The influence of different muscle mass measurements on the diagnosis of cancer cachexia.

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Blauwhoff-Buskermolen, Susanne; Langius, Jacqueline A E; Becker, Annemarie; Verheul, Henk M W; de van der Schueren, Marian A E

2017-08-01

Progressive loss of muscle mass is a major characteristic of cancer cachexia. Consensus definitions for cachexia provide different options to measure muscle mass. This study describes the effect of different methods to determine muscle mass on the diagnosis of cancer cachexia. In addition, the association of cachexia with other features of cachexia, quality of life, and survival was explored. Prior to chemotherapy, cachexia was assessed by weight loss, body mass index, and muscle mass measurements, the latter by mid-upper arm muscle area (MUAMA), computed tomography (CT) scans, and bio-electrical impedance analysis (BIA). In addition, appetite, inflammation, muscle strength, fatigue, quality of life, and survival were measured, and associations with cachexia were explored. Included were 241 patients with advanced cancer of the lung (36%), colon/rectum (31%), prostate (18%), or breast (15%). Mean age was 64 ± 10 years; 54% was male. Prevalence of low muscle mass was as follows: 13% with MUAMA, 59% with CT, and 93% with BIA. In turn, the prevalence of cachexia was 37, 43, and 48%, whereby weight loss >5% was the most prominent component of being defined cachectic. Irrespective of type of muscle measurement, patients with cachexia presented more often with anorexia, inflammation, low muscle strength, and fatigue and had lower quality of life. Patients with cachexia had worse overall survival compared with patients without cachexia: HRs 2.00 (1.42-2.83) with MUAMA, 1.64 (1.15-2.34) with CT, and 1.50 (1.05-2.14) with BIA. Although the prevalence of low muscle mass in patients with cancer depended largely on the type of muscle measurement, this had little influence on the diagnosis of cancer cachexia (as the majority of patients was already defined cachectic based on weight loss). New studies are warranted to further elucidate the additional role of muscle measurements in the diagnosis of cachexia and the association with clinical outcomes. © 2017 The Authors

Growth hormone mitigates loss of periosteal bone formation and muscle mass in disuse osteopenic rats.

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Grubbe, M-C; Thomsen, J S; Nyengaard, J R; Duruox, M; Brüel, A

2014-12-01

Growth hormone (GH) is a potent anabolic agent capable of increasing both bone and muscle mass. The aim was to investigate whether GH could counteract disuse-induced loss of bone and muscle mass in a rat model. Paralysis was induced by injecting 4 IU Botox (BTX) into the muscles of the right hind limb. Sixty female Wistar rats, 14 weeks old, were divided into the following groups: baseline, controls, BTX, BTX+GH, and GH. GH was given at a dosage of 5 mg/kg/d for 4 weeks. Compared with controls, BTX resulted in lower periosteal bone formation rate (BFR/BS,-79%, Pbone mineral density (aBMD, -13%, Pbone volume (BV/TV, -26%, Pbone strength (-12%, Pbone strength was found. In addition, GH partly prevented loss of muscle mass (+29% vs. BTX, P<0.001), and tended to prevent loss of muscle CSA (+11%, P=0.064). In conclusion, GH mitigates disuse-induced loss of periosteal BFR/BS at the mid-femur and rectus femoris muscle mass.

mTOR as a Key Regulator in Maintaining Skeletal Muscle Mass

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Mee-Sup Yoon

2017-10-01

Full Text Available Maintenance of skeletal muscle mass is regulated by the balance between anabolic and catabolic processes. Mammalian target of rapamycin (mTOR is an evolutionarily conserved serine/threonine kinase, and is known to play vital roles in protein synthesis. Recent findings have continued to refine our understanding of the function of mTOR in maintaining skeletal muscle mass. mTOR controls the anabolic and catabolic signaling of skeletal muscle mass, resulting in the modulation of muscle hypertrophy and muscle wastage. This review will highlight the fundamental role of mTOR in skeletal muscle growth by summarizing the phenotype of skeletal-specific mTOR deficiency. In addition, the evidence that mTOR is a dual regulator of anabolism and catabolism in skeletal muscle mass will be discussed. A full understanding of mTOR signaling in the maintenance of skeletal muscle mass could help to develop mTOR-targeted therapeutics to prevent muscle wasting.

