obese subjects with normal glucose tolerance and without FHD and 13 obese patients with diabetes (n=7) or FHD (n=6). By using specifically designed formulae, we calculated four insulin-sensitivity indices (ISI) from basal level (b) and area values (a) (during OGTT) of insulinaemia, glycaemia (gly) or FFA (ffa), namely: ISI (gly)-b, ISI (gly)-a, ISI (ffa)-b and ISI (ffa)-a. In patients with diabetes or FHD, MET improved ISI (gly)-b (0.79 +/- 0.06 vs. 0.59 +/- 0.07, p<0.001) and ISI (gly)-a (0.69 +/- 0.09 vs. 0.51 +/- 0.07, p<0.05), whereas only minor changes occurred for ISI (ffa)-b and ISI (ffa)-a. In contrast, in simple obese subjects, MET induced further deterioration of both ISI (gly)-a (0.47 +/- 0.07 vs. 0.64 +/- 0.10, p<0.01) and ISI (ffa)-a (0.43 +/- 0.07 vs. 0.55 +/- 0.08, p<0.05). Fasting level and total area of lactate were high in the obese patients and were not affected by MET. A statistically significant increase (p<0.01), however, was observed for the 'decremental' area of lactate in obese subjects with diabetes or FHD, which might probably contribute to the reduction of insulin resistance induced by the drug in these patients. Although the low number of subjects studied precludes absolute conclusions, data would suggest that MET improved ISI towards glucose but not towards FFA, in the diabetic and

  19. BCAA Metabolism and Insulin Sensitivity - Dysregulated by Metabolic Status?

    Science.gov (United States)

    Gannon, Nicholas P; Schnuck, Jamie K; Vaughan, Roger A

    2018-03-01

    Branched-chain amino acids (BCAAs) appear to influence several synthetic and catabolic cellular signaling cascades leading to altered phenotypes in mammals. BCAAs are most notably known to increase protein synthesis through modulating protein translation, explaining their appeal to resistance and endurance athletes for muscle hypertrophy, expedited recovery, and preservation of lean body mass. In addition to anabolic effects, BCAAs may increase mitochondrial content in skeletal muscle and adipocytes, possibly enhancing oxidative capacity. However, elevated circulating BCAA levels have been correlated with severity of insulin resistance. It is hypothesized that elevated circulating BCAAs observed in insulin resistance may result from dysregulated BCAA degradation. This review summarizes original reports that investigated the ability of BCAAs to alter glucose uptake in consequential cell types and experimental models. The review also discusses the interplay of BCAAs with other metabolic factors, and the role of excess lipid (and possibly energy excess) in the dysregulation of BCAA catabolism. Lastly, this article provides a working hypothesis of the mechanism(s) by which lipids may contribute to altered BCAA catabolism, which often accompanies metabolic disease. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Effect of vitamin K supplementation on insulin sensitivity: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Suksomboon N

    2017-05-01

    Full Text Available Naeti Suksomboon,1 Nalinee Poolsup,2 Htoo Darli Ko Ko1 1Department of Pharmacy, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand; 2Department of Pharmacy, Faculty of Pharmacy, Silpakorn University, Nakhon-Pathom, Thailand Objective: To perform a systematic review and meta-analysis of randomized, placebo-controlled trials to assess the effect of vitamin K supplementation on insulin sensitivity.Data sources: MEDLINE, the Cochrane Library, CINAHL, Web of Science, Scopus, clinicaltrials.gov, and clinicaltrialresults.org were searched up to January 2017. Reference lists of related papers were also scanned.Study selection: Randomized controlled trials were selected if they compared vitamin K supplementation with placebo or no treatment and reported homeostasis model assessment of insulin resistance, fasting plasma glucose, fasting plasma insulin, C-reactive protein, adiponectin, leptin, or interleukin-6 levels.Data extraction: Data extraction and study quality assessment were performed independently by two investigators using a standardized data extraction form. Any inconsistencies were resolved by a third reviewer. Effect estimates were pooled using inverse-variance weighted method. Heterogeneity was assessed by the I2 and Q statistic.Results: A total of eight trials involving 1,077 participants met the inclusion criteria. A wide variety of participants were enrolled, including older men, postmenopausal women, prediabetic premenopausal women, and participants with a history of diabetes, hypertension, or vascular disease. Vitamin K1 and vitamin K2 (MK-4 and MK-7 subtypes were assessed. Supplementation period ranged from 4 weeks to 3 years. Vitamin K supplementation did not affect insulin sensitivity as measured by homeostasis model assessment of insulin resistance, fasting plasma glucose, fasting plasma insulin, C-reactive protein, adiponectin, leptin, and interleukin-6 levels.Conclusion: Our analysis suggests no effect of vitamin K

  1. Long-term treatment with losartan versus atenolol improves insulin sensitivity in hypertension: ICARUS, a LIFE substudy

    DEFF Research Database (Denmark)

    Olsen, Michael H; Fossum, Eigil; Høieggen, Aud

    2005-01-01

    Hypertension and insulin resistance might be associated through peripheral vascular hypertrophy/rarefaction which compromises skeletal muscle blood flow and decreases glucose uptake, inducing insulin resistance. We hypothesized that treatment with losartan as compared to atenolol would improve...... insulin sensitivity through regression of peripheral vascular hypertrophy/rarefaction....

  2. High intensity interval training improves liver and adipose tissue insulin sensitivity

    Science.gov (United States)

    Marcinko, Katarina; Sikkema, Sarah R.; Samaan, M. Constantine; Kemp, Bruce E.; Fullerton, Morgan D.; Steinberg, Gregory R.

    2015-01-01

    Objective Endurance exercise training reduces insulin resistance, adipose tissue inflammation and non-alcoholic fatty liver disease (NAFLD), an effect often associated with modest weight loss. Recent studies have indicated that high-intensity interval training (HIIT) lowers blood glucose in individuals with type 2 diabetes independently of weight loss; however, the organs affected and mechanisms mediating the glucose lowering effects are not known. Intense exercise increases phosphorylation and inhibition of acetyl-CoA carboxylase (ACC) by AMP-activated protein kinase (AMPK) in muscle, adipose tissue and liver. AMPK and ACC are key enzymes regulating fatty acid metabolism, liver fat content, adipose tissue inflammation and insulin sensitivity but the importance of this pathway in regulating insulin sensitivity with HIIT is unknown. Methods In the current study, the effects of 6 weeks of HIIT were examined using obese mice with serine–alanine knock-in mutations on the AMPK phosphorylation sites of ACC1 and ACC2 (AccDKI) or wild-type (WT) controls. Results HIIT lowered blood glucose and increased exercise capacity, food intake, basal activity levels, carbohydrate oxidation and liver and adipose tissue insulin sensitivity in HFD-fed WT and AccDKI mice. These changes occurred independently of weight loss or reductions in adiposity, inflammation and liver lipid content. Conclusions These data indicate that HIIT lowers blood glucose levels by improving adipose and liver insulin sensitivity independently of changes in adiposity, adipose tissue inflammation, liver lipid content or AMPK phosphorylation of ACC. PMID:26909307

  3. [Effect of oral administration of ascorbic acid on insulin sensitivity and lipid profile in obese individuals].

    Science.gov (United States)

    Martínez-Abundis, E; Pascoe-González, S; González-Ortiz, M; Mora-Martínez, J M; Cabrera-Pivaral, C E

    2001-01-01

    The aim of this study was to identify the effect of an oral ascorbic acid (AA) supplement on lipid profile and insulin sensitivity in obese people. A randomized double-blind clinical trial placebo controlled was performed in 16 obese male volunteers [body mass index (BMI) 30-40 kg/m2]. Eight received orally 1 g of AA daily for four weeks and the other eight volunteers received placebo by the same scheme and period of time. Before and after the pharmacological intervention were measured total cholesterol, high-density-lipoprotein (HDL) cholesterol, triglycerides, glucose, creatinine and uric acid. Low-density-lipoprotein (LDL) cholesterol and very-low-density-lipoprotein (VLDL) triglycerides were calculated using formulas. In order to assess insulin sensitivity before and after the intervention, the steady-state glucose (SSG) was calculated from the insulin suppression test modified with octreotide. There were not significant differences in clinical characteristics between both groups. Basal metabolic profile and SSG were similar between both groups. There were not significant differences in both groups between before and after the intervention in metabolic profile and insulin sensitivity. AA did not modify the lipid profile nor insulin sensitivity in the group of obese people studied.

  4. Infection with Soil-Transmitted Helminths Is Associated with Increased Insulin Sensitivity.

    Directory of Open Access Journals (Sweden)

    Aprilianto E Wiria

    Full Text Available Given that helminth infections have been shown to improve insulin sensitivity in animal studies, which may be explained by beneficial effects on energy balance or by a shift in the immune system to an anti-inflammatory profile, we investigated whether soil-transmitted helminth (STH-infected subjects are more insulin sensitive than STH-uninfected subjects.We performed a cross-sectional study on Flores island, Indonesia, an area with high prevalence of STH infections.From 646 adults, stool samples were screened for Trichuris trichiura by microscopy and for Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale, and Strongyloides stercoralis by qPCR. No other helminth was found. We collected data on body mass index (BMI, kg/m2, waist-to-hip ratio (WHR, fasting blood glucose (FBG, mmol/L, insulin (pmol/L, high sensitive C-reactive protein (ng/ml and Immunoglobulin E (IU/ml. The homeostatic model assessment for insulin resistance (HOMAIR was calculated and regression models were used to assess the association between STH infection status and insulin resistance.424 (66% participants had at least one STH infection. STH infected participants had lower BMI (23.2 vs 22.5 kg/m2, p value = 0.03 and lower HOMAIR (0.97 vs 0.81, p value = 0.05. In an age-, sex- and BMI-adjusted model a significant association was seen between the number of infections and HOMAIR: for every additional infection with STH species, the HOMAIR decreased by 0.10 (p for linear trend 0.01. This effect was mainly accounted for by a decrease in insulin of 4.9 pmol/L for every infection (p for trend = 0.07.STH infections are associated with a modest improvement of insulin sensitivity, which is not accounted for by STH effects on BMI alone.

  5. Anti-hyperglycemic and insulin sensitizer effects of turmeric and its principle constituent curcumin.

    Science.gov (United States)

    Ghorbani, Zeinab; Hekmatdoost, Azita; Mirmiran, Parvin

    2014-10-01

    Turmeric is obtained from the plant Curcuma longa L; its major constituent, curcumin, is a polyphenol with multiple effects which can modulate some signaling pathways. Insulin resistance is a major risk factor for chronic diseases such as type 2 diabetes, atherosclerotic, metabolic syndrome and cardiovascular disease. In addition, Insulin resistance in peripheral tissue is one of the most important reasons of hyperglycemia which can cause global or systemic effects. The present study reviewed studies published in PubMed from 1998 to 2013, indicating the role of curcumin in attenuation of many pathophysiological processes involved in development and progression of hyperglycemia and insulin resistance. Curcumin can reduce blood glucose level by reducing the hepatic glucose production, suppression of hyperglycemia-induced inflammatory state, stimulation of glucose uptake by up-regulation of GLUT4, GLUT2 and GLUT3 genes expressions, activation of AMP kinase, promoting the PPAR ligand-binding activity, stimulation of insulin secretion from pancreatic tissues, improvement in pancreatic cell function, and reduction of insulin resistance. Curcumin has antihyperglycemic and insulin sensitizer effects. Thereby, more studies evaluating the effects of curcumin on hyperglycemic state and insulin resistance in related disorders such as diabetes are recommended.

  6. Substrate Metabolism and Insulin Sensitivity During Fasting in Obese Human Subjects: Impact of GH Blockade.

    Science.gov (United States)

    Pedersen, Morten Høgild; Svart, Mads Vandsted; Lebeck, Janne; Bidlingmaier, Martin; Stødkilde-Jørgensen, Hans; Pedersen, Steen Bønløkke; Møller, Niels; Jessen, Niels; Jørgensen, Jens O L

    2017-04-01

    Insulin resistance and metabolic inflexibility are features of obesity and are amplified by fasting. Growth hormone (GH) secretion increases during fasting and GH causes insulin resistance. To study the metabolic effects of GH blockade during fasting in obese subjects. Nine obese males were studied thrice in a randomized design: (1) after an overnight fast (control), (2) after 72 hour fasting (fasting), and (3) after 72 hour fasting with GH blockade (pegvisomant) [fasting plus GH antagonist (GHA)]. Each study day consisted of a 4-hour basal period followed by a 2-hour hyperinsulinemic, euglycemic clamp combined with indirect calorimetry, assessment of glucose and palmitate turnover, and muscle and fat biopsies. GH levels increased with fasting (P fasting-induced reduction of serum insulin-like growth factor I was enhanced by GHA (P Fasting increased lipolysis and lipid oxidation independent of GHA, but fasting plus GHA caused a more pronounced suppression of lipid intermediates in response to hyperinsulinemic, euglycemic clamp. Fasting-induced insulin resistance was abrogated by GHA (P Fasting plus GHA also caused elevated glycerol levels and reduced levels of counterregulatory hormones. Fasting significantly reduced the expression of antilipolytic signals in adipose tissue independent of GHA. Suppression of GH activity during fasting in obese subjects reverses insulin resistance and amplifies insulin-stimulated suppression of lipid intermediates, indicating that GH is an important regulator of substrate metabolism, insulin sensitivity, and metabolic flexibility also in obese subjects. Copyright © 2017 by the Endocrine Society

  7. Insulin Sensitivity and Glucose Homeostasis Can Be Influenced by Metabolic Acid Load

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    Lucio Della Guardia

    2018-05-01

    Full Text Available Recent epidemiological findings suggest that high levels of dietary acid load can affect insulin sensitivity and glucose metabolism. Consumption of high protein diets results in the over-production of metabolic acids which has been associated with the development of chronic metabolic disturbances. Mild metabolic acidosis has been shown to impair peripheral insulin action and several epidemiological findings suggest that metabolic acid load markers are associated with insulin resistance and impaired glycemic control through an interference intracellular insulin signaling pathways and translocation. In addition, higher incidence of diabetes, insulin resistance, or impaired glucose control have been found in subjects with elevated metabolic acid load markers. Hence, lowering dietary acid load may be relevant for improving glucose homeostasis and prevention of type 2 diabetes development on a long-term basis. However, limitations related to patient acid load estimation, nutritional determinants, and metabolic status considerably flaws available findings, and the lack of solid data on the background physiopathology contributes to the questionability of results. Furthermore, evidence from interventional studies is very limited and the trials carried out report no beneficial results following alkali supplementation. Available literature suggests that poor acid load control may contribute to impaired insulin sensitivity and glucose homeostasis, but it is not sufficiently supportive to fully elucidate the issue and additional well-designed studies are clearly needed.

  8. Differentiation of the insulin-sensitive glucose transporter in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Frost, S.C.; Baly, D.L.; Cushman, S.W.; Lane, M.D.; Simpson, I.A.

    1986-01-01

    3T3-L1 fibroblasts differentiate in culture to resemble adipocytes both morphologically and biochemically. Insulin-sensitive glucose transport, as measured by 2-deoxy-[1- 14 C]- glucose uptake in the undifferentiated cell is small (2X). In contrast, the rate of glucose transport in fully differentiated cells is elevated 15-fold over basal in the presence of insulin. To determine if this is due to an increase in the number of transporters/cell or accessibility to the transporters, the number of transporters was measured in subcellular fractions over differentiation using a 3 H-cytochalasin B binding assay. The increase in the rate of insulin-sensitive glucose transport directly parallels an increase in the number of transporters which reside in an insulin-responsive intracellular compartment. This observation was confirmed by identifying the transporters by immunoblotting using an antibody generated against the human erythrocyte transporter. The molecular weight of this transporter increases over differentiation from a single band of 40kDa to a heterogeneous triplet of 40, 44 and 48kDa. These data suggest that the transporter undergoes differential processing and that the functional, insulin-responsive transporter may be different from the insulin-insensitive (basal) transporter

  9. Artemisia Extract Improves Insulin Sensitivity in Women With Gestational Diabetes Mellitus by Up-Regulating Adiponectin.

    Science.gov (United States)

    Sun, Xia; Sun, Hong; Zhang, Jing; Ji, Xianghong

    2016-12-01

    Gestational diabetes mellitus (GDM) has affected a great number of pregnant women worldwide. Artemisia extracts have been found to exhibit a potent antidiabetic effect in the treatment of type 2 diabetes mellitus. We aimed to examine the effects of Artemisia extract on insulin resistance and lipid profiles in pregnant GDM patients. Patients in their second trimester were randomly assigned to the Artemisia extract group (AE) or to a placebo group (PO). They were instructed to consume either AE or PO daily for a period of 10 weeks. Glucose and insulin profiles and adiponectin level were assessed at baseline (week 0) and after the treatment (week 10). Compared to the PO group, fasting plasma glucose, serum insulin levels, homeostasis model of assessment of insulin resistance (HOMA-IR), and β-cell function (HOMA-B) were significantly reduced in the AE group participants. Moreover, levels of circulating adiponectin were also significantly up-regulated in the AE group, which also positively contributed to improved insulin sensitivity. Daily administration of Artemisia extract improves insulin sensitivity by up-regulating adiponectin in women with gestational diabetes mellitus. © 2016, The American College of Clinical Pharmacology.

  10. Human skeletal muscle ceramide content is not a major factor in muscle insulin sensitivity

    DEFF Research Database (Denmark)

    Skovbro, M; Baranowski, M; Skov-Jensen, C

    2008-01-01

    -hyperinsulinaemic clamp was performed for 120 and 90 min for step 1 and step 2, respectively. Muscle biopsies were obtained from vastus lateralis at baseline, and after steps 1 and 2. RESULTS: Glucose infusion rates increased in response to insulin infusion, and significant differences were present between groups (T2D......AIMS/HYPOTHESIS: In skeletal muscle, ceramides may be involved in the pathogenesis of insulin resistance through an attenuation of insulin signalling. This study investigated total skeletal muscle ceramide fatty acid content in participants exhibiting a wide range of insulin sensitivities. METHODS......: The middle-aged male participants (n=33) were matched for lean body mass and divided into four groups: type 2 diabetes (T2D, n=8), impaired glucose tolerance (IGT, n=9), healthy controls (CON, n=8) and endurance-trained (TR, n=8). A two step (28 and 80 mU m(-2) min(-1)) sequential euglycaemic...

  11. Hormone-sensitive lipase deficiency suppresses insulin secretion from pancreatic islets of Lepob/ob mice

    International Nuclear Information System (INIS)

    Sekiya, Motohiro; Yahagi, Naoya; Tamura, Yoshiaki; Okazaki, Hiroaki; Igarashi, Masaki; Ohta, Keisuke; Takanashi, Mikio; Kumagai, Masayoshi; Takase, Satoru; Nishi, Makiko; Takeuchi, Yoshinori; Izumida, Yoshihiko; Kubota, Midori; Ohashi, Ken; Iizuka, Yoko; Yagyu, Hiroaki; Gotoda, Takanari; Nagai, Ryozo; Shimano, Hitoshi; Yamada, Nobuhiro

    2009-01-01

    It has long been a matter of debate whether the hormone-sensitive lipase (HSL)-mediated lipolysis in pancreatic β-cells can affect insulin secretion through the alteration of lipotoxicity. We generated mice lacking both leptin and HSL (Lep ob/ob /HSL -/- ) and explored the role of HSL in pancreatic β-cells in the setting of obesity. Lep ob/ob /HSL -/- developed elevated blood glucose levels and reduced plasma insulin levels compared with Lep ob/ob /HSL +/+ in a fed state, while the deficiency of HSL did not affect glucose homeostasis in Lep +/+ background. The deficiency of HSL exacerbated the accumulation of triglycerides in Lep ob/ob islets, leading to reduced glucose-stimulated insulin secretion. The deficiency of HSL also diminished the islet mass in Lep ob/ob mice due to decreased cell proliferation. In conclusion, HSL affects insulin secretary capacity especially in the setting of obesity.

  12. Sensitive double-antibody method for simultaneous determination of insulin and growth hormone

    International Nuclear Information System (INIS)

    Koparanova, O.; Sotirov, G.; Tyrkolev, N.

    1982-01-01

    A method is described for simultaneous determination of insulin and growth hormone in one sample, using double-antibody technique. The method is characterized by appreciable sensitivity (2.5 μE/ml for insulin and a.2 ng/ml for growth hormone), exactness (variation quotient 6-16 per cent) and reproducibility (96.9-117 per cent). There was no statistically significant difference in the insulin and growth hormone values of the same sera, determined by the here suggested and the standard methods. The necessary test material for examination of either hormone is minimal (0.2 ml). One may thus extend the possibilities for radioimmunologic determination of insulin and growth hormone, when only minor amounts of serum or other biological fluid are available. The method is also less time consuming. Results are reported of statistical processing of an experimental model and different sera determined by the standard method and the one described by the authors. (author)

  13. Insulin receptor binding and tyrosine kinase activity in skeletal muscle from normal pregnant women and women with gestational diabetes

    DEFF Research Database (Denmark)

    Damm, P.; Handberg, A.; Kühl, C.

    1993-01-01

    OBJECTIVE: To ascertain whether the decreased glucose tolerance and insulin resistance found in normal and gestational diabetic pregnancy might be associated with changes in insulin receptor function. METHODS: Eight nonpregnant healthy women (nonpregnant controls), eight healthy pregnant women...... (pregnant controls), and eight women with gestational diabetes were investigated. All were non-obese. Muscle biopsies were obtained from the vastus lateralis muscle, and insulin binding and tyrosine kinase activities in partially purified skeletal muscle insulin receptors were studied. The pregnant controls...... with gestational diabetes compared to nonpregnant controls (P pregnant women did not differ from the other two groups. Postpartum, no differences in insulin binding were found between the groups. Basal and maximal tyrosine kinase activities toward the exogenous substrate poly(Glu4Tyr1) were...

  14. Does overnight normalization of plasma glucose by insulin infusion affect assessment of glucose metabolism in Type 2 diabetes?

    DEFF Research Database (Denmark)

    Staehr, P; Højlund, Kurt; Hother-Nielsen, O

    2003-01-01

    AIMS: In order to perform euglycaemic clamp studies in Type 2 diabetic patients, plasma glucose must be reduced to normal levels. This can be done either (i) acutely during the clamp study using high-dose insulin infusion, or (ii) slowly overnight preceding the clamp study using a low-dose insulin...... infusion. We assessed whether the choice of either of these methods to obtain euglycaemia biases subsequent assessment of glucose metabolism and insulin action. METHODS: We studied seven obese Type 2 diabetic patients twice: once with (+ ON) and once without (- ON) prior overnight insulin infusion. Glucose...... turnover rates were quantified by adjusted primed-constant 3-3H-glucose infusions, and insulin action was assessed in 4-h euglycaemic, hyperinsulinaemic (40 mU m-2 min-1) clamp studies using labelled glucose infusates (Hot-GINF). RESULTS: Basal plasma glucose levels (mean +/- sd) were 5.5 +/- 0.5 and 10...

  15. The transcription factor Prep1 controls hepatic insulin sensitivity and gluconeogenesis by targeting nuclear localization of FOXO1

    International Nuclear Information System (INIS)

    Kulebyakin, Konstantin; Penkov, Dmitry; Blasi, Francesco; Akopyan, Zhanna; Tkachuk, Vsevolod

    2016-01-01

    Liver plays a key role in controlling body carbohydrate homeostasis by switching between accumulation and production of glucose and this way maintaining constant level of glucose in blood. Increased blood glucose level triggers release of insulin from pancreatic β-cells. Insulin represses hepatic glucose production and increases glucose accumulation. Insulin resistance is the main cause of type 2 diabetes and hyperglycemia. Currently thiazolidinediones (TZDs) targeting transcriptional factor PPARγ are used as insulin sensitizers for treating patients with type 2 diabetes. However, TZDs are reported to be associated with cardiovascular and liver problems and stimulate obesity. Thus, it is necessary to search new approaches to improve insulin sensitivity. A promising candidate is transcriptional factor Prep1, as it was shown earlier it could affect insulin sensitivity in variety of insulin-sensitive tissues. The aim of the present study was to evaluate a possible involvement of transcriptional factor Prep1 in control of hepatic glucose accumulation and production. We created mice with liver-specific Prep1 knockout and discovered that hepatocytes derived from these mice are much more sensitive to insulin, comparing to their WT littermates. Incubation of these cells with 100 nM insulin results in almost complete inhibition of gluconeogenesis, while in WT cells this repression is only partial. However, Prep1 doesn't affect gluconeogenesis in the absence of insulin. Also, we observed that nuclear content of gluconeogenic transcription factor FOXO1 was greatly reduced in Prep1 knockout hepatocytes. These findings suggest that Prep1 may control hepatic insulin sensitivity by targeting FOXO1 nuclear stability. - Highlights: • A novel model of liver-specific Prep1 knockout is established. • Ablation of Prep1 in hepatocytes increases insulin sensitivity. • Prep1 controls hepatic insulin sensitivity by regulating localization of FOXO1. • Prep1 regulates

  16. One week treatment with the IL-1 receptor antagonist anakinra leads to a sustained improvement in insulin sensitivity in insulin resistant patients with type 1 diabetes mellitus

    NARCIS (Netherlands)

    Asseldonk, van E.J.P.; Poppel, van P.C.M.; Ballak, D.B.; Stienstra, Rinke; Netea, M.G.; Tack, C.J.

    2015-01-01

    Inflammation associated with obesity is involved in the development of insulin resistance. We hypothesized that anti-inflammatory treatment with the Interleukin-1 receptor antagonist anakinra would improve insulin sensitivity.In an open label proof-of-concept study, we included overweight

  17. Association of oxidative status and insulin sensitivity in periparturient dairy cattle: an observational study.

    Science.gov (United States)

    Abuelo, A; Hernández, J; Benedito, J L; Castillo, C

    2016-04-01

    Post-parturient insulin resistance (IR) is a common feature in all mammalian animals. However, in dairy cows, it can be exacerbated because of high milk yield, leading to excessive negative energy balance, which is related with increased disease incidence, reduced milk production and worsened reproductive performance. IR has been extensively investigated in humans suffering from diabetes mellitus. In these subjects, it is known that oxidative stress (OS) plays a causative role in the onset of IR. Although OS occurs in transitional dairy cattle, there are yet no studies that investigated the association between IR and OS in dairy cattle. Therefore, the aim of this study was to investigate whether there is a relationship between OS and IR in dairy cattle. Serum samples were taken repeatedly from 22 dairy cows from 2 months prior to the expected calving date to 2 months after calving and were analysed for markers of metabolic and redox balance. Surrogate indices of insulin sensitivity were also calculated. Generalised linear mixed models revealed an effect of the oxidative status on peripheral insulin concentration and on indices of insulin sensitivity. Hence, field trials should investigate the effectiveness of antioxidant therapy on insulin sensitivity in peripheral tissues during the transition period of dairy cattle. Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH.

  18. Central GLP-2 enhances hepatic insulin sensitivity via activating PI3K signaling in POMC neurons

    Science.gov (United States)

    Shi, Xuemei; Zhou, Fuguo; Li, Xiaojie; Chang, Benny; Li, Depei; Wang, Yi; Tong, Qingchun; Xu, Yong; Fukuda, Makoto; Zhao, Jean J.; Li, Defa; Burrin, Douglas G.; Chan, Lawrence; Guan, Xinfu

    2013-01-01

    Glucagon-like peptides (GLP-1/2) are co-produced and highlighted as key modulators to improve glucose homeostasis and insulin sensitivity after bariatric surgery. However, it is unknown if CNS GLP-2 plays any physiological role in the control of glucose homeostasis and insulin sensitivity. We show that mice lacking GLP-2 receptor (GLP-2R) in POMC neurons display glucose intolerance and hepatic insulin resistance. GLP-2R activation in POMC neurons is required for GLP-2 to enhance insulin-mediated suppression of hepatic glucose production (HGP) and gluconeogenesis. GLP-2 directly modulates excitability of POMC neurons in GLP-2R- and PI3K-dependent manners. GLP-2 initiates GLP-2R-p85α interaction and facilitates PI3K-Akt-dependent FoxO1 nuclear exclusion in POMC neurons. Central GLP-2 suppresses basal HGP and enhances insulin sensitivity, which are abolished in POMC-p110α KO mice. Thus, CNS GLP-2 plays a key physiological role in the control of hepatic glucose production through activating PI3K-dependent modulation of membrane excitability and nuclear transcription of POMC neurons in the brain. PMID:23823479

  19. Central GLP-2 enhances hepatic insulin sensitivity via activating PI3K signaling in POMC neurons.

    Science.gov (United States)

    Shi, Xuemei; Zhou, Fuguo; Li, Xiaojie; Chang, Benny; Li, Depei; Wang, Yi; Tong, Qingchun; Xu, Yong; Fukuda, Makoto; Zhao, Jean J; Li, Defa; Burrin, Douglas G; Chan, Lawrence; Guan, Xinfu

    2013-07-02

    Glucagon-like peptides (GLP-1/GLP-2) are coproduced and highlighted as key modulators to improve glucose homeostasis and insulin sensitivity after bariatric surgery. However, it is unknown if CNS GLP-2 plays any physiological role in the control of glucose homeostasis and insulin sensitivity. We show that mice lacking GLP-2 receptor (GLP-2R) in POMC neurons display glucose intolerance and hepatic insulin resistance. GLP-2R activation in POMC neurons is required for GLP-2 to enhance insulin-mediated suppression of hepatic glucose production (HGP) and gluconeogenesis. GLP-2 directly modulates excitability of POMC neurons in GLP-2R- and PI3K-dependent manners. GLP-2 initiates GLP-2R-p85α interaction and facilitates PI3K-Akt-dependent FoxO1 nuclear exclusion in POMC neurons. Central GLP-2 suppresses basal HGP and enhances insulin sensitivity, which are abolished in POMC-p110α KO mice. Thus, CNS GLP-2 plays a key physiological role in the control of HGP through activating PI3K-dependent modulation of membrane excitability and nuclear transcription of POMC neurons in the brain. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. The Attainment of High Sensitivity and Precision in Radioimmunoassay Techniques as Exemplified in a Simple Assay of Serum Insulin

    Energy Technology Data Exchange (ETDEWEB)

    Albano, Janet; Ekins, R. P. [Institute of Nuclear Medicine, Middlesex Hospital Medical School, London (United Kingdom)

    1970-02-15

    Recent controversy has underlined the fundamental confusion surrounding the concepts of assay ''sensitivity'' and ''precision'' and, in particular, their optimization in radioimmunoassay and other saturation assay procedures. Many formal definitions of sensitivity (e.g. that laid down by the American Chemical Society) express this concept in terms of the slope of the ''dose'' response curve; nevertheless, in common usage, the term is normally regarded as a synonym for the detection limit of the measurement technique. However, a technique which is ''sensitive'' in the formal sense may not display a low limit of detection, and it is readily demonstrable that, in radioimmunoassay systems in particular, there are circumstances in which increase in the slope of the response curve may lead to an increase in the detection limit of the assay. The authors have based their insulin assay protocols on mathematical principles specifically designed to lead to the minimization of the detection limit. The method depends on the use of (uncoated) charcoal for the separation of free and bound labelled insulin in incubation mixtures in which insulin-free human serum is used as diluent. The detection limit of the method is approximately 1 pg/ml of incubation mixture, corresponding to roughly 0.25 {mu}U/ml of serum at the serum dilutions used. In a formal comparative study, the method has been shown to be more sensitive, precise and accurate than other methods relying on double antibody or chromato-electrophoietic separation. The relevance of such factors as high specific activity labelled hormone to the attainment of high sensitivity is discussed. (author)

  1. Synergistic effects of leucine and resveratrol on insulin sensitivity and fat metabolism in adipocytes and mice

    Directory of Open Access Journals (Sweden)

    Bruckbauer Antje

    2012-08-01

    Full Text Available Abstract Background Sirtuins are important regulators of glucose and fat metabolism, and sirtuin activation has been proposed as a therapeutic target for insulin resistance and diabetes. We have shown leucine to increase mitochondrial biogenesis and fat oxidation via Sirt1 dependent pathways. Resveratrol is a widely recognized activator of Sirt; however, the biologically-effective high concentrations used in cell and animal studies are generally impractical or difficult to achieve in humans. Accordingly, we sought to determine whether leucine would exhibit synergy with low levels of resveratrol on sirtuin-dependent outcomes in adipocytes and in diet-induced obese (DIO mice. Methods 3T3-L1 mouse adipocytes were treated with Leucine (0.5 mM, β-hydroxy-β-methyl butyrate (HMB (5 μM or Resveratrol (200 nM alone or in combination. In addition, diet-induced obese mice were treated for 6-weeks with low (2 g/kg diet or high (10 g/kg diet dose HMB, Leucine (24 g/kg diet; 200% of normal level or low (12.5 mg/kg diet or high (225 mg/kg diet dose resveratrol, alone or as combination with leucine-resveratrol or HMB-resveratrol. Results Fatty acid oxidation, AMPK, Sirt1 and Sirt3 activity in 3T3-L1 adipocytes and in muscle cells, were significantly increased by the combinations compared to the individual treatments. Similarly, 6-week feeding of low-dose resveratrol combined with either leucine or its metabolite HMB to DIO mice increased adipose Sirt1 activity, muscle glucose and palmitate uptake (measured via PET/CT, insulin sensitivity (HOMAIR, improved inflammatory stress biomarkers (CRP, IL-6, MCP-1, adiponectin and reduced adiposity comparable to the effects of high dose resveratrol, while low-dose resveratrol exerted no independent effect. Conclusion These data demonstrate that either leucine or its metabolite HMB may be combined with a low concentration of resveratrol to exert synergistic effects on Sirt1-dependent outcomes; this may result in more

  2. Insulin binding and stimulation of hexose and amino acid transport by normal and receptor-defective human fibroblasts

    International Nuclear Information System (INIS)

    Longo, N.; Nagata, N.; Danner, D.; Priest, J.; Elsas, L.

    1986-01-01

    The authors analyzed insulin receptors in cells cultured from a sibship of related parents who had two offspring with severe insulin resistance (Leprechaunism). 124 I-Insulin (1 ng/ml) binding to skin fibroblasts from the proband, mother, and father was 9, 60 and 62% of control cells, respectively, at equilibrium, Non-linear regression analysis, utilizing a two receptors model, of curvilinear Scatchard plots indicated a reduced number of high-affinity binding sites in both parents. Influx of L-Proline (System A), L-Serine (ASC) and L-Leucine (L) was similar in control and mutant cells. Similarly, during the depletion of intracellular amino acid pools, there was a release from transinhibition for System A and a decrease of transstimulation of Systems ASC and L in both cell lines. Surprisingly, insulin augmented, normally, A system influx with an ED 50 = 70 ng/ml at 24 0 C and 7 ng/ml at 37 0 C. By contrast insulin failed to simulated 3-0-methyl-D-glucose influx into the proband's cells, while normal cells were stimulated 30% with an ED 50 of 6 ng/ml. These results indicate that defective high-affinity insulin binding is inherited as an autosomal recessive trait; that general membrane functions are intact; that insulin regulates A system amino acid and hexose transport by two different mechanisms; and, that the latter mechanism is impaired by this family's receptor mutation

  3. Improved insulin sensitivity after exercise training is linked to reduced plasma C14:0 ceramide in obesity and type 2 diabetes.