The impact of low muscle mass definition on the prevalence of sarcopenia in older Australians.

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Yu, Solomon; Appleton, Sarah; Adams, Robert; Chapman, Ian; Wittert, Gary; Visvanathan, Thavarajah; Visvanathan, Renuka

2014-01-01

Sarcopenia is the presence of low muscle mass and low muscle function. The aim of this study was to establish cutoffs for low muscle mass using three published methods and to compare the prevalence of sarcopenia in older Australians. Gender specific cutoffs levels were identified for low muscle mass using three different methods. Low grip strength was determined using established cutoffs of standard deviation (SD) of a young reference population; (b) <7.36 kg/m(2) for men and <5.81 kg/m(2) for women from the lowest 20% percentile of the older group; and (c) <-2.15 for men and <-1.42 for women from the lowest 20% of the residuals of linear regressions of appendicular skeletal mass, adjusted for fat mass and height. Prevalence of sarcopenia in older (65 years and older) people by these three methods for men was 2.5%, 6.2%, and 6.4% and for women 0.3%, 9.3%, and 8.5%, respectively. Sarcopenia is common but consensus on the best method to confirm low muscle mass is required.

Muscle strength rather than muscle mass is associated with osteoporosis in older Chinese adults

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Yixuan Ma

2018-02-01

Conclusion: Based on our study, muscle strength rather than muscle mass is negatively associated with OS in older people; thus, we should pay more attention to muscle strength training in the early stage of the OS.

Counteracting age-related loss of skeletal muscle mass

DEFF Research Database (Denmark)

Bechshøft, Rasmus; Reitelseder, Søren; Højfeldt, Grith

2016-01-01

Background Aging is associated with decreased muscle mass and functional capacity, which in turn decrease quality of life. The number of citizens over the age of 65 years in the Western world will increase by 50 % over the next four decades, and this demographic shift brings forth new challenges...... at both societal and individual levels. Only a few longitudinal studies have been reported, but whey protein supplementation seems to improve muscle mass and function, and its combination with heavy strength training appears even more effective. However, heavy resistance training may reduce adherence...... Intervention Study will generate scientific evidence and recommendations to counteract age-related loss of skeletal muscle mass in elderly individuals....

The adipokine leptin increases skeletal muscle mass and significantly alters skeletal muscle miRNA expression profile in aged mice

International Nuclear Information System (INIS)

Hamrick, Mark W.; Herberg, Samuel; Arounleut, Phonepasong; He, Hong-Zhi; Shiver, Austin; Qi, Rui-Qun; Zhou, Li; Isales, Carlos M.

2010-01-01

Research highlights: → Aging is associated with muscle atrophy and loss of muscle mass, known as the sarcopenia of aging. → We demonstrate that age-related muscle atrophy is associated with marked changes in miRNA expression in muscle. → Treating aged mice with the adipokine leptin significantly increased muscle mass and the expression of miRNAs involved in muscle repair. → Recombinant leptin therapy may therefore be a novel approach for treating age-related muscle atrophy. -- Abstract: Age-associated loss of muscle mass, or sarcopenia, contributes directly to frailty and an increased risk of falls and fractures among the elderly. Aged mice and elderly adults both show decreased muscle mass as well as relatively low levels of the fat-derived hormone leptin. Here we demonstrate that loss of muscle mass and myofiber size with aging in mice is associated with significant changes in the expression of specific miRNAs. Aging altered the expression of 57 miRNAs in mouse skeletal muscle, and many of these miRNAs are now reported to be associated specifically with age-related muscle atrophy. These include miR-221, previously identified in studies of myogenesis and muscle development as playing a role in the proliferation and terminal differentiation of myogenic precursors. We also treated aged mice with recombinant leptin, to determine whether leptin therapy could improve muscle mass and alter the miRNA expression profile of aging skeletal muscle. Leptin treatment significantly increased hindlimb muscle mass and extensor digitorum longus fiber size in aged mice. Furthermore, the expression of 37 miRNAs was altered in muscles of leptin-treated mice. In particular, leptin treatment increased the expression of miR-31 and miR-223, miRNAs known to be elevated during muscle regeneration and repair. These findings suggest that aging in skeletal muscle is associated with marked changes in the expression of specific miRNAs, and that nutrient-related hormones such as leptin

The adipokine leptin increases skeletal muscle mass and significantly alters skeletal muscle miRNA expression profile in aged mice

Energy Technology Data Exchange (ETDEWEB)

Hamrick, Mark W., E-mail: mhamrick@mail.mcg.edu [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Herberg, Samuel; Arounleut, Phonepasong [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); He, Hong-Zhi [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Shiver, Austin [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Qi, Rui-Qun [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Zhou, Li [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Department of Internal Medicine, Henry Ford Health System, Detroit, MI (United States); Isales, Carlos M. [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); others, and

2010-09-24

Research highlights: {yields} Aging is associated with muscle atrophy and loss of muscle mass, known as the sarcopenia of aging. {yields} We demonstrate that age-related muscle atrophy is associated with marked changes in miRNA expression in muscle. {yields} Treating aged mice with the adipokine leptin significantly increased muscle mass and the expression of miRNAs involved in muscle repair. {yields} Recombinant leptin therapy may therefore be a novel approach for treating age-related muscle atrophy. -- Abstract: Age-associated loss of muscle mass, or sarcopenia, contributes directly to frailty and an increased risk of falls and fractures among the elderly. Aged mice and elderly adults both show decreased muscle mass as well as relatively low levels of the fat-derived hormone leptin. Here we demonstrate that loss of muscle mass and myofiber size with aging in mice is associated with significant changes in the expression of specific miRNAs. Aging altered the expression of 57 miRNAs in mouse skeletal muscle, and many of these miRNAs are now reported to be associated specifically with age-related muscle atrophy. These include miR-221, previously identified in studies of myogenesis and muscle development as playing a role in the proliferation and terminal differentiation of myogenic precursors. We also treated aged mice with recombinant leptin, to determine whether leptin therapy could improve muscle mass and alter the miRNA expression profile of aging skeletal muscle. Leptin treatment significantly increased hindlimb muscle mass and extensor digitorum longus fiber size in aged mice. Furthermore, the expression of 37 miRNAs was altered in muscles of leptin-treated mice. In particular, leptin treatment increased the expression of miR-31 and miR-223, miRNAs known to be elevated during muscle regeneration and repair. These findings suggest that aging in skeletal muscle is associated with marked changes in the expression of specific miRNAs, and that nutrient

Comparison of skeletal muscle mass to fat-free mass ratios among different ethnic groups.

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Abe, T; Bemben, M G; Kondo, M; Kawakami, Y; Fukunaga, T

2012-01-01

Asians seem to have less skeletal muscle mass (SMM) than other ethnic groups, but it is not clear whether relative SMM, i.e., SMM / height square or SMM to fat-free mass (FFM) ratio, differs among different ethnic groups at the same level of body mass index (BMI). To compare the SMM to fat-free mass (FFM) ratio as well as anthropometric variables and body composition among 3 ethnic groups. Three hundred thirty-nine Japanese, 343 Brazilian, and 183 German men and women were recruited for this cross-sectional study. Muscle thickness (MTH) and subcutaneous fat thickness (FTH) were measured by ultrasound at nine sites on the anterior and posterior aspects of the body. FTH was used to estimate the body density, from which fat mass and fat-free mass (FFM) was calculated by using Brozek equation. Total SMM was estimated from ultrasound-derived prediction equations. Percentage body fat was similar among the ethnic groups in men, while Brazilians were higher than Japanese in women. In German men and women, absolute SMM and FFM were higher than in their Japanese and Brazilians counterparts. SMM index and SMM:FFM ratios were similar among the ethnic groups in women, excluding SMM:FFM ratio in Brazilian. In men, however, these relative values (SMM index and SMM:FFM ratio) were still higher in Germans. After adjusting for age and BMI, the SMM index and SMM:FFM ratios were lower in Brazilian men and women compared with the other two ethnic groups, while the SMM index and SMM:FFM ratios were similar in Japanese and German men and women, excluding SMM:FFM ratio in women. Our results suggest that relative SMM is not lower in Asian populations compared with European populations after adjusted by age and BMI.