    Science.gov (United States)

    Kasumov, Takhar; Solomon, Thomas P J; Hwang, Calvin; Huang, Hazel; Haus, Jacob M; Zhang, Renliang; Kirwan, John P

    2015-07-01

    To assess the effect of exercise training on insulin sensitivity and plasma ceramides in obesity and type 2 diabetes (T2D). Twenty-four adults with obesity and normal glucose tolerance (NGT, n = 14) or diabetes (n = 10) were studied before and after a 12-week supervised exercise-training program (5 days/week, 1 h/day, 80-85% of maximum heart rate). Changes in body composition were assessed using hydrostatic weighing and computed tomography. Peripheral tissue insulin sensitivity was assessed by a 40 mU/m(2) /min hyperinsulinemic euglycemic clamp. Plasma ceramides (C14:0, C16:0, C18:0, C18:1, C20:0, C24:0, and C24:1) were quantified using electrospray ionization tandem mass spectrometry after separation with HPLC. Plasma ceramides were similar for the subjects with obesity and NGT and the subjects with diabetes, despite differences in glucose tolerance. Exercise significantly reduced body weight and adiposity and increased peripheral insulin sensitivity in both groups (P exercise training-induced improvements in insulin sensitivity, and plasma C14:0 ceramide may provide a specific target for investigating lipid-related insulin resistance in obesity and T2D. © 2015 The Obesity Society.

  4. High alanine aminotransferase is associated with decreased hepatic insulin sensitivity and predicts the development of type 2 diabetes

    DEFF Research Database (Denmark)

    Vozarova, Barbora; Stefan, Norbert; Lindsay, Robert S

    2002-01-01

    -sectionally associated with obesity and whole-body and hepatic insulin resistance and prospectively associated with a decline in hepatic insulin sensitivity and the development of type 2 diabetes. Our findings indicate that high ALT is a marker of risk for type 2 diabetes and suggest a potential role of the liver...... with prospective changes in liver or whole-body insulin sensitivity and/or insulin secretion and whether these elevated enzymes predict the development of type 2 diabetes in Pima Indians. We measured ALT, AST, and GGT in 451 nondiabetic (75-g oral glucose tolerance test) Pima Indians (aged 30 +/- 6 years, body fat...... 33 +/- 8%, ALT 45 +/- 29 units/l, AST 34 +/- 18 units/l, and GGT 56 +/- 40 units/l [mean +/- SD]) who were characterized for body composition (hydrodensitometry or dual-energy X-ray absorptiometry), whole-body insulin sensitivity (M), and hepatic insulin sensitivity (hepatic glucose output [HGO...

  5. Bioluminescence imaging of β cells and intrahepatic insulin gene activity under normal and pathological conditions.

    Directory of Open Access Journals (Sweden)

    Tokio Katsumata

    Full Text Available In diabetes research, bioluminescence imaging (BLI has been applied in studies of β-cell impairment, development, and islet transplantation. To develop a mouse model that enables noninvasive imaging of β cells, we generated a bacterial artificial chromosome (BAC transgenic mouse in which a mouse 200-kbp genomic fragment comprising the insulin I gene drives luciferase expression (Ins1-luc BAC transgenic mouse. BLI of mice was performed using the IVIS Spectrum system after intraperitoneal injection of luciferin, and the bioluminescence signal from the pancreatic region analyzed. When compared with MIP-Luc-VU mice [FVB/N-Tg(Ins1-lucVUPwrs/J] expressing luciferase under the control of the 9.2-kbp mouse insulin I promoter (MIP, the bioluminescence emission from Ins1-luc BAC transgenic mice was enhanced approximately 4-fold. Streptozotocin-treated Ins1-luc BAC transgenic mice developed severe diabetes concomitant with a sharp decline in the BLI signal intensity in the pancreas. Conversely, mice fed a high-fat diet for 8 weeks showed an increase in the signal, reflecting a decrease or increase in the β-cell mass. Although the bioluminescence intensity of the islets correlated well with the number of isolated islets in vitro, the intensity obtained from a living mouse in vivo did not necessarily reflect an absolute quantification of the β-cell mass under pathological conditions. On the other hand, adenovirus-mediated gene transduction of β-cell-related transcription factors in Ins1-luc BAC transgenic mice generated luminescence from the hepatic region for more than 1 week. These results demonstrate that BLI in Ins1-luc BAC transgenic mice provides a noninvasive method of imaging islet β cells and extrapancreatic activity of the insulin gene in the liver under normal and pathological conditions.

  6. Assessment of insulin resistance in Chinese PCOS patients with normal glucose tolerance.

    Science.gov (United States)

    Gao, Jing; Zhou, Li; Hong, Jie; Chen, Chen

    2017-11-01

    The study aimed to investigate insulin resistance (IR) status in polycystic ovary syndrome (PCOS) women with normal glucose tolerance (NGT), and further to evaluate feasible diagnostic method for those patients. Three hundred and twenty-five PCOS women with NGT and ninety-five healthy age-matched controls were recruited with Rotterdam criterion and 75 g oral glucose tolerance test (OGTT). IR status was estimated following a glycemic and insulinemic OGTT (0, 30, 60, 120, and 180 min). A modified HOMA-IR formula was applied to each time-course value of glycemia and insulinemia. The predictive performance of each IR index was analyzed with the use of ROC curves. Compared with healthy controls, both non-obese and obese PCOS patients with NGT had a higher BMI, serum glucose, insulin value (p PCOS-NGT was a HOMA-M30 value of 20.36 or more (AUC: 0.753). In obese PCOS-NGT population, the best predictive performance was obtained by a HOMA-M60 value of 32.17 or more (AUC: 0.868). IR was common in Chinese PCOS women with NGT, and the early assessment of IR should be heeded. We recommended HOMA-M30 (Cutoff: 20.36) and HOMA-M60 (Cutoff: 32.17) as the best predictive parameters for non-obese and obese PCOS-NGT patients, respectively.

  7. Brain pericyte-derived soluble factors enhance insulin sensitivity in GT1-7 hypothalamic neurons.

    Science.gov (United States)

    Takahashi, Hiroyuki; Takata, Fuyuko; Matsumoto, Junichi; Machida, Takashi; Yamauchi, Atsushi; Dohgu, Shinya; Kataoka, Yasufumi

    2015-02-20

    Insulin signaling in the hypothalamus plays an important role in food intake and glucose homeostasis. Hypothalamic neuronal functions are modulated by glial cells; these form an extensive network connecting the neurons and cerebral vasculature, known as the neurovascular unit (NVU). Brain pericytes are periendothelial accessory structures of the blood-brain barrier and integral members of the NVU. However, the interaction between pericytes and neurons is largely unexplored. Here, we investigate whether brain pericytes could affect hypothalamic neuronal insulin signaling. Our immunohistochemical observations demonstrated the existence of pericytes in the mouse hypothalamus, exhibiting immunoreactivity of platelet-derived growth factor receptor β (a pericyte marker), and laminin, a basal lamina marker. We then exposed a murine hypothalamic neuronal cell line, GT1-7, to conditioned medium obtained from primary cultures of rat brain pericytes. Pericyte-conditioned medium (PCM), but not astrocyte- or aortic smooth muscle cell-conditioned medium, increased the insulin-stimulated phosphorylation of Akt in GT1-7 cells in a concentration-dependent manner. PCM also enhanced insulin-stimulated tyrosine phosphorylation of insulin receptor β without changing its expression or localization in cytosolic or plasma membrane fractions. These results suggest that pericytes, rather than astrocytes, increase insulin sensitivity in hypothalamic neurons by releasing soluble factors under physiological conditions in the NVU. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. GLP-1 does not not acutely affect insulin sensitivity in healthy man

    DEFF Research Database (Denmark)

    Orskov, L; Holst, J J; Møller, J

    1996-01-01

    Previous studies have suggested that glucagon-like peptide-1 (GLP-1) (7-36 amide) may have the direct effect of increasing insulin sensitivity in healthy man. To evaluate this hypothesis we infused GLP-1 in seven lean healthy men during a hyper insulinaemic (0.8 mU.kg-1.min-1), euglycaemic (5 mmo...

  9. Genetic variants associated with glycine metabolism and their role in insulin sensitivity and type 2 diabetes

    DEFF Research Database (Denmark)

    Xie, Weijia; Wood, Andrew R; Lyssenko, Valeriya

    2013-01-01

    . The top-ranking metabolites were in the glutathione and glycine biosynthesis pathways. We aimed to identify common genetic variants associated with metabolites in these pathways and test their role in insulin sensitivity and type 2 diabetes. With 1,004 nondiabetic individuals from the RISC study, we...

  10. Strength Exercise Improves Muscle Mass and Hepatic Insulin Sensitivity in Obese Youth

    NARCIS (Netherlands)

    Van Der Heijden, Gert-Jan; Wang, Zhiyue J.; Chu, Zili; Toffolo, Gianna; Manesso, Erica; Sauer, Pieter J. J.; Sunehag, Agneta L.

    VAN DER HEIJDEN, G.-J., Z. J. WANG, Z. CHU, G. TOFFOLO, E. MANESSO, P. J. J. SAUER, and A. L. SUNEHAG. Strength Exercise Improves Muscle Mass and Hepatic Insulin Sensitivity in Obese Youth. Med. Sci. Sports Exerc., Vol. 42, No. 11, pp. 1973-1980, 2010. Introduction: Data on the metabolic effects of

  11. Gender differences in skeletal muscle substrate metabolism - molecular mechanisms and insulin sensitivity

    DEFF Research Database (Denmark)

    Lundsgaard, Annemarie; Kiens, Bente

    2014-01-01

    higher insulin sensitivity of female skeletal muscle can be related to gender-specific regulation of molecular metabolism will be topic for discussion. Gender differences in muscle fiber type distribution and substrate availability to and in skeletal muscle are highly relevant for substrate metabolism...

  12. Moderate alcohol consumption increases insulin sensitivity and ADIPOQ expression in postmenopausal women: A randomised, crossover trial

    NARCIS (Netherlands)

    Joosten, M.M.; Beulens, J.W.J.; Kersten, S.; Hendriks, H.F.J.

    2008-01-01

    Aims/hypothesis: To determine whether 6 weeks of daily, moderate alcohol consumption increases expression of the gene encoding adiponectin (ADIPOQ) and plasma levels of the protein, and improves insulin sensitivity in postmenopausal women. Methods: In a randomised, open-label, crossover trial

  13. Infection with Soil-Transmitted Helminths Is Associated with Increased Insulin Sensitivity

    NARCIS (Netherlands)

    Wiria, A.E.; Hamid, F.; Wammes, L.J.; Prasetyani, M.A.; Dekkers, O.M.; May, L.; Kaisar, M.M.; Verweij, J.J.; Guigas, B.; Partono, F.; Sartono, E.; Supali, T.; Yazdanbakhsh, M.; Smit, J.W.A.

    2015-01-01

    OBJECTIVE: Given that helminth infections have been shown to improve insulin sensitivity in animal studies, which may be explained by beneficial effects on energy balance or by a shift in the immune system to an anti-inflammatory profile, we investigated whether soil-transmitted helminth

  14. Strength Exercise Improves Muscle Mass and Hepatic Insulin Sensitivity in Obese Youth

    NARCIS (Netherlands)

    Van Der Heijden, Gert-Jan; Wang, Zhiyue J.; Chu, Zili; Toffolo, Gianna; Manesso, Erica; Sauer, Pieter J. J.; Sunehag, Agneta L.

    2010-01-01

    VAN DER HEIJDEN, G.-J., Z. J. WANG, Z. CHU, G. TOFFOLO, E. MANESSO, P. J. J. SAUER, and A. L. SUNEHAG. Strength Exercise Improves Muscle Mass and Hepatic Insulin Sensitivity in Obese Youth. Med. Sci. Sports Exerc., Vol. 42, No. 11, pp. 1973-1980, 2010. Introduction: Data on the metabolic effects of

  15. Insulin sensitivity in relation to fat distribution and plasma adipocytokines among abusers of anabolic androgenic steroids.

    Science.gov (United States)

    Rasmussen, Jon Jarløv; Schou, Morten; Selmer, Christian; Johansen, Marie Louise; Gustafsson, Finn; Frystyk, Jan; Dela, Flemming; Faber, Jens; Kistorp, Caroline

    2017-09-01

    Abuse of anabolic androgenic steroids (AAS) is prevalent among young men, but information regarding effects on insulin sensitivity and fat distribution is limited. The objective was to investigate insulin sensitivity in relation to fat distribution and adipocytokines among current and former AAS abusers compared with controls. Cross-sectional study among men involved in recreational strength training. Current and former AAS abusers (n=37 and n=33) and controls (n=30) volunteered from the community. We assessed insulin sensitivity by Matsuda index (oral glucose tolerance test). Using overnight fasting blood samples, adiponectin and leptin were measured. Body composition and fat distribution, including visceral adipose tissue (VAT), were assessed by dual energy X-ray absorptiometry. Current and former AAS abusers displayed lower Matsuda index than controls (%-difference (95%CI) from controls, -26% (-45; -1) and -39% (-55; -18)). Testosterone was markedly higher among current AAS abusers and subnormal among former AAS abusers compared with controls. Current AAS abusers displayed higher mean VAT than controls (388 (17) vs 293 (12) cm 3 , P<.001) whereas body fat %, adiponectin and leptin concentrations were lower. In contrast, former AAS abusers showed highest leptin concentrations and body fat %. Multivariate linear regressions identified VAT as independent predictor of lower Matsuda index among current AAS abusers compared with controls; while body fat % independently predicted lower Matsuda index among former AAS abusers. Both current and former AAS abusers displayed lower insulin sensitivity which could be mediated by higher VAT and total body fat %, respectively. © 2017 John Wiley & Sons Ltd.

  16. Effects of 7 days of exercise training on insulin sensitivity and responsiveness in type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Kirwan, John P; Solomon, Thomas; Wojta, Daniel M

    2009-01-01

    sensitivity and responsiveness and 2) short-term exercise training results in improved suppression of hepatic glucose production by insulin. Fourteen obese patients with type 2 diabetes, age 64 +/- 2 yr, underwent a two-stage hyperinsulinemic euglycemic clamp procedure, first stage 40 mU.m(-2).min(-1) insulin......The objectives of this study were to determine whether 1) the improvement in insulin action induced by short-term exercise training in patients with type 2 diabetes is due to an improvement in insulin sensitivity, an improvement in insulin responsiveness, or a combination of improved insulin...... infusion, second stage 1,000 mU.m(-2).min(-1) insulin infusion, together with a [3-(3)H]glucose infusion, before and after 7 days of exercise. The training consisted of 30 min of cycling and 30 min of treadmill walking at approximately 70% of maximal aerobic capacity daily for 7 days. The exercise program...

  17. DNA methylation and histone deacetylation regulating insulin sensitivity due to chronic cold exposure.

    Science.gov (United States)

    Wang, Xiaoqing; Wang, Lai; Sun, Yizheng; Li, Ruiping; Deng, Jinbo; Deng, Jiexin

    2017-02-01

    In this study, we investigated the causal relationship between chronic cold exposure and insulin resistance and the mechanisms of how DNA methylation and histone deacetylation regulate cold-reduced insulin resistance. 46 adult male mice from postnatal day 90-180 were randomly assigned to control group and cold-exposure group. Mice in cold-exposure group were placed at temperature from -1 to 4 °C for 30 days to mimic chronic cold environment. Then, fasting blood glucose, blood insulin level and insulin resistance index were measured with enzymatic methods. Immunofluorescent labeling was carried out to visualize the insulin receptor substrate 2 (IRS2), Obese receptor (Ob-R, a leptin receptor), voltage-dependent anion channel protein 1 (VDAC1), cytochrome C (cytC), 5-methylcytosine (5-mC) positive cells in hippocampal CA1 area. Furthermore, the expressions of some proteins mentioned above were detected with Western blot. The results showed: ① Chronic cold exposure could reduce the insulin resistance index (P cold-exposure group than in control group with both immunohistochemical staining and Western blot (P cold exposure increased DNA methylation and histone deacetylation in the pyramidal cells of CA1 area and led to an increase in the expression of histone deacetylase 1 (HDAC1) and DNA methylation relative enzymes (P cold exposure can improve insulin sensitivity, with the involvement of DNA methylation, histone deacetylation and the regulation of mitochondrial energy metabolism. These epigenetic modifications probably form the basic mechanism of cold-reduced insulin resistance. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Acupuncture treatment for insulin sensitivity of women with polycystic ovary syndrome and insulin resistance: a study protocol for a randomized controlled trial.

    Science.gov (United States)

    Li, Juan; Ng, Ernest Hung Yu; Stener-Victorin, Elisabet; Hu, Zhenxing; Shao, Xiaoguang; Wang, Haiyan; Li, Meifang; Lai, Maohua; Xie, Changcai; Su, Nianjun; Yu, Chuyi; Liu, Jia; Wu, Taixiang; Ma, Hongxia

    2017-03-09

    Our prospective pilot study of acupuncture affecting insulin sensitivity on polycystic ovary syndrome (PCOS) combined with insulin resistance (IR) showed that acupuncture had a significant effect on improving the insulin sensitivity of PCOS. But there is still no randomized controlled trial to determine the effect of acupuncture on the insulin sensitivity in women with PCOS and IR. In this article, we present the protocol of a randomized controlled trial to compare the effect of true acupuncture on the insulin sensitivity of these patients compared with metformin and sham acupuncture. Acupuncture may be an effective therapeutic alternative that is superior to metformin and sham acupuncture in improving the insulin sensitivity of PCOS combined with IR. This study is a multi-center, controlled, double-blind, and randomized clinical trial aiming to evaluate the effect of acupuncture on the insulin sensitivity in PCOS combined with IR. In total 342 patients diagnosed with PCOS and IR will be enrolled. Participants will be randomized to one of the three groups: (1) true acupuncture + metformin placebo; (2) sham acupuncture + metformin, and (3) sham acupuncture + metformin placebo. Participants and assessors will be blinded. The acupuncture intervention will be given 3 days per week for a total of 48 treatment sessions during 4 months. Metformin (0.5 g per pill) or placebo will be given, three times per day, and for 4 months. Primary outcome measures are changes in homeostasis model assessment of insulin resistance (HOMA-IR) and improvement rate of HOMA-IR by oral glucose tolerance test (OGTT) and insulin releasing test (Ins). Secondary outcome measures are homeostasis model assessment-β (HOMA-β), area under the curve for glucose and insulin, frequency of regular menstrual cycles and ovulation, body composition, metabolic profile, hormonal profile, questionnaires, side effect profile, and expectation and credibility of treatment. Outcome measures are

  19. Anxiety sensitivity in adolescents with somatoform autonomic dysfunction and adolescents with insulin dependent diabetes mellitus

    OpenAIRE

    Pisarić Maja; Nišević Sanja

    2011-01-01

    Anxiety sensitivity is defined as a belief that anxiety or fear may cause illness, embarrassment, or additional anxiety. The main purpose of this study was to find out if there were differences among adolescents with insulin dependent diabetes mellitus, adolescents with somatoform autonomic dysfunction and their healthy peers in different aspects of psychological functioning and anxiety sensitivity. The sample consisted of 93 subjects, aged 12 to 16. Hamburg Neuroticism and Extraversion...

  20. Coordinated balancing of muscle oxidative metabolism through PGC-1{alpha} increases metabolic flexibility and preserves insulin sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Summermatter, Serge [Biozentrum, Division of Pharmacology/Neurobiology, University of Basel, Klingelbergstrasse 50-70, CH-4056 Basel (Switzerland); Troxler, Heinz [Division of Clinical Chemistry and Biochemistry, Department of Pediatrics, University Children' s Hospital, University of Zurich, Steinwiesstrasse 75, CH-8032 Zurich (Switzerland); Santos, Gesa [Biozentrum, Division of Pharmacology/Neurobiology, University of Basel, Klingelbergstrasse 50-70, CH-4056 Basel (Switzerland); Handschin, Christoph, E-mail: christoph.handschin@unibas.ch [Biozentrum, Division of Pharmacology/Neurobiology, University of Basel, Klingelbergstrasse 50-70, CH-4056 Basel (Switzerland)

    2011-04-29

    Highlights: {yields} PGC-1{alpha} enhances muscle oxidative capacity. {yields} PGC-1{alpha} promotes concomitantly positive and negative regulators of lipid oxidation. {yields} Regulator abundance enhances metabolic flexibility and balances oxidative metabolism. {yields} Balanced oxidation prevents detrimental acylcarnitine and ROS generation. {yields} Absence of detrimental metabolites preserves insulin sensitivity -- Abstract: The peroxisome proliferator-activated receptor {gamma} coactivator 1{alpha} (PGC-1{alpha}) enhances oxidative metabolism in skeletal muscle. Excessive lipid oxidation and electron transport chain activity can, however, lead to the accumulation of harmful metabolites and impair glucose homeostasis. Here, we investigated the effect of over-expression of PGC-1{alpha} on metabolic control and generation of insulin desensitizing agents in extensor digitorum longus (EDL), a muscle that exhibits low levels of PGC-1{alpha} in the untrained state and minimally relies on oxidative metabolism. We demonstrate that PGC-1{alpha} induces a strictly balanced substrate oxidation in EDL by concomitantly promoting the transcription of activators and inhibitors of lipid oxidation. Moreover, we show that PGC-1{alpha} enhances the potential to uncouple oxidative phosphorylation. Thereby, PGC-1{alpha} boosts elevated, yet tightly regulated oxidative metabolism devoid of side products that are detrimental for glucose homeostasis. Accordingly, PI3K activity, an early phase marker for insulin resistance, is preserved in EDL muscle. Our findings suggest that PGC-1{alpha} coordinately coactivates the simultaneous transcription of gene clusters implicated in the positive and negative regulation of oxidative metabolism and thereby increases metabolic flexibility. Thus, in mice fed a normal chow diet, over-expression of PGC-1{alpha} does not alter insulin sensitivity and the metabolic adaptations elicited by PGC-1{alpha} mimic the beneficial effects of endurance training

  1. Coordinated balancing of muscle oxidative metabolism through PGC-1α increases metabolic flexibility and preserves insulin sensitivity

    International Nuclear Information System (INIS)

    Summermatter, Serge; Troxler, Heinz; Santos, Gesa; Handschin, Christoph

    2011-01-01

    Highlights: → PGC-1α enhances muscle oxidative capacity. → PGC-1α promotes concomitantly positive and negative regulators of lipid oxidation. → Regulator abundance enhances metabolic flexibility and balances oxidative metabolism. → Balanced oxidation prevents detrimental acylcarnitine and ROS generation. → Absence of detrimental metabolites preserves insulin sensitivity -- Abstract: The peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) enhances oxidative metabolism in skeletal muscle. Excessive lipid oxidation and electron transport chain activity can, however, lead to the accumulation of harmful metabolites and impair glucose homeostasis. Here, we investigated the effect of over-expression of PGC-1α on metabolic control and generation of insulin desensitizing agents in extensor digitorum longus (EDL), a muscle that exhibits low levels of PGC-1α in the untrained state and minimally relies on oxidative metabolism. We demonstrate that PGC-1α induces a strictly balanced substrate oxidation in EDL by concomitantly promoting the transcription of activators and inhibitors of lipid oxidation. Moreover, we show that PGC-1α enhances the potential to uncouple oxidative phosphorylation. Thereby, PGC-1α boosts elevated, yet tightly regulated oxidative metabolism devoid of side products that are detrimental for glucose homeostasis. Accordingly, PI3K activity, an early phase marker for insulin resistance, is preserved in EDL muscle. Our findings suggest that PGC-1α coordinately coactivates the simultaneous transcription of gene clusters implicated in the positive and negative regulation of oxidative metabolism and thereby increases metabolic flexibility. Thus, in mice fed a normal chow diet, over-expression of PGC-1α does not alter insulin sensitivity and the metabolic adaptations elicited by PGC-1α mimic the beneficial effects of endurance training on muscle metabolism in this context.

  2. Circadian hormone profiles and insulin sensitivity in patients with Addison's disease: a comparison of continuous subcutaneous hydrocortisone infusion with conventional glucocorticoid replacement therapy.

    Science.gov (United States)

    Björnsdottir, Sigridur; Øksnes, Marianne; Isaksson, Magnus; Methlie, Paal; Nilsen, Roy M; Hustad, Steinar; Kämpe, Olle; Hulting, Anna-Lena; Husebye, Eystein S; Løvås, Kristian; Nyström, Thomas; Bensing, Sophie

    2015-07-01

    Conventional glucocorticoid replacement therapy in patients with Addison's disease (AD) is unphysiological with possible adverse effects on mortality, morbidity and quality of life. The diurnal cortisol profile can likely be restored by continuous subcutaneous hydrocortisone infusion (CSHI). The aim of this study was to compare circadian hormone rhythms and insulin sensitivity in conventional thrice-daily regimen of glucocorticoid replacement therapy with CSHI treatment in patients with AD. An open, randomized, two-period, 12-week crossover multicentre trial in Norway and Sweden. Ten Norwegian patients were admitted for 24-h sampling of hormone profiles. Fifteen Swedish patients underwent euglycaemic-hyperinsulinaemic clamp. Thrice-daily regimen of oral hydrocortisone (OHC) and CSHI treatment. We measured the circadian rhythm of cortisol, adrenocorticotropic hormone (ACTH), growth hormone (GH), insulin-like growth factor-1, (IGF-1), IGF-binding protein-3 (IGFBP-3), glucose, insulin and triglycerides during OHC and CSHI treatment. Euglycaemic-hyperinsulinaemic clamp was used to assess insulin sensitivity. Continuous subcutaneous hydrocortisone infusion provided a more physiological circadian cortisol curve including a late-night cortisol surge. ACTH levels showed a near normal circadian variation for CSHI. CSHI prevented a continuous decrease in glucose during the night. No difference in insulin sensitivity was observed between the two treatment arms. Continuous subcutaneous hydrocortisone infusion replacement re-established a circadian cortisol rhythm and normalized the ACTH levels. Patients with CSHI replacement had a more stable night-time glucose level compared with OHC without compromising insulin sensitivity. Thus, restoring night-time cortisol levels might be advantageous for patients with AD. © 2015 John Wiley & Sons Ltd.

  3. ROLE OF INSULIN SENSITIZERS ON CARDIOVASCULAR RISK FACTORS IN POLYCYSTIC OVARIAN SYNDROME: A META-ANALYSIS.

    Science.gov (United States)

    Thethi, Tina K; Katalenich, Bonnie; Nagireddy, Prathima; Chabbra, Pankdeep; Kuhadiya, Nitesh; Fonseca, Vivian

    2015-06-01

    Polycystic ovarian syndrome (PCOS) is associated with an increase in cardiovascular (CV) risk factors such as insulin resistance, with accompanying hyperinsulinemia and hyperlipidemia, which are predisposing factors for type 2 diabetes mellitus and CV disease. The aim of this meta-analysis is to examine the effect of insulin sensitizers on clinical and biochemical features of PCOS and risk factors for CV disease. A systematic literature review was conducted, and randomized controlled clinical trials were identified by a search of bibliographic databases: Medline database (from 1966 forward), EMBASE (January 1985 forward), and Cochrane Central Register of Controlled Trials. Reviews of reference lists further identified candidate trials. Data was independently abstracted in duplicate by 2 investigators using a standardized data-collection form. Articles without a comparison group and randomization allocation were excluded. Reviewers worked independently and in duplicate to determine the methodological quality of trials, then collected data on patient characteristics, interventions, and outcomes. Of 455 studies, 44 trials were eligible. A random effects model was used. Significant unadjusted results favoring treatment with insulin sensitizers were obtained for body mass index (BMI) (effect size [ES] of 0.58), waist to hip ratio (WHR) (ES of 0.02), low-density-lipoprotein cholesterol (LDL-C) (ES of 0.11), fasting insulin (ES of 2.82), fasting glucose (ES of 0.10), free testosterone (ES of 1.88), and androstenedione level (ES of 0.76). Treatment with insulin sensitizers in women with PCOS results in improvement in CV factors such as BMI, WHR, LDL-C, fasting insulin, glucose, free testosterone, and androstenedione.

  4. Effect of weight reduction on insulin sensitivity, sex hormone-binding globulin, sex hormones and gonadotrophins in obese children

    DEFF Research Database (Denmark)

    Birkebaek, N H; Lange, Aksel; Holland-Fischer, P

    2010-01-01

    Obesity in men is associated with reduced insulin sensitivity and hypoandrogenism, while obesity in women is associated with reduced insulin sensitivity and hyperandrogenism. In children, the effect of obesity and weight reduction on the hypothalamo-pituitary-gonadal axis is rarely investigated. ....... The aim of the present study was to investigate the effect of weight reduction in obese Caucasian children on insulin sensitivity, sex hormone-binding globulin (SHBG), DHEAS and the hypothalamo-pituitary-gonadal axis.......Obesity in men is associated with reduced insulin sensitivity and hypoandrogenism, while obesity in women is associated with reduced insulin sensitivity and hyperandrogenism. In children, the effect of obesity and weight reduction on the hypothalamo-pituitary-gonadal axis is rarely investigated...

  5. Metabolic markers associated with insulin resistance predict type 2 diabetes in Koreans with normal blood pressure or prehypertension.

    Science.gov (United States)

    Sung, Ki-Chul; Park, Hyun-Young; Kim, Min-Ju; Reaven, Gerald

    2016-03-22

    Questions remain as to the association between essential hypertension and increased incidence of type 2 diabetes (T2DM). The premise of this analysis is that insulin resistance/compensatory hyperinsulinemia is a major predictor of T2DM, and the greater the prevalence of insulin resistance within any population, normotensive or hypertensive, the more likely T2DM will develop. The hypothesis to be tested is that surrogate estimates of insulin resistance will predict incident T2DM to a significant degree in persons with normal blood pressure or prehypertension. Analysis of data from a population-based survey of 10, 038 inhabitants of rural and urban areas of Korea, ≥40 years-old, initiated in 2001, with measures of demographic and metabolic characteristics at baseline and 8-years later. Participants were classified as having normal blood pressure or prehypertension, and three simple manifestations of insulin resistance related to the pathophysiology of T2DM used to predict incident T2DM: (1) glycemia (plasma glucose concentration 2-hour after 75 g oral glucose challenge = 2-hour PG); (2) hyperinsulinemia (plasma insulin concentration 2-hour after 75 g oral glucose challenge = 2-hour PI); and (3) dyslipidemia (ratio of fasting plasma triglyceride/high/density lipoprotein cholesterol concentration = TG/HDL-C ratio). Fully adjusted hazard ratios (HR, 95 % CI) for incident T2DM were highest (P insulin resistance was the 2-hour PI concentration. Subjects with normal blood pressure in the highest quartile of 2-hour PI concentrations were significantly associated with incident T2DM, with HRs of 1.5 (1.02-2.20, P = 0.25) and 2.02 (1.35-3.02, P insulin resistance (glycemia, insulinemia, and dyslipidemia) predict the development of T2DM in patients with either normal blood pressure or prehypertension.

  6. Insulin and leptin levels in overweight and normal-weight Iranian adolescents: The CASPIAN-III study

    Directory of Open Access Journals (Sweden)

    Ehsan Bahrami

    2014-01-01

    Full Text Available Background: In this study, we aim to compare insulin and leptin levels in adolescents with or without excess weight and in those with or without abdominal obesity. Materials and Methods : This case-control study was conducted among 486 samples. We randomly selected 243 overweight and an equal number of normal-weight adolescents from among participants of the third survey of a national surveillance program entitled "Childhood and Adolescence Surveillance and PreventIon of Adult Non-communicable diseases study." Serum insulin and leptin were compared between two groups and their correlation was determined with other variables. Results: The mean age and body mass index (BMI of participants were 14.10 ± 2.82 years and 22.12 ± 6.49 kg/m 2 , respectively. Leptin and insulin levels were higher in overweight than in normal-weight adolescents (P < 0.05. Leptin level was higher in children with abdominal obesity than in their other counterparts (P < 0.001. Leptin level was correlated with age, fasting blood glucose, BMI, and insulin level. Conclusion: Insulin and leptin levels were higher among overweight and obese children, which may reflect insulin and leptin-resistance. Given the complications of excess weight from early life, prevention and controlling childhood obesity should be considered as a health priority.

  7. Insulin

    Science.gov (United States)

    ... For Consumers Home For Consumers Consumer Information by Audience For Women Women's Health Topics Insulin Share Tweet ... I start having side effects? What is my target blood sugar level? How often should I check ...

  8. Rebelling against the (Insulin Resistance: A Review of the Proposed Insulin-Sensitizing Actions of Soybeans, Chickpeas, and Their Bioactive Compounds

    Directory of Open Access Journals (Sweden)

    Jaime L. Clark

    2018-03-01

    Full Text Available Insulin resistance is a major risk factor for diseases such as type 2 diabetes and metabolic syndrome. Current methods for management of insulin resistance include pharmacological therapies and lifestyle modifications. Several clinical studies have shown that leguminous plants such as soybeans and pulses (dried beans, dried peas, chickpeas, lentils are able to reduce insulin resistance and related type 2 diabetes parameters. However, to date, no one has summarized the evidence supporting a mechanism of action for soybeans and pulses that explains their ability to lower insulin resistance. While it is commonly assumed that the biological activities of soybeans and pulses are due to their antioxidant activities, these bioactive compounds may operate independent of their antioxidant properties and, thus, their ability to potentially improve insulin sensitivity via alternative mechanisms needs to be acknowledged. Based on published studies using in vivo and in vitro models representing insulin resistant states, the proposed mechanisms of action for insulin-sensitizing actions of soybeans, chickpeas, and their bioactive compounds include increasing glucose transporter-4 levels, inhibiting adipogenesis by down-regulating peroxisome proliferator-activated receptor-γ, reducing adiposity, positively affecting adipokines, and increasing short-chain fatty acid-producing bacteria in the gut. Therefore, this review will discuss the current evidence surrounding the proposed mechanisms of action for soybeans and certain pulses, and their bioactive compounds, to effectively reduce insulin resistance.

  9. Effect of glibenclamide on insulin release at moderate and high blood glucose levels in normal man

    NARCIS (Netherlands)

    Ligtenberg, JJM; Venker, CE; Sluiter, WJ; VanHaeften, TW

    Insulin release occurs in two phases; sulphonylurea derivatives may have different potencies in stimulating first-and second-phase insulin release. We studied the effect of glibenclamide on insulin secretion at submaximally and maximally stimulating blood glucose levels with a primed hyperglycaemic

  10. Reversal of diet-induced obesity increases insulin transport into cerebrospinal fluid and restores sensitivity to the anorexic action of central insulin in male rats.

    Science.gov (United States)

    Begg, Denovan P; Mul, Joram D; Liu, Min; Reedy, Brianne M; D'Alessio, David A; Seeley, Randy J; Woods, Stephen C

    2013-03-01

    Diet-induced obesity (DIO) reduces the ability of centrally administered insulin to reduce feeding behavior and also reduces the transport of insulin from the periphery to the central nervous system (CNS). The current study was designed to determine whether reversal of high-fat DIO restores the anorexic efficacy of central insulin and whether this is accompanied by restoration of the compromised insulin transport. Adult male Long-Evans rats were initially maintained on either a low-fat chow diet (LFD) or a high-fat diet (HFD). After 22 weeks, half of the animals on the HFD were changed to the LFD, whereas the other half continued on the HFD for an additional 8 weeks, such that there were 3 groups: 1) a LFD control group (Con; n = 18), 2) a HFD-fed, DIO group (n = 17), and 3) a HFD to LFD, DIO-reversal group (DIO-rev; n = 18). The DIO reversal resulted in a significant reduction of body weight and epididymal fat weight relative to the DIO group. Acute central insulin administration (8 mU) reduced food intake and caused weight loss in Con and DIO-rev but not DIO rats. Fasting cerebrospinal fluid insulin was higher in DIO than Con animals. However, after a peripheral bolus injection of insulin, cerebrospinal fluid insulin increased in Con and DIO-rev rats but not in the DIO group. These data provide support for previous reports that DIO inhibits both the central effects of insulin and insulin's transport to the CNS. Importantly, DIO-rev restored sensitivity to the effects of central insulin on food intake and insulin transport into the CNS.