Supplemental protein in support of muscle mass and health: advantage whey.

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Devries, Michaela C; Phillips, Stuart M

2015-03-01

Skeletal muscle is an integral body tissue playing key roles in strength, performance, physical function, and metabolic regulation. It is essential for athletes to ensure that they have optimal amounts of muscle mass to ensure peak performance in their given sport. However, the role of maintaining muscle mass during weight loss and as we age is an emerging concept, having implications in chronic disease prevention, functional capacity, and quality of life. Higher-protein diets have been shown to: (1) promote gains in muscle mass, especially when paired with resistance training; (2) spare muscle mass loss during caloric restriction; and (3) attenuate the natural loss of muscle mass that accompanies aging. Protein quality is important to the gain and maintenance of muscle mass. Protein quality is a function of protein digestibility, amino acid content, and the resulting amino acid availability to support metabolic function. Whey protein is one of the highest-quality proteins given its amino acid content (high essential, branched-chain, and leucine amino acid content) and rapid digestibility. Consumption of whey protein has a robust ability to stimulate muscle protein synthesis. In fact, whey protein has been found to stimulate muscle protein synthesis to a greater degree than other proteins such as casein and soy. This review examines the existing data supporting the role for protein consumption, with an emphasis on whey protein, in the regulation of muscle mass and body composition in response to resistance training, caloric restriction, and aging. © 2015 Institute of Food Technologists®

Premature loss of muscle mass and function in type 2 diabetes.

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Guerrero, N; Bunout, D; Hirsch, S; Barrera, G; Leiva, L; Henríquez, S; De la Maza, M P

2016-07-01

Muscle mass and function are among the most relevant factors that contribute to an optimal quality of life, and are strong predictors of mortality in the elderly. Loss of lean tissues and deterioration of muscle function have been described as one of the many complications of type 2 diabetes mellitus (DM2), but most studies do not isolate age as an intervening factor. To study whether adult DM2 patients up to 60years of age have decreased muscle mass and function compared with healthy non-diabetic (ND) subjects of similar age. Appendicular fat-free mass (ApFFM) by dual X-ray absorptiometry (DEXA), handgrip strength (HS), quadriceps strength (QS), 12 min walking capacity (12MW) and the Timed Up and Go test (TUG) were measured in 100 DM2 patients and 39 ND controls. Muscle quality, or the ratio between lean mass and muscle strength of upper and lower limbs, and the functional limitations associated with pain and stiffness assessed according to the Western Ontario and McMaster Universities Arthrosis Index (WOMAC) were also recorded. Specific tests were performed to rule out microvascular diabetic complications (retinal and peripheral nerves), metabolic control, kidney function and vitamin D status and examine their association with ApFFM and function. ApFFM was significantly higher among DM2 female patients and lower among diabetic men. However opposite results were obtained when individual values were corrected for body mass index (BMI), specifically among women, who were more likely to be obese. As for muscle strength and global functionality tests, significantly better performances in TUG, 12MW, QS and HS were observed among ND subjects of both sexes. These differences prevailed even after excluding diabetic patients with microvascular complications as well as those with more than 10years of diabetes. Muscle quality was also significantly better among ND women. Higher scores of pain and stiffness in the WOMAC scale correlated with 12MW and TUG in both groups but

A New Equation to Estimate Muscle Mass from Creatinine and Cystatin C.

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Sun-wook Kim

Full Text Available With evaluation for physical performance, measuring muscle mass is an important step in detecting sarcopenia. However, there are no methods to estimate muscle mass from blood sampling.To develop a new equation to estimate total-body muscle mass with serum creatinine and cystatin C level, we designed a cross-sectional study with separate derivation and validation cohorts. Total body muscle mass and fat mass were measured using dual-energy x-ray absorptiometry (DXA in 214 adults aged 25 to 84 years who underwent physical checkups from 2010 to 2013 in a single tertiary hospital. Serum creatinine and cystatin C levels were also examined.Serum creatinine was correlated with muscle mass (P < .001, and serum cystatin C was correlated with body fat mass (P < .001 after adjusting glomerular filtration rate (GFR. After eliminating GFR, an equation to estimate total-body muscle mass was generated and coefficients were calculated in the derivation cohort. There was an agreement between muscle mass calculated by the novel equation and measured by DXA in both the derivation and validation cohort (P < .001, adjusted R2 = 0.829, β = 0.95, P < .001, adjusted R2 = 0.856, β = 1.03, respectively.The new equation based on serum creatinine and cystatin C levels can be used to estimate total-body muscle mass.

TAK1 regulates skeletal muscle mass and mitochondrial function

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Hindi, Sajedah M.; Sato, Shuichi; Xiong, Guangyan; Bohnert, Kyle R.; Gibb, Andrew A.; Gallot, Yann S.; McMillan, Joseph D.; Hill, Bradford G.

2018-01-01

Skeletal muscle mass is regulated by a complex array of signaling pathways. TGF-β–activated kinase 1 (TAK1) is an important signaling protein, which regulates context-dependent activation of multiple intracellular pathways. However, the role of TAK1 in the regulation of skeletal muscle mass remains unknown. Here, we report that inducible inactivation of TAK1 causes severe muscle wasting, leading to kyphosis, in both young and adult mice.. Inactivation of TAK1 inhibits protein synthesis and induces proteolysis, potentially through upregulating the activity of the ubiquitin-proteasome system and autophagy. Phosphorylation and enzymatic activity of AMPK are increased, whereas levels of phosphorylated mTOR and p38 MAPK are diminished upon inducible inactivation of TAK1 in skeletal muscle. In addition, targeted inactivation of TAK1 leads to the accumulation of dysfunctional mitochondria and oxidative stress in skeletal muscle of adult mice. Inhibition of TAK1 does not attenuate denervation-induced muscle wasting in adult mice. Finally, TAK1 activity is highly upregulated during overload-induced skeletal muscle growth, and inactivation of TAK1 prevents myofiber hypertrophy in response to functional overload. Overall, our study demonstrates that TAK1 is a key regulator of skeletal muscle mass and oxidative metabolism. PMID:29415881

Non-Hodgkin lymphoma in skeletal muscle manifesting as homogeneous masses with CT attenuation similar to muscle

International Nuclear Information System (INIS)

Panicek, D.M.; Lautin, J.L.; Schwartz, L.H.; Castellino, R.A.

1997-01-01

Two cases are presented of masses in muscle due to non-Hodgkin lymphoma (NHL) that were homogeneous and isoattenuating to normal muscle on CT. In each case, the mass was clinically suspected of representing soft tissue sarcoma. However, the masses were relatively inapparent on CT, being visible predominantly as mass effect - an appearance unlike that of soft tissue sarcomas. It is important to be aware that NHL in muscle can be difficult to detect at CT, even with intravenous contrast enhancement; therefore, a clinically apparent mass should not be dismissed on the basis of an apparently unremarkable CT scan of the region. Such findings should suggest the diagnosis of NHL rather than sarcoma. (orig.)

Myostatin inhibition in muscle, but not adipose tissue, decreases fat mass and improves insulin sensitivity.

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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.

Baseline muscle mass is a poor predictor of functional overload-induced gain in the mouse model

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Audrius Kilikevicius

2016-11-01

Full Text Available Genetic background contributes substantially to individual variability in muscle mass. Muscle hypertrophy in response to resistance training can also vary extensively. However, it is less clear if muscle mass at baseline is predictive of the hypertrophic response.The aim of this study was to examine the effect of genetic background on variability in muscle mass at baseline and in the adaptive response of the mouse fast- and slow-twitch muscles to overload. Males of eight laboratory mouse strains: C57BL/6J (B6, n=17, BALB/cByJ (n=7, DBA/2J (D2, n=12, B6.A-(rs3676616-D10Utsw1/Kjn (B6.A, n=9, C57BL/6J-Chr10A/J/NaJ (B6.A10, n=8, BEH+/+ (n=11, BEH (n=12 and DUHi (n=12, were studied. Compensatory growth of soleus and plantaris muscles was triggered by a 4-week overload induced by synergist unilateral ablation. Muscle weight in the control leg (baseline varied from 5.2±07 mg soleus and 11.4±1.3 mg plantaris in D2 mice to 18.0±1.7 mg soleus in DUHi and 43.7±2.6 mg plantaris in BEH (p<0.001 for both muscles. In addition, soleus in the B6.A10 strain was ~40% larger (p<0.001 compared to the B6. Functional overload increased muscle weight, however, the extent of gain was strain-dependent for both soleus (p<0.01 and plantaris (p<0.02 even after accounting for the baseline differences. For the soleus muscle, the BEH strain emerged as the least responsive, with a 1.3-fold increase, compared to a 1.7-fold gain in the most responsive D2 strain, and there was no difference in the gain between the B6.A10 and B6 strains. The BEH strain appeared the least responsive in the gain of plantaris as well, 1.3-fold, compared to ~1.5-fold gain in the remaining strains. We conclude that variation in muscle mass at baseline is not a reliable predictor of that in the overload-induced gain. This suggests that a different set of genes influence variability in muscle mass acquired in the process of normal development, growth and maintenance, and in the process of adaptive