  11. Modification and Validation of the Triglyceride-to-HDL Cholesterol Ratio as a Surrogate of Insulin Sensitivity in White Juveniles and Adults without Diabetes Mellitus: The Single Point Insulin Sensitivity Estimator (SPISE).

    Science.gov (United States)

    Paulmichl, Katharina; Hatunic, Mensud; Højlund, Kurt; Jotic, Aleksandra; Krebs, Michael; Mitrakou, Asimina; Porcellati, Francesca; Tura, Andrea; Bergsten, Peter; Forslund, Anders; Manell, Hannes; Widhalm, Kurt; Weghuber, Daniel; Anderwald, Christian-Heinz

    2016-09-01

    The triglyceride-to-HDL cholesterol (TG/HDL-C) ratio was introduced as a tool to estimate insulin resistance, because circulating lipid measurements are available in routine settings. Insulin, C-peptide, and free fatty acids are components of other insulin-sensitivity indices but their measurement is expensive. Easier and more affordable tools are of interest for both pediatric and adult patients. Study participants from the Relationship Between Insulin Sensitivity and Cardiovascular Disease [43.9 (8.3) years, n = 1260] as well as the Beta-Cell Function in Juvenile Diabetes and Obesity study cohorts [15 (1.9) years, n = 29] underwent oral-glucose-tolerance tests and euglycemic clamp tests for estimation of whole-body insulin sensitivity and calculation of insulin sensitivity indices. To refine the TG/HDL ratio, mathematical modeling was applied including body mass index (BMI), fasting TG, and HDL cholesterol and compared to the clamp-derived M-value as an estimate of insulin sensitivity. Each modeling result was scored by identifying insulin resistance and correlation coefficient. The Single Point Insulin Sensitivity Estimator (SPISE) was compared to traditional insulin sensitivity indices using area under the ROC curve (aROC) analysis and χ(2) test. The novel formula for SPISE was computed as follows: SPISE = 600 × HDL-C(0.185)/(TG(0.2) × BMI(1.338)), with fasting HDL-C (mg/dL), fasting TG concentrations (mg/dL), and BMI (kg/m(2)). A cutoff value of 6.61 corresponds to an M-value smaller than 4.7 mg · kg(-1) · min(-1) (aROC, M:0.797). SPISE showed a significantly better aROC than the TG/HDL-C ratio. SPISE aROC was comparable to the Matsuda ISI (insulin sensitivity index) and equal to the QUICKI (quantitative insulin sensitivity check index) and HOMA-IR (homeostasis model assessment-insulin resistance) when calculated with M-values. The SPISE seems well suited to surrogate whole-body insulin sensitivity from inexpensive fasting single-point blood draw and BMI

  12. Di-(2-ethylhexyl phthalate metabolites in urine show age-related changes and associations with adiposity and parameters of insulin sensitivity in childhood.

    Directory of Open Access Journals (Sweden)

    Arianna Smerieri

    Full Text Available Phthalates might be implicated with obesity and insulin sensitivity. We evaluated the levels of primary and secondary metabolites of Di-(2-ethylhexyl phthalate (DEHP in urine in obese and normal-weight subjects both before and during puberty, and investigated their relationships with auxological parameters and indexes of insulin sensitivity.DEHP metabolites (MEHP, 6-OH-MEHP, 5-oxo-MEHP, 5-OH-MEHP, and 5-CX-MEHP, were measured in urine by RP-HPLC-ESI-MS. Traditional statistical analysis and a data mining analysis using the Auto-CM analysis were able to offer an insight into the complex biological connections between the studied variables.The data showed changes in DEHP metabolites in urine related with obesity, puberty, and presence of insulin resistance. Changes in urine metabolites were related with age, height and weight, waist circumference and waist to height ratio, thus to fat distribution. In addition, clear relationships in both obese and normal-weight subjects were detected among MEHP, its products of oxidation and measurements of insulin sensitivity.It remains to be elucidated whether exposure to phthalates per se is actually the risk factor or if the ability of the body to metabolize phthalates is actually the key point. Further studies that span from conception to elderly subjects besides further understanding of DEHP metabolism are warranted to clarify these aspects.

  13. The macrophage A2B adenosine receptor regulates tissue insulin sensitivity.

    Directory of Open Access Journals (Sweden)

    Hillary Johnston-Cox

    Full Text Available High fat diet (HFD-induced type 2 diabetes continues to be an epidemic with significant risk for various pathologies. Previously, we identified the A2b adenosine receptor (A2bAR, an established regulator of inflammation, as a regulator of HFD-induced insulin resistance. In particular, HFD was associated with vast upregulation of liver A2bAR in control mice, and while mice lacking this receptor showed augmented liver inflammation and tissue insulin resistance. As the A2bAR is expressed in different tissues, here, we provide the first lead to cellular mechanism by demonstrating that the receptor's influence on tissue insulin sensitivity is mediated via its expression in macrophages. This was shown using a newly generated transgenic mouse model expressing the A2bAR gene in the macrophage lineage on an otherwise A2bAR null background. Reinstatement of macrophage A2bAR expression in A2bAR null mice fed HFD restored insulin tolerance and tissue insulin signaling to the level of control mice. The molecular mechanism for this effect involves A2bAR-mediated changes in cyclic adenosine monophosphate in macrophages, reducing the expression and release of inflammatory cytokines, which downregulate insulin receptor-2. Thus, our results illustrate that macrophage A2bAR signaling is needed and sufficient for relaying the protective effect of the A2bAR against HFD-induced tissue inflammation and insulin resistance in mice.

  14. Relationship Between β-cell Response and Insulin Sensitivity in Horses based on the Oral Sugar Test and the Euglycemic Hyperinsulinemic Clamp.

    Science.gov (United States)

    Lindåse, S; Nostell, K; Söder, J; Bröjer, J

    2017-09-01

    A hyperbolic relationship between β-cell response and insulin sensitivity (IS) has been described in several species including rodents, dogs, and humans. This relationship has not been elucidated in the horse. To determine whether the hyperbolic relationship between β-cell response and IS exists in horses by using indices of β-cell response from the oral sugar test (OST) and IS measurements from the euglycemic hyperinsulinemic clamp (EHC). A second aim was to compare how well IS estimates from the OST and EHC correlate. Forty-nine horses with different degrees of insulin regulation (normal-to-severe insulin dysregulation). Cross-sectional study. Horses were examined with an OST and an EHC. Decreased IS was associated with increased β-cell response in the horses. Nine of 12 comparisons between indices of β-cell response and IS measures fulfilled the criteria for a hyperbolic relationship. Indices of IS calculated from the OST correlated highly with the insulin-dependent glucose disposal rate (M) and the insulin-dependent glucose disposal rate per unit of insulin (M/I) determined from the EHC (r = 0.81-0.87). A hyperbolic relationship between β-cell response and IS exists in horses, which suggest that horses with insulin dysregulation respond not only with postprandial hyperinsulinemia but are also insulin resistant. The OST is primarily a test for β-cell response rather than a test for IS, but calculated indices of IS from the OST may be useful to estimate IS in horses, especially when the horse is insulin resistant. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  15. Insulin-sensitive phospholipid signaling systems and glucose transport. Update II.

    Science.gov (United States)

    Farese, R V

    2001-04-01

    Insulin provokes rapid changes in phospholipid metabolism and thereby generates biologically active lipids that serve as intracellular signaling factors that regulate glucose transport and glycogen synthesis. These changes include: (i) activation of phosphatidylinositol 3-kinase (PI3K) and production of PIP3; (ii) PIP3-dependent activation of atypical protein kinase Cs (PKCs); (iii) PIP3-dependent activation of PKB; (iv) PI3K-dependent activation of phospholipase D and hydrolysis of phosphatidylcholine with subsequent increases in phosphatidic acid (PA) and diacylglycerol (DAG); (v) PI3K-independent activation of glycerol-3-phosphate acylytansferase and increases in de novo synthesis of PA and DAG; and (vi) activation of DAG-sensitive PKCs. Recent findings suggest that atypical PKCs and PKB serve as important positive regulators of insulin-stimulated glucose metabolism, whereas mechanisms that result in the activation of DAG-sensitive PKCs serve mainly as negative regulators of insulin signaling through PI3K. Atypical PKCs and PKB are rapidly activated by insulin in adipocytes, liver, skeletal muscles, and other cell types by a mechanism requiring PI3K and its downstream effector, 3-phosphoinositide-dependent protein kinase-1 (PDK-1), which, in conjunction with PIP3, phosphorylates critical threonine residues in the activation loops of atypical PKCs and PKB. PIP3 also promotes increases in autophosphorylation and allosteric activation of atypical PKCs. Atypical PKCs and perhaps PKB appear to be required for insulin-induced translocation of the GLUT 4 glucose transporter to the plasma membrane and subsequent glucose transport. PKB also appears to be the major regulator of glycogen synthase. Together, atypical PKCs and PKB serve as a potent, integrated PI3K/PDK-1-directed signaling system that is used by insulin to regulate glucose metabolism.

  16. Fabrication of Glucose-Sensitive Layer-by-Layer Films for Potential Controlled Insulin Release Applications

    Directory of Open Access Journals (Sweden)

    Talusan Timothy Jemuel E.

    2015-01-01

    Full Text Available Self-regulated drug delivery systems (DDS are potential alternative to the conventional method of introducing insulin to the body due to their controlled drug release mechanism. In this study, Layer-by-Layer technique was utlized to manufacture drug loaded, pH responsive thin films. Insulin was alternated with pH-sensitive, [2-(dimethyl amino ethyl aminoacrylate] (PDMAEMA and topped of with polymer/glucose oxidase (GOD layers. Similarly, films using a different polymer, namely Poly(Acrylic Acid (PAA were also fabricated. Exposure of the films to glucose solutions resulted to the production of gluconic acid causing a polymer conformation change due to protonation, thus releasing the embedded insulin. The insulin release was monitored by subjecting the dipping glucose solutions to Bradford Assay. Films exhibited a reversal in drug release profile in the presence of glucose as compared to without glucose. PAA films were also found out to release more insulin compared to that of the PDMAEMA films.The difference in the profile of the two films were due to different polymer-GOD interactions, since both films exhibited almost identical profiles when embedded with Poly(sodium 4-styrenesulfonate (PSS instead of GOD.

  17. Alternative translation initiation of Caveolin-2 desensitizes insulin signaling through dephosphorylation of insulin receptor by PTP1B and causes insulin resistance.

    Science.gov (United States)

    Kwon, Hayeong; Jang, Donghwan; Choi, Moonjeong; Lee, Jaewoong; Jeong, Kyuho; Pak, Yunbae

    2018-06-01

    Insulin resistance, defined as attenuated sensitivity responding to insulin, impairs insulin action. Direct causes and molecular mechanisms of insulin resistance have thus far remained elusive. Here we show that alternative translation initiation (ATI) of Caveolin-2 (Cav-2) regulates insulin sensitivity. Cav-2β isoform yielded by ATI desensitizes insulin receptor (IR) via dephosphorylation by protein-tyrosine phosphatase 1B (PTP1B), and subsequent endocytosis and lysosomal degradation of IR, causing insulin resistance. Blockage of Cav-2 ATI protects against insulin resistance by preventing Cav-2β-PTP1B-directed IR desensitization, thereby normalizing insulin sensitivity and glucose uptake. Our findings show that Cav-2β is a negative regulator of IR signaling, and identify a mechanism causing insulin resistance through control of insulin sensitivity via Cav-2 ATI. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Effect of fructose consumption on insulin sensitivity in nondiabetic subjects: a systematic review and meta-analysis of diet-intervention trials.

    Science.gov (United States)

    Ter Horst, Kasper W; Schene, Merle R; Holman, Rebecca; Romijn, Johannes A; Serlie, Mireille J

    2016-12-01

    High fructose consumption has been suggested to contribute to several features of metabolic syndrome including insulin resistance, but to our knowledge, no previous meta-analyses have investigated the effect of fructose on insulin sensitivity in nondiabetic subjects. We performed a systematic review and meta-analysis of controlled diet-intervention studies in nondiabetic subjects to determine the effect of fructose on insulin sensitivity. We searched MEDLINE, EMBASE, and the Cochrane Library for relevant trials on the basis of predetermined eligibility criteria. Two investigators independently performed the study selection, quality assessment, and data extraction. Results were pooled with the use of the generic inverse-variance method with random effects weighting and were expressed as mean differences (MDs) or standardized mean differences (SMDs) with 95% CIs. Twenty-nine articles that described 46 comparisons in 1005 normal-weight and overweight or obese participants met the eligibility criteria. An energy-matched (isocaloric) exchange of dietary carbohydrates by fructose promoted hepatic insulin resistance (SMD: 0.47; 95% CI: 0.03, 0.91; P = 0.04) but had no effect on fasting plasma insulin concentrations (MD: -0.79 pmol/L; 95% CI: -6.41, 4.84 pmol/L; P = 0.78), the homeostasis model assessment of insulin resistance (HOMA-IR) (MD: 0.13; 95% CI: -0.07, 0.34; P = 0.21), or glucose disposal rates under euglycemic hyperinsulinemic clamp conditions (SMD: 0.00; 95% CI: 20.41, 0.41; P = 1.00). Hypercaloric fructose (∼25% excess of energy compared with that of the weight-maintenance control diet) raised fasting plasma insulin concentrations (MD: 3.38 pmol/L; 95% CI: 0.03, 6.73 pmol/L; P fructose consumption, in isocaloric exchange or in hypercaloric supplementation, promotes the development of hepatic insulin resistance in nondiabetic adults without affecting peripheral or muscle insulin sensitivity. Larger and longer-term studies are needed to assess whether real

  19. Early growth response-1 negative feedback regulates skeletal muscle postprandial insulin sensitivity via activating Ptp1b transcription.

    Science.gov (United States)

    Wu, Jing; Tao, Wei-Wei; Chong, Dan-Yang; Lai, Shan-Shan; Wang, Chuang; Liu, Qi; Zhang, Tong-Yu; Xue, Bin; Li, Chao-Jun

    2018-03-15

    Postprandial insulin desensitization plays a critical role in maintaining whole-body glucose homeostasis by avoiding the excessive absorption of blood glucose; however, the detailed mechanisms that underlie how the major player, skeletal muscle, desensitizes insulin action remain to be elucidated. Herein, we report that early growth response gene-1 ( Egr-1) is activated by insulin in skeletal muscle and provides feedback inhibition that regulates insulin sensitivity after a meal. The inhibition of the transcriptional activity of Egr-1 enhanced the phosphorylation of the insulin receptor (InsR) and Akt, thus increasing glucose uptake in L6 myotubes after insulin stimulation, whereas overexpression of Egr-1 decreased insulin sensitivity. Furthermore, deletion of Egr-1 in the skeletal muscle improved systemic insulin sensitivity and glucose tolerance, which resulted in lower blood glucose levels after refeeding. Mechanistic analysis demonstrated that EGR-1 inhibited InsR phosphorylation and glucose uptake in skeletal muscle by binding to the proximal promoter region of protein tyrosine phosphatase-1B (PTP1B) and directly activating transcription. PTP1B knockdown largely restored insulin sensitivity and enhanced glucose uptake, even under conditions of EGR-1 overexpression. Our results indicate that EGR-1/PTP1B signaling negatively regulates postprandial insulin sensitivity and suggest a potential therapeutic target for the prevention and treatment of excessive glucose absorption.-Wu, J., Tao, W.-W., Chong, D.-Y., Lai, S.-S., Wang, C., Liu, Q., Zhang, T.-Y., Xue, B., Li, C.-J. Early growth response-1 negative feedback regulates skeletal muscle postprandial insulin sensitivity via activating Ptp1b transcription.

  20. The transcription factor Prep1 controls hepatic insulin sensitivity and gluconeogenesis by targeting nuclear localization of FOXO1.

    Science.gov (United States)

    Kulebyakin, Konstantin; Penkov, Dmitry; Blasi, Francesco; Akopyan, Zhanna; Tkachuk, Vsevolod

    2016-12-02

    Liver plays a key role in controlling body carbohydrate homeostasis by switching between accumulation and production of glucose and this way maintaining constant level of glucose in blood. Increased blood glucose level triggers release of insulin from pancreatic β-cells. Insulin represses hepatic glucose production and increases glucose accumulation. Insulin resistance is the main cause of type 2 diabetes and hyperglycemia. Currently thiazolidinediones (TZDs) targeting transcriptional factor PPARγ are used as insulin sensitizers for treating patients with type 2 diabetes. However, TZDs are reported to be associated with cardiovascular and liver problems and stimulate obesity. Thus, it is necessary to search new approaches to improve insulin sensitivity. A promising candidate is transcriptional factor Prep1, as it was shown earlier it could affect insulin sensitivity in variety of insulin-sensitive tissues. The aim of the present study was to evaluate a possible involvement of transcriptional factor Prep1 in control of hepatic glucose accumulation and production. We created mice with liver-specific Prep1 knockout and discovered that hepatocytes derived from these mice are much more sensitive to insulin, comparing to their WT littermates. Incubation of these cells with 100 nM insulin results in almost complete inhibition of gluconeogenesis, while in WT cells this repression is only partial. However, Prep1 doesn't affect gluconeogenesis in the absence of insulin. Also, we observed that nuclear content of gluconeogenic transcription factor FOXO1 was greatly reduced in Prep1 knockout hepatocytes. These findings suggest that Prep1 may control hepatic insulin sensitivity by targeting FOXO1 nuclear stability. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Myostatin inhibition in muscle, but not adipose tissue, decreases fat mass and improves insulin sensitivity.

    Directory of Open Access Journals (Sweden)

    Tingqing Guo

    Full Text Available Myostatin (Mstn is a secreted growth factor expressed in skeletal muscle and adipose tissue that negatively regulates skeletal muscle mass. Mstn(-/- mice have a dramatic increase in muscle mass, reduction in fat mass, and resistance to diet-induced and genetic obesity. To determine how Mstn deletion causes reduced adiposity and resistance to obesity, we analyzed substrate utilization and insulin sensitivity in Mstn(-/- mice fed a standard chow. Despite reduced lipid oxidation in skeletal muscle, Mstn(-/- mice had no change in the rate of whole body lipid oxidation. In contrast, Mstn(-/- mice had increased glucose utilization and insulin sensitivity as measured by indirect calorimetry, glucose and insulin tolerance tests, and hyperinsulinemic-euglycemic clamp. To determine whether these metabolic effects were due primarily to the loss of myostatin signaling in muscle or adipose tissue, we compared two transgenic mouse lines carrying a dominant negative activin IIB receptor expressed specifically in adipocytes or skeletal muscle. We found that inhibition of myostatin signaling in adipose tissue had no effect on body composition, weight gain, or glucose and insulin tolerance in mice fed a standard diet or a high-fat diet. In contrast, inhibition of myostatin signaling in skeletal muscle, like Mstn deletion, resulted in increased lean mass, decreased fat mass, improved glucose metabolism on standard and high-fat diets, and resistance to diet-induced obesity. Our results demonstrate that Mstn(-/- mice have an increase in insulin sensitivity and glucose uptake, and that the reduction in adipose tissue mass in Mstn(-/- mice is an indirect result of metabolic changes in skeletal muscle. These data suggest that increasing muscle mass by administration of myostatin antagonists may be a promising therapeutic target for treating patients with obesity or diabetes.

  2. Four days of simulated shift work reduces insulin sensitivity in humans.

    Science.gov (United States)

    Bescos, R; Boden, M J; Jackson, M L; Trewin, A J; Marin, E C; Levinger, I; Garnham, A; Hiam, D S; Falcao-Tebas, F; Conte, F; Owens, J A; Kennaway, D J; McConell, G K

    2018-06-01

    The aim of this study was to investigate the effects of 4 consecutive simulated night shifts on glucose homeostasis, mitochondrial function and central and peripheral rhythmicities compared with a simulated day shift schedule. Seventeen healthy adults (8M:9F) matched for sleep, physical activity and dietary/fat intake participated in this study (night shift work n = 9; day shift work n = 8). Glucose tolerance and insulin sensitivity before and after 4 nights of shift work were measured by an intravenous glucose tolerance test and a hyperinsulinaemic euglycaemic clamp respectively. Muscles biopsies were obtained to determine insulin signalling and mitochondrial function. Central and peripheral rhythmicities were assessed by measuring salivary melatonin and expression of circadian genes from hair samples respectively. Fasting plasma glucose increased (4.4 ± 0.1 vs. 4.6 ± 0.1 mmol L -1 ; P = .001) and insulin sensitivity decreased (25 ± 7%, P night shift, with no changes following the day shift. Night shift work had no effect on skeletal muscle protein expression (PGC1α, UCP3, TFAM and mitochondria Complex II-V) or insulin-stimulated pAkt Ser473, pTBC1D4Ser318 and pTBC1D4Thr642. Importantly, the metabolic changes after simulated night shifts occurred despite no changes in the timing of melatonin rhythmicity or hair follicle cell clock gene expression across the wake period (Per3, Per1, Nr1d1 and Nr1d2). Only 4 days of simulated night shift work in healthy adults is sufficient to reduce insulin sensitivity which would be expected to increase the risk of T2D. © 2018 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  3. Insulin-like factor 3 serum levels in 135 normal men and 85 men with testicular disorders

    DEFF Research Database (Denmark)

    Bay, K; Hartung, S; Ivell, R

    2005-01-01

    Insulin-like factor 3 (INSL3) serum levels were measured in 135 andrologically well-characterized normal men and 85 patients with testicular disorders to investigate how the hormone, which is a major secretory product of human Leydig cells, is related to testosterone (T), LH, and semen quality. I...

  4. Fibroblast growth factor 21 improves insulin sensitivity and synergizes with insulin in human adipose stem cell-derived (hASC adipocytes.

    Directory of Open Access Journals (Sweden)

    Darwin V Lee

    Full Text Available Fibroblast growth factor 21 (FGF21 has evolved as a major metabolic regulator, the pharmacological administration of which causes weight loss, insulin sensitivity and glucose control in rodents and humans. To understand the molecular mechanisms by which FGF21 exerts its metabolic effects, we developed a human in vitro model of adipocytes to examine crosstalk between FGF21 and insulin signaling. Human adipose stem cell-derived (hASC adipocytes were acutely treated with FGF21 alone, insulin alone, or in combination. Insulin signaling under these conditions was assessed by measuring tyrosine phosphorylation of insulin receptor (InsR, insulin receptor substrate-1 (IRS-1, and serine 473 phosphorylation of Akt, followed by a functional assay using 14C-2-deoxyglucose [14C]-2DG to measure glucose uptake in these cells. FGF21 alone caused a modest increase of glucose uptake, but treatment with FGF21 in combination with insulin had a synergistic effect on glucose uptake in these cells. The presence of FGF21 also effectively lowered the insulin concentration required to achieve the same level of glucose uptake compared to the absence of FGF21 by 10-fold. This acute effect of FGF21 on insulin signaling was not due to IR, IGF-1R, or IRS-1 activation. Moreover, we observed a substantial increase in basal S473-Akt phosphorylation by FGF21 alone, in contrast to the minimal shift in basal glucose uptake. Taken together, our data demonstrate that acute co-treatment of hASC-adipocytes with FGF21 and insulin can result in a synergistic improvement in glucose uptake. These effects were shown to occur at or downstream of Akt, or separate from the canonical insulin signaling pathway.

  5. A comparison of osteoprotegerin with adiponectin and high-sensitivity C-reactive protein (hsCRP) as a marker for insulin resistance.

    LENUS (Irish Health Repository)

    O'Sullivan, Eoin P

    2013-01-01

    Insulin resistance (IR) is associated with low adiponectin and elevated high sensitivity C-reactive protein (hsCRP). Osteoprotegerin (OPG) has been shown to be elevated in type 2 diabetes, but whether it reflects underlying IR is unclear. We aimed to compare the ability of serum OPG with adiponectin and hsCRP to act as a marker for IR in individuals with normal and abnormal glucose tolerance.

  6. A high-fat, high-saturated fat diet decreases insulin sensitivity without changing intra-abdominal fat in weight-stable overweight and obese adults.

    Science.gov (United States)

    von Frankenberg, Anize D; Marina, Anna; Song, Xiaoling; Callahan, Holly S; Kratz, Mario; Utzschneider, Kristina M

    2017-02-01

    We sought to determine the effects of dietary fat on insulin sensitivity and whether changes in insulin sensitivity were explained by changes in abdominal fat distribution or very low-density lipoprotein (VLDL) fatty acid composition. Overweight/obese adults with normal glucose tolerance consumed a control diet (35 % fat/12 % saturated fat/47 % carbohydrate) for 10 days, followed by a 4-week low-fat diet (LFD, n = 10: 20 % fat/8 % saturated fat/62 % carbohydrate) or high-fat diet (HFD, n = 10: 55 % fat/25 % saturated fat/27 % carbohydrate). All foods and their eucaloric energy content were provided. Insulin sensitivity was measured by labeled hyperinsulinemic-euglycemic clamps, abdominal fat distribution by MRI, and fasting VLDL fatty acids by gas chromatography. The rate of glucose disposal (Rd) during low- and high-dose insulin decreased on the HFD but remained unchanged on the LFD (Rd-low: LFD: 0.12 ± 0.11 vs. HFD: -0.37 ± 0.15 mmol/min, mean ± SE, p vs. HFD: -0.71 ± 0.26 mmol/min, p = 0.08). Hepatic insulin sensitivity did not change. Changes in subcutaneous fat were positively associated with changes in insulin sensitivity on the LFD (r = 0.78, p fat. The LFD led to an increase in VLDL palmitic (16:0), stearic (18:0), and palmitoleic (16:1n7c) acids, while no changes were observed on the HFD. Changes in VLDL n-6 docosapentaenoic acid (22:5n6) were strongly associated with changes in insulin sensitivity on both diets (LFD: r = -0.77; p fat and saturated fat adversely affects insulin sensitivity and thereby might contribute to the development of type 2 diabetes. CLINICALTRIALS. NCT00930371.

  7. Analysis of the variation levels of APN, insulin, sensitive C-reactive protein and leptin in the serum of patients with type 2 diabetes mellitus

    International Nuclear Information System (INIS)

    Du Tongxing; Wang Zizheng; Wang Shukui; Qi Shaokang; Tao Xiaojun

    2005-01-01

    To study the mechanism of pancreatic 13 cell dysfunction and tissue resistance to insulin, and to provide basis for early diagnosis and therapy of the disease, the levels of APN, insulin, sensitive C-reactive protein and leptin in the serum of patients with type 2 diabetes mellitus were determined. Altogether 184 untreatea type 2 diabetes mellitus patients, 30 normal people as the control group, and another 75 type 2 diabetes mellitus patients who have been treated for a year were enrolled in this study. The serum levels of the above indexes were determined by chemiluminescence immunoassay, enzyme immunoassay and radioimmunoassay. The results showed that there were obvious differences in the levels of insulin, leptin, C-reacting protein and insulin antibody between the normal control group and the group of the untreated type 2 diabetes mellitus patients (P<0.01), especially there was significant difference in the level of APN(P<0. 001). Among the 75 type 2 diabetes meltitus patients who have received a year's treatment, all the indexes except for APN and insulin antibody were decreased statistically, while the APN level was increased significantly (P<0.01) than that before the treatment. The determination of markers of type 2 diabetes mellitus is of great significance for its early diagnosis, therapy, prognosis and mechanism research. (authors)

  8. Researching Effective Strategies to Improve Insulin Sensitivity in Children and Teenagers - RESIST. A randomised control trial investigating the effects of two different diets on insulin sensitivity in young people with insulin resistance and/or pre-diabetes.

    Directory of Open Access Journals (Sweden)

    De Sukanya

    2010-09-01

    Full Text Available Abstract Background Concomitant with the rise in childhood obesity there has been a significant increase in the number of adolescents with clinical features of insulin resistance and prediabetes. Clinical insulin resistance and prediabetes are likely to progress to type 2 diabetes and early atherosclerosis if not targeted for early intervention. There are no efficacy trials of lifestyle intervention in this group to inform clinical practice. The primary aim of this randomised control trial (RCT is to determine the efficacy and effectiveness of two different structured lifestyle interventions differing in diet composition on insulin sensitivity, in adolescents with clinical insulin resistance and/or prediabetes treated with metformin. Methods/design This study protocol describes the design of an ongoing RCT. We are recruiting 108 (54 each treatment arm 10 to 17 year olds with clinical features of insulin resistance and/or prediabetes, through physician referral, into a multi-centred RCT. All participants are prescribed metformin and participate in a diet and exercise program. The lifestyle program is the same for all participants except for diet composition. The diets are a high carbohydrate, low fat diet and a moderate carbohydrate, increased protein diet. The program commences with an intensive 3 month dietary intervention, implemented by trained dietitians, followed by a 3 month intensive gym and home based exercise program, supervised by certified physical trainers. To measure the longer term effectiveness, after the intensive intervention trial participants are managed by either their usual physician or study physician and followed up by the study dietitians for an additional 6 months. The primary outcome measure, change in insulin sensitivity, is measured at 3, 6 and 12 months. Discussion Clinical insulin resistance and prediabetes in the paediatric population are rapidly emerging clinical problems with serious health outcomes. With

  9. Early enhancements of hepatic and later of peripheral insulin sensitivity combined with increased postprandial insulin secretion contribute to improved glycemic control after Roux-en-Y gastric bypass

    DEFF Research Database (Denmark)

    Bojsen-Møller, Kirstine N; Dirksen, Carsten; Jørgensen, Nils Bruun

    2014-01-01

    after RYGB. Participants were included after a preoperative diet induced total weight loss of -9.2±1.2%. Hepatic and peripheral insulin sensitivity were assessed using the hyperinsulinemic euglycemic clamp combined with glucose tracer technique and beta-cell function evaluated in response...... after surgery. Insulin mediated glucose disposal and suppression of fatty acids did not improve immediately after surgery but increased at 3 months and 1 year likely related to the reduction in body weight. Insulin secretion increased after RYGB, but only in patients with type 2 diabetes and only...

  10. Effect of High Fat and High Sugar Diet on Glucose Tolerance, Insulin Response to Glucose Load and Insulin Sensitivity in Rats

    OpenAIRE

    岡﨑, 悟

    1987-01-01

    To investigate the precipitating effects of the westernized diet on diabetes mellitus, glucose tolerance and insulin response to oral glucose load (1.5g/kg body weight) and insulin sensitivity to exogenous insulin (0.2U/kg) were studied in rats fed an experimental diet for 8 weeks. Four experimental diets were used : low fat-no sugar diet (energy ratio of 10% fat, 70% starch, a model of the traditional Japanese diet), high fat-high sugar diet (40% fat, 20% starch, 20% sugar, a model of the we...

  11. Genes contributing to pain sensitivity in the normal population

    DEFF Research Database (Denmark)

    Williams, Frances M.K.; Scollen, Serena; Cao, Dandan

    2012-01-01

    Sensitivity to pain varies considerably between individuals and is known to be heritable. Increased sensitivity to experimental pain is a risk factor for developing chronic pain, a common and debilitating but poorly understood symptom. To understand mechanisms underlying pain sensitivity and to s...

  12. Cinnamon extract improves insulin sensitivity in the brain and lowers liver fat in mouse models of obesity.

    Science.gov (United States)

    Sartorius, Tina; Peter, Andreas; Schulz, Nadja; Drescher, Andrea; Bergheim, Ina; Machann, Jürgen; Schick, Fritz; Siegel-Axel, Dorothea; Schürmann, Annette; Weigert, Cora; Häring, Hans-Ulrich; Hennige, Anita M

    2014-01-01

    Treatment of diabetic subjects with cinnamon demonstrated an improvement in blood glucose concentrations and insulin sensitivity but the underlying mechanisms remained unclear. This work intends to elucidate the impact of cinnamon effects on the brain by using isolated astrocytes, and an obese and diabetic mouse model. Cinnamon components (eugenol, cinnamaldehyde) were added to astrocytes and liver cells to measure insulin signaling and glycogen synthesis. Ob/ob mice were supplemented with extract from cinnamomum zeylanicum for 6 weeks and cortical brain activity, locomotion and energy expenditure were evaluated. Insulin action was determined in brain and liver tissues. Treatment of primary astrocytes with eugenol promoted glycogen synthesis, whereas the effect of cinnamaldehyde was attenuated. In terms of brain function in vivo, cinnamon extract improved insulin sensitivity and brain activity in ob/ob mice, and the insulin-stimulated locomotor activity was improved. In addition, fasting blood glucose levels and glucose tolerance were greatly improved in ob/ob mice due to cinnamon extracts, while insulin secretion was unaltered. This corresponded with lower triglyceride and increased liver glycogen content and improved insulin action in liver tissues. In vitro, Fao cells exposed to cinnamon exhibited no change in insulin action. Together, cinnamon extract improved insulin action in the brain as well as brain activity and locomotion. This specific effect may represent an important central feature of cinnamon in improving insulin action in the brain, and mediates metabolic alterations in the periphery to decrease liver fat and improve glucose homeostasis.

  13. Interaction between leucine and phosphodiesterase 5 inhibition in modulating insulin sensitivity and lipid metabolism

    Directory of Open Access Journals (Sweden)

    Fu L

    2015-05-01

    Full Text Available Lizhi Fu,1 Fenfen Li,1 Antje Bruckbauer,2 Qiang Cao,1 Xin Cui,1 Rui Wu,1 Hang Shi,1 Bingzhong Xue,1 Michael B Zemel21Department of Biology, Center for Obesity Reversal, Georgia State University, Atlanta, GA, 2NuSirt Biopharma Inc., Nashville, TN, USA Purpose: Leucine activates SIRT1/AMP-activated protein kinase (AMPK signaling and markedly potentiates the effects of other sirtuin and AMPK activators on insulin signaling and lipid metabolism. Phosphodiesterase 5 inhibition increases nitric oxide–cGMP signaling, which in turn exhibits a positive feedback loop with both SIRT1 and AMPK, thus amplifying peroxisome proliferator-activated receptor γ co-activator α (PGC1α-mediated effects. Methods: We evaluated potential synergy between leucine and PDE5i on insulin sensitivity and lipid metabolism in vitro and in diet-induced obese (DIO mice. Results: Leucine (0.5 mM exhibited significant synergy with subtherapeutic doses (0.1–10 nM of PDE5-inhibitors (sildenafil and icariin on fat oxidation, nitric oxide production, and mitochondrial biogenesis in hepatocytes, adipocytes, and myotubes. Effects on insulin sensitivity, glycemic control, and lipid metabolism were then assessed in DIO-mice. DIO-mice exhibited fasting and postprandial hyperglycemia, insulin resistance, and hepatic steatosis, which were not affected by the addition of leucine (24 g/kg diet. However, the combination of leucine and a subtherapeutic dose of icariin (25 mg/kg diet for 6 weeks reduced fasting glucose (38%, P<0.002, insulin (37%, P<0.05, area under the glucose tolerance curve (20%, P<0.01, and fully restored glucose response to exogenous insulin challenge. The combination also inhibited hepatic lipogenesis, stimulated hepatic and muscle fatty acid oxidation, suppressed hepatic inflammation, and reversed high-fat diet-induced steatosis. Conclusion: These robust improvements in insulin sensitivity, glycemic control, and lipid metabolism indicate therapeutic potential for

  14. pH sensitive thiolated cationic hydrogel for oral insulin delivery.

    Science.gov (United States)

    Sonia, T A; Sharma, Chandra P

    2014-04-01

    The objective of this work is to study the efficacy of pH sensitive thiolated Polydimethylaminoethylmethacrylate for oral delivery of insulin. Synthesis of pH sensitive thiolated Polydimethylaminoethylmethacrylate (PDCPA) was carried out by crosslinking Polymethacrylic acid with thiolated Polydimethylaminoethylmethacrylate (PDCys) via carbodiimide chemistry. Prior to in vivo experiment, various physicochemical and biological characterisation were carried out to evaluate the efficacy of PDCPA. Modification was confirmed by IR and NMR spectroscopy. The particle size was found to be 284 nm with a zeta potential of 37.3+/-1.58 mV. Texture analyser measurements showed that PDCPA is more mucoadhesive than the parent polymer. Transepithelial electrical measurements showed a reduction of greater than 50% on incubation with PDCPA particles. Permeation studies showed that PDCPA is more permeable than the parent polymer. On in vivo evaluation on male diabetic rats, insulin loaded PDCPA exhibited a blood glucose reduction of 19%.

  15. Effects of hypothyroidism on the sensitivity of glycolysis and glycogen synthesis to insulin in the soleus muscle of the rat.

    Science.gov (United States)

    Dimitriadis, G D; Leighton, B; Parry-Billings, M; West, D; Newsholme, E A

    1989-01-01

    1. The effects of hypothyroidism on the sensitivity of glycolysis and glycogen synthesis to insulin were investigated in the isolated, incubated soleus muscle of the rat. 2. Hypothyroidism, which was induced by administration of propylthiouracil to the rats, decreased fasting plasma levels of free fatty acids and increased plasma levels of glucose but did not significantly change plasma levels of insulin. 3. The sensitivity of the rates of glycogen synthesis to insulin was increased at physiological, but decreased at supraphysiological, concentrations of insulin. 4. The rates of glycolysis in the hypothyroid muscles were decreased at all insulin concentrations studied and the EC50 for insulin was increased more than 8-fold; the latter indicates decreased sensitivity of this process to insulin. However, at physiological concentrations of insulin, the rates of glucose phosphorylation in the soleus muscles of hypothyroid rats were not different from controls. This suggests that hypothyroidism affects glucose metabolism in muscle not by affecting glucose transport but by decreasing the rate of glucose 6-phosphate conversion to lactate and increasing the rate of conversion of glucose 6-phosphate to glycogen. 5. The rates of glucose oxidation were decreased in the hypothyroid muscles at all insulin concentrations. PMID:2649073

  16. Loss-of-function myostatin mutation increases insulin sensitivity and browning of white fat in Meishan pigs.

    Science.gov (United States)

    Cai, Chunbo; Qian, Lili; Jiang, Shengwang; Sun, Youde; Wang, Qingqing; Ma, Dezun; Xiao, Gaojun; Li, Biao; Xie, Shanshan; Gao, Ting; Chen, Yaoxing; Liu, Jie; An, Xiaorong; Cui, Wentao; Li, Kui

    2017-05-23

    Myostatin-deficient mice showed a remarkable hypertrophy of skeletal muscle, with a decreased fat mass and enhanced insulin sensitivity. Currently, it is unclear if the inhibition of myostatin could be used as an approach to treat human obesity and insulin resistance. In this study, we investigated if the inhibition of porcine myostatin has any effect on fat deposition and insulin sensitivity using genetically engineered Meishan pigs containing a myostatin loss-of-function mutation (Mstn -/- ). Our results indicated that, when compared with wild-type pigs, the amount of subcutaneous fat and leaf fat of Mstn -/- pigs were significantly decreased mainly due to the browning of subcutaneous adipose tissue. Additionally, the serum insulin level decreased and the insulin sensitivity increased significantly in Mstn -/- pigs. Moreover, we found a significant increase in levels of insulin receptor and insulin receptor substrate proteins in skeletal muscle of Mstn -/- pigs, which then activating the insulin signaling pathway. Irisin-mediated regulation is not the only pathway for the activation of insulin signal in Mstn -/- skeletal muscle. This study provides valuable insight for the treatment of human obesity and diabetes mellitus.

  17. Total adiponectin and adiponectin multimeric complexes in relation to weight loss-induced improvements in insulin sensitivity in obese women

    DEFF Research Database (Denmark)

    Polak, J.; Kovacova, Z.; Holst, C.

    2008-01-01

    , and LMW). The HMW form was suggested to be closely associated with insulin sensitivity. This study investigated whether diet-induced changes in insulin sensitivity were associated with changes in adiponectin multimeric complexes. SUBJECTS: Twenty obese women with highest and twenty obese women with lowest...... diet induced changes in insulin sensitivity (responders and non-responders respectively), matched for weight loss (body mass index (BMI)=34.5 (s.d. 2.9) resp. 36.5 kg/m(2) (s.d. 4.0) for responders and non-responders), were selected from 292 women who underwent a 10-week low-caloric diet (LCD; 600 kcal...

  18. Short-Term Exercise Training Improves Insulin Sensitivity but Does Not Inhibit Inflammatory Pathways in Immune Cells from Insulin-Resistant Subjects

    Directory of Open Access Journals (Sweden)

    Sara M. Reyna

    2013-01-01

    Full Text Available Background. Exercise has an anti-inflammatory effect against, and immune cells play critical roles in the development, of insulin resistance and atherosclerotic vascular disease (AVD. Thus, the goal of this study was to determine whether exercise improves insulin sensitivity in insulin-resistant subjects by downregulating proinflammatory signaling in immune cells. Methods. Seventeen lean, 8 obese nondiabetic, and 11 obese type 2 diabetic individuals underwent an aerobic exercise program for 15 days and an insulin clamp before and after exercise. Peripheral mononuclear cells (PMNC were obtained for determination of Toll-like receptor (TLR 2 and 4 protein content and mitogen-activated protein kinase phosphorylation. Results. Compared with that in lean individuals, TLR4 protein content was increased by 4.2-fold in diabetic subjects. This increase in TLR4 content was accompanied by a 3.0-fold increase in extracellular signal-regulated kinase (ERK phosphorylation. Exercise improved insulin sensitivity in the lean, obese, and type 2 diabetes groups. However, exercise did not affect TLR content or ERK phosphorylation. Conclusions. TLR4 content and ERK phosphorylation are increased in PMNC of type 2 diabetic individuals. While exercise improves insulin sensitivity, this effect is not related to changes in TLR2/TLR4 content or ERK phosphorylation in PMNC of type 2 diabetic individuals.

  19. Short-term exercise training improves insulin sensitivity but does not inhibit inflammatory pathways in immune cells from insulin-resistant subjects.

    Science.gov (United States)

    Reyna, Sara M; Tantiwong, Puntip; Cersosimo, Eugenio; Defronzo, Ralph A; Sriwijitkamol, Apiradee; Musi, Nicolas

    2013-01-01

    Background. Exercise has an anti-inflammatory effect against, and immune cells play critical roles in the development, of insulin resistance and atherosclerotic vascular disease (AVD). Thus, the goal of this study was to determine whether exercise improves insulin sensitivity in insulin-resistant subjects by downregulating proinflammatory signaling in immune cells. Methods. Seventeen lean, 8 obese nondiabetic, and 11 obese type 2 diabetic individuals underwent an aerobic exercise program for 15 days and an insulin clamp before and after exercise. Peripheral mononuclear cells (PMNC) were obtained for determination of Toll-like receptor (TLR) 2 and 4 protein content and mitogen-activated protein kinase phosphorylation. Results. Compared with that in lean individuals, TLR4 protein content was increased by 4.2-fold in diabetic subjects. This increase in TLR4 content was accompanied by a 3.0-fold increase in extracellular signal-regulated kinase (ERK) phosphorylation. Exercise improved insulin sensitivity in the lean, obese, and type 2 diabetes groups. However, exercise did not affect TLR content or ERK phosphorylation. Conclusions. TLR4 content and ERK phosphorylation are increased in PMNC of type 2 diabetic individuals. While exercise improves insulin sensitivity, this effect is not related to changes in TLR2/TLR4 content or ERK phosphorylation in PMNC of type 2 diabetic individuals.

  20. Effect of Ursolic Acid on Metabolic Syndrome, Insulin Sensitivity, and Inflammation.

    Science.gov (United States)

    Ramírez-Rodríguez, Alejandra M; González-Ortiz, Manuel; Martínez-Abundis, Esperanza; Acuña Ortega, Natalhie

    2017-09-01

    To evaluate the effect of ursolic acid on metabolic syndrome, insulin sensitivity, and inflammation, a randomized, double-blind, placebo-controlled clinical trial was carried out in 24 patients (30-60 years) with a diagnosis of metabolic syndrome without treatment. They were randomly assigned to two groups of 12 patients, each to receive orally 150 mg of ursolic acid or homologated placebo once a day for 12 weeks. Before and after the intervention, the components of metabolic syndrome, insulin sensitivity (Matsuda index), and inflammation profile (interleukin-6 and C-reactive protein) were evaluated. After ursolic acid administration, the remission of metabolic syndrome occurred in 50% of patients (P = .005) with significant differences in body weight (75.7 ± 11.5 vs. 71 ± 11 kg, P = .002), body mass index (BMI) (29.9 + 3.6 vs. 24.9 ± 1.2 kg/m 2 , P = .049), waist circumference (93 ± 8.9 vs. 83 + 8.6 cm, P = .008), fasting glucose (6.0 ± 0.5 vs. 4.7 ± 0.4 mmol/L, P = .002), and insulin sensitivity (3.1 ± 1.1 vs. 4.2 ± 1.2, P = .003). Ursolic acid administration leads to transient remission of metabolic syndrome, reducing body weight, BMI, waist circumference and fasting glucose, as well as increasing insulin sensitivity.

  1. Effect of vitamin K supplementation on insulin sensitivity: a meta-analysis

    OpenAIRE

    Suksomboon,Naeti; Poolsup,Nalinee; Darli Ko Ko,Htoo

    2017-01-01

    Naeti Suksomboon,1 Nalinee Poolsup,2 Htoo Darli Ko Ko1 1Department of Pharmacy, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand; 2Department of Pharmacy, Faculty of Pharmacy, Silpakorn University, Nakhon-Pathom, Thailand Objective: To perform a systematic review and meta-analysis of randomized, placebo-controlled trials to assess the effect of vitamin K supplementation on insulin sensitivity.Data sources: MEDLINE, the Cochrane Library, CINAHL, Web of Science, Scopus, clinicaltrials...

  2. Identification of adipokine clusters related to parameters of fat mass, insulin sensitivity and inflammation.

    Directory of Open Access Journals (Sweden)

    Gesine Flehmig

    Full Text Available In obesity, elevated fat mass and ectopic fat accumulation are associated with changes in adipokine secretion, which may link obesity to inflammation and the development of insulin resistance. However, relationships among individual adipokines and between adipokines and parameters of obesity, glucose metabolism or inflammation are largely unknown. Serum concentrations of 20 adipokines were measured in 141 Caucasian obese men (n = 67 and women (n = 74 with a wide range of body weight, glycemia and insulin sensitivity. Unbiased, distance-based hierarchical cluster analyses were performed to recognize patterns among adipokines and their relationship with parameters of obesity, glucose metabolism, insulin sensitivity and inflammation. We identified two major adipokine clusters related to either (1 body fat mass and inflammation (leptin, ANGPTL3, DLL1, chemerin, Nampt, resistin or insulin sensitivity/hyperglycemia, and lipid metabolism (vaspin, clusterin, glypican 4, progranulin, ANGPTL6, GPX3, RBP4, DLK1, SFRP5, BMP7, adiponectin, CTRP3 and 5, omentin. In addition, we found distinct adipokine clusters in subgroups of patients with or without type 2 diabetes (T2D. Logistic regression analyses revealed ANGPTL6, DLK1, Nampt and progranulin as strongest adipokine correlates of T2D in obese individuals. The panel of 20 adipokines predicted T2D compared to a combination of HbA1c, HOMA-IR and fasting plasma glucose with lower sensitivity (78% versus 91% and specificity (76% versus 94%. Therefore, adipokine patterns may currently not be clinically useful for the diagnosis of metabolic diseases. Whether adipokine patterns are relevant for the predictive assessment of intervention outcomes needs to be further investigated.

  3. Glucose-Responsive Insulin Delivery by Microneedle-Array Patches Loaded with Hypoxia-Sensitive Vesicles.

    Science.gov (United States)

    Yu, Jicheng; Zhang, Yuqi; Gu, Zhen

    2017-01-01

    In this chapter, we describe the preparation of glucose-responsive vesicles (GRVs) and the fabrication of GRV-loaded microneedle-array patches for insulin delivery. The GRVs were formed of hypoxia-sensitive hyaluronic acid (HS-HA), the synthesis of which is presented in detail. We also describe the procedure to evaluate the in vivo efficacy of this smart patch in a mouse model of chemically induced type 1 diabetes through transcutaneous administration.

  4. Constitutive insulin sensitivity and obesity my be caused by PTEN mutations

    Directory of Open Access Journals (Sweden)

    E A Pigarova

    2012-12-01

    Full Text Available Реферат по статье: Pal A, Barber TM, Van de Bunt M, Rudge SA, Zhang Q, Lachlan KL, Cooper NS, Linden H, Levy JC, Wakelam MJ, Walker L, Karpe F, Gloyn AL. PTEN mutations as a cause of constitutive insulin sensitivity and obesity. N Engl J Med. 2012 Sep 13;367(11:1002-11.

  5. Acute activation of GLP-1-expressing neurons promotes glucose homeostasis and insulin sensitivity

    OpenAIRE

    Xuemei Shi; Shaji Chacko; Feng Li; Depei Li; Douglas Burrin; Lawrence Chan; Xinfu Guan

    2017-01-01

    Objective: Glucagon-like peptides are co-released from enteroendocrine L cells in the gut and preproglucagon (PPG) neurons in the brainstem. PPG-derived GLP-1/2 are probably key neuroendocrine signals for the control of energy balance and glucose homeostasis. The objective of this study was to determine whether activation of PPG neurons per se modulates glucose homeostasis and insulin sensitivity in vivo. Methods: We generated glucagon (Gcg) promoter-driven Cre transgenic mice and injected...

  6. Plasma lipid fatty acid composition, desaturase activities and insulin sensitivity in Amerindian women.

    Science.gov (United States)

    Vessby, B; Ahrén, B; Warensjö, E; Lindgärde, F

    2012-03-01

    Two Amerindian populations--Shuar women living in the Amazonian rain forest under traditional conditions and urbanized women in a suburb of Lima were studied. The fatty acid composition in plasma lipids and the relationships between fatty acid composition and metabolic variables were studied, as well as in a reference group of Swedish women. Fasting plasma was used for analyses of glucose, insulin, leptin and fatty acid composition. Women in Lima had more body fat, higher fasting insulin and leptin and lower insulin sensitivity than the Shuar women, who had insulin sensitivity similar to Swedish women. Shuar women had very high proportions (mean; SD) of palmitoleic (13.2; 3.9%) and oleic (33.9; 3.7%) acids in the plasma cholesteryl esters with very low levels of linoleic acid (29.1; 6.1 3%), as expected on a low fat, high carbohydrate diet. The estimated activity of delta 9 (SCD-1) desaturase was about twice as high in the Shuar compared with Lima women, suggesting neo lipogenesis, while the delta 5 desaturase activity did not differ. The Lima women, as well as the Swedish, showed strong positive correlations between SCD-1 activity on the one hand and fasting insulin and HOMA index on the other. These associations were absent in the Shuar women. The high SCD-1 activity in the Shuar women may reflect increased lipogenesis in adipose tissue. It also illustrates how a low fat diet rich in non-refined carbohydrates can be linked to a good metabolic situation. Copyright © 2010. Published by Elsevier B.V.

  7. Effects of Rosiglitazone, Glyburide, and Metformin on β-Cell Function and Insulin Sensitivity in ADOPT

    Science.gov (United States)

    Kahn, Steven E.; Lachin, John M.; Zinman, Bernard; Haffner, Steven M.; Aftring, R. Paul; Paul, Gitanjali; Kravitz, Barbara G.; Herman, William H.; Viberti, Giancarlo; Holman, Rury R.

    2011-01-01

    OBJECTIVE ADOPT (A Diabetes Outcome Progression Trial) demonstrated that initial monotherapy with rosiglitazone provided superior durability of glycemic control compared with metformin and glyburide in patients with recently diagnosed type 2 diabetes. Herein, we examine measures of β-cell function and insulin sensitivity from an oral glucose tolerance test (OGTT) over a 4-year period among the three treatments. RESEARCH DESIGN AND METHODS Recently diagnosed, drug-naïve patients with type 2 diabetes (4,360 total) were treated for a median of 4.0 years with rosiglitazone, metformin, or glyburide and were examined with periodic metabolic testing using an OGTT. RESULTS Measures of β-cell function and insulin sensitivity from an OGTT showed more favorable changes over time with rosiglitazone versus metformin or glyburide. Persistent improvements were seen in those who completed 4 years of monotherapy and marked deterioration of β-cell function in those who failed to maintain adequate glucose control with initial monotherapy. CONCLUSIONS The favorable combined changes in β-cell function and insulin sensitivity over time with rosiglitazone appear to be responsible for its superior glycemic durability over metformin and glyburide as initial monotherapy in type 2 diabetes. PMID:21415383

  8. Impact of streptozotocin on altering normal glucose homeostasis during insulin testing in diabetic rats compared to normoglycemic rats

    Directory of Open Access Journals (Sweden)

    Qinna NA

    2015-05-01

    Full Text Available Nidal A Qinna,1 Adnan A Badwan2 1Department of Pharmacology and Biomedical Sciences, Faculty of Pharmacy and Medical Sciences, University of Petra, 2Research and Innovation Centre, The Jordanian Pharmaceutical Manufacturing Co. Plc. (JPM, Amman, Jordan Abstract: Streptozotocin (STZ is currently the most used diabetogenic agent in testing insulin and new antidiabetic drugs in animals. Due to the toxic and disruptive nature of STZ on organs, apart from pancreas, involved in preserving the body’s normal glucose homeostasis, this study aims to reassess the action of STZ in inducing different glucose response states in diabetic rats while testing insulin. Diabetic Sprague-Dawley rats induced with STZ were classified according to their initial blood glucose levels into stages. The effect of randomizing rats in such a manner was investigated for the severity of interrupting normal liver, pancreas, and kidney functions. Pharmacokinetic and pharmacodynamic actions of subcutaneously injected insulin in diabetic and nondiabetic rats were compared. Interruption of glucose homeostasis by STZ was challenged by single and repeated administrations of injected insulin and oral glucose to diabetic rats. In diabetic rats with high glucose (451–750 mg/dL, noticeable changes were seen in the liver and kidney functions compared to rats with lower basal glucose levels. Increased serum levels of recombinant human insulin were clearly indicated by a significant increase in the calculated maximum serum concentration and area under the concentration–time curve. Reversion of serum glucose levels to normal levels pre- and postinsulin and oral glucose administrations to STZ diabetic rats were found to be variable. In conclusion, diabetic animals were more responsive to insulin than nondiabetic animals. STZ was capable of inducing different levels of normal glucose homeostasis disruption in rats. Both pharmacokinetic and pharmacodynamic actions of insulin were

  9. Impact of Insulin Resistance on Silent and Ongoing Myocardial Damage in Normal Subjects: The Takahata Study

    Directory of Open Access Journals (Sweden)

    Taro Narumi

    2012-01-01

    Full Text Available Background. Insulin resistance (IR is part of the metabolic syndrome (Mets that develops after lifestyle changes and obesity. Although the association between Mets and myocardial injury is well known, the effect of IR on myocardial damage remains unclear. Methods and Results. We studied 2200 normal subjects who participated in a community-based health check in the town of Takahata in northern Japan. The presence of IR was assessed by homeostasis model assessment ratio, and the serum level of heart-type fatty acid binding protein (H-FABP was measured as a maker of silent and ongoing myocardial damage. H-FABP levels were significantly higher in subjects with IR and Mets than in those without metabolic disorder regardless of gender. Multivariate logistic analysis showed that the presence of IR was independently associated with latent myocardial damage (odds ratio: 1.574, 95% confidence interval 1.1–2.3 similar to the presence of Mets. Conclusions. In a screening of healthy subjects, IR and Mets were similarly related to higher H-FABP levels, suggesting that there may be an asymptomatic population in the early stages of metabolic disorder that is exposed to myocardial damage and might be susceptible to silent heart failure.

  10. Anti-insulin antibody test

    Science.gov (United States)

    Insulin antibodies - serum; Insulin Ab test; Insulin resistance - insulin antibodies; Diabetes - insulin antibodies ... Normally, there are no antibodies against insulin in your blood. ... different laboratories. Some labs use different measurements or ...

  11. A genome-wide siRNA screen to identify modulators of insulin sensitivity and gluconeogenesis.

    Directory of Open Access Journals (Sweden)

    Ruojing Yang

    Full Text Available BACKGROUND: Hepatic insulin resistance impairs insulin's ability to suppress hepatic glucose production (HGP and contributes to the development of type 2 diabetes (T2D. Although the interests to discover novel genes that modulate insulin sensitivity and HGP are high, it remains challenging to have a human cell based system to identify novel genes. METHODOLOGY/PRINCIPAL FINDINGS: To identify genes that modulate hepatic insulin signaling and HGP, we generated a human cell line stably expressing beta-lactamase under the control of the human glucose-6-phosphatase (G6PC promoter (AH-G6PC cells. Both beta-lactamase activity and endogenous G6PC mRNA were increased in AH-G6PC cells by a combination of dexamethasone and pCPT-cAMP, and reduced by insulin. A 4-gene High-Throughput-Genomics assay was developed to concomitantly measure G6PC and pyruvate-dehydrogenase-kinase-4 (PDK4 mRNA levels. Using this assay, we screened an siRNA library containing pooled siRNA targeting 6650 druggable genes and identified 614 hits that lowered G6PC expression without increasing PDK4 mRNA levels. Pathway analysis indicated that siRNA-mediated knockdown (KD of genes known to positively or negatively affect insulin signaling increased or decreased G6PC mRNA expression, respectively, thus validating our screening platform. A subset of 270 primary screen hits was selected and 149 hits were confirmed by target gene KD by pooled siRNA and 7 single siRNA for each gene to reduce G6PC expression in 4-gene HTG assay. Subsequently, pooled siRNA KD of 113 genes decreased PEPCK and/or PGC1alpha mRNA expression thereby demonstrating their role in regulating key gluconeogenic genes in addition to G6PC. Last, KD of 61 of the above 113 genes potentiated insulin-stimulated Akt phosphorylation, suggesting that they suppress gluconeogenic gene by enhancing insulin signaling. CONCLUSIONS/SIGNIFICANCE: These results support the proposition that the proteins encoded by the genes identified in

  12. Insulin sensitizing and alpha-glucoamylase inhibitory action of sennosides, rheins and rhaponticin in Rhei Rhizoma.

    Science.gov (United States)

    Choi, Soo Bong; Ko, Byoung Seob; Park, Seong Kyu; Jang, Jin Sun; Park, Sunmin

    2006-01-25

    Extracts from Rhei Rhizoma extracts (RR) have been reported to attenuate metabolic disorders such as diabetic nephropathy, hypercholesterolemia and platelet aggregation. With this study we investigated the anti-diabetic action of 70% ethanol RR extract in streptozotocin-induced diabetic mice, and determined the action mechanism of active compounds of RR in vitro. In the diabetic mice, serum glucose levels at fasting and post-prandial states and glucose area under the curve at modified oral glucose tolerance tests were lowered without altering serum insulin levels, indicating that RR contained potential anti-diabetic agents. The fractions fractionated from RR extracts by XAD-4 column revealed that 60%, 80% and 100% methanol fractions enhanced insulin sensitivity and inhibited alpha-glucoamylase activity. The major compounds of these fractions were sennosides, rhein and rhaponticin. Rhaponticin and rhein enhanced insulin-stimulated glucose uptake in 3T3-L1 adipocytes. Rhaponticin increased adipocytes with a differentiating effect similar to pioglitazone, but rhein and sennoside B decreased triglyceride accumulation. Sennoside A and B inhibited alpha-glucoamylase activity as much as acarbose. In conclusion, a crude extract of RR improves glucose intolerance by enhancing insulin-stimulated glucose uptake and decreasing carbohydrate digestion via inhibiting alpha-glucoamylase activity. Rhein and rhaponticin are potential candidates for hypoglycemic agents.

  13. Microcirculatory Improvement Induced by Laparoscopic Sleeve Gastrectomy Is Related to Insulin Sensitivity Retrieval.

    Science.gov (United States)

    Ministrini, Stefano; Fattori, Chiara; Ricci, Maria Anastasia; Bianconi, Vanessa; Paltriccia, Rita; Boni, Marcello; Paganelli, Maria Teresa; Vaudo, Gaetano; Lupattelli, Graziana; Pasqualini, Leonella

    2018-05-12

    Microvascular dysfunction is a potential factor explaining the association of obesity, insulin resistance, and vascular damage in morbidly obese subjects. The purpose of the study was to evaluate possible determinants of microcirculatory improvement 1 year after laparoscopic sleeve gastrectomy (LSG) intervention. Thirty-seven morbidly obese subjects eligible for bariatric surgery were included in the study. Post-occlusive reactive hyperemia (PORH) of the forearm skin was measured as area of hyperemia (AH) by laser-Doppler flowmetry before LSG and after a 1-year follow-up. After intervention, we observed a significant reduction in BMI, HOMA index, HbA1c, and a significant increase of AH in all patients after surgery; this variation was significant only in those patients having insulin resistance or prediabetes/diabetes. Although significant correlation between the increase of AH and the reduction of both BMI, HOMA index, and HbA1c was observed, BMI was the only independent predictor of AH variation after LSG at the linear regression analysis. Our study shows that LSG intervention is correlated with a significant improvement in the microvascular function of morbidly obese subjects; this improvement seems to be related to the baseline degree of insulin-resistance and to the retrieval of insulin-sensitivity post-intervention.

  14. 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...... AGE concentrations were measured (liquid chromatography tandem mass spectrometry) to estimate AGE intake and excretion. RESULTS When adjusted for changes in anthropometric measures during the intervention, the low-AGE diet decreased urinary AGEs, fasting insulin concentrations, and HOMA-IR, compared...

  15. Differential effects of age and sex on insulin sensitivity and body composition in adolescent offspring of women with type 1 diabetes: results from the EPICOM study

    DEFF Research Database (Denmark)

    Lohse, Zuzana; Knorr, Sine; Bytoft, Birgitte

    2018-01-01

    in fasting OGTT-derived indices for insulin sensitivity (BIGTT-SI0-30-120, Matsuda index, HOMA-IR) and insulin secretion (acute insulin response [BIGTT-AIR0-0-30-120], insulinogenic index, HOMA of insulin secretory function [HOMA-β], disposition index) and physical activity (International Physical Activity...

  16. A Single Day of Excessive Dietary Fat Intake Reduces Whole-Body Insulin Sensitivity: The Metabolic Consequence of Binge Eating

    Directory of Open Access Journals (Sweden)

    Siôn A. Parry

    2017-07-01

    Full Text Available Consuming excessive amounts of energy as dietary fat for several days or weeks can impair glycemic control and reduce insulin sensitivity in healthy adults. However, individuals who demonstrate binge eating behavior overconsume for much shorter periods of time; the metabolic consequences of such behavior remain unknown. The aim of this study was to determine the effect of a single day of high-fat overfeeding on whole-body insulin sensitivity. Fifteen young, healthy adults underwent an oral glucose tolerance test before and after consuming a high-fat (68% of total energy, high-energy (78% greater than daily requirements diet for one day. Fasting and postprandial plasma concentrations of glucose, insulin, non-esterified fatty acids, and triglyceride were measured and the Matsuda insulin sensitivity index was calculated. One day of high-fat overfeeding increased postprandial glucose area under the curve (AUC by 17.1% (p < 0.0001 and insulin AUC by 16.4% (p = 0.007. Whole-body insulin sensitivity decreased by 28% (p = 0.001. In conclusion, a single day of high-fat, overfeeding impaired whole-body insulin sensitivity in young, healthy adults. This highlights the rapidity with which excessive consumption of calories through high-fat food can impair glucose metabolism, and suggests that acute binge eating may have immediate metabolic health consequences for the individual.

  17. Serum Is Not Necessary for Prior Pharmacological Activation of AMPK to Increase Insulin Sensitivity of Mouse Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    Nicolas O. Jørgensen

    2018-04-01

    Full Text Available Exercise, contraction, and pharmacological activation of AMP-activated protein kinase (AMPK by 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR have all been shown to increase muscle insulin sensitivity for glucose uptake. Intriguingly, improvements in insulin sensitivity following contraction of isolated rat and mouse skeletal muscle and prior AICAR stimulation of isolated rat skeletal muscle seem to depend on an unknown factor present in serum. One study recently questioned this requirement of a serum factor by showing serum-independency with muscle from old rats. Whether a serum factor is necessary for prior AICAR stimulation to increase insulin sensitivity of mouse skeletal muscle is not known. Therefore, we investigated the necessity of serum for this effect of AICAR in mouse skeletal muscle. We found that the ability of prior AICAR stimulation to improve insulin sensitivity of mouse skeletal muscle did not depend on the presence of serum during AICAR stimulation. Although prior AICAR stimulation did not enhance proximal insulin signaling, insulin-stimulated phosphorylation of Tre-2/BUB2/CDC16- domain family member 4 (TBC1D4 Ser711 was greater in prior AICAR-stimulated muscle compared to all other groups. These results imply that the presence of a serum factor is not necessary for prior AMPK activation by AICAR to enhance insulin sensitivity of mouse skeletal muscle.

  18. Design and clinical pilot testing of the model-based dynamic insulin sensitivity and secretion test (DISST).

    Science.gov (United States)

    Lotz, Thomas F; Chase, J Geoffrey; McAuley, Kirsten A; Shaw, Geoffrey M; Docherty, Paul D; Berkeley, Juliet E; Williams, Sheila M; Hann, Christopher E; Mann, Jim I

    2010-11-01

    Insulin resistance is a significant risk factor in the pathogenesis of type 2 diabetes. This article presents pilot study results of the dynamic insulin sensitivity and secretion test (DISST), a high-resolution, low-intensity test to diagnose insulin sensitivity (IS) and characterize pancreatic insulin secretion in response to a (small) glucose challenge. This pilot study examines the effect of glucose and insulin dose on the DISST, and tests its repeatability. DISST tests were performed on 16 subjects randomly allocated to low (5 g glucose, 0.5 U insulin), medium (10 g glucose, 1 U insulin) and high dose (20 g glucose, 2 U insulin) protocols. Two or three tests were performed on each subject a few days apart. Average variability in IS between low and medium dose was 10.3% (p=.50) and between medium and high dose 6.0% (p=.87). Geometric mean variability between tests was 6.0% (multiplicative standard deviation (MSD) 4.9%). Geometric mean variability in first phase endogenous insulin response was 6.8% (MSD 2.2%). Results were most consistent in subjects with low IS. These findings suggest that DISST may be an easily performed dynamic test to quantify IS with high resolution, especially among those with reduced IS. © 2010 Diabetes Technology Society.

  19. Glycine Increases Insulin Sensitivity and Glutathione Biosynthesis and Protects against Oxidative Stress in a Model of Sucrose-Induced Insulin Resistance

    Directory of Open Access Journals (Sweden)

    Mohammed El-Hafidi

    2018-01-01

    Full Text Available Oxidative stress and redox status play a central role in the link between insulin resistance (IR and lipotoxicity in metabolic syndrome. This mechanistic link may involve alterations in the glutathione redox state. We examined the effect of glycine supplementation to diet on glutathione biosynthesis, oxidative stress, IR, and insulin cell signaling in liver from sucrose-fed (SF rats characterized by IR and oxidative stress. Our hypothesis is that the correction of glutathione levels by glycine treatment leads to reduced oxidative stress, a mechanism associated with improved insulin signaling and IR. Glycine treatment decreases the levels of oxidative stress markers in liver from SF rats and increases the concentrations of glutathione (GSH and γ-glutamylcysteine and the amount of γ-glutamylcysteine synthetase (γ-GCS, a key enzyme of GSH biosynthesis in liver from SF rats. In liver from SF rats, glycine also decreases the insulin-induced phosphorylation of insulin receptor substrate-1 (ISR-1 in serine residue and increases the phosphorylation of insulin receptor β-subunit (IR-β in tyrosine residue. Thus, supplementing diets with glycine to correct GSH deficiency and to reduce oxidative stress provides significant metabolic benefits to SF rats by improving insulin sensitivity.

  20. Synthesis of cytochrome c oxidase 1 (SCO1) inhibits insulin sensitivity by decreasing copper levels in adipocytes.

    Science.gov (United States)

    Wei, Xiang-Bo; Guo, Liang; Liu, Yang; Zhou, Shui-Rong; Liu, Yuan; Dou, Xin; Du, Shao-Yue; Ding, Meng; Peng, Wan-Qiu; Qian, Shu-Wen; Huang, Hai-Yan; Tang, Qi-Qun

    2017-09-23

    Dysregulation of insulin signaling leads to type 2 diabetes mellitus (T2DM) and other metabolic disorders. Obesity is an important contributor to insulin resistance, and although the understanding of this relationship has improved in recent years, the mechanism of obesity-induced insulin resistance is not completely understood. Disorders of copper metabolism tend to accompany the development of obesity, which increases the risk of insulin resistance. Synthesis of cytochrome c oxidase 1 (SCO1) functions in the assembly of cytochrome c oxidase (COX) and cellular copper homeostasis. However, the role of SCO1 in the regulation of metabolism remains unknown. Here, we found that obese mice had higher expression of SCO1 and lower levels of copper in white adipose tissue (WAT) than did the control mice. Overexpression of SCO1 in adipocytes was associated with copper deficiency. Copper increased insulin sensitivity by decreasing the level of phosphatase and tensin homolog (PTEN) protein. Ectopic expression of SCO1 led to insulin resistance and was accompanied by a decrease in intracellular copper level, and addition of copper abolished the inhibitory effect of SCO1 on insulin sensitivity. Our results demonstrated a novel role of SCO1 in modulating insulin sensitivity via the regulation of copper concentration in WAT and suggested a potential therapeutic target for T2DM. Copyright © 2017. Published by Elsevier Inc.

  1. Anxiety sensitivity in adolescents with somatoform autonomic dysfunction and adolescents with insulin dependent diabetes mellitus.

    Science.gov (United States)

    Pisarić, Maja; Nisević, Sanja

    2011-01-01

    Anxiety sensitivity is defined as a belief that anxiety or fear may cause illness, embarrassment, or additional anxiety. The main purpose of this study was to find out if there were differences among adolescents with insulin dependent diabetes mellitus, adolescents with somatoform autonomic dysfunction and their healthy peers in different aspects of psychological functioning and anxiety sensitivity. The sample consisted of 93 subjects, aged 12 to 16. Hamburg Neuroticism and Extraversion Scale, Child Behaviour Checklist and Childhood Anxiety Sensitivity Index were administrated. The adolescents with somatoform autonomic dysfunction had significantly higher scores on neuroticism scale, different Child Behaviour Checklist subscales, and on anxiety sensitivity. Both groups with diagnosed illness had lower scores on extraversion scale compared to healthy peers. This study has shown that the adolescents with somatoform autonomic dysfunction are more prone to fears regarding bodily functioning, and that they are at a higher risk of developing an anxiety disorder.

  2. 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.

  3. A low-fat Diet improves insulin sensitivity in patients with type 1 diabetes

    DEFF Research Database (Denmark)

    Rosenfalck, AM; Almdal, Thomas Peter; Viggers, Lone

    2006-01-01

    diet (P = 0.039). The daily protein and carbohydrate intake increased (+4.4% of total energy intake, P = 0.0049 and +2.5%, P = 0.34, respectively), while alcohol intake decreased (-3.2% of total energy intake, P = 0.02). There was a significant improvement in insulin sensitivity on the isocaloric, low-fat......AIMS: To compare the effects on insulin sensitivity, body composition and glycaemic control of the recommended standard weight-maintaining diabetes diet and an isocaloric low-fat diabetes diet during two, 3-month periods in patients with Type 1 diabetes. METHODS: Thirteen Type 1 patients were...... by the insulin clamp technique at baseline and after each of the diet intervention periods. RESULTS: On an isocaloric low-fat diet, Type 1 diabetic patients significantly reduced the proportion of fat in the total daily energy intake by 12.1% (or -3.6% of total energy) as compared with a conventional diabetes...