The effect Mat Pilates practice on muscle mass in elderly women

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Leliz Cristina Sampaio Queiroz

2016-01-01

Full Text Available Objective: to verify that the Mat Pilates practice increases muscle mass in elderly women. Methods: quasi-experimental study with primary data collection and with a convenience sample. The muscle mass of 43 elderly was evaluated for 11 weeks, by calculating the arm muscle area, before and after the intervention. Results:statistically significant difference was observed (p<0.002 between the average value of the arm muscle area, before (35.56cm2 and after the exercises (42.72cm2. Conclusion: mat Pilates program generates positive effect on increasing the muscle mass of elderly.

The Impact of Low Muscle Mass Definition on the Prevalence of Sarcopenia in Older Australians

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Solomon Yu

2014-01-01

Full Text Available Background. Sarcopenia is the presence of low muscle mass and low muscle function. The aim of this study was to establish cutoffs for low muscle mass using three published methods and to compare the prevalence of sarcopenia in older Australians. Methods. Gender specific cutoffs levels were identified for low muscle mass using three different methods. Low grip strength was determined using established cutoffs of <30 kg for men and <20 kg for women to estimate the prevalence of sarcopenia. Results. Gender specific cutoffs levels for low muscle mass identified were (a <6.89 kg/m2 for men and <4.32 kg/m2 for women, <2 standard deviation (SD of a young reference population; (b <7.36 kg/m2 for men and <5.81 kg/m2 for women from the lowest 20% percentile of the older group; and (c <−2.15 for men and <−1.42 for women from the lowest 20% of the residuals of linear regressions of appendicular skeletal mass, adjusted for fat mass and height. Prevalence of sarcopenia in older (65 years and older people by these three methods for men was 2.5%, 6.2%, and 6.4% and for women 0.3%, 9.3%, and 8.5%, respectively. Conclusions. Sarcopenia is common but consensus on the best method to confirm low muscle mass is required.

Effect of transcutaneous electrical muscle stimulation on postoperative muscle mass and protein synthesis

DEFF Research Database (Denmark)

Vinge, O; Edvardsen, L; Jensen, F

1996-01-01

In an experimental study, 13 patients undergoing major elective abdominal surgery were given postoperative transcutaneous electrical muscle stimulation (TEMS) to the quadriceps femoris muscle on one leg; the opposite leg served as control. Changes in cross-sectional area (CSA) and muscle protein ...... protein synthesis and muscle mass after abdominal surgery and should be evaluated in other catabolic states with muscle wasting.......In an experimental study, 13 patients undergoing major elective abdominal surgery were given postoperative transcutaneous electrical muscle stimulation (TEMS) to the quadriceps femoris muscle on one leg; the opposite leg served as control. Changes in cross-sectional area (CSA) and muscle protein...... synthesis were assessed by computed tomography and ribosome analysis of percutaneous muscle biopsies before surgery and on the sixth postoperative day. The percentage of polyribosomes in the ribosome suspension decreased significantly (P

Psoas Muscle Cross-sectional Area as a Measure of Whole-body Lean Muscle Mass in Maintenance Hemodialysis Patients.