  4. Anti-myostatin antibody increases muscle mass and strength and improves insulin sensitivity in old mice.

    Science.gov (United States)

    Camporez, João-Paulo G; Petersen, Max C; Abudukadier, Abulizi; Moreira, Gabriela V; Jurczak, Michael J; Friedman, Glenn; Haqq, Christopher M; Petersen, Kitt Falk; Shulman, Gerald I

    2016-02-23

    Sarcopenia, or skeletal muscle atrophy, is a debilitating comorbidity of many physiological and pathophysiological processes, including normal aging. There are no approved therapies for sarcopenia, but the antihypertrophic myokine myostatin is a potential therapeutic target. Here, we show that treatment of young and old mice with an anti-myostatin antibody (ATA 842) for 4 wk increased muscle mass and muscle strength in both groups. Furthermore, ATA 842 treatment also increased insulin-stimulated whole body glucose metabolism in old mice, which could be attributed to increased insulin-stimulated skeletal muscle glucose uptake as measured by a hyperinsulinemic-euglycemic clamp. Taken together, these studies provide support for pharmacological inhibition of myostatin as a potential therapeutic approach for age-related sarcopenia and metabolic disease.

  5. Insulin resistance according to β-cell function in women with polycystic ovary syndrome and normal glucose tolerance.

    Science.gov (United States)

    Song, Do Kyeong; Hong, Young Sun; Sung, Yeon-Ah; Lee, Hyejin

    2017-01-01

    Polycystic ovary syndrome (PCOS) is associated with insulin resistance (IR) and compensatory hyperinsulinemia. IR is recognized as a major risk factor for the development of type 2 diabetes mellitus. However, few studies have investigated IR in women with PCOS and normal glucose tolerance. The objective of this study was to evaluate IR and β-cell function in women with PCOS and normal glucose tolerance. Additionally, we sought to evaluate the usefulness of oral glucose tolerance test (OGTT)-derived IR indices in lean women with PCOS. We recruited 100 women with PCOS and normal glucose tolerance and 100 age- and BMI-matched women as controls. IR and insulin secretory indices, including the homeostasis-model assessment (HOMA)-IR, HOMA-M120, HOMA-F and the Stumvoll index, were calculated from an OGTT. Increased β-cell function was defined as>75th percentile for the HOMA-F in control women. Women with PCOS had higher values for post-load 2-hour glucose, fasting insulin, post-load 2-hour insulin, HOMA-IR, HOMA-M120, HOMA-F and lower values for the Stumvoll index than the controls (all PsWomen with PCOS and increased β-cell function showed lower Stumvoll index values than the matched controls (Plean women with PCOS (all PsWomen with PCOS and normal glucose tolerance showed higher IR than controls matched for age, BMI, and β-cell function. β-cell function was increased in women with PCOS when compared to the matched controls, but not when the lean subjects were compared to the matched controls separately. Therefore, early evaluation of IR in women with PCOS and normal glucose tolerance may be needed.

  6. Sup(13)C NMR studies of glucose disposal in normal and non-insulin-dependent diabetic humans

    International Nuclear Information System (INIS)

    Shulman, G.I.; Rothman, D.L.; Shulman, R.G.

    1990-01-01

    To examine the extent to which the defect in insulin action in subjects with non-insulin-dependent diabetes mellitus (NIDDM) can be accounted for by impairment of muscle glycogen synthesis, we performed combined hyperglycemic-hyperinsulinemic clamp studies with [ 13 C]glucose in five subjects with NIDDM and in six age- and weight-matched healthy subjects. The rate of incorporation of intravenously infused [1- 13 C]glucose into muscle glycogen was measured directly in the gastrocnemius muscle by means of a nuclear magnetic resonance (NMR) spectrometer with a 15.5 min time resolution and a 13 C surface coil. The steady-state plasma concentrations of insulin and glucose were similar in both study groups. The mean (±SE) rate of glycogen synthesis, as determined by 13 C NMR, was 78±28 and 183±39 μmol-glucosyl units (kg muscle tissue (wet mass)) -1 min -1 in the diabetic and normal subjects, respectively. The mean glucose uptake was markedly reduced in the diabetic as compared with the normal subjects. The mean rate of non-oxidative glucose metabolism was 22±4 μmol kg -1 min -1 in the diabetic subjects and 42±4 μmol kg -1 min -1 in the normal subjects. When these rates are extrapolated to apply to the whole body, the synthesis of muscle glycogen would account for most of the total-body glucose uptake and all of the non-oxidative glucose metabolism in both normal and diabetic subjects. We conclude that muscle glycogen synthesis is the principal pathway of glucose disposal in both normal and diabetic subjects and that defects in muscle glycogen synthesis have a dominant role in the insulin resistance that occurs in persons with NIDDM. (author)

  7. Pioglitazone improves insulin sensitivity, reduces visceral fat and stimulates lipolysis in non diabetic dialyzed patients

    Directory of Open Access Journals (Sweden)

    Anne Zanchi

    2012-06-01

    Full Text Available Insulin resistance is common in dialyzed patients and is associated with increased mortality and protein-energy wasting. The aim of this study was to investigate the effect of pioglitazone (PIO, a powerful insulin sensitizer, on insulin sensitivity, body composition and adipose tissue metabolism, in dialyzed patients. A double blind randomized cross-over study was performed in non diabetic dialysis patients. Each patient followed 2 treatment phases of 16 weeks, starting either with oral PIO 45 mg/d or placebo (PL, and then switched to the other phase. At the end of each phase, patients underwent hyperinsulinemic euglycemic clamps, dual energy X-ray absorptiometry, an abdominal CT, and extensive plasma biochemical analysis. Twelve patients including 8 HD (59.6±4.4 y and 4 PD patients (43.5±3.6 y were recruited. Nine patients completed both phases and 3 patients dropped out (renal transplantation/2 HD and peritonitis/1 PD. PIO was safe and well tolerated. Under PIO, insulin sensitivity improved, as assessed by increased total glucose disposal rate (1.98±0.24 for PIO versus 1.58±0.12 umol/kg/min for PL, p<0.05, and reduced glucose endogenous hepatic production. PIO did not affect post-dialysis body weight, total fat and lean body mass, but significantly reduced visceral adipose tissue (VAT area and the VAT/SAT (subcutaneous adipose tissue ratio. HDL-cholesterol significantly increased. PIO decreased CRP (3.96±1.44 mg/l vs 7.88±2.56, p<0.05, plasma leptin, and dramatically reduced leptin/adiponectin ratio. Glycerol turnover, circulating glycerol and non esterified fatty acids were paradoxically increased. In conclusion, the improvement in insulin sensitivity by PIO, in non diabetic dialyzed patients, was associated with favorable metabolic effects, reduction in inflammation and body fat redistribution. The stimulation of systemic lipolysis was a surprising finding which may reflect adipose tissue remodeling and/or a paradoxical lypolitic

  8. Probiotics modulate gut microbiota and improve insulin sensitivity in DIO mice.

    Science.gov (United States)

    Bagarolli, Renata A; Tobar, Natália; Oliveira, Alexandre G; Araújo, Tiago G; Carvalho, Bruno M; Rocha, Guilherme Z; Vecina, Juliana F; Calisto, Kelly; Guadagnini, Dioze; Prada, Patrícia O; Santos, Andrey; Saad, Sara T O; Saad, Mario J A

    2017-12-01

    Obesity and type 2 diabetes are characterized by subclinical inflammatory process. Changes in composition or modulation of the gut microbiota may play an important role in the obesity-associated inflammatory process. In the current study, we evaluated the effects of probiotics (Lactobacillus rhamnosus, L. acidophilus and Bifidobacterium bifidumi) on gut microbiota, changes in permeability, and insulin sensitivity and signaling in high-fat diet and control animals. More importantly, we investigated the effects of these gut modulations on hypothalamic control of food intake, and insulin and leptin signaling. Swiss mice were submitted to a high-fat diet (HFD) with probiotics or pair-feeding for 5 weeks. Metagenome analyses were performed on DNA samples from mouse feces. Blood was drawn to determine levels of glucose, insulin, LPS, cytokines and GLP-1. Liver, muscle, ileum and hypothalamus tissue proteins were analyzed by Western blotting and real-time polymerase chain reaction. In addition, liver and adipose tissues were analyzed using histology and immunohistochemistry. The HFD induced huge alterations in gut microbiota accompanied by increased intestinal permeability, LPS translocation and systemic low-grade inflammation, resulting in decreased glucose tolerance and hyperphagic behavior. All these obesity-related features were reversed by changes in the gut microbiota profile induced by probiotics. Probiotics also induced an improvement in hypothalamic insulin and leptin resistance. Our data demonstrate that the intestinal microbiome is a key modulator of inflammatory and metabolic pathways in both peripheral and central tissues. These findings shed light on probiotics as an important tool to prevent and treat patients with obesity and insulin resistance. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Correlation between the Plasma Insulin and Glucose Concentration in Normal Korean Adults

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jang Kyu; Sung, Ho Kyung; Kim, Jin Eui [Radiological Research Institute, Seoul (Korea, Republic of)

    1971-09-15

    The correlation between the plasma insulin, and glucose concentration was studied in healthy Korean adults consisting of 20 males and 22 females of 16 to 38 years of age. The blood samples of above subjects were obtained through cubital vein at arbitrary times during their usual working hours. Plasma insulin was assayed by means of double antibody system of radioimmunoassay technics, and blood glucose was determined by means of Van Slyke-Folch method. Results were as follows : 1. There were no differences in the blood sugar levels in relation to the plasma insulin concentration either by sex or age. 2. In the case, when the plasma insulin concentration was within 50 mmuU/ml, the correlation between the insulin, and glucose concentration existed, the ratio of which was expressed as; Plasma glucose concentration (mg/dl)=91.9 + 0.08 X Insulin concentration r=0.62. 3. Insulinogenic index was 12.4%, which was somewhat higher than other reports. 4. It is suggested that the correlation between plasma insulin and glucose concentration could be determined at arbitrary times instead of fasting times.

  10. Association of Tumor Growth Factor-β and Interferon-γ Serum Levels With Insulin Resistance in Normal Pregnancy.

    Science.gov (United States)

    Sotoodeh Jahromi, Abdolreza; Sanie, Mohammad Sadegh; Yusefi, Alireza; Zabetian, Hassan; Zareian, Parvin; Hakimelahi, Hossein; Madani, Abdolhossien; Hojjat-Farsangi, Mohammad

    2015-09-28

    Pregnancy is related to change in glucose metabolism and insulin production. The aim of our study was to determine the association of serum IFN-γ and TGF- β levels with insulin resistance during normal pregnancy. This cross sectional study was carried out on 97 healthy pregnant (in different trimesters) and 28 healthy non-pregnant women. Serum TGF-β and IFN- γ level were measured by ELISA method. Pregnant women had high level TGF-β and low level IFN-γ as compared non-pregnant women. Maternal serum TGF-β concentration significantly increased in third trimester as compared first and second trimester of pregnancy. Maternal serum IFN-γ concentration significantly decreased in third trimester as compared first and second trimester of pregnancy. Pregnant women exhibited higher score of HOMA IR as compared non-pregnant women. There were association between gestational age with body mass index (r=0.28, P=0.005), TGF-β (r=0.45, PInsulin resistance and TGF-β (r=0.17, p=0.05). Our findings suggest that changes in maternal cytokine level in healthy pregnant women were anti-inflammatory. Furthermore, Tumor Growth Factor-β appears has a role in induction insulin resistance in healthy pregnant women. However, further studies needed to evaluate role of different cytokines on insulin resistance in normal pregnancy.

  11. Skeletal muscle phosphatidylcholine and phosphatidylethanolamine are related to insulin sensitivity and respond to acute exercise in humans.

    Science.gov (United States)

    Newsom, Sean A; Brozinick, Joseph T; Kiseljak-Vassiliades, Katja; Strauss, Allison N; Bacon, Samantha D; Kerege, Anna A; Bui, Hai Hoang; Sanders, Phil; Siddall, Parker; Wei, Tao; Thomas, Melissa; Kuo, Ming Shang; Nemkov, Travis; D'Alessandro, Angelo; Hansen, Kirk C; Perreault, Leigh; Bergman, Bryan C

    2016-06-01

    Several recent reports indicate that the balance of skeletal muscle phosphatidylcholine (PC) and phosphatidylethanolamine (PE) is a key determinant of muscle contractile function and metabolism. The purpose of this study was to determine relationships between skeletal muscle PC, PE and insulin sensitivity, and whether PC and PE are dynamically regulated in response to acute exercise in humans. Insulin sensitivity was measured via intravenous glucose tolerance in sedentary obese adults (OB; n = 14), individuals with type 2 diabetes (T2D; n = 15), and endurance-trained athletes (ATH; n = 15). Vastus lateralis muscle biopsies were obtained at rest, immediately after 90 min of cycle ergometry at 50% maximal oxygen consumption (V̇o2 max), and 2-h postexercise (recovery). Skeletal muscle PC and PE were measured via infusion-based mass spectrometry/mass spectrometry analysis. ATH had greater levels of muscle PC and PE compared with OB and T2D (P insulin sensitivity (both P insulin sensitivity among the entire cohort (r = -0.43, P = 0.01). Muscle PC and PE were altered by exercise, particularly after 2 h of recovery, in a highly group-specific manner. However, muscle PC:PE ratio remained unchanged in all groups. In summary, total muscle PC and PE are positively related to insulin sensitivity while PC:PE ratio is inversely related to insulin sensitivity in humans. A single session of exercise significantly alters skeletal muscle PC and PE levels, but not PC:PE ratio. Copyright © 2016 the American Physiological Society.

  12. Flux sensitivity of a piecewise normal and superconducting metal loop

    International Nuclear Information System (INIS)

    Buettiker, M.; Klapwijk, T.M.

    1986-01-01

    We consider a loop composed of a superconducting segment and a normal segment with an Aharonov-Bohm flux through the hole of the loop. The normal segment is assumed to be long compared to the superconducting coherence length xi but short compared to a mean inelastic diffusion length. The elementary excitation spectrum of the ground state of this loop is periodic with period hc/2e as long as the superconducting segment is larger than xi. If the superconducting segment length becomes of the order of xi, quasiparticles can tunnel through the superconducting gap and give rise to an excitation spectrum which is periodic with period hc/e. .AE

  13. Characterization of the insulin-sensitive low Km cAMP phosphodiesterase from rat adipose tissue

    International Nuclear Information System (INIS)

    Degerman, E.; Belfrage, P.; Manganiello, V.C.

    1986-01-01

    Particulate, but not soluble, low K/sub m/ cAMP phosphodiesterase (PDE) activity of rat adipocytes was increased 50-100% during incubation (10 min) of intact cells with 1-3 nM insulin; activation was less with higher or lower insulin concentrations. Activation was maintained during solubilization with an alkyl polyoxyethylene non-ionic detergent C 13 , E 12 and NaBr and chromatography on DEAE. Enzyme from DEAE was further purified by chromatography on Sepahadex G-200 and Blue-Sepharose. Activity (with 0.5 μM [ 3 H]cAMP) was rather sensitive to inhibition by p-chloromercuribenzoate (IC 50 , 1 μM) and less so by 2,2'-dithiobis-(5-nitropyridine) (160 μM), N-ethylmaleimide (525 μM) and iodoacetamide (750 μM). PDE activity was also rather sensitive to inhibition by cilostamide (IC 50 , ∼40 nM) and the cardiotonic drugs CI 930 (450 nM) and milrinone (630 nM) but rather insensitive to RO 20-1724 (190 μM). Based on effects of these inhibitors, the hormone-sensitive low K/sub m/ particulate cAMP PDE from rat adipocytes seems to be analogous to the insulin-activated particulate PDE from 3T3-L1 adipocytes and the cilostamide-sensitive soluble low K/sub m/ cAMP PDE from bovine liver (designated as III-C), platelets, heart, and other tissues

  14. Characterization of the insulin-sensitive low Km cAMP phosphodiesterase from rat adipose tissue

    Energy Technology Data Exchange (ETDEWEB)

    Degerman, E.; Belfrage, P.; Manganiello, V.C.

    1986-05-01

    Particulate, but not soluble, low K/sub m/ cAMP phosphodiesterase (PDE) activity of rat adipocytes was increased 50-100% during incubation (10 min) of intact cells with 1-3 nM insulin; activation was less with higher or lower insulin concentrations. Activation was maintained during solubilization with an alkyl polyoxyethylene non-ionic detergent C/sub 13/, E/sub 12/ and NaBr and chromatography on DEAE. Enzyme from DEAE was further purified by chromatography on Sepahadex G-200 and Blue-Sepharose. Activity (with 0.5 ..mu..M (/sup 3/H)cAMP) was rather sensitive to inhibition by p-chloromercuribenzoate (IC/sub 50/, 1 ..mu..M) and less so by 2,2'-dithiobis-(5-nitropyridine) (160 ..mu..M), N-ethylmaleimide (525 ..mu..M) and iodoacetamide (750 ..mu..M). PDE activity was also rather sensitive to inhibition by cilostamide (IC/sub 50/, approx.40 nM) and the cardiotonic drugs CI 930 (450 nM) and milrinone (630 nM) but rather insensitive to RO 20-1724 (190 ..mu..M). Based on effects of these inhibitors, the hormone-sensitive low K/sub m/ particulate cAMP PDE from rat adipocytes seems to be analogous to the insulin-activated particulate PDE from 3T3-L1 adipocytes and the cilostamide-sensitive soluble low K/sub m/ cAMP PDE from bovine liver (designated as III-C), platelets, heart, and other tissues.

  15. State of the Art Review: Emerging Therapies: The Use of Insulin Sensitizers in the Treatment of Adolescents with Polycystic Ovary Syndrome (PCOS).

    Science.gov (United States)

    Geller, David H; Pacaud, Danièle; Gordon, Catherine M; Misra, Madhusmita

    2011-08-26

    PCOS, a heterogeneous disorder characterized by cystic ovarian morphology, androgen excess, and/or irregular periods, emerges during or shortly after puberty. Peri- and post-pubertal obesity, insulin resistance and consequent hyperinsulinemia are highly prevalent co-morbidities of PCOS and promote an ongoing state of excess androgen. Given the relationship of insulin to androgen excess, reduction of insulin secretion and/or improvement of its action at target tissues offer the possibility of improving the physical stigmata of androgen excess by correction of the reproductive dysfunction and preventing metabolic derangements from becoming entrenched. While lifestyle changes that concentrate on behavioral, dietary and exercise regimens should be considered as first line therapy for weight reduction and normalization of insulin levels in adolescents with PCOS, several therapeutic options are available and in wide use, including oral contraceptives, metformin, thiazolidenediones and spironolactone. Overwhelmingly, the data on the safety and efficacy of these medications derive from the adult PCOS literature. Despite the paucity of randomized control trials to adequately evaluate these modalities in adolescents, their use, particularly that of metformin, has gained popularity in the pediatric endocrine community. In this article, we present an overview of the use of insulin sensitizing medications in PCOS and review both the adult and (where available) adolescent literature, focusing specifically on the use of metformin in both mono- and combination therapy.

  16. State of the Art Review: Emerging Therapies: The Use of Insulin Sensitizers in the Treatment of Adolescents with Polycystic Ovary Syndrome (PCOS)

    Science.gov (United States)

    2011-01-01

    PCOS, a heterogeneous disorder characterized by cystic ovarian morphology, androgen excess, and/or irregular periods, emerges during or shortly after puberty. Peri- and post-pubertal obesity, insulin resistance and consequent hyperinsulinemia are highly prevalent co-morbidities of PCOS and promote an ongoing state of excess androgen. Given the relationship of insulin to androgen excess, reduction of insulin secretion and/or improvement of its action at target tissues offer the possibility of improving the physical stigmata of androgen excess by correction of the reproductive dysfunction and preventing metabolic derangements from becoming entrenched. While lifestyle changes that concentrate on behavioral, dietary and exercise regimens should be considered as first line therapy for weight reduction and normalization of insulin levels in adolescents with PCOS, several therapeutic options are available and in wide use, including oral contraceptives, metformin, thiazolidenediones and spironolactone. Overwhelmingly, the data on the safety and efficacy of these medications derive from the adult PCOS literature. Despite the paucity of randomized control trials to adequately evaluate these modalities in adolescents, their use, particularly that of metformin, has gained popularity in the pediatric endocrine community. In this article, we present an overview of the use of insulin sensitizing medications in PCOS and review both the adult and (where available) adolescent literature, focusing specifically on the use of metformin in both mono- and combination therapy. PMID:21899727

  17. State of the Art Review: Emerging Therapies: The Use of Insulin Sensitizers in the Treatment of Adolescents with Polycystic Ovary Syndrome (PCOS

    Directory of Open Access Journals (Sweden)

    Gordon Catherine M

    2011-08-01

    Full Text Available Abstract PCOS, a heterogeneous disorder characterized by cystic ovarian morphology, androgen excess, and/or irregular periods, emerges during or shortly after puberty. Peri- and post-pubertal obesity, insulin resistance and consequent hyperinsulinemia are highly prevalent co-morbidities of PCOS and promote an ongoing state of excess androgen. Given the relationship of insulin to androgen excess, reduction of insulin secretion and/or improvement of its action at target tissues offer the possibility of improving the physical stigmata of androgen excess by correction of the reproductive dysfunction and preventing metabolic derangements from becoming entrenched. While lifestyle changes that concentrate on behavioral, dietary and exercise regimens should be considered as first line therapy for weight reduction and normalization of insulin levels in adolescents with PCOS, several therapeutic options are available and in wide use, including oral contraceptives, metformin, thiazolidenediones and spironolactone. Overwhelmingly, the data on the safety and efficacy of these medications derive from the adult PCOS literature. Despite the paucity of randomized control trials to adequately evaluate these modalities in adolescents, their use, particularly that of metformin, has gained popularity in the pediatric endocrine community. In this article, we present an overview of the use of insulin sensitizing medications in PCOS and review both the adult and (where available adolescent literature, focusing specifically on the use of metformin in both mono- and combination therapy.

  18. Triglyceride glucose index as a surrogate measure of insulin sensitivity in obese adolescents with normoglycemia, prediabetes, and type 2 diabetes mellitus: comparison with the hyperinsulinemic-euglycemic clamp.

    Science.gov (United States)

    Mohd Nor, Noor Shafina; Lee, SoJung; Bacha, Fida; Tfayli, Hala; Arslanian, Silva

    2016-09-01

    There is a need for simple surrogate estimates of insulin sensitivity in epidemiological studies of obese youth because the hyperinsulinemic-euglycemic clamp is not feasible on a large scale. (i) To examine the triglyceride glucose (TyG) index (Ln[fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2]) and its relationship to in vivo insulin sensitivity in obese adolescents (OB) along the spectrum of glucose tolerance and (ii) to compare TyG index with triglyceride/high-density lipoprotein TG/HDL and 1/fasting insulin (1/IF ), other surrogates of insulin sensitivity. Cross-sectional data in 225 OB with normal glucose tolerance (NGT), prediabetes (preDM), and type 2 diabetes (T2DM) who had a 3-h hyperinsulinemic-euglycemic clamp and fasting lipid measurement. Insulin-stimulated glucose disposal (Rd) declined significantly across the glycemic groups from OB-NGT to OB-preDM to OB-T2DM with a corresponding increase in TyG index (8.3 ± 0.5, 8.6 ± 0.5, 8.9 ± 0.6, p index to Rd was -0.419 (p index for diagnosis of insulin resistance was 8.52 [receiver operating characteristic-area under the ROC curves (ROC-AUC) 0.750, p index, 1/IF , body mass index (BMI) z-score, glycemic group, and sex. The TyG index affords an easily and widely available simple laboratory method as a surrogate estimate of insulin sensitivity that could be used repeatedly in large-scale observational and/or interventional cohorts of OB. Although not superior to 1/IF , TyG index offers the advantage of having a standardized method of measuring triglyceride and glucose, which is not the case for insulin assays. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Trajectories of glycaemia, insulin sensitivity, and insulin secretion before diagnosis of type 2 diabetes: an analysis from the Whitehall II study

    DEFF Research Database (Denmark)

    Tabák, A.G.; Jokela, M.; Akbaraly, T.N.

    2009-01-01

    BACKGROUND: Little is known about the timing of changes in glucose metabolism before occurrence of type 2 diabetes. We aimed to characterise trajectories of fasting and postload glucose, insulin sensitivity, and insulin secretion in individuals who develop type 2 diabetes. METHODS: We analysed data...... from our prospective occupational cohort study (Whitehall II study) of 6538 (71% male and 91% white) British civil servants without diabetes mellitus at baseline. During a median follow-up period of 9.7 years, 505 diabetes cases were diagnosed (49.1% on the basis of oral glucose tolerance test). We...... assessed retrospective trajectories of fasting and 2-h postload glucose, homoeostasis model assessment (HOMA) insulin sensitivity, and HOMA beta-cell function from up to 13 years before diabetes diagnosis (diabetic group) or at the end of follow-up (non-diabetics). FINDINGS: Multilevel models adjusted...

  20. Effect of Postural Change on Plasma Insulin Concentration in Normal Volunteer

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Ho Kyung; Koh, Joo Whan; Joo, Jong Koo; Kim, Jin Yong; Lee, Jang Kyu [Korea Atomic Research Institute, Seoul (Korea, Republic of)

    1974-03-15

    The concentrations of some blood constituents are known to be influenced by the postural change. The blood glucose and insulin concentrations were measured, first, in the supine, and then (30 minutes later) in the erect positions under the fasting state. The effects of a duretic, furose-mide, were also studied under the same condition for 5 consecutive days. The materials were 5 healthy volunteers aging 20-29 years old with out any diabetic past, or family histories. The blood glucose was measured by the Nelson's method, and plasma insulin by the radioimmunoassay method. Following are the results; 1) The plasma insulin concentration in the erect position is slightly higher than in the supine position, however, the increase is statistically insignificant because of the notable individual variations in the values of the supine position. 2) Four out of 5 cases show the increase of about 80% of plasma insulin in the erect position, which is statistically significant if analyzed on the basis of frequency distribution. 3) The blood glucose concentration showed no postural changes. 4) The increase of the plasma insulin concentration in the erect position seems to the result of limited extra vasation of insulin in the lower extremities.

  1. A simple method for measuring glucose utilization of insulin-sensitive tissues by using the brain as a reference

    International Nuclear Information System (INIS)

    Namba, Hiroki; Nakagawa, Keiichi; Iyo, Masaomi; Fukushi, Kiyoshi; Irie, Toshiaki

    1994-01-01

    A simple method, without measurement of the plasma input function, to obtain semiquantitative values of glucose utilization in tissues other than the brain with radioactive deoxyglucose is reported. The brain, in which glucose utilization is essentially insensitive to plasma glucose and insulin concentrations, was used as an internal reference. The effects of graded doses of oral glucose loading (0.5, 1 and 2 mg/g body weight) on insulin-sensitive tissues (heart, muscle and fat tissue) were studied in the rat. By using the brain-reference method, dose-dependent increases in glucose utilization were clearly shown in all the insulin-sensitive tissues examined. The method seems to be of value for measurement of glucose utilization using radioactive deoxyglucose and positron emission tomography in the heart or other insulin-sensitive tissues, especially during glucose loading. (orig.)

  2. Cannabinoid 2 Receptor Agonist Improves Systemic Sensitivity to Insulin in High-Fat Diet/Streptozotocin-Induced Diabetic Mice

    Directory of Open Access Journals (Sweden)

    Xiuyuan Zhang

    2016-12-01

    Full Text Available Background/Aims: The endocannabinoid signalling (ECS system has been known to regulate glucose homeostasis. Previous studies have suggested that the cannabinoid 2 (CB2 receptor may play a regulatory role on insulin secretion, immune modulation and insulin resistance. Given that diabetes and insulin resistance are attributable to elevated inflammatory tone, we investigated the role of CB2 receptor on glucose tolerance and insulin sensitivity in high-fat diet (HFD/streptozotocin (STZ-induced mice. Methods: Diabetes was induced in male ICR mice by HFD/STZ and exposed to a CB2 receptor agonist, SER601, for 2- or 4-weeks via subcutaneous implantation of osmotic minipumps. Glucose and insulin tolerance tests were performed at the end of treatment. Islets were isolated for assessment of β-cell function. Pancreases and skeletal muscles were also obtained for histological analyses. Results: Despite a lack of impact on glucose tolerance, substantial improvement on insulin sensitivity was observed in SER601-treated mice, which could partly be attributed to improved islet β-cell function, shown as increased glucose-induced insulin secretion and insulin content. No changes on islet macrophage infiltration or skeletal muscle fat deposition were detectable from SER601-treated mice. However, a major decrease in body weight was recorded at the end of 4-week SER601 exposure, accompanied by a lack of epididymal adipose mass in SER601-treated mice. Conclusion: Our data suggest a lipolytic role of SER601 in HFD/STZ-induced diabetic mice, which results in significant improvement of systemic insulin sensitivity. Thus, the CB2 receptor may be considered a promising target for therapeutic development against insulin resistance and obesity-related diabetes.

  3. Brain GLUT4 Knockout Mice Have Impaired Glucose Tolerance, Decreased Insulin Sensitivity, and Impaired Hypoglycemic Counterregulation.

    Science.gov (United States)

    Reno, Candace M; Puente, Erwin C; Sheng, Zhenyu; Daphna-Iken, Dorit; Bree, Adam J; Routh, Vanessa H; Kahn, Barbara B; Fisher, Simon J

    2017-03-01

    GLUT4 in muscle and adipose tissue is important in maintaining glucose homeostasis. However, the role of insulin-responsive GLUT4 in the central nervous system has not been well characterized. To assess its importance, a selective knockout of brain GLUT4 (BG4KO) was generated by crossing Nestin-Cre mice with GLUT4-floxed mice. BG4KO mice had a 99% reduction in GLUT4 protein expression throughout the brain. Despite normal feeding and fasting glycemia, BG4KO mice were glucose intolerant, demonstrated hepatic insulin resistance, and had reduced glucose uptake in the brain. In response to hypoglycemia, BG4KO mice had impaired glucose sensing, noted by impaired epinephrine and glucagon responses and impaired c-fos activation in the hypothalamic paraventricular nucleus. Moreover, in vitro glucose sensing of glucose-inhibitory neurons from the ventromedial hypothalamus was impaired in BG4KO mice. In summary, BG4KO mice are glucose intolerant, insulin resistant, and have impaired glucose sensing, indicating a critical role for brain GLUT4 in sensing and responding to changes in blood glucose. © 2017 by the American Diabetes Association.

  4. Brain GLUT4 Knockout Mice Have Impaired Glucose Tolerance, Decreased Insulin Sensitivity, and Impaired Hypoglycemic Counterregulation

    Science.gov (United States)

    Reno, Candace M.; Puente, Erwin C.; Sheng, Zhenyu; Daphna-Iken, Dorit; Bree, Adam J.; Routh, Vanessa H.; Kahn, Barbara B.

    2017-01-01

    GLUT4 in muscle and adipose tissue is important in maintaining glucose homeostasis. However, the role of insulin-responsive GLUT4 in the central nervous system has not been well characterized. To assess its importance, a selective knockout of brain GLUT4 (BG4KO) was generated by crossing Nestin-Cre mice with GLUT4-floxed mice. BG4KO mice had a 99% reduction in GLUT4 protein expression throughout the brain. Despite normal feeding and fasting glycemia, BG4KO mice were glucose intolerant, demonstrated hepatic insulin resistance, and had reduced glucose uptake in the brain. In response to hypoglycemia, BG4KO mice had impaired glucose sensing, noted by impaired epinephrine and glucagon responses and impaired c-fos activation in the hypothalamic paraventricular nucleus. Moreover, in vitro glucose sensing of glucose-inhibitory neurons from the ventromedial hypothalamus was impaired in BG4KO mice. In summary, BG4KO mice are glucose intolerant, insulin resistant, and have impaired glucose sensing, indicating a critical role for brain GLUT4 in sensing and responding to changes in blood glucose. PMID:27797912

  5. Adiponectin in mice with altered growth hormone action: links to insulin sensitivity and longevity?

    Science.gov (United States)

    Lubbers, Ellen R.; List, Edward O.; Jara, Adam; Sackman-Sala, Lucila; Cordoba-Chacon, Jose; Gahete, Manuel D.; Kineman, Rhonda D.; Boparai, Ravneet; Bartke, Andrzej; Kopchick, John J.; Berryman, Darlene E.

    2013-01-01

    Adiponectin is positively correlated with longevity and negatively correlated with many obesity-related diseases. While there are several circulating forms of adiponectin, the high molecular weight (HMW) version has been suggested to have the predominant bioactivity. Adiponectin gene expression and cognate serum protein levels are of particular interest in mice with altered growth hormone (GH) signaling as these mice exhibit extremes in obesity that are positively associated with insulin sensitivity and lifespan as opposed to the typical negative association of these factors. While a few studies have reported total adiponectin levels in young adult mice with altered GH signaling, much remains unresolved, including changes in adiponectin levels with advancing age, proportion of total adiponectin in the HMW form, adipose depot of origin, and differential effects of GH versus IGF1. Therefore, the purpose of this study was to address these issues using assorted mouse lines with altered GH signaling. Our results show that adiponectin is generally negatively associated with GH activity, regardless of age. Further, the amount of HMW adiponectin is consistently linked with the level of total adiponectin and not necessarily with previously reported lifespan or insulin sensitivity of these mice. Interestingly, circulating adiponectin levels correlated strongly with inguinal fat mass, implying the effects of GH on adiponectin are depot-specific. Interestingly rbGH, but not IGF1, decreased circulating total and HMW adiponectin levels. Taken together, these results fill important gaps in the literature related to GH and adiponectin and question the frequently reported associations of total and HMW adiponectin with insulin sensitivity and longevity. PMID:23261955

  6. Adiponectin in mice with altered GH action: links to insulin sensitivity and longevity?

    Science.gov (United States)

    Lubbers, Ellen R; List, Edward O; Jara, Adam; Sackman-Sala, Lucila; Cordoba-Chacon, Jose; Gahete, Manuel D; Kineman, Rhonda D; Boparai, Ravneet; Bartke, Andrzej; Kopchick, John J; Berryman, Darlene E

    2013-03-01

    Adiponectin is positively correlated with longevity and negatively correlated with many obesity-related diseases. While there are several circulating forms of adiponectin, the high-molecular-weight (HMW) version has been suggested to have the predominant bioactivity. Adiponectin gene expression and cognate serum protein levels are of particular interest in mice with altered GH signaling as these mice exhibit extremes in obesity that are positively associated with insulin sensitivity and lifespan as opposed to the typical negative association of these factors. While a few studies have reported total adiponectin levels in young adult mice with altered GH signaling, much remains unresolved, including changes in adiponectin levels with advancing age, proportion of total adiponectin in the HMW form, adipose depot of origin, and differential effects of GH vs IGF1. Therefore, the purpose of this study was to address these issues using assorted mouse lines with altered GH signaling. Our results show that adiponectin is generally negatively associated with GH activity, regardless of age. Further, the amount of HMW adiponectin is consistently linked with the level of total adiponectin and not necessarily with previously reported lifespan or insulin sensitivity of these mice. Interestingly, circulating adiponectin levels correlated strongly with inguinal fat mass, implying that the effects of GH on adiponectin are depot specific. Interestingly, rbGH, but not IGF1, decreased circulating total and HMW adiponectin levels. Taken together, these results fill important gaps in the literature related to GH and adiponectin and question the frequently reported associations of total and HMW adiponectin with insulin sensitivity and longevity.

  7. Moderate Alcoholic Beer Consumption: The Effects on the Lipid Profile and Insulin Sensitivity of Adult Men.

    Science.gov (United States)

    Nogueira, Luciana C; do Rio, Rafaela F; Lollo, Pablo C B; Ferreira, Isabel M P L V O

    2017-07-01

    Beer is the most consumed alcoholic beverage in the world. The purpose was to compare the effects of consuming alcoholic beer (AB) and nonalcoholic beer (NAB) on the biochemical blood parameters. Two beers were produced under known and controlled conditions from the same raw material, NAB (0.6%, v/v) and AB with the addition of 6% grain alcohol. Fifteen healthy adult men (aged 20 to 57 y) underwent 3 treatments (30 d per treatment). In Treatment 1 (Baseline), they followed their usual diet without drinking any alcoholic beverage; in Treatment 2, they added the daily consumption of 330 mL NAB; and in Treatment 3, they added the daily consumption of 330 mL AB. It was found that the use of AB for 30 d (16 g alcohol/d) reduced the blood insulin and fasting glucose, reducing insulin resistance. These data suggest that the daily intake of 330 mL AB could statistically change the lipid profile and insulin sensitivity of adult men. The volunteers were healthy before and remained so after the intervention, with no change in their clinical status. © 2017 Institute of Food Technologists®.

  8. Hepatic Cholesterol-25-Hydroxylase Overexpression Improves Systemic Insulin Sensitivity in Mice

    Directory of Open Access Journals (Sweden)

    Britta Noebauer

    2017-01-01

    Full Text Available Obesity is a major risk factor for several diseases including diabetes, heart disease, and some forms of cancer and due to its rapidly increasing prevalence it has become one of the biggest problems medicine is facing today. All the more surprising, a substantial percentage of obese patients are metabolically healthy when classified based on insulin resistance and systemic inflammation. Oxysterols are naturally occurring molecules that play important role in various metabolic and inflammatory processes and their levels are elevated in patients suffering from obesity and diabetes. 25-Hydroxycholesterol (25-OHC is produced in cells from cholesterol by the enzyme cholesterol 25-hydroxylase (Ch25h and is involved in lipid metabolism, inflammatory processes, and cell proliferation. Here, we investigated the role of hepatic Ch25h in the transition from metabolically healthy obesity to insulin resistance and diabetes. Using several different experimental approaches, we demonstrated the significance of Ch25h on the border of “healthy” and “diseased” states of obesity. Adenovirus-mediated Ch25h overexpression in mice improved glucose tolerance and insulin sensitivity and lowered HOMA-IR. Our data suggest that low hepatic Ch25h levels could be considered a risk marker for unhealthy obesity.

  9. Minor long-term changes in weight have beneficial effects on insulin sensitivity and beta-cell function in obese subjects

    DEFF Research Database (Denmark)

    Rosenfalck, A M; Hendel, Helle Westergren; Rasmussen, M H

    2002-01-01

    To evaluate the long-term effect of changes in body composition induced by weight loss on insulin sensitivity (SI), non-insulin mediated glucose disposal, glucose effectiveness (SG)and beta-cell function.......To evaluate the long-term effect of changes in body composition induced by weight loss on insulin sensitivity (SI), non-insulin mediated glucose disposal, glucose effectiveness (SG)and beta-cell function....

  10. Global transcriptome profiling identifies KLF15 and SLC25A10 as modifiers of adipocytes insulin sensitivity in obese women.

    Directory of Open Access Journals (Sweden)

    Agné Kulyté

    Full Text Available Although the mechanisms linking obesity to insulin resistance (IR and type 2 diabetes (T2D are not entirely understood, it is likely that alterations of adipose tissue function are involved. The aim of this study was to identify new genes controlling insulin sensitivity in adipocytes from obese women with either insulin resistant (OIR or sensitive (OIS adipocytes. Insulin sensitivity was first determined by measuring lipogenesis in isolated adipocytes from abdominal subcutaneous white adipose tissue (WAT in a large observational study. Lipogenesis was measured under conditions where glucose transport was the rate limiting step and reflects in vivo insulin sensitivity. We then performed microarray-based transcriptome profiling on subcutaneous WAT specimen from a subgroup of 9 lean, 21 OIS and 18 obese OIR women. We could identify 432 genes that were differentially expressed between the OIR and OIS group (FDR ≤5%. These genes are enriched in pathways related to glucose and amino acid metabolism, cellular respiration, and insulin signaling, and include genes such as SLC2A4, AKT2, as well as genes coding for enzymes in the mitochondria respiratory chain. Two IR-associated genes, KLF15 encoding a transcription factor and SLC25A10 encoding a dicarboxylate carrier, were selected for functional evaluation in adipocytes differentiated in vitro. Knockdown of KLF15 and SLC25A10 using siRNA inhibited insulin-stimulated lipogenesis in adipocytes. Transcriptome profiling of siRNA-treated cells suggested that KLF15 might control insulin sensitivity by influencing expression of PPARG, PXMP2, AQP7, LPL and genes in the mitochondrial respiratory chain. Knockdown of SLC25A10 had only modest impact on the transcriptome, suggesting that it might directly influence insulin sensitivity in adipocytes independently of transcription due to its important role in fatty acid synthesis. In summary, this study identifies novel genes associated with insulin sensitivity in

  11. Aegeline inspired synthesis of novel β3-AR agonist improves insulin sensitivity in vitro and in vivo models of insulin resistance.

    Science.gov (United States)

    Rajan, Sujith; Satish, Sabbu; Shankar, Kripa; Pandeti, Sukanya; Varshney, Salil; Srivastava, Ankita; Kumar, Durgesh; Gupta, Abhishek; Gupta, Sanchita; Choudhary, Rakhi; Balaramnavar, Vishal M; Narender, Tadigoppula; Gaikwad, Anil N

    2018-03-07

    In our drug discovery program of natural product, earlier we have reported Aegeline that is N-acylated-1-amino-2- alcohol, which was isolated from the leaves of Aeglemarmelos showed anti-hyperlipidemic activity for which the QSAR studies predicted the compound to be the β3-AR agonist, but the mechanism of its action was not elucidated. In our present study, we have evaluated the β3-AR activity of novel N-acyl-1-amino-3-arylopropanol synthetic mimics of aegeline and its beneficial effect in insulin resistance. In this study, we have proposed the novel pharmacophore model using reported molecules for antihyperlipidemic activity. The reported pharmacophore features were also compared with the newly developed pharmacophore model for the observed biological activity. Based on 3D pharmacophore modeling of known β3AR agonist, we screened 20 synthetic derivatives of Aegeline from the literature. From these, the top scoring compound 10C was used for further studies. The in-slico result was further validated in HEK293T cells co-trransfected with human β3-AR and CRE-Luciferase reporter plasmid for β3-AR activity.The most active compound was selected and β3-AR activity was further validated in white and brown adipocytes differentiated from human mesenchymal stem cells (hMSCs). Insulin resistance model developed in hMSC derived adipocytes was used to study the insulin sensitizing property. 8 week HFD fed C57BL6 mice was given 50 mg/Kg of the selected compound and metabolic phenotyping was done to evaluate its anti-diabetic effect. As predicted by in-silico 3D pharmacophore modeling, the compound 10C was found to be the most active and specific β3-AR agonist with EC 50 value of 447 nM. The compound 10C activated β3AR pathway, induced lipolysis, fatty acid oxidation and increased oxygen consumption rate (OCR) in human adipocytes. Compound 10C induced expression of brown adipocytes specific markers and reverted chronic insulin induced insulin resistance in white

  12. Biomarkers and insulin sensitivity in women with Polycystic Ovary Syndrome: Characteristics and predictive capacity.

    Science.gov (United States)

    Cassar, Samantha; Teede, Helena J; Harrison, Cheryce L; Joham, Anju E; Moran, Lisa J; Stepto, Nigel K

    2015-07-01

    Polycystic ovary syndrome (PCOS) is a common endocrine disorder associated with metabolic complications. Metabolic biomarkers with roles in obesity, glycaemic control and lipid metabolism are potentially relevant in PCOS. The aim was to investigate metabolic biomarkers in lean and overweight women with and without PCOS and to determine whether any biomarker was able to predict insulin resistance in PCOS. Cross-sectional study. Eighty-four women (22 overweight and 22 lean women with PCOS, 18 overweight and 22 lean women without PCOS) were recruited from the community and categorized based on PCOS and BMI status. Primary outcomes were metabolic biomarkers [ghrelin, resistin, visfatin, glucagon-like peptide-1 (GLP-1), leptin, plasminogen activator inhibitor -1 (PAI-1), glucose-dependent insulinotropic polypeptide (GIP) and C-Peptide] measured using the Bio-Plex Pro Diabetes assay and insulin sensitivity as assessed by glucose infusion rate on euglycaemic-hyperinsulinaemic clamp. The biomarkers C-peptide, leptin, ghrelin and visfatin were different between overweight and lean women, irrespective of PCOS status. The concentration of circulating biomarkers did not differ between women with PCOS diagnosed by the Rotterdam criteria or National Institute of Health criteria. PAI-1 was the only biomarker that significantly predicted insulin resistance in both control women (P = 0.04) and women with PCOS (P = 0.01). Biomarkers associated with metabolic diseases appear more strongly associated with obesity rather than PCOS status. PAI-1 may also be a novel independent biomarker and predictor of insulin resistance in women with and without PCOS. © 2014 John Wiley & Sons Ltd.

  13. Deleterious effects of omitting breakfast on insulin sensitivity and fasting lipid profiles in healthy lean women.

    Science.gov (United States)

    Farshchi, Hamid R; Taylor, Moira A; Macdonald, Ian A

    2005-02-01

    Breakfast consumption is recommended, despite inconclusive evidence of health benefits. The study's aim was to ascertain whether eating breakfast (EB) or omitting breakfast (OB) affects energy intake, energy expenditure, and circulating insulin, glucose, and lipid concentrations in healthy women. In a randomized crossover trial, 10 women [x+/-SD body mass index (BMI; in kg/m2): 23.2+/-1.4] underwent two 14-d EB or OB interventions separated by a 2-wk interval. In the EB period, subjects consumed breakfast cereal with 2%-fat milk before 0800 and a chocolate-covered cookie between 1030 and 1100. In the OB period, subjects consumed the cookie between 1030 and 1100 and the cereal and milk between 1200 and 1330. Subjects then consumed 4 additional meals with content similar to usual at predetermined times later in the day and recorded food intake on 3 d during each period. Fasting and posttest meal glucose, lipid, and insulin concentrations and resting energy expenditure were measured before and after each period. Reported energy intake was significantly lower in the EB period (P=0.001), and resting energy expenditure did not differ significantly between the 2 periods. OB was associated with significantly higher fasting total and LDL cholesterol than was EB (3.14 and 3.43 mmol/L and 1.55 and 1.82 mmol/L, respectively; P=0.001). The area under the curve of insulin response to the test meal was significantly lower after EB than after OB (P<0.01). OB impairs fasting lipids and postprandial insulin sensitivity and could lead to weight gain if the observed higher energy intake was sustained.

  14. Proof of Concept: Matrix metalloproteinase inhibitor decreases inflammation and improves muscle insulin sensitivity in people with type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Frankwich Karen

    2012-10-01

    Full Text Available Abstract Background Obesity is a state of subclinical inflammation resulting in loss of function of insulin receptors and decreased insulin sensitivity. Inhibition of the inflammatory enzymes, matrix metalloproteinases (MMPs, for 6 months in rodent models restores insulin receptor function and insulin sensitivity. Methods This 12-week double-blind, randomized, placebo (PL-controlled proof-of-concept study was performed to determine if the MMP inhibitor (MMPI, doxycycline, decreased global markers of inflammation and enhanced muscle insulin sensitivity in obese people with type 2 diabetes (DM2. The study included non-DM2 controls (n = 15, and DM2 subjects randomized to PL (n = 13 or doxycycline 100 mg twice daily (MMPI; n = 11. All participants were evaluated on Day 1; MMPI and PL groups were also evaluated after 84 days of treatment. Results There was a significant decrease in inflammatory markers C-reactive protein (P  Conclusions This study demonstrated short term treatment of people with diabetes with an MMPI resulted in decreased inflammation and improved insulin sensitivity. Larger, longer studies are warranted to determine if doxycycline can improve glucose control in people with diabetes. Trial Registration Clinicaltrials.gov NCT01375491

  15. LPS-Enhanced Glucose-Stimulated Insulin Secretion Is Normalized by Resveratrol

    DEFF Research Database (Denmark)

    Nøhr, Mark K; Dudele, Anete; Poulsen, Morten M

    2016-01-01

    we test the effect of LPS and the anti-inflammatory compound resveratrol on glucose homeostasis, insulin levels and inflammation. Mice were subcutaneously implanted with osmotic mini pumps infusing either low-dose LPS or saline for 28 days. Half of the mice were treated with resveratrol delivered...... through the diet. LPS caused increased inflammation of the liver and adipose tissue (epididymal and subcutaneous) together with enlarged spleens and increased number of leukocytes in the blood. Resveratrol specifically reduced the inflammatory status in epididymal fat (reduced expression of TNFa and Il1b......, whereas the increased macrophage infiltration was unaltered) without affecting the other tissues investigated. By LC-MS, we were able to quantitate resveratrol metabolites in epididymal but not subcutaneous adipose tissue. LPS induced insulin resistance as the glucose-stimulated insulin secretion during...

  16. Blockade of oestrogen biosynthesis in peripubertal boys: effects on lipid metabolism, insulin sensitivity, and body composition.

    Science.gov (United States)

    Hero, Matti; Ankarberg-Lindgren, Carina; Taskinen, Marja-Riitta; Dunkel, Leo

    2006-09-01

    In males, the pubertal increase in sex hormone production has been associated with proatherogenic changes in lipid and carbohydrate metabolism. Aromatase inhibitors, a novel treatment modality for some growth disorders, may significantly influence these risk factors for cardiovascular disease by suppressing oestrogen biosynthesis and stimulating gonadal androgen production. In the current study, we explored the effects of aromatase inhibition on lipid metabolism, insulin sensitivity, body composition and serum adiponectin in peripubertal boys. Prospective, double-blind, randomised, placebo-controlled clinical study. Thirty-one boys, aged 9.0-14.5 years, with idiopathic short stature were treated with the aromatase inhibitor letrozole (2.5 mg/day) or placebo for 2 years. During the treatment, the concentrations of sex hormones, IGF-I, lipids, lipoproteins and adiponectin were followed-up. The percentage of fat mass (FM) was assessed by skinfold measurements and insulin resistance by homeostasis model assessment (HOMA) index. In pubertal boys, who received letrozole, high-density lipoprotein cholesterol (HDL-C) decreased by 0.47 mmol/l (P<0.01) during the study. Simultaneously, their percentage of FM decreased from 17.0 to 10.5 (P<0.001), in an inverse relationship with serum testosterone. The concentrations of low-density lipoprotein cholesterol, triglycerides and HOMA index remained at pretreatment level in both groups. Serum adiponectin decreased similarly in letrozole- and placebo-treated pubertal boys (2.9 and 3.3 mg/l respectively). In males, aromatase inhibition reduces HDL-C and decreases relative FM after the start of puberty. The treatment does not adversely affect insulin sensitivity in lean subjects.

  17. Over-expression of Follistatin-like 3 attenuates fat accumulation and improves insulin sensitivity in mice

    DEFF Research Database (Denmark)

    Brandt, Claus; Hansen, Rasmus Hvass; Hansen, Jakob Bondo

    2015-01-01

    -fat feeding. Body weight, food intake, fat accumulation by MR scanning, and glucose, insulin and glucagon tolerance were evaluated, as was the response in body weight and metabolic parameters to 24h fasting. Effects of fstl3 on pancreatic insulin and glucagon content, and pancreatic islet morphology were......OBJECTIVE: Follistatin-like 3 (fstl3), a natural inhibitor of members of the TGF-β family, increases during resistance training in human plasma. Fstl3 primarily binds myostatin and activin A, and thereby inhibits their functions. We hypothesize that blocking myostatin and activin A signalling....../glucagon ratio. Accordingly, fstl3 transfection improved counter-regulation to 24h fasting. CONCLUSION: Fstl3 over-expression regulates insulin and glucagon sensitivities through increased muscular insulin action, as well as increased hepatic glucagon sensitivity and pancreatic glucagon content....

  18. The relationship between heat shock protein 72 expression in skeletal muscle and insulin sensitivity is dependent on adiposity

    DEFF Research Database (Denmark)

    Henstridge, Darren C; Forbes, Josephine M; Penfold, Sally A

    2010-01-01

    Decreased gene expression of heat shock protein 72 (HSP72) in skeletal muscle is associated with insulin resistance in humans. We aimed to determine whether HSP72 protein expression in insulin-sensitive tissues is related to criterion standard measures of adiposity and insulin resistance in a young...... healthy human population free of hyperglycemia. Healthy participants (N = 17; age, 30 ± 3 years) underwent measurement of body composition (dual-energy x-ray absorptiometry), a maximum aerobic capacity test (VO(2max)), an oral glucose tolerance test, and a hyperinsulinemic-euglycemic clamp (M) to access...... insulin sensitivity. Skeletal muscle and subcutaneous adipose tissue biopsies were obtained by percutaneous needle biopsy. HSP72 protein expression in skeletal muscle was inversely related to percentage body fat (r = -0.54, P

  19. pH-sensitive chitosan/alginate core-shell nanoparticles for efficient and safe oral insulin delivery.

    Science.gov (United States)

    Mukhopadhyay, Piyasi; Chakraborty, Souma; Bhattacharya, Sourav; Mishra, Roshnara; Kundu, P P

    2015-01-01

    Chitosan-alginate (CS/ALG) nanoparticles were prepared by formation of an ionotropic pre-gelation of an alginate (ALG) core entrapping insulin, followed by chitosan (CS) polyelectrolyte complexation, for successful oral insulin administration. Mild preparation process without harsh chemicals is aimed at improving insulin bio-efficiency in in vivo model. The nanoparticles showed an average particle size of 100-200 nm in dynamic light scattering (DLS), with almost spherical or sub-spherical shape and ∼ 85% of insulin encapsulation. Again, retention of almost entire amount of encapsulated insulin in simulated gastric buffer followed by its sustained release in simulated intestinal condition proved its pH sensitivity in in vitro release studies. Significant hypoglycemic effects with improved insulin-relative bioavailability (∼ 8.11%) in in vivo model revealed the efficacy of these core-shell nanoparticles of CS/ALG as an oral insulin carrier. No systemic toxicity was found after its peroral treatment, suggesting these core-shell nanoparticles as a promising device for potential oral insulin delivery. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. NASH Therapy: omega 3 supplementation, vitamin E, insulin sensitizers and statin drugs

    Directory of Open Access Journals (Sweden)

    Stephen Caldwell

    2017-06-01

    Full Text Available Non-alcoholic steatohepatitis (NASH is the more aggressive form of non-alcoholic fatty liver disease (NAFLD. NASH can progress to hepatic fibrosis, cirrhosis, portal hypertension and primary liver cancer. Therapy is evolving with a substantial number of trials of promising new agents now in progress. In this article however, we will examine data for several older forms of therapy which have been fairly extensively studied over the years: Polyunsaturated Fatty Acid (PUFA supplements, vitamin E, insulin sensitizing agents with a focus on pioglitazone and statin agents. Early interest in PUFA derived from their potential benefit in cardio-metabolic disease and the close association of NAFLD/NASH with Metabolic Syndrome. Results have been variable although most studies show reduction of liver fat without other major effects and their effects are influenced by concomitant weight loss and underlying genetic factors. Vitamin E has had some efficacy in pediatric NASH but questionable efficacy in even mild NASH among adults. Pioglitazone has shown significant histological benefit in a number of trials but concern over side-effects (especially weight gain have dampened enthusiasm. A newer insulin sensitizer, liraglutide, has also shown promise in a small randomized, controlled trial. Very limited data exists regarding the histological effects of the statins in NASH and these agents appear to be fairly neutral with neither clear cut benefit nor detriment. Their use is best guided by cardiovascular risks rather than liver histology.

  1. Effect of trans-fatty acid intake on insulin sensitivity and intramuscular lipids - a randomized trial in overweight postmenopausal women

    DEFF Research Database (Denmark)

    Bendsen, Nathalie Tommerup; Haugaard, Steen; Larsen, Thomas Meinert

    2011-01-01

    lipid deposition in abdominally obese women. In a double-blind, parallel dietary intervention study, 52 healthy but overweight postmenopausal women were randomized to receive either partially hydrogenated soybean oil (15 g/d TFA) or a control oil (mainly oleic and palmitic acid) for 16 weeks. Three......-nine women completed the study. Insulin sensitivity (assessed by ISI(composite)), β-cell function (the disposition index), and the metabolic clearance rate of insulin were not significantly affected by the dietary intervention. Neither was the ability of insulin to suppress plasma nonesterified fatty acid...

  2. The consequences of long-term glycogen synthase kinase-3 inhibition on normal and insulin resistant rat hearts.

    Science.gov (United States)

    Flepisi, T B; Lochner, Amanda; Huisamen, Barbara

    2013-10-01

    Glycogen synthase kinase-3 (GSK-3) is a serine-threonine protein kinase, discovered as a regulator of glycogen synthase. GSK-3 may regulate the expression of SERCA-2a potentially affecting myocardial contractility. It is known to phosphorylate and inhibit IRS-1, thus disrupting insulin signalling. This study aimed to determine whether myocardial GSK-3 protein and its substrate proteins are dysregulated in obesity and insulin resistance, and whether chronic GSK-3 inhibition can prevent or reverse this. Weight matched male Wistar rats were rendered obese by hyperphagia using a special diet (DIO) for 16 weeks and compared to chow fed controls. Half of each group was treated with the GSK-3 inhibitor CHIR118637 (30 mg/kg/day) from week 12 to16 of the diet period. Biometric and biochemical parameters were measured and protein expression determined by Western blotting and specific antibodies. Ca(2+)ATPase activity was determined spectrophotometrically. Cardiomyocytes were prepared by collagenase perfusion and insulin stimulated 2-deoxy-glucose uptake determined. DIO rats were significantly heavier than controls, associated with increased intra-peritoneal fat and insulin resistance. GSK-3 inhibition did not affect weight but improved insulin resistance, also on cellular level. It had no effect on GSK-3 expression but elevated its phospho/total ratio and elevated IRS-2 expression. Obesity lowered SERCA-2a expression and activity while GSK-3 inhibition alleviated this. The phospho/total ratio of phospholamban underscored inhibition of SERCA-2a in obesity. In addition, signs of myocardial hypertrophy were observed in treated control rats. GSK-3 inhibition could not reverse all the detrimental effects of obesity but may be harmful in normal rat hearts. It regulates IRS-2, SERCA-2a and phospholamban expression but not IRS-1.

  3. Coordinate Transcriptomic and Metabolomic Effects of the Insulin Sensitizer Rosiglitazone on Fundamental Metabolic Pathways in Liver, Soleus Muscle, and Adipose Tissue in Diabetic db/db Mice

    Directory of Open Access Journals (Sweden)

    Sabrina Le Bouter

    2010-01-01

    Full Text Available Rosiglitazone (RSG, developed for the treatment of type 2 diabetes mellitus, is known to have potent effects on carbohydrate and lipid metabolism leading to the improvement of insulin sensitivity in target tissues. To further assess the capacity of RSG to normalize gene expression in insulin-sensitive tissues, we compared groups of 18-day-treated db/db mice with increasing oral doses of RSG (10, 30, and 100 mg/kg/d with untreated non-diabetic littermates (db/+. For this aim, transcriptional changes were measured in liver, inguinal adipose tissue (IAT and soleus muscle using microarrays and real-time PCR. In parallel, targeted metabolomic assessment of lipids (triglycerides (TGs and free fatty acids (FFAs in plasma and tissues was performed by UPLC-MS methods. Multivariate analyses revealed a relationship between the differential gene expressions in liver and liver trioleate content and between blood glucose levels and a combination of differentially expressed genes measured in liver, IAT, and muscle. In summary, we have integrated gene expression and targeted metabolomic data to present a comprehensive overview of RSG-induced changes in a diabetes mouse model and improved the molecular understanding of how RSG ameliorates diabetes through its effect on the major insulin-sensitive tissues.

  4. Serum IGF1 and insulin levels in girls with normal and precocious puberty

    DEFF Research Database (Denmark)

    Sørensen, Kaspar; Aksglaede, Lise; Petersen, Jørgen Holm

    2012-01-01

    IGF1 plays an important role in growth and metabolism during puberty. IGF1 levels are increased in girls with central precocious puberty (CPP). However, the relationship with insulin before and during gonadal suppression is unknown. In addition, the influence of the exon 3-deleted GH receptor gene...

  5. Subthalamic nucleus stimulation does not influence basal glucose metabolism or insulin sensitivity in patients with Parkinson's disease.

    Science.gov (United States)

    Lammers, Nicolette M; Sondermeijer, Brigitte M; Twickler, Th B Marcel; de Bie, Rob M; Ackermans, Mariëtte T; Fliers, Eric; Schuurman, P Richard; La Fleur, Susanne E; Serlie, Mireille J

    2014-01-01

    Animal studies have shown that central dopamine signaling influences glucose metabolism. As a first step to show this association in an experimental setting in humans, we studied whether deep brain stimulation (DBS) of the subthalamic nucleus (STN), which modulates the basal ganglia circuitry, alters basal endogenous glucose production (EGP) or insulin sensitivity in patients with Parkinson's disease (PD). We studied 8 patients with PD treated with DBS STN, in the basal state and during a hyperinsulinemic euglycemic clamp using a stable glucose isotope, in the stimulated and non-stimulated condition. We measured EGP, hepatic insulin sensitivity, peripheral insulin sensitivity (Rd), resting energy expenditure (REE), glucoregulatory hormones, and Parkinson symptoms, using the Unified Parkinson's Disease Rating Scale (UPDRS). Basal plasma glucose and EGP did not differ between the stimulated and non-stimulated condition. Hepatic insulin sensitivity was similar in both conditions and there were no significant differences in Rd and plasma glucoregulatory hormones between DBS on and DBS off. UPDRS was significantly higher in the non-stimulated condition. DBS of the STN in patients with PD does not influence basal EGP or insulin sensitivity. These results suggest that acute modulation of the motor basal ganglia circuitry does not affect glucose metabolism in humans.

  6. Insulin resistance according to β-cell function in women with polycystic ovary syndrome and normal glucose tolerance.

    Directory of Open Access Journals (Sweden)

    Do Kyeong Song

    Full Text Available Polycystic ovary syndrome (PCOS is associated with insulin resistance (IR and compensatory hyperinsulinemia. IR is recognized as a major risk factor for the development of type 2 diabetes mellitus. However, few studies have investigated IR in women with PCOS and normal glucose tolerance. The objective of this study was to evaluate IR and β-cell function in women with PCOS and normal glucose tolerance. Additionally, we sought to evaluate the usefulness of oral glucose tolerance test (OGTT-derived IR indices in lean women with PCOS.We recruited 100 women with PCOS and normal glucose tolerance and 100 age- and BMI-matched women as controls. IR and insulin secretory indices, including the homeostasis-model assessment (HOMA-IR, HOMA-M120, HOMA-F and the Stumvoll index, were calculated from an OGTT. Increased β-cell function was defined as>75th percentile for the HOMA-F in control women.Women with PCOS had higher values for post-load 2-hour glucose, fasting insulin, post-load 2-hour insulin, HOMA-IR, HOMA-M120, HOMA-F and lower values for the Stumvoll index than the controls (all Ps<0.05. Women with PCOS and increased β-cell function showed lower Stumvoll index values than the matched controls (P<0.05. The HOMA-F was significantly associated with the HOMA-M120 and Stumvoll index when adjusted for age and BMI in a multiple regression analysis (all Ps<0.05. The HOMA-M120 was positively correlated with triglycerides and free testosterone, and the Stumvoll index was negatively correlated with triglycerides and free testosterone in lean women with PCOS (all Ps<0.05.Women with PCOS and normal glucose tolerance showed higher IR than controls matched for age, BMI, and β-cell function. β-cell function was increased in women with PCOS when compared to the matched controls, but not when the lean subjects were compared to the matched controls separately. Therefore, early evaluation of IR in women with PCOS and normal glucose tolerance may be needed.

  7. The Mediterranean diet improves hepatic steatosis and insulin sensitivity in individuals with non-alcoholic fatty liver disease.

    Science.gov (United States)

    Ryan, Marno C; Itsiopoulos, Catherine; Thodis, Tania; Ward, Glenn; Trost, Nicholas; Hofferberth, Sophie; O'Dea, Kerin; Desmond, Paul V; Johnson, Nathan A; Wilson, Andrew M

    2013-07-01

    Non-alcoholic fatty liver disease (NAFLD) affects up to 30% of the population and signifies increased risk of liver fibrosis and cirrhosis, type 2 diabetes, and cardiovascular disease. Therapies are limited. Weight loss is of benefit but is difficult to maintain. We aimed at examining the effect of the Mediterranean diet (MD), a diet high in monounsaturated fatty acids, on steatosis and insulin sensitivity, using gold standard techniques. Twelve non-diabetic subjects (6 Females/6 Males) with biopsy-proven NAFLD were recruited for a randomised, cross-over 6-week dietary intervention study. All subjects undertook both the MD and a control diet, a low fat-high carbohydrate diet (LF/HCD), in random order with a 6-week wash-out period in- between. Insulin sensitivity was determined with a 3-h hyperinsulinemic-euglycemic clamp study and hepatic steatosis was assessed with localized magnetic resonance (1)H spectroscopy ((1)H-MRS). At baseline, subjects were abdominally obese with elevated fasting concentrations of glucose, insulin, triglycerides, ALT, and GGT. Insulin sensitivity at baseline was low (M=2.7 ± 1.0 mg/kg/min(-1)). Mean weight loss was not different between the two diets (p=0.22). There was a significant relative reduction in hepatic steatosis after the MD compared with the LF/HCD: 39 ± 4% versus 7 ± 3%, as measured by (1)H-MRS (p=0.012). Insulin sensitivity improved with the MD, whereas after the LF/HCD there was no change (p=0.03 between diets). Even without weight loss, MD reduces liver steatosis and improves insulin sensitivity in an insulin-resistant population with NAFLD, compared to current dietary advice. This diet should be further investigated in subjects with NAFLD. Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  8. Involvement of insulin-degrading enzyme in insulin- and atrial natriuretic peptide-sensitive internalization of amyloid-β peptide in mouse brain capillary endothelial cells.

    Science.gov (United States)

    Ito, Shingo; Ohtsuki, Sumio; Murata, Sho; Katsukura, Yuki; Suzuki, Hiroya; Funaki, Miho; Tachikawa, Masanori; Terasaki, Tetsuya

    2014-01-01

    Cerebral clearance of amyloid-β peptide (Aβ), which is implicated in Alzheimer's disease, involves elimination across the blood-brain barrier (BBB), and we previously showed that an insulin-sensitive process is involved in the case of Aβ1-40. The purpose of this study was to clarify the molecular mechanism of the insulin-sensitive Aβ1-40 elimination across mouse BBB. An in vivo cerebral microinjection study demonstrated that [125I]hAβ1-40 elimination from mouse brain was inhibited by human natriuretic peptide (hANP), and [125I]hANP elimination was inhibited by hAβ1-40, suggesting that hAβ1-40 and hANP share a common elimination process. Internalization of [125I]hAβ1-40 into cultured mouse brain capillary endothelial cells (TM-BBB4) was significantly inhibited by either insulin, hANP, other natriuretic peptides or insulin-degrading enzyme (IDE) inhibitors, but was not inhibited by phosphoramidon or thiorphan. Although we have reported the involvement of natriuretic peptide receptor C (Npr-C) in hANP internalization, cells stably expressing Npr-C internalized [125I]hANP but not [125I]hAβ1-40, suggesting that there is no direct interaction between Npr-C and hAβ1-40. IDE was detected in plasma membrane of TM-BBB4 cells, and internalization of [125I]hAβ1-40 by TM-BBB4 cells was reduced by IDE-targeted siRNAs. We conclude that elimination of hAβ1-40 from mouse brain across the BBB involves an insulin- and ANP-sensitive process, mediated by IDE expressed in brain capillary endothelial cells.

  9. Evidence for a relationship between VEGF and BMI independent of insulin sensitivity by glucose clamp procedure in a homogenous group healthy young men.

    Directory of Open Access Journals (Sweden)

    Michaela Loebig

    Full Text Available BACKGROUND: This is the first study to experimentally explore the direct relationship between circulating VEGF levels and body mass index (BMI as well as to unravel the role of insulin sensitivity in this context under standardized glucose clamp conditions as the methodical gold-standard. In order to control for known influencing factors such as gender, medication, and arterial hypertension, we examined a highly homogeneous group of young male subjects. Moreover, to encompass also subjects beyond the normal BMI range, low weight and obese participants were additionally included and stress hormones as a main regulator of VEGF were assessed. METHODOLOGY/PRINCIPAL FINDINGS: Under euglycemic clamp conditions, VEGF was measured in 15 normal weight (BMI 20-25 kg/m(2, 15 low weight (BMI30 kg/m(2 male subjects aged 18-30 years and the insulin sensitivity index (ISI was calculated. Since stress axis activation promotes VEGF secretion, concentrations of ACTH, cortisol, and catecholamines were monitored. Despite of comparable ACTH (P = 0.145, cortisol (P = 0.840, and norepinephrine (P = 0.065 levels, VEGF concentrations differed significantly between BMI-groups (P = 0.008 with higher concentrations in obese subjects as compared to normal weight (P = 0.061 and low weight subjects (P = 0.002. Pearson's correlation analysis revealed a positive relationship between BMI and VEGF levels (r = 0.407; P = 0.010 but no correlation of VEGF with ISI (r = 0.224; P = 0.175. CONCLUSIONS/SIGNIFICANCE: Our data demonstrate a positive correlation between concentrations of circulating VEGF levels and BMI in healthy male subjects under highly controlled conditions. This relationship which is apparently disconnected from insulin sensitivity may be part of some pathogenetic mechanisms underlying obesity and type 2 diabetes.

  10. Effect of intravenous glucose infusion on renal function in normal man and in insulin-dependent diabetics

    DEFF Research Database (Denmark)

    Frandsen, M; Parving, H H; Christiansen, JS

    1981-01-01

    The effect of intravenous glucose infusion on glomerular filtration rate and renal plasma flow (constant infusion technique using 125I-iothalamate and 131I-hippuran) and on urinary excretion of albumin and beta-2-microglobulin were studied in ten normal subjects and seven metabolically well......-controlled insulin-dependent diabetics. Following glucose infusion in normal subjects (n = 10) blood glucose increased from 4.7 +/- 0.1 to 10.9 +/- 0.4 mmol/l (SEM) (p less than or equal to 0.01). Glomerular filtration rate increased from 116 +/- 2 to 123 +/- 3 ml/mi x 1.73 m2 (p less than or equal to 0.01), while...... no change in renal plasma flow was seen - 552 +/- 11 versus 553 +/- 18 ml/min x 1.73 m2. Volume expansion with intravenous saline infusion in six of the normal subjects induced no changes in blood glucose or kidney function. In seven strictly controlled insulin-dependent diabetics, blood glucose values were...

  11. Increased reactive oxygen species production and lower abundance of complex I subunits and carnitine palmitoyltransferase 1B protein despite normal mitochondrial respiration in insulin-resistant human skeletal muscle.