Science.gov (United States)

Morrell, Glen R; Ikizler, Talat A; Chen, Xiaorui; Heilbrun, Marta E; Wei, Guo; Boucher, Robert; Beddhu, Srinivasan

2016-07-01

We investigate whether psoas or paraspinous muscle area measured on a single L4-L5 image is a useful measure of whole lean body mass (LBM) compared to dedicated midthigh magnetic resonance imaging (MRI). Observational study. Outpatient dialysis units and a research clinic. One hundred five adult participants on maintenance hemodialysis. No control group was used. Psoas muscle area, paraspinous muscle area, and midthigh muscle area (MTMA) were measured by magnetic resonance imaging. LBM was measured by dual-energy absorptiometry scan. In separate multivariable linear regression models, psoas, paraspinous, and MTMA were associated with increase in LBM. In separate multivariate logistic regression models, C statistics for diagnosis of sarcopenia (defined as <25th percentile of LBM) were 0.69 for paraspinous muscle area, 0.81 for psoas muscle area, and 0.89 for MTMA. With sarcopenia defined as <10th percentile of LBM, the corresponding C statistics were 0.71, 0.92, and 0.94. We conclude that psoas muscle area provides a good measure of whole-body muscle mass, better than paraspinous muscle area but slightly inferior to midthigh measurement. Hence, in body composition studies a single axial MR image at the L4-L5 level can be used to provide information on both fat and muscle and may eliminate the need for time-consuming measurement of muscle area in the thigh. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Delayed recovery of skeletal muscle mass following hindlimb immobilization in mTOR heterozygous mice.

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Susan M Lang

Full Text Available The present study addressed the hypothesis that reducing mTOR, as seen in mTOR heterozygous (+/- mice, would exaggerate the changes in protein synthesis and degradation observed during hindlimb immobilization as well as impair normal muscle regrowth during the recovery period. Atrophy was produced by unilateral hindlimb immobilization and data compared to the contralateral gastrocnemius. In wild-type (WT mice, the gradual loss of muscle mass plateaued by day 7. This response was associated with a reduction in basal protein synthesis and development of leucine resistance. Proteasome activity was consistently elevated, but atrogin-1 and MuRF1 mRNAs were only transiently increased returning to basal values by day 7. When assessed 7 days after immobilization, the decreased muscle mass and protein synthesis and increased proteasome activity did not differ between WT and mTOR(+/- mice. Moreover, the muscle inflammatory cytokine response did not differ between groups. After 10 days of recovery, WT mice showed no decrement in muscle mass, and this accretion resulted from a sustained increase in protein synthesis and a normalization of proteasome activity. In contrast, mTOR(+/- mice failed to fully replete muscle mass at this time, a defect caused by the lack of a compensatory increase in protein synthesis. The delayed muscle regrowth of the previously immobilized muscle in the mTOR(+/- mice was associated with a decreased raptor•4EBP1 and increased raptor•Deptor binding. Slowed regrowth was also associated with a sustained inflammatory response (e.g., increased TNFα and CD45 mRNA during the recovery period and a failure of IGF-I to increase as in WT mice. These data suggest mTOR is relatively more important in regulating the accretion of muscle mass during recovery than the loss of muscle during the atrophy phase, and that protein synthesis is more sensitive than degradation to the reduction in mTOR during muscle regrowth.

Delayed recovery of skeletal muscle mass following hindlimb immobilization in mTOR heterozygous mice.

Science.gov (United States)