    Science.gov (United States)

    Lefort, Natalie; Glancy, Brian; Bowen, Benjamin; Willis, Wayne T; Bailowitz, Zachary; De Filippis, Elena A; Brophy, Colleen; Meyer, Christian; Højlund, Kurt; Yi, Zhengping; Mandarino, Lawrence J

    2010-10-01

    The contribution of mitochondrial dysfunction to skeletal muscle insulin resistance remains elusive. Comparative proteomics are being applied to generate new hypotheses in human biology and were applied here to isolated mitochondria to identify novel changes in mitochondrial protein abundance present in insulin-resistant muscle. Mitochondria were isolated from vastus lateralis muscle from lean and insulin-sensitive individuals and from obese and insulin-resistant individuals who were otherwise healthy. Respiration and reactive oxygen species (ROS) production rates were measured in vitro. Relative abundances of proteins detected by mass spectrometry were determined using a normalized spectral abundance factor method. NADH- and FADH(2)-linked maximal respiration rates were similar between lean and obese individuals. Rates of pyruvate and palmitoyl-DL-carnitine (both including malate) ROS production were significantly higher in obesity. Mitochondria from obese individuals maintained higher (more negative) extramitochondrial ATP free energy at low metabolic flux, suggesting that stronger mitochondrial thermodynamic driving forces may underlie the higher ROS production. Tandem mass spectrometry identified protein abundance differences per mitochondrial mass in insulin resistance, including lower abundance of complex I subunits and enzymes involved in the oxidation of branched-chain amino acids (BCAA) and fatty acids (e.g., carnitine palmitoyltransferase 1B). We provide data suggesting normal oxidative capacity of mitochondria in insulin-resistant skeletal muscle in parallel with high rates of ROS production. Furthermore, we show specific abundance differences in proteins involved in fat and BCAA oxidation that might contribute to the accumulation of lipid and BCAA frequently associated with the pathogenesis of insulin resistance.

  12. STUDY ON COMPARISON OF THE EFFECT OF TOPICAL INSULIN WITH NORMAL SALINE DRESSING IN HEALING OF DIABETIC FOOT ULCERS

    Directory of Open Access Journals (Sweden)

    Chinnam Venkata Reddy

    2017-05-01

    Full Text Available BACKGROUND Numerous topical medication and gels are promoted for ulcer care and healing. Relatively, few have proved to be more efficacious than saline wet-to-dry dressings. The present study was aimed to compare the effect of topical insulin and normal saline dressing in healing of diabetic foot ulcers. MATERIALS AND METHODS The present two-year hospital-based randomised-controlled trial was conducted in the Department of General Surgery, Rangaraya Medical College, Kakinada, from April 2015 to March 2017. A total of 60 patients with diabetic foot ulcers were studied. Based on the envelop method, patients were divided into two groups of 30 patients each that is group A (topical insulin and group B (normal saline. RESULTS In this males (66.67% in group A and 83.33% in group B outnumbered females in both the groups with male-to-female ratio of 2:1 in group A and 4:1 in group B. The mean age in group A was 52.00 ± 11.00 years, and in group B, it was 57.00 ± 9.80 years (p=1.000. Among patients with group A, significant reduction of mean ulcer area was observed (307.23 ± 169.87 mm2 with higher mean percentage reduction (35.19 ± 19.00 percent, whereas in group B, the mean percentage reduction was significantly less (18.82 ± 4.06 percent with less reduction of mean final ulcer area (149.90 ± 64.45 mm2 (p<0.001. CONCLUSION Overall, topical insulin dressing provided favourable outcome in patients with diabetic foot ulcer by significant reduction in wound area when compared to normal saline dressing and it had positive role in reducing the wound infection if present.

  13. The Relationship between Adiposity and Insulin Sensitivity in African Women Living with the Polycystic Ovarian Syndrome: A Clamp Study

    Directory of Open Access Journals (Sweden)

    Emmanuella Doh

    2016-01-01

    Full Text Available Objectives. We aimed to assess the variation of insulin sensitivity in relation to obesity in women living with PCOS in a sub-Sahara African setting. Methods. We studied body composition, insulin sensitivity, and resting energy expenditure in 14 PCOS patients (6 obese and 8 nonobese compared to 10 matched nonobese non-PCOS subjects. Insulin sensitivity was assessed using the gold standard 80 mU/m2/min euglycemic-hyperinsulinemic clamp and resting energy expenditure was measured by indirect calorimetry. Results. Insulin sensitivity adjusted to lean mass was lowest in obese PCOS subjects and highest in healthy subjects (11.2 [10.1–12.4] versus 12.9 [12.1–13.8] versus 16.6 [13.8–17.9], p=0.012; there was a tendency for resting energy expenditure adjusted for total body mass to decrease across the groups highest in obese PCOS subjects (1411 [1368–1613] versus 1274 [1174–1355] versus 1239 [1195–1454], p=0.306. Conclusion. In this sub-Saharan population, insulin resistance is associated with PCOS per se but is further aggravated by obesity. Obesity did not seem to be explained by low resting energy expenditure suggesting that dietary intake may be a determinant of the obesity in this context.

  14. Atrial Natriuretic Peptide in the high normal range is associated with lower prevalence of insulin resistance

    DEFF Research Database (Denmark)

    Jujić, Amra; Nilsson, Peter M; Persson, Margaretha

    2016-01-01

    was inversely associated with insulin resistance calculated as HOMA-IR (per 1 SD change β= -0.066, p-value 0.001) at follow-up. Logistic regression analysis showed that each 1 SD increment of baseline ANP levels resulted in lower risk of belonging to upper quartile of HOMA-IR at follow-up (OR 0.88; CI 95 % 0...

  15. Developmental Programming: Prenatal and Postnatal Androgen Antagonist and Insulin Sensitizer Interventions Prevent Advancement of Puberty and Improve LH Surge Dynamics in Prenatal Testosterone-Treated Sheep.

    Science.gov (United States)

    Padmanabhan, Vasantha; Veiga-Lopez, Almudena; Herkimer, Carol; Abi Salloum, Bachir; Moeller, Jacob; Beckett, Evan; Sreedharan, Rohit

    2015-07-01

    Prenatal T excess induces maternal hyperinsulinemia, early puberty, and reproductive/metabolic defects in the female similar to those seen in women with polycystic ovary syndrome. This study addressed the organizational/activational role of androgens and insulin in programming pubertal advancement and periovulatory LH surge defects. Treatment groups included the following: 1) control; 2) prenatal T; 3) prenatal T plus prenatal androgen antagonist, flutamide; 4) prenatal T plus prenatal insulin sensitizer, rosiglitazone; 5) prenatal T and postnatal flutamide; 6) prenatal T and postnatal rosiglitazone; and 7) prenatal T and postnatal metformin. Prenatal treatments spanned 30-90 days of gestation and postnatal treatments began at approximately 8 weeks of age and continued throughout. Blood samples were taken twice weekly, beginning at approximately 12 weeks of age to time puberty. Two-hour samples after the synchronization with prostaglandin F2α were taken for 120 hours to characterize LH surge dynamics at 7 and 19 months of age. Prenatal T females entered puberty earlier than controls, and all interventions prevented this advancement. Prenatal T reduced the percentage of animals having LH surge, and females that presented LH surge exhibited delayed timing and dampened amplitude of the LH surge. Prenatal androgen antagonist, but not other interventions, restored LH surges without normalizing the timing of the surge. Normalization of pubertal timing with prenatal/postnatal androgen antagonist and insulin sensitizer interventions suggests that pubertal advancement is programmed by androgenic actions of T involving insulin as a mediary. Restoration of LH surges by cotreatment with androgen antagonist supports androgenic programming at the organizational level.

  16. Postreceptor defects causing insulin resistance in normoinsulinemic non-insulin-dependent diabetes mellitus

    International Nuclear Information System (INIS)

    Bolinder, J.; Ostman, J.; Arner, P.

    1982-01-01

    The mechanisms of the diminished hypoglycemic response to insulin in non-insulin-dependent diabetes mellitus (NIDDM) with normal levels of circulating plasma insulin were investigated. Specific binding of mono- 125 I (Tyr A14)-insulin to isolated adipocytes and effects of insulin (5--10,000 microunits/ml) on glucose oxidation and lipolysis were determined simultaneously in subcutaneous adipose tissue of seven healthy subjects of normal weight and seven untreated NIDDM patients with normal plasma insulin levels. The two groups were matched for age, sex, and body weight. Insulin binding, measured in terms of receptor number and affinity, was normal in NIDDM, the total number of receptors averaging 350,000 per cell. Neither sensitivity nor the maximum antilipolytic effect of insulin was altered in NIDDM patients as compared with control subjects; the insulin concentration producing half the maximum effect (ED50) was 10 microunits/ml. As regards the effect of insulin on glucose oxidation, for the control subjects ED50 was 30 microunits/ml, whereas in NIDDM patients, insulin exerted no stimulatory effect. The results obtained suggest that the effect of insulin on glucose utilization in normoinsulinemic NIDDM may be diminished in spite of normal insulin binding to receptors. The resistance may be due solely to postreceptor defects, and does not involve antilipolysis

  17. A Systematic Comparison of Purification and Normalization Protocols for Quantitative MicroRNA Expressional Profiling in Insulin-Producing Cells

    DEFF Research Database (Denmark)

    Vestergaard, Anna Lindeløv; Blankestijn, Maaike; Stahl, Jonathan Lucien

    2016-01-01

    As microRNAs (miRs) are gaining increasing attention as key regulators of cellular processes, expressional quantification is widely applied. However, in the processing of relatively quantified data, the importance of testing the stability of several reference mRNAs and/or miRs and choosing among...... these for normalization is often overlooked, potentially leading to biased results. Here, we have optimized the purification of miR-enriched total RNA from pancreatic insulin-producing INS-1 cells. Additionally, we optimized and analyzed miR expression by a qPCR-based microarray and by specific qPCR and tested...

  18. Validation of different measures of insulin sensitivity of glucose metabolism in dairy cows using the hyperinsulinemic euglycemic clamp test as the gold standard.

    Science.gov (United States)

    De Koster, J; Hostens, M; Hermans, K; Van den Broeck, W; Opsomer, G

    2016-10-01

    The aim of the present research was to compare different measures of insulin sensitivity in dairy cows at the end of the dry period. To do so, 10 clinically healthy dairy cows with a varying body condition score were selected. By performing hyperinsulinemic euglycemic clamp (HEC) tests, we previously demonstrated a negative association between the insulin sensitivity and insulin responsiveness of glucose metabolism and the body condition score of these animals. In the same animals, other measures of insulin sensitivity were determined and the correlation with the HEC test, which is considered as the gold standard, was calculated. Measures derived from the intravenous glucose tolerance test (IVGTT) are based on the disappearance of glucose after an intravenous glucose bolus. Glucose concentrations during the IVGTT were used to calculate the area under the curve of glucose and the clearance rate of glucose. In addition, glucose and insulin data from the IVGTT were fitted in the minimal model to derive the insulin sensitivity parameter, Si. Based on blood samples taken before the start of the IVGTT, basal concentrations of glucose, insulin, NEFA, and β-hydroxybutyrate were determined and used to calculate surrogate indices for insulin sensitivity, such as the homeostasis model of insulin resistance, the quantitative insulin sensitivity check index, the revised quantitative insulin sensitivity check index and the revised quantitative insulin sensitivity check index including β-hydroxybutyrate. Correlation analysis revealed no association between the results obtained by the HEC test and any of the surrogate indices for insulin sensitivity. For the measures derived from the IVGTT, the area under the curve for the first 60 min of the test and the Si derived from the minimal model demonstrated good correlation with the gold standard. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Early insulin sensitivity after restrictive bariatric surgery, inconsistency between HOMA-IR and steady-state plasma glucose levels.

    Science.gov (United States)

    van Dielen, Francois M H; Nijhuis, Jeroen; Rensen, Sander S M; Schaper, Nicolaas C; Wiebolt, Janneke; Koks, Afra; Prakken, Fred J; Buurman, Wim A; Greve, Jan Willem M

    2010-01-01

    The low-grade inflammatory condition present in morbid obesity is thought to play a causative role in the pathophysiology of insulin resistance (IR). Bariatric surgery fails to improve this inflammatory condition during the first months after surgery. Considering the close relation between inflammation and IR, we conducted a study in which insulin sensitivity was measured during the first months after bariatric surgery. Different methods to measure IR shortly after bariatric surgery have given inconsistent data. For example, the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) levels have been reported to decrease rapidly after bariatric surgery, although clamp techniques have shown sustained insulin resistance. In the present study, we evaluated the use of steady-state plasma glucose (SSPG) levels to assess insulin sensitivity 2 months after bariatric surgery. Insulin sensitivity was measured using HOMA-IR and SSPG levels in 11 subjects before surgery and at 26% excess weight loss (approximately 2 months after restrictive bariatric surgery). The SSPG levels after 26% excess weight loss did not differ from the SSPG levels before surgery (14.3 +/- 5.4 versus 14.4 +/- 2.7 mmol/L). In contrast, the HOMA-IR values had decreased significantly (3.59 +/- 1.99 versus 2.09 +/- 1.02). During the first months after restrictive bariatric surgery, we observed a discrepancy between the HOMA-IR and SSPG levels. In contrast to the HOMA-IR values, the SSPG levels had not improved, which could be explained by the ongoing inflammatory state after bariatric surgery. These results suggest that during the first months after restrictive bariatric surgery, HOMA-IR might not be an adequate marker of insulin sensitivity. Copyright 2010 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

  20. Gender dimorphism in aspartame-induced impairment of spatial cognition and insulin sensitivity.

    Science.gov (United States)

    Collison, Kate S; Makhoul, Nadine J; Zaidi, Marya Z; Saleh, Soad M; Andres, Bernard; Inglis, Angela; Al-Rabiah, Rana; Al-Mohanna, Futwan A

    2012-01-01

    Previous studies have linked aspartame consumption to impaired retention of learned behavior in rodents. Prenatal exposure to aspartame has also been shown to impair odor-associative learning in guinea pigs; and recently, aspartame-fed hyperlipidemic zebrafish exhibited weight gain, hyperglycemia and acute swimming defects. We therefore investigated the effects of chronic lifetime exposure to aspartame, commencing in utero, on changes in blood glucose parameters, spatial learning and memory in C57BL/6J mice. Morris Water Maze (MWM) testing was used to assess learning and memory, and a random-fed insulin tolerance test was performed to assess glucose homeostasis. Pearson correlation analysis was used to investigate the associations between body characteristics and MWM performance outcome variables. At 17 weeks of age, male aspartame-fed mice exhibited weight gain, elevated fasting glucose levels and decreased insulin sensitivity compared to controls (Pdifferent from controls. Reference memory during a probe test was affected in both genders, with the aspartame-fed mice spending significantly less time searching for the former location of the platform. Interestingly, the extent of visceral fat deposition correlated positively with non-spatial search strategies such as floating and thigmotaxis, and negatively with time spent in the target quadrant and swimming across the location of the escape platform. These data suggest that lifetime exposure to aspartame, commencing in utero, may affect spatial cognition and glucose homeostasis in C57BL/6J mice, particularly in males.

  1. Influence of an oral contraceptive containing drospirenone on insulin sensitivity of healthy women.

    Science.gov (United States)

    Cagnacci, Angelo; Piacenti, Ilaria; Zanin, Renata; Xholli, Anjeza; Tirelli, Alessandra

    2014-07-01

    Oral contraceptives (OCs) containing androgenic second and third generation progestins decrease insulin sensitivity (SI). In this study we investigated whether an oral contraceptive containing the anti-androgenic progestin drospirenone (DRSP) still alters SI. Lipid modifications were investigated as well. Eleven young healthy women were allocated to receive for 6 months ethinyl-estradiol (EE) 30μg plus DRSP (3mg). SI and glucose utilization independent of insulin (Sg) was investigated by the minimal model method. Lipid modifications were also analyzed. SI did not vary during EE/DRSP (from 3.72±2.62 to 3.29±2.93; p=0.73). Similarly, values of Sg did not vary (from 0.03±0.02 to 0.032±0.014; p=0.87). An increase was observed in HDL cholesterol (9.4±9.8mg/dl; p=0.05) and triglycerides (46.9±75.1mg/dl; p=0.046), with no modification in LDL cholesterol (-4.64±1.704mg/dl; p=0.6). EE/DRSP does not deteriorate SI. These results are reassuring for the long-term use of this association. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. Prevention of diabetes and cardiovascular disease in women with PCOS: treatment with insulin sensitizers.

    Science.gov (United States)

    Sharma, Susmeeta T; Nestler, John E

    2006-06-01

    Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility in United States, affecting 6-10% of females in the reproductive age group. Recent studies have shown that insulin resistance plays an important role in the pathogenesis of PCOS. Traditionally, management of PCOS consisted mainly of ovulation induction, treatment of acne and hirsutism, and prevention of endometrial cancer. However, with mounting evidence showing that PCOS is associated with dysmetabolic syndrome and an increased risk for developing diabetes and heart disease, this can no longer be our sole focus. Current data support a strong recommendation that women with PCOS should undergo comprehensive evaluation for diabetes and recognized cardiovascular risk factors and receive appropriate treatment as needed. Lifestyle modifications remain the first-line therapy for all obese women with PCOS. However, many obese women with PCOS find weight loss difficult to achieve and maintain, and this is not an option for lean women with PCOS. For these reasons, insulin-sensitizing drugs are proving to be a promising and unique therapeutic option for chronic treatment of PCOS.

  3. Characterization of lipid metabolism in insulin-sensitive adipocytes differentiated from immortalized human mesenchymal stem cells

    International Nuclear Information System (INIS)

    Prawitt, Janne; Niemeier, Andreas; Kassem, Moustapha; Beisiegel, Ulrike; Heeren, Joerg

    2008-01-01

    There is a great demand for cell models to study human adipocyte function. Here we describe the adipogenic differentiation of a telomerase-immortalized human mesenchymal stem cell line (hMSC-Tert) that maintains numerous features of terminally differentiated adipocytes even after prolonged withdrawal of the peroxisome proliferator activated receptor γ (PPARγ) agonist rosiglitazone. Differentiated hMSC-Tert developed the characteristic monolocular phenotype of mature adipocytes. The expression of adipocyte specific markers was highly increased during differentiation. Most importantly, the presence of the PPARγ agonist rosiglitazone was not required for the stable expression of lipoprotein lipase, adipocyte fatty acid binding protein and perilipin on mRNA and protein levels. Adiponectin expression was post-transcriptionally down-regulated in the absence of rosiglitazone. Insulin sensitivity as measured by insulin-induced phosphorylation of Akt and S6 ribosomal protein was also independent of rosiglitazone. In addition to commonly used adipogenic markers, we investigated further PPARγ-stimulated proteins with a role in lipid metabolism. We observed an increase of lipoprotein receptor (VLDLR, LRP1) and apolipoprotein E expression during differentiation. Despite this increased expression, the receptor-mediated endocytosis of lipoproteins was decreased in differentiated adipocytes, suggesting that these proteins may have an additional function in adipose tissue beyond lipoprotein uptake

  4. Inactivation of the Class II PI3K-C2β Potentiates Insulin Signaling and Sensitivity

    Directory of Open Access Journals (Sweden)

    Samira Alliouachene

    2015-12-01

    Full Text Available In contrast to the class I phosphoinositide 3-kinases (PI3Ks, the organismal roles of the kinase activity of the class II PI3Ks are less clear. Here, we report that class II PI3K-C2β kinase-dead mice are viable and healthy but display an unanticipated enhanced insulin sensitivity and glucose tolerance, as well as protection against high-fat-diet-induced liver steatosis. Despite having a broad tissue distribution, systemic PI3K-C2β inhibition selectively enhances insulin signaling only in metabolic tissues. In a primary hepatocyte model, basal PI3P lipid levels are reduced by 60% upon PI3K-C2β inhibition. This results in an expansion of the very early APPL1-positive endosomal compartment and altered insulin receptor trafficking, correlating with an amplification of insulin-induced, class I PI3K-dependent Akt signaling, without impacting MAPK activity. These data reveal PI3K-C2β as a critical regulator of endosomal trafficking, specifically in insulin signaling, and identify PI3K-C2β as a potential drug target for insulin sensitization.

  5. Effects of inhibition of interleukin-6 signalling on insulin sensitivity and lipoprotein (a levels in human subjects with rheumatoid diseases.

    Directory of Open Access Journals (Sweden)

    Olaf Schultz

    2010-12-01

    Full Text Available Interleukin-6 (IL-6 is a pro-inflammatory cytokine that has been found to be increased in type 2 diabetic subjects. However, it still remains unclear if these elevated IL-6 levels are co-incidental or if this cytokine is causally related to the development of insulin resistance and type 2 diabetes in humans. Therefore, in the present study we examined insulin sensitivity, serum adipokine levels and lipid parameters in human subjects before and after treatment with the IL-6 receptor antibody Tocilizumab.11 non-diabetic patients with rheumatoid disease were included in the study. HOMA-IR was calculated and serum levels for leptin, adiponectin, triglycerides, LDL-cholesterol, HDL-cholesterol and lipoprotein (a (Lp (a were measured before as well as one and three months after Tocilizumab treatment. The HOMA index for insulin resistance decreased significantly. While leptin concentrations were not altered by inhibition of IL-6 signalling, adiponectin concentrations significantly increased. Thus the leptin to adiponectin ratio, a novel marker for insulin resistance, exhibited a significant decrease. Serum triglycerides, LDL-cholesterol and HDL-cholesterol tended to be increased whereas Lp (a levels significantly decreased.Inhibition of IL-6 signalling improves insulin sensitivity in humans with immunological disease suggesting that elevated IL-6 levels in type 2 diabetic subjects might be causally involved in the pathogenesis of insulin resistance. Furthermore, our data indicate that inhibition of IL-6 signalling decreases Lp (a serum levels, which might reduce the cardiovascular risk of human subjects.

  6. Favorable effects of insulin sensitizers pertinent to peripheral arterial disease in type 2 diabetes: results from the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial.

    Science.gov (United States)

    Althouse, Andrew D; Abbott, J Dawn; Sutton-Tyrrell, Kim; Forker, Alan D; Lombardero, Manuel S; Buitrón, L Virginia; Pena-Sing, Ivan; Tardif, Jean-Claude; Brooks, Maria Mori

    2013-10-01

    The aim of this manuscript was to report the risk of incident peripheral arterial disease (PAD) in a large randomized clinical trial that enrolled participants with stable coronary artery disease and type 2 diabetes and compare the risk between assigned treatment arms. The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial randomly assigned participants to insulin sensitization (IS) therapy versus insulin-providing (IP) therapy for glycemic control. Results showed similar 5-year mortality in the two glycemic treatment arms. In secondary analyses reported here, we examine the effects of treatment assignment on the incidence of PAD. A total of 1,479 BARI 2D participants with normal ankle-brachial index (ABI) (0.91-1.30) were eligible for analysis. The following PAD-related outcomes are evaluated in this article: new low ABI≤0.9, a lower-extremity revascularization, lower-extremity amputation, and a composite of the three outcomes. During an average 4.6 years of follow-up, 303 participants experienced one or more of the outcomes listed above. Incidence of the composite outcome was significantly lower among participants assigned to IS therapy than those assigned to IP therapy (16.9 vs. 24.1%; Pdiabetes who are free from PAD, a glycemic control strategy of insulin sensitization may be the preferred therapeutic strategy to reduce the incidence of PAD and subsequent outcomes.

  7. Bimodal effect on pancreatic β-cells of secretory products from normal or insulin-resistant human skeletal muscle

    DEFF Research Database (Denmark)

    Bouzakri, Karim; Plomgaard, Peter; Berney, Thierry

    2011-01-01

    Type 2 diabetes is characterized by insulin resistance with a relative deficiency in insulin secretion. This study explored the potential communication between insulin-resistant human skeletal muscle and primary (human and rat) β-cells.......Type 2 diabetes is characterized by insulin resistance with a relative deficiency in insulin secretion. This study explored the potential communication between insulin-resistant human skeletal muscle and primary (human and rat) β-cells....

  8. The effect of menopause on carotid artery remodeling, insulin sensitivity, and plasma adiponectin in healthy women

    DEFF Research Database (Denmark)

    Muscelli, Elza; Kozàkovà, Michaela; Flyvbjerg, Allan

    2009-01-01

    BACKGROUND: The mechanisms by which menopause may influence the systemic subclinical atherosclerosis are unexplained. The aim of this cross-sectional study was to evaluate the associations between early menopause, established cardiovascular (c-v) risk factors, metabolic parameters (insulin...... secretion and sensitivity, plasma adiponectin), and carotid intima-media thickness (IMT) in healthy women. METHODS: In 74 menopausal women (mean age = 51 +/- 3 years, mean duration of menopause = 2.9 +/- 1.2 years) and in 74 nonmenopausal women comparable for age and body mass index (BMI), common carotid...... by mathematical modeling. RESULTS: CCA diameter (5.55 +/- 0.46 vs. 5.21+/- 0.51 mm, P menopausal women, whereas CCA IMT/diameter ratio and IMT in other carotid...

  9. High-intensity interval training improves insulin sensitivity in older individuals

    DEFF Research Database (Denmark)

    Søgaard, D; Lund, M T; Scheuer, C M

    2017-01-01

    AIM: Metabolic health may deteriorate with age as a result of altered body composition and decreased physical activity. Endurance exercise is known to counter these changes delaying or even preventing onset of metabolic diseases. High-intensity interval training (HIIT) is a time efficient...... alternative to regular endurance exercise, and the aim of this study was to investigate the metabolic benefit of HIIT in older subjects. METHODS: Twenty-two sedentary male (n = 11) and female (n = 11) subjects aged 63 ± 1 years performed HIIT training three times/week for 6 weeks on a bicycle ergometer. Each...... HIIT session consisted of five 1-minute intervals interspersed with 1½-minute rest. Prior to the first and after the last HIIT session whole-body insulin sensitivity, measured by a hyperinsulinaemic-euglycaemic clamp, plasma lipid levels, HbA1c, glycaemic parameters, body composition and maximal oxygen...

  10. Variable reliability of surrogate measures of insulin sensitivity after Roux-en-Y gastric bypass

    DEFF Research Database (Denmark)

    Bojsen-Møller, Kirstine N; Dirksen, Carsten; Svane, Maria Saur

    2017-01-01

    ) are frequently used, but have not been validated after RYGB. Our aim was to evaluate whether surrogate indices reliably estimate changes in insulin sensitivity after RYGB. Four fasting (inverse-HOMA-IR, HOMA2-%S, QUICKI, revised-QUICKI) and three OGTT-derived surrogates (Matsuda, Gutt, OGIS) were compared...... postoperatively. Post-RYGB changes in inverse-HOMA-IR and HOMA2-%S did not correlate with changes in Rd at any visit, but were comparable to changes in HISI at 1 week. Changes in QUICKI and revised-QUICKI correlated with Rd/I after surgery. Changes in Matsuda and Gutt did not correlate with changes in Rd/I and Rd...

  11. High-intensity interval training improves insulin sensitivity in older individuals.

    Science.gov (United States)

    Søgaard, D; Lund, M T; Scheuer, C M; Dehlbaek, M S; Dideriksen, S G; Abildskov, C V; Christensen, K K; Dohlmann, T L; Larsen, S; Vigelsø, A H; Dela, F; Helge, J W

    2018-04-01

    Metabolic health may deteriorate with age as a result of altered body composition and decreased physical activity. Endurance exercise is known to counter these changes delaying or even preventing onset of metabolic diseases. High-intensity interval training (HIIT) is a time efficient alternative to regular endurance exercise, and the aim of this study was to investigate the metabolic benefit of HIIT in older subjects. Twenty-two sedentary male (n = 11) and female (n = 11) subjects aged 63 ± 1 years performed HIIT training three times/week for 6 weeks on a bicycle ergometer. Each HIIT session consisted of five 1-minute intervals interspersed with 1½-minute rest. Prior to the first and after the last HIIT session whole-body insulin sensitivity, measured by a hyperinsulinaemic-euglycaemic clamp, plasma lipid levels, HbA1c, glycaemic parameters, body composition and maximal oxygen uptake were assessed. Muscle biopsies were obtained wherefrom content of glycogen and proteins involved in muscle glucose handling were determined. Insulin sensitivity (P = .011) and maximal oxygen uptake increased (P body fat (P < .05) decreased after 6 weeks of HIIT. HbA1c decreased only in males (P = .001). Muscle glycogen content increased in both genders (P = .001) and in line GLUT4 (P < .05), glycogen synthase (P = .001) and hexokinase II (P < .05) content all increased. Six weeks of HIIT significantly improves metabolic health in older males and females by reducing age-related risk factors for cardiometabolic disease. © 2017 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  12. Resistin, an adipokine, may affect the improvement of insulin sensitivity in the metabolic syndrome patient treated with metformin.

    Science.gov (United States)

    Yuan, Hong; Weng, Chunyan; Yang, Youbo; Huang, Lihua; Xing, Xiaowei

    2013-12-01

    The metabolic syndrome (MS) is a cluster of metabolic disorders arising from insulin resistance, characterized by the presence of central obesity, impaired fasting glucose level, dyslipidemia and hypertension. As the first-line medication, metformin is commonly used for MS to reduce insulin resistance. Comparing with rosiglitazone, metformin does not increase cardiovascular mortality risk in patients with MS. However, metformin is not good enough in improving insulin sensitivity. Its molecular mechanism is still not clear. Recent studies have demonstrated that resistin, an adipokine, could induce IR by both AMPK-dependent and AMPK-independent pathways. Though there were conflicting findings of resistin in metabolic syndrome or type 2 diabetes mellitus in different studies, resistin was significant decreased in the rosiglitazone treated patients than in the metformin-treated patients in most of studies. Here, we hypothesized that resistin, an adipokine, may affect the improvement of insulin sensitivity in the metabolic syndrome patient treated with metformin. This hypothesis could explain why rosiglitazone is superior to metformin in enhancement of insulin sensitivity. Copyright © 2013. Published by Elsevier Ltd.

  13. Resistance training associated with the administration of anabolic-androgenic steroids improves insulin sensitivity in ovariectomized rats

    Directory of Open Access Journals (Sweden)

    Urtado CB

    2011-11-01

    Full Text Available Christiano Bertoldo Urtado1,2, Guilherme Borges Pereira3, Marilia Bertoldo Urtado4, Érica Blascovi de Carvalho2, Gerson dos Santos Leite1, Felipe Fedrizzi Donatto1, Claudio de Oliveira Assumpção1, Richard Diego Leite3, Carlos Alberto da Silva1, Marcelo Magalhães de Sales5, Ramires Alsamir Tibana5, Silvia Cristina Crepaldi Alves1, Jonato Prestes51Health Sciences, Methodist University of Piracicaba, Piracicaba, SP, 2Center for Investigation in Pediatrics, Faculty of Medical Sciences, State University of Campinas, Campinas, SP, 3Department of Physiological Sciences, Federal University of São Carlos, São Carlos, SP, 4Laboratory of Orofacial Pain, Division of Oral Physiology, Piracicaba Dental School, State University of Campinas, Campinas, SP, 5Graduation Program in Physical Education, Catholic University of Brasilia, Brasilia, DF, BrazilAbstract: The aim of the present study was to investigate the effects of anabolic-androgenic steroids and resistance training (RT on insulin sensitivity in ovariectomized rats. Adult female Wistar rats were divided into ten experimental groups (n = 5 animals per group: (1 sedentary (Sed-Intact; (2 sedentary ovariectomized (Sed-Ovx; (3 sedentary nandrolone (Sed-Intact-ND; (4 sedentary ovariectomized plus nandrolone (Sed-Ovx-ND; (5 trained (TR-Intact; (6 trained nandrolone (TR-Intact-ND; (7 trained ovariectomized (TR-Ovx; (8 trained ovariectomized plus nandrolone; (9 trained sham; and (10 trained ovariectomized plus sham. Four sessions of RT were used, during which the animals climbed a 1.1 m vertical ladder with weights attached to their tails. The sessions were performed once every 3 days, with between four and nine climbs and with eight to twelve dynamic movements per climb. To test the sensitivity of insulin in the pancreas, glucose and insulin tolerance tests were performed. For insulin sensitivity, there was a statistically significant interaction for the TR-Ovx group, which presented higher sensitivity

  14. Insulin sensitivity and serum TCDD in Air Force veterans occupationally exposed to herbicides during the Vietnam war

    Energy Technology Data Exchange (ETDEWEB)

    Kern, P.; Said, S. [Univ. of Arkansas for Medical Sciences, Little Rock (United States); Jackson, W. Jr; Michalek, J. [Air Force Research Lab., San Antonio (United States)

    2004-09-15

    Between 1961 and 1971, the United States Air Force sprayed 12 million gallons of the defoliant ''Agent Orange'' on 3.6 million acres of Vietnam. Agent Orange was a 1:1 mixture of 2,4-dichlorophenoxyacetic acid and 2,4,5- trichlorophenoxyacetic acid, and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was a contaminant of the defoliant, from less than 0.05 to almost 50 parts per million. Numerous Vietnam veterans were exposed to TCDD when Agent Orange and other TCDD-contaminated herbicides were sprayed in large quantities in Vietnam and TCDD has been found at many toxic waste disposal sites in the United States. Some of the highest exposure to TCDD occurred in members of Operation Ranch Hand, the Air Force unit responsible for spraying herbicides from fix-wing aircraft in Vietnam. The Air Force Health Study (AFHS), an epidemiological study of Ranch Hand veterans, was launched in 1980 to address veteran concerns regarding Agent Orange exposure. A link between TCDD and diabetes has been demonstrated in several studies. Among the Ranch Hand veterans with high blood levels of TCDD, there was a significant increase in the prevalence of diabetes and a decrease in the age at which diabetes was diagnosed. In a study from Seveso, Italy, where 45,000 people had varying levels of exposure to TCDD, there were significant increases in mortality from coronary artery disease and diabetes. Several studies have demonstrated a relationship between blood TCDD levels and hyperinsulinemia. The data suggest that non-diabetic individuals exposed to TCDD have an increased risk of insulin-resistance, being able to maintain normal blood glucose levels but only because of very high concentrations of insulin. As a result of available evidence, public policy decisions have been made, such as a decision by the Veterans Administration that diabetes is a service-connected condition in Agent Orange-exposed Vietnam veterans. Here we study the relation between TCDD insulin sensitivity

  15. Acromegaly with Normal Insulin-Like Growth Factor-1 Levels and Congestive Heart Failure as the First Clinical Manifestation

    Directory of Open Access Journals (Sweden)

    Hyae Min Lee

    2015-09-01

    Full Text Available The leading cause of morbidity and mortality in patients with acromegaly is cardiovascular complications. Myocardial exposure to excessive growth hormone can cause ventricular hypertrophy, hypertension, arrhythmia, and diastolic dysfunction. However, congestive heart failure as a result of systolic dysfunction is observed only rarely in patients with acromegaly. Most cases of acromegaly exhibit high levels of serum insulin-like growth factor-1 (IGF-1. Acromegaly with normal IGF-1 levels is rare and difficult to diagnose. Here, we report a rare case of an acromegalic patient whose first clinical manifestation was severe congestive heart failure, despite normal IGF-1 levels. We diagnosed acromegaly using a glucose-loading growth hormone suppression test. Cardiac function and myocardial hypertrophy improved 6 months after transsphenoidal resection of a pituitary adenoma.

  16. Effects of kiwi consumption on plasma lipids, fibrinogen and insulin resistance in the context of a normal diet.

    Science.gov (United States)

    Recio-Rodriguez, Jose I; Gomez-Marcos, Manuel A; Patino-Alonso, Maria C; Puigdomenech, Elisa; Notario-Pacheco, Blanca; Mendizabal-Gallastegui, Nere; de la Fuente, Aventina de la Cal; Otegui-Ilarduya, Luis; Maderuelo-Fernandez, Jose A; de Cabo Laso, Angela; Agudo-Conde, Cristina; Garcia-Ortiz, Luis

    2015-09-15

    Among fruits, kiwi is one of the richest in vitamins and polyphenols and has strong anti-oxidant effects. We aimed to analyze the relationship between the consumption of kiwi and plasma lipid values, fibrinogen, and insulin resistance in adults within the context of a normal diet and physical-activity. Cross-sectional study. Participants (N = 1469), who were free of cardiovascular diseases, completed a visit, which included the collection of information concerning the participant's usual diet and kiwi consumption using a previously validated, semi-quantitative, 137-item food-frequency-questionnaire. Fasting laboratory determinations included plasma lipids, fibrinogen and insulin resistance. Regular physical-activity was determined using accelerometry. Consumers of at least 1 kiwi/week presented higher plasma values of HDL-cholesterol (mean difference 4.50 [95% CI: 2.63 to 6.36]) and lower triglyceride values (mean difference -20.03 [95% CI: -6.77 to -33.29]), fibrinogen values (mean difference -13.22 [95% CI: -2.18 to -24.26]) and HOMAir values (mean difference -0.30 [95% CI: -0.09 to -0.50]) (p Consumption of at least one kiwi/week is associated with lower plasma concentrations of fibrinogen and improved plasma lipid profile in the context of a normal diet and regular exercise.

  17. Distal gastrectomy in pancreaticoduodenectomy is associated with accelerated gastric emptying, enhanced postprandial release of GLP-1, and improved insulin sensitivity

    DEFF Research Database (Denmark)

    Harmuth, Stefan; Wewalka, Marlene; Holst, Jens Juul

    2014-01-01

    resistance (HOMA-IR) and oral glucose insulin sensitivity were calculated from glucose and insulin concentrations. RESULTS: Patients with Whipple procedure as compared to PPPD had accelerated gastric emptying (p = 0.01) which correlated with early (0-30 min) integrated GLP-1 (AUC30; r (2) = 0.61; p = 0.......02) and insulin sensitivity (r (2) = 0.41; p = 0.026) and inversely with HOMA-IR (r (2) = 0.17; p = 0.033). Two of 13 Whipple patients (15 %) as compared to seven of 13 after PPPD (54 %) had postload glucose concentrations (i.e. 120 min postmeal) ≥200 mg/dl (p 

  18. Modification and Validation of the Triglyceride-to-HDL Cholesterol Ratio as a Surrogate of Insulin Sensitivity in White Juveniles and Adults without Diabetes Mellitus

    DEFF Research Database (Denmark)

    Paulmichl, Katharina; Hatunic, Mensud; Højlund, Kurt

    2016-01-01

    BACKGROUND: The triglyceride-to-HDL cholesterol (TG/HDL-C) ratio was introduced as a tool to estimate insulin resistance, because circulating lipid measurements are available in routine settings. Insulin, C-peptide, and free fatty acids are components of other insulin-sensitivity indices...... but their measurement is expensive. Easier and more affordable tools are of interest for both pediatric and adult patients. METHODS: Study participants from the Relationship Between Insulin Sensitivity and Cardiovascular Disease [43.9 (8.3) years, n = 1260] as well as the Beta-Cell Function in Juvenile Diabetes...... and Obesity study cohorts [15 (1.9) years, n = 29] underwent oral-glucose-tolerance tests and euglycemic clamp tests for estimation of whole-body insulin sensitivity and calculation of insulin sensitivity indices. To refine the TG/HDL ratio, mathematical modeling was applied including body mass index (BMI...

  19. Insulin resistance in obesity can be reliably identified from fasting plasma insulin.

    Science.gov (United States)

    ter Horst, K W; Gilijamse, P W; Koopman, K E; de Weijer, B A; Brands, M; Kootte, R S; Romijn, J A; Ackermans, M T; Nieuwdorp, M; Soeters, M R; Serlie, M J

    2015-12-01

    Insulin resistance is the major contributor to cardiometabolic complications of obesity. We aimed to (1) establish cutoff points for insulin resistance from euglycemic hyperinsulinemic clamps (EHCs), (2) identify insulin-resistant obese subjects and (3) predict insulin resistance from routinely measured variables. We assembled data from non-obese (n=112) and obese (n=100) men who underwent two-step EHCs using [6,6-(2)H2]glucose as tracer (insulin infusion dose 20 and 60 mU m(-2) min(-1), respectively). Reference ranges for hepatic and peripheral insulin sensitivity were calculated from healthy non-obese men. Based on these reference values, obese men with preserved insulin sensitivity or insulin resistance were identified. Cutoff points for insulin-mediated suppression of endogenous glucose production (EGP) and insulin-stimulated glucose disappearance rate (Rd) were 46.5% and 37.3 μmol kg(-)(1) min(-)(1), respectively. Most obese men (78%) had EGP suppression within the reference range, whereas only 12% of obese men had Rd within the reference range. Obese men with Rd obese men in age, body mass index (BMI), body composition, fasting glucose or cholesterol, but did have higher fasting insulin (110±49 vs 63±29 pmol l(-1), Pobese men could be identified with good sensitivity (80%) and specificity (75%) from fasting insulin >74 pmol l(-1). Most obese men have hepatic insulin sensitivity within the range of non-obese controls, but below-normal peripheral insulin sensitivity, that is, insulin resistance. Fasting insulin (>74 pmol l(-1) with current insulin immunoassay) may be used for identification of insulin-resistant (or metabolically unhealthy) obese men in research and clinical settings.

  20. Intrauterine growth-restricted sheep fetuses exhibit smaller hindlimb muscle fibers and lower proportions of insulin-sensitive Type I fibers near term.

    Science.gov (United States)

    Yates, Dustin T; Cadaret, Caitlin N; Beede, Kristin A; Riley, Hannah E; Macko, Antoni R; Anderson, Miranda J; Camacho, Leticia E; Limesand, Sean W

    2016-06-01

    Intrauterine growth restriction (IUGR) reduces muscle mass and insulin sensitivity in offspring. Insulin sensitivity varies among muscle fiber types, with Type I fibers being most sensitive. Differences in fiber-type ratios are associated with insulin resistance in adults, and thus we hypothesized that near-term IUGR sheep fetuses exhibit reduced size and proportions of Type I fibers. Placental insufficiency-induced IUGR fetuses were ∼54% smaller (P fetal muscles develop smaller fibers and have proportionally fewer Type I fibers, which is indicative of developmental adaptations that may help explain the link between IUGR and adulthood insulin resistance. Copyright © 2016 the American Physiological Society.

  1. A common polymorphism near the interleukin-6 gene modifies the association between dietary fat intake and insulin sensitivity

    Directory of Open Access Journals (Sweden)

    Cuda C

    2012-01-01

    Full Text Available Cristina Cuda1, Bibiana Garcia-Bailo1,2, Mohamed Karmali1,2, Ahmed El-Sohemy1, Alaa Badawi21Department of Nutritional Sciences, University of Toronto, 2Office of Biotechnology, Genomics and Population Health, Public Health Agency of Canada, Toronto, Ontario, CanadaBackground: Increasing evidence suggests a role for inflammation in the development of type 2 diabetes. Elevated levels of inflammatory cytokines, including interleukin-6, have been associated with insulin resistance, and dietary lipids can increase cytokine production. The objective of this study was to determine whether a single nucleotide polymorphism near the IL6 gene (rs7801406 modifies the relationship between dietary fat and markers of insulin sensitivity.Methods: Subjects were healthy men and women aged 20–29 years from the Toronto Nutrigenomics and Health Study. Dietary intake was estimated using a one-month semiquantitative food frequency questionnaire. Fasting blood samples were taken for genotyping and biomarker measurement.Results: The single nucleotide polymorphism was not associated with any of the measures of insulin sensitivity. However, it modified the relationship between total dietary fat and the homeostasis model assessment of insulin resistance (P = 0.053 for interaction. Total fat intake was positively related to HOMA-IR in individuals homozygous for the G allele (ß = 0.005 ± 0.002, P = 0.03, but not among heterozygotes. There was an inverse relationship between total fat intake and HOMA-IR in individuals who were homozygous for the A allele (β= –0.012 ± 0.006, P = 0.047.Conclusion: These findings suggest that dietary fat influences insulin sensitivity differently depending on genotype.Keywords: interleukin-6, insulin sensitivity, nutrigenomics, dietary fat

  2. Regular meal frequency creates more appropriate insulin sensitivity and lipid profiles compared with irregular meal frequency in healthy lean women.

    Science.gov (United States)

    Farshchi, H R; Taylor, M A; Macdonald, I A

    2004-07-01

    To investigate the impact of irregular meal frequency on circulating lipids, insulin, glucose and uric acid concentrations which are known cardiovascular risk factors. A randomised crossover dietary intervention study. Nottingham, UK--Healthy free-living women. A total of nine lean healthy women aged 18-42 y recruited via advertisement. A randomised crossover trial with two phases of 14 days each. In Phase 1, subjects consumed their normal diet on either 6 occasions per day (regular) or by following a variable meal frequency (3-9 meals/day, irregular). In Phase 2, subjects followed the alternative meal pattern to that followed in Phase 1, after a 2-week (wash-out) period. Subjects were asked to come to the laboratory after an overnight fast at the start and end of each phase. Blood samples were taken for measurement of circulating glucose, lipids, insulin and uric acid concentrations before and for 3 h after consumption of a high-carbohydrate test meal. Fasting glucose and insulin values were not affected by meal frequency, but peak insulin and AUC of insulin responses to the test meal were higher after the irregular compared to the regular eating patterns (P meal frequency was associated with higher fasting total (P meal frequency appears to produce a degree of insulin resistance and higher fasting lipid profiles, which may indicate a deleterious effect on these cardiovascular risk factors. : The Ministry of Health and Medical Education, IR Iran.

  3. Branched-chain amino acid restriction in Zucker-fatty rats improves muscle insulin sensitivity by enhancing efficiency of fatty acid oxidation and acyl-glycine export

    Directory of Open Access Journals (Sweden)

    Phillip J. White

    2016-07-01

    Full Text Available Objective: A branched-chain amino acid (BCAA-related metabolic signature is strongly associated with insulin resistance and predictive of incident diabetes and intervention outcomes. To better understand the role that this metabolite cluster plays in obesity-related metabolic dysfunction, we studied the impact of BCAA restriction in a rodent model of obesity in which BCAA metabolism is perturbed in ways that mirror the human condition. Methods: Zucker-lean rats (ZLR and Zucker-fatty rats (ZFR were fed either a custom control, low fat (LF diet, or an isonitrogenous, isocaloric LF diet in which all three BCAA (Leu, Ile, Val were reduced by 45% (LF-RES. We performed comprehensive metabolic and physiologic profiling to characterize the effects of BCAA restriction on energy balance, insulin sensitivity, and glucose, lipid and amino acid metabolism. Results: LF-fed ZFR had higher levels of circulating BCAA and lower levels of glycine compared to LF-fed ZLR. Feeding ZFR with the LF-RES diet lowered circulating BCAA to levels found in LF-fed ZLR. Activity of the rate limiting enzyme in the BCAA catabolic pathway, branched chain keto acid dehydrogenase (BCKDH, was lower in liver but higher in skeletal muscle of ZFR compared to ZLR and was not responsive to diet in either tissue. BCAA restriction had very little impact on metabolites studied in liver of ZFR where BCAA content was low, and BCKDH activity was suppressed. However, in skeletal muscle of LF-fed ZFR compared to LF-fed ZLR, where BCAA content and BCKDH activity were increased, accumulation of fatty acyl CoAs was completely normalized by dietary BCAA restriction. BCAA restriction also normalized skeletal muscle glycine content and increased urinary acetyl glycine excretion in ZFR. These effects were accompanied by lower RER and improved skeletal muscle insulin sensitivity in LF-RES fed ZFR as measured by hyperinsulinemic-isoglycemic clamp. Conclusions: Our data are consistent with a model wherein

  4. Effects of the insulin sensitizer pioglitazone on menstrual irregularity, insulin resistance and hyperandrogenism in young women with polycystic ovary syndrome.

    Science.gov (United States)

    Stabile, Gaspare; Borrielli, Irene; Artenisio, Alfredo Carducci; Bruno, Lucia Maria; Benvenga, Salvatore; Giunta, Loretta; La Marca, Antonio; Volpe, Annibale; Pizzo, Alfonsa

    2014-06-01

    Polycystic ovary syndrome (PCOS) is the most common endocrine cause of menstrual irregularities, hirsutism and acne. Women with PCOS present elevated plasma insulin levels, both fasting and after a glucose load, as an indirect evidence of insulin resistance. PCOS women may also present hypertension, low levels of HDL cholesterol, hypertriglyceridemia, visceral obesity and a higher level of CRP and fibrinogen that can predict an atherosclerotic risk. This study was carried out on 15 young women with PCOS selected according to the 2003 diagnostic criteria of The Rotterdam Consensus Statement and 15 Control women. PCOS women were treated with pioglitazone 30 mg/day and at the beginning and after 6 months of treatment were evaluated: menstrual cycle trend, hirsutism and acne, total cholesterolemia and HDL, triglyceridemia, fibrinogenemia, C-reactive protein, oral glucose tolerance test, glycated hemoglobin, FSH, LH, 17OH-progesterone, 17β-estradiol, free and total testosterone, SHBG, DHEA-S, Δ4-androstenedione and adiponectin. Treatment with pioglitazone improves the irregularities of menses and hirsutism. Six months of treatment modify other parameters linked with a higher risk of type 2 diabetes mellitus and cardiovascular diseases: adiponectin increased with reduction of insulin resistance while fibrinogen and CRP levels decreased. Copyright © 2014 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  5. Normal axonal ion channel function in large peripheral nerve fibers following chronic ciguatera sensitization.

    Science.gov (United States)

    Vucic, Steve; Kiernan, Matthew C

    2008-03-01

    Although the acute clinical effects of ciguatera poisoning, due to ingestion of ciguatoxin, are mediated by activation of transient Na+ channels, the mechanisms underlying ciguatera sensitization remain undefined. Axonal excitability studies were performed by stimulating the median motor and sensory nerves in two patients with ciguatera sensitization. Excitability parameters were all within normal limits, thereby arguing against dysfunction of axonal membrane ion channels in large-diameter fibers in ciguatera sensitization.

  6. Egg white hydrolysate shows insulin mimetic and sensitizing effects in 3T3-F442A pre-adipocytes.

    Directory of Open Access Journals (Sweden)

    Forough Jahandideh

    Full Text Available Insulin resistance and inflammation in adipose tissue is a key mechanism underlying metabolic syndrome, a growing health problem characterized by diabetes, obesity and hypertension. Previous work from our research group has demonstrated the potential of egg white ovotransferrin derived bioactive peptides against hypertension, oxidative stress and inflammation in vitro and in vivo. Egg white hydrolysate (EWH has also shown anti-hypertensive effects in spontaneously hypertensive rats. Given the interplay among hypertension, inflammation, oxidative stress and metabolic syndrome, the objective of the study was to test the EWH on differentiation, insulin signaling and inflammatory responses in 3T3-F442A pre-adipocytes. Our study suggested that EWH could promote adipocyte differentiation as shown by increased lipid accumulation, increased release of adiponectin and upregulation of peroxisome proliferator associated receptor gamma (PPARγ and CCAAT/ enhancer binding protein alpha (C/EBP-α. In addition to enhanced insulin effects on the upregulation of protein kinase B/Akt phosphorylation, EWH treatment increased extracellular signal regulated kinase 1/2 (ERK1/2 phosphorylation to a level similar to that of insulin, indicating insulin sensitizing and mimetic properties of the EWH. EWH further attenuated cytokine induced inflammatory marker; cyclooxygenase -2 (COX-2 by 48.78%, possibly through the AP-1 pathway by down regulating c-Jun phosphorylation in adipocytes. Given the critical role of adipose in the pathogenesis of insulin resistance and metabolic syndrome, EWH may have potential applications in the prevention and management of metabolic syndrome and its complications.

  7. Elevated C-peptide and insulin predict increased risk of colorectal adenomas in normal mucosa

    International Nuclear Information System (INIS)

    Vidal, Adriana C; Keku, Temitope O; Lund, Pauline Kay; Hoyo, Cathrine; Galanko, Joseph; Burcal, Lauren; Holston, Rachel; Massa, Berri; Omofoye, Oluwaseun; Sandler, Robert S

    2012-01-01

    Lower concentrations of the insulin–like growth factor binding protein-1 (IGFBP-1) and elevated concentrations of insulin or C-peptide have been associated with an increase in colorectal cancer risk (CRC). However few studies have evaluated IGFBP-1 and C-peptide in relation to adenomatous polyps, the only known precursor for CRC. Between November 2001 and December 2002, we examined associations between circulating concentrations of insulin, C-peptide, IGFBP-1 and apoptosis among 190 individuals with one or more adenomatous polyps and 488 with no adenomatous polyps using logistic regression models. Individuals with the highest concentrations of C-peptide were more likely to have adenomas (OR = 2.2, 95% CI 1.4-4.0) than those with the lowest concentrations; associations that appeared to be stronger in men (OR = 4.4, 95% CI 1.7-10.9) than women. Individuals with high insulin concentrations also had a higher risk of adenomas (OR = 3.5, 95% CI 1.7-7.4), whereas higher levels of IGFBP-1 were associated with a reduced risk of adenomas in men only (OR = 0.3, 95% CI 0.1-0.7). Overweight and obese individuals with higher C-peptide levels (>1 st Q) were at increased risk for lower apoptosis index (OR = 2.5, 95% CI 0.9-7.1), an association that remained strong in overweight and obese men (OR = 6.3, 95% CI 1.0-36.7). Higher levels of IGFBP-1 in overweight and obese individuals were associated with a reduced risk of low apoptosis (OR = 0.3, 95% CI 0.1-1.0). Associations between these peptides and the apoptosis index in overweight and obese individuals, suggest that the mechanism by which C-peptide could induce adenomas may include its anti-apoptotic properties. This study suggests that hyperinsulinemia and IGF hormones predict adenoma risk, and that outcomes associated with colorectal carcinogenesis maybe modified by gender

  8. Life in the fat lane: seasonal regulation of insulin sensitivity, food intake, and adipose biology in brown bears.

    Science.gov (United States)

    Rigano, K S; Gehring, J L; Evans Hutzenbiler, B D; Chen, A V; Nelson, O L; Vella, C A; Robbins, C T; Jansen, H T

    2017-05-01

    Grizzly bears (Ursus arctos horribilis) have evolved remarkable metabolic adaptations including enormous fat accumulation during the active season followed by fasting during hibernation. However, these fluctuations in body mass do not cause the same harmful effects associated with obesity in humans. To better understand these seasonal transitions, we performed insulin and glucose tolerance tests in captive grizzly bears, characterized the annual profiles of circulating adipokines, and tested the anorectic effects of centrally administered leptin at different times of the year. We also used bear gluteal adipocyte cultures to test insulin and beta-adrenergic sensitivity in vitro. Bears were insulin resistant during hibernation but were sensitive during the spring and fall active periods. Hibernating bears remained euglycemic, possibly due to hyperinsulinemia and hyperglucagonemia. Adipokine concentrations were relatively low throughout the active season but peaked in mid-October prior to hibernation when fat content was greatest. Serum glycerol was highest during hibernation, indicating ongoing lipolysis. Centrally administered leptin reduced food intake in October, but not in August, revealing seasonal variation in the brain's sensitivity to its anorectic effects. This was supported by strong phosphorylated signal transducer and activator of transcription 3 labeling within the hypothalamus of hibernating bears; labeling virtually disappeared in active bears. Adipocytes collected during hibernation were insulin resistant when cultured with hibernation serum but became sensitive when cultured with active season serum. Heat treatment of active serum blocked much of this action. Clarifying the cellular mechanisms responsible for the physiology of hibernating bears may inform new treatments for metabolic disorders.

  9. Lactose in milk replacer can partly be replaced by glucose, fructose, or glycerol without affecting insulin sensitivity in veal calves

    NARCIS (Netherlands)

    Pantophlet, A. J.; Gilbert, M. S.; van den Borne, J. J. G. C.; Gerrits, W. J. J.; Roelofsen, H.; Priebe, M. G.; Vonk, R. J.

    Calf milk replacer (MR) contains 40 to 50% lactose. Lactose strongly fluctuates in price and alternatives are desired. Also, problems with glucose homeostasis and insulin sensitivity (i.e., high incidence of hyperglycemia and hyperinsulinemia) have been described for heavy veal calves (body weight

  10. GQ-16, a Novel Peroxisome Proliferator-activated Receptor gamma (PPAR gamma) Ligand, Promotes Insulin Sensitization without Weight Gain

    NARCIS (Netherlands)

    Amato, Angelica A.; Rajagopalan, Senapathy; Lin, Jean Z.; Carvalho, Bruno M.; Figueira, Ana C. M.; Lu, Jenny; Ayers, Stephen D.; Mottin, Melina; Silveira, Rodrigo L.; Telles de Souza, Paulo; Mourao, Rosa H. V.; Saad, Mario J. A.; Togashi, Marie; Simeoni, Luiz A.; Abdalla, Dulcineia S. P.; Skaf, Munir S.; Polikparpov, Igor; Lima, Maria C. A.; Galdino, Suely L.; Brennan, Richard G.; Baxter, John D.; Pitta, Ivan R.; Webb, Paul; Phillips, Kevin J.; Neves, Francisco A. R.

    2012-01-01

    The recent discovery that peroxisome proliferator-activated receptor gamma (PPAR gamma) targeted anti-diabetic drugs function by inhibiting Cdk5-mediated phosphorylation of the receptor has provided a new viewpoint to evaluate and perhaps develop improved insulin-sensitizing agents. Herein we report

  11. Training Does Not Alter Muscle Ceramide and Diacylglycerol in Offsprings of Type 2 Diabetic Patients Despite Improved Insulin Sensitivity

    DEFF Research Database (Denmark)

    Sogaard, Ditte; Ostergard, Torben; Blachnio-Zabielska, Agnieszka U.

    2016-01-01

    not change in response to the endurance training except for an overall reduction in C22:0-Cer (). Finally, the intervention induced an increase in AKT protein expression (Off: %; Con: %, ). This study showed no relation between insulin sensitivity and ceramide or DAG content suggesting that ceramide and DAG...

  12. Improvement of Insulin Sensitivity after Lean Donor Feces in Metabolic Syndrome Is Driven by Baseline Intestinal Microbiota Composition

    DEFF Research Database (Denmark)

    Kootte, Ruud S.; Levin, Evgeni; Salojärvi, Jarkko

    2017-01-01

    be predicted based on baseline fecal microbiota composition. Kootte et al. show that fecal microbiota transplantation from lean donors to obese patients with metabolic syndrome improves insulin sensitivity, a transient effect associated with changes in microbiota composition and fasting plasma metabolites...

  13. Supplementation of Diet With Galacto-oligosaccharides Increases Bifidobacteria, but Not Insulin Sensitivity, in Obese Prediabetic Individuals

    DEFF Research Database (Denmark)

    Canfora, Emanuel E; van der Beek, Christina M; Hermes, Gerben D A

    2017-01-01

    on peripheral insulin sensitivity, measured by the hyperinsulinemic-euglycemic clamp method. RESULTS: Supplementation of diets with GOS, but not placebo, increased the abundance of Bifidobacterium species in feces by 5-fold (P = .009; q = 0.144). Microbial richness or diversity in fecal samples were...

  14. The effect of dietary phytosphingosine on cholesterol levels and insulin sensitivity in subjects with the metabolic syndrome

    NARCIS (Netherlands)

    Snel, M.; Sleddering, M.A.; Pijl, H.; Nieuwenhuizen, W.F.; Frölich, M.; Havekes, L.M.; Romijn, J.A.; Jazet, I.M.

    2010-01-01

    Background: Sphingolipids, like phytosphingosine (PS) are part of cellular membranes of yeasts, vegetables and fruits. Addition of PS to the diet decreases serum cholesterol and free fatty acid (FFA) levels in rodents and improves insulin sensitivity.Objective:To study the effect of dietary

  15. The effect of dietary phytosphingosine on cholesterol levels and insulin sensitivity in subjects with the metabolic syndrome

    NARCIS (Netherlands)

    Snel, M.; Sleddering, M. A.; Pijl, H.; Nieuwenhuizen, W. F.; Frölich, M.; Havekes, L. M.; Romijn, J. A.; Jazet, I. M.

    2010-01-01

    Sphingolipids, like phytosphingosine (PS) are part of cellular membranes of yeasts, vegetables and fruits. Addition of PS to the diet decreases serum cholesterol and free fatty acid (FFA) levels in rodents and improves insulin sensitivity. To study the effect of dietary supplementation with PS on

  16. Deletion of hepatic carbohydrate response element binding protein (ChREBP impairs glucose homeostasis and hepatic insulin sensitivity in mice

    Directory of Open Access Journals (Sweden)

    Tara Jois

    2017-11-01

    Conclusions: Overall, hepatic ChREBP is protective in regards to hepatic insulin sensitivity and whole body glucose homeostasis. Hepatic ChREBP action can influence other peripheral tissues and is likely essential in coordinating the body's response to different feeding states.

  17. Age-dependent nongenetic influences of birth weight and adult body fat on insulin sensitivity in twins

    DEFF Research Database (Denmark)

    Monrad, Rikke Nygaard; Grunnet, Louise Groth; Rasmussen, Eva Lind

    2009-01-01

    We hypothesized a nongenetic influence of birth weight (BW) and twin and zygosity status on dual-energy x-ray absorptiometry determined adult total and regional body composition and a quantitative equal, although independent, importance of adult body composition and BW for insulin sensitivity....

  18. Co-targeting the HER and IGF/insulin receptor axis in breast cancer, with triple targeting with endocrine therapy for hormone-sensitive disease.

    Science.gov (United States)

    Chakraborty, Ashok; Hatzis, Christos; DiGiovanna, Michael P

    2017-05-01

    Interactions between HER2, estrogen receptor (ER), and insulin-like growth factor I receptor (IGF1R) are implicated in resistance to monotherapies targeting these receptors. We have previously shown in pre-clinical studies synergistic anti-tumor effects for co-targeting each pairwise combination of HER2, IGF1R, and ER. Strikingly, synergy for HER2/IGF1R targeting occurred not only in a HER2+ model, but also in a HER2-normal model. The purpose of the current study was therefore to determine the generalizability of synergistic anti-tumor effects of co-targeting HER2/IGF1R, the anti-tumor activity of triple-targeting HER2/IGF1R/ER in hormone-dependent cell lines, and the effect of using the multi-targeting drugs neratinib (pan-HER) and BMS-754807 (dual IGF1R/insulin receptor). Proliferation and apoptosis assays were performed in a large panel of cell lines representing varying receptor expression levels. Mechanistic effects were studied using phospho-protein immunoblotting. Analyses of drug interaction effects were performed using linear mixed-effects regression models. Enhanced anti-proliferative effects of HER/IGF-insulin co-targeting were seen in most, though not all, cell lines, including HER2-normal lines. For ER+ lines, triple targeting with inclusion of anti-estrogen generally resulted in the greatest anti-tumor effects. Double or triple targeting generally resulted in marked increases in apoptosis in the sensitive lines. Mechanistic studies demonstrated that the synergy between drugs was correlated with maximal inhibition of Akt and ERK pathway signaling. Dual HER/IGF-insulin targeting, and triple targeting with inclusion of anti-estrogen drugs, shows striking anti-tumor activity across breast cancer types, and drugs with broader receptor specificity may be more effective than single receptor selective drugs, particularly for ER- cells.

  19. Adiponectin concentration is associated with muscle insulin sensitivity, AMPK phosphorylation and ceramide content in skeletal muslce of men, but not women

    DEFF Research Database (Denmark)

    Høeg, Louise Dalgas; Sjøberg, Kim Anker; Lundsgaard, Annemarie

    2013-01-01

    Adiponectin is an adipokine that regulates metabolism and increases insulin sensitivity. Mechanisms behind this insulin sensitizing effect have been investigated in rodents, but little is known in humans especially in skeletal muscle. Women have higher serum concentrations of adiponectin than men...

  20. Comparable sensitivity of postmenopausal and young women to the effects of intranasal insulin on food intake and working memory.

    Science.gov (United States)

    Krug, Rosemarie; Benedict, Christian; Born, Jan; Hallschmid, Manfred

    2010-12-01

    We have previously shown that enhancing brain insulin signaling by intranasal administration of a single dose of the hormone acutely reduces food intake in young men but not women, whereas its improving effects on spatial and working memory are restricted to young women. Against the background of animal studies suggesting that low estrogen concentrations are a prerequisite for the anorexigenic impact of central nervous insulin, we extended our foregoing study by assessing intranasal insulin effects in postmenopausal women with comparatively low estrogen concentrations, expecting them to be more sensitive than young women to the anorexigenic effects of the hormone. In a within-subject, double-blind comparison performed at the University of Lübeck, 14 healthy postmenopausal women (body mass index, 23.71±0.6 kg/m2; age, 57.61±1.14 yr) were intranasally administered 160 IU regular human insulin or vehicle. Subjects performed a working memory task (digit span) and a hippocampus-dependent visuospatial memory task. Subsequently, free-choice food intake from an ad libitum breakfast buffet was measured. Contrary to expectations, results in postmenopausal women mirrored those found in young women (22.44±0.63 yr), i.e. insulin administration did not affect food intake (P>0.46), but did enhance performance in the prefrontal cortex-dependent working memory task (Pwomen do not modulate the effects of intranasal insulin in females, suggesting that in humans as opposed to rats, estrogen signaling does not critically alter central nervous system sensitivity to the effects of insulin on energy homeostasis and cognition.

  1. Gut microbiota metabolites, amino acid metabolites and improvements in insulin sensitivity and glucose metabolism: the POUNDS Lost trial.

    Science.gov (United States)

    Heianza, Yoriko; Sun, Dianjianyi; Li, Xiang; DiDonato, Joseph A; Bray, George A; Sacks, Frank M; Qi, Lu

    2018-06-02

    Alterations in gut microbiota have been linked to host insulin resistance, diabetes and impaired amino acid metabolism. We investigated whether changes in gut microbiota-dependent metabolite of trimethylamine N-oxide (TMAO) and its nutrient precursors (choline and L-carnitine) were associated with improvements in glucose metabolism and diabetes-related amino acids in a weight-loss diet intervention. We included 504 overweight and obese adults who were randomly assigned to one of four energy-reduced diets varying in macronutrient intake. The 6-month changes (Δ) in TMAO, choline and L-carnitine levels after the intervention were calculated. Greater decreases in choline and L-carnitine were significantly (p<0.05) associated with greater improvements in fasting insulin concentrations and homeostasis model assessment of insulin resistance (HOMA-IR) at 6 months. The reduction of choline was significantly related to 2-year improvements in glucose and insulin resistance. We found significant linkages between dietary fat intake and ΔTMAO for changes in fasting glucose, insulin and HOMA-IR (p interaction <0.05); a greater increase in TMAO was related to lesser improvements in the outcomes among participants who consumed a high-fat diet. In addition, ΔL-carnitine and Δcholine were significantly related to changes in amino acids (including branched-chain and aromatic amino acids). Interestingly, the associations of ΔTMAO, Δcholine and ΔL-carnitine with diabetes-related traits were independent of the changes in amino acids. Our findings underscore the importance of changes in TMAO, choline and L-carnitine in improving insulin sensitivity during a weight-loss intervention for obese patients. Dietary fat intake may modify the associations of TMAO with insulin sensitivity and glucose metabolism. NCT00072995. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless

  2. Thrombospondin1 deficiency reduces obesity-associated inflammation and improves insulin sensitivity in a diet-induced obese mouse model.

    Directory of Open Access Journals (Sweden)

    Yanzhang Li

    Full Text Available Obesity is prevalent worldwide and is associated with insulin resistance. Advanced studies suggest that obesity-associated low-grade chronic inflammation contributes to the development of insulin resistance and other metabolic complications. Thrombospondin 1 (TSP1 is a multifunctional extracellular matrix protein that is up-regulated in inflamed adipose tissue. A recent study suggests a positive correlation of TSP1 with obesity, adipose inflammation, and insulin resistance. However, the direct effect of TSP1 on obesity and insulin resistance is not known. Therefore, we investigated the role of TSP1 in mediating obesity-associated inflammation and insulin resistance by using TSP1 knockout mice.Male TSP1-/- mice and wild type littermate controls were fed a low-fat (LF or a high-fat (HF diet for 16 weeks. Throughout the study, body weight and fat mass increased similarly between the TSP1-/- mice and WT mice under HF feeding conditions, suggesting that TSP1 deficiency does not affect the development of obesity. However, obese TSP1-/- mice had improved glucose tolerance and increased insulin sensitivity compared to the obese wild type mice. Macrophage accumulation and inflammatory cytokine expression in adipose tissue were reduced in obese TSP1-/- mice. Consistent with the local decrease in pro-inflammatory cytokine levels, systemic inflammation was also decreased in the obese TSP1-/- mice. Furthermore, in vitro data demonstrated that TSP1 deficient macrophages had decreased mobility and a reduced inflammatory phenotype.TSP1 deficiency did not affect the development of high-fat diet induced obesity. However, TSP1 deficiency reduced macrophage accumulation in adipose tissue and protected against obesity related inflammation and insulin resistance. Our data demonstrate that TSP1 may play an important role in regulating macrophage function and mediating obesity-induced inflammation and insulin resistance. These data suggest that TSP1 may serve as a

  3. Histochemical evidence for the differential surface labeling, uptake, and intracellular transport of a colloidal gold-labeled insulin complex by normal human blood cells.

    Science.gov (United States)

    Ackerman, G A; Wolken, K W

    1981-10-01

    A colloidal gold-labeled insulin-bovine serum albumin (GIA) reagent has been developed for the ultrastructural visualization of insulin binding sites on the cell surface and for tracing the pathway of intracellular insulin translocation. When applied to normal human blood cells, it was demonstrated by both visual inspection and quantitative analysis that the extent of surface labeling, as well as the rate and degree of internalization of the insulin complex, was directly related to cell type. Further, the pathway of insulin (GIA) transport via round vesicles and by tubulo-vesicles and saccules and its subsequent fate in the hemic cells was also related to cell variety. Monocytes followed by neutrophils bound the greatest amount of labeled insulin. The majority of lymphocytes bound and internalized little GIA, however, between 5-10% of the lymphocytes were found to bind considerable quantities of GIA. Erythrocytes rarely bound the labeled insulin complex, while platelets were noted to sequester large quantities of the GIA within their extracellular canalicular system. GIA uptake by the various types of leukocytic cells appeared to occur primarily by micropinocytosis and by the direct opening of cytoplasmic tubulo-vesicles and saccules onto the cell surface in regions directly underlying surface-bound GIA. Control procedures, viz., competitive inhibition of GIA labeling using an excess of unlabeled insulin in the incubation medium, preincubation of the GIA reagent with an antibody directed toward porcine insulin, and the incorporation of 125I-insulin into the GIA reagent, indicated the specificity and selectivity of the GIA histochemical procedure for the localization of insulin binding sites.

  4. Histochemical evidence for the differential surface labeling, uptake, and intracellular transport of a colloidal gold-labeled insulin complex by normal human blood cells

    International Nuclear Information System (INIS)

    Ackerman, G.A.; Wolken, K.W.

    1981-01-01

    A colloidal gold-labeled insulin-bovine serum albumin (GIA) reagent has been developed for the ultrastructural visualization of insulin binding sites on the cell surface and for tracing the pathway of intracellular insulin translocation. When applied to normal human blood cells, it was demonstrate