Lang, Susan M; Kazi, Abid A; Hong-Brown, Ly; Lang, Charles H

2012-01-01

The present study addressed the hypothesis that reducing mTOR, as seen in mTOR heterozygous (+/-) mice, would exaggerate the changes in protein synthesis and degradation observed during hindlimb immobilization as well as impair normal muscle regrowth during the recovery period. Atrophy was produced by unilateral hindlimb immobilization and data compared to the contralateral gastrocnemius. In wild-type (WT) mice, the gradual loss of muscle mass plateaued by day 7. This response was associated with a reduction in basal protein synthesis and development of leucine resistance. Proteasome activity was consistently elevated, but atrogin-1 and MuRF1 mRNAs were only transiently increased returning to basal values by day 7. When assessed 7 days after immobilization, the decreased muscle mass and protein synthesis and increased proteasome activity did not differ between WT and mTOR(+/-) mice. Moreover, the muscle inflammatory cytokine response did not differ between groups. After 10 days of recovery, WT mice showed no decrement in muscle mass, and this accretion resulted from a sustained increase in protein synthesis and a normalization of proteasome activity. In contrast, mTOR(+/-) mice failed to fully replete muscle mass at this time, a defect caused by the lack of a compensatory increase in protein synthesis. The delayed muscle regrowth of the previously immobilized muscle in the mTOR(+/-) mice was associated with a decreased raptor•4EBP1 and increased raptor•Deptor binding. Slowed regrowth was also associated with a sustained inflammatory response (e.g., increased TNFα and CD45 mRNA) during the recovery period and a failure of IGF-I to increase as in WT mice. These data suggest mTOR is relatively more important in regulating the accretion of muscle mass during recovery than the loss of muscle during the atrophy phase, and that protein synthesis is more sensitive than degradation to the reduction in mTOR during muscle regrowth.

Deficits in muscle strength, mass, quality and mobility in people with chronic obstructive pulmonary disease

DEFF Research Database (Denmark)

Roig, Marc; Eng, Janice J; MacIntyre, Donna L

2011-01-01

PURPOSE: Midthigh intramuscular fat (IF), a feature of reduced muscle quality, is an important predictor of self-reported mobility loss in the elderly. This study compared measures of muscle strength, mass, IF, and mobility in patients with chronic obstructive pulmonary disease (COPD) and healthy...

Osteocalcin is necessary and sufficient to maintain muscle mass in older mice

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Paula Mera

2016-10-01

Full Text Available Objective: A decrease in muscle protein turnover and therefore in muscle mass is a hallmark of aging. Because the circulating levels of the bone-derived hormone osteocalcin decline steeply during aging in mice, monkeys and humans we asked here whether this hormone might regulate muscle mass as mice age. Methods: We examined muscle mass and strength in mice lacking osteocalcin (Ocn−/− or its receptor in all cells (Gprc6a−/− or specifically in myofibers (Gprc6aMck−/− as well as in 9 month-old WT mice receiving exogenous osteocalcin for 28 days. We also examined protein synthesis in WT and Gprc6a−/− mouse myotubes treated with osteocalcin. Results: We show that osteocalcin signaling in myofibers is necessary to maintain muscle mass in older mice in part because it promotes protein synthesis in myotubes without affecting protein breakdown. We further show that treatment with exogenous osteocalcin for 28 days is sufficient to increase muscle mass of 9-month-old WT mice. Conclusion: This study uncovers that osteocalcin is necessary and sufficient to prevent age-related muscle loss in mice. Author Video: Author Video Watch what authors say about their articles Keywords: Osteocalcin, Muscle mass, Aging

Skeletal muscle mass recovery from atrophy in IL-6 knockout mice.

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Washington, T A; White, J P; Davis, J M; Wilson, L B; Lowe, L L; Sato, S; Carson, J A

2011-08-01

Skeletal muscle interleukin-6 (IL-6) expression is induced by continuous contraction, overload-induced hypertrophy and during muscle regeneration. The loss of IL-6 can alter skeletal muscle's growth and extracellular matrix remodelling response to overload-induced hypertrophy. Insulin-like growth factor-1 (IGF-1) gene expression and related signalling through Akt/mTOR is a critical regulator of muscle mass. The significance of IL-6 expression during the recovery from muscle atrophy is unclear. This study's purpose was to determine the effect of IL-6 loss on mouse gastrocnemius (GAS) muscle mass during recovery from hindlimb suspension (HS)-induced atrophy. Female C57BL/6 [wild type (WT)] and IL-6 knockout (IL-6 KO) mice at 10 weeks of age were assigned to control, HS or HS followed by normal cage ambulation groups. GAS muscle atrophy was induced by 10 days of HS. HS induced a 20% loss of GAS mass in both WT and IL-6 KO mice. HS+7 days of recovery restored WT GAS mass to cage-control values. GAS mass from IL-6 KO mice did not return to cage-control values until HS+14 days of recovery. Both IGF-1 mRNA expression and Akt/mTOR signalling were increased in WT muscle after 1 day of recovery. In IL-6 KO muscle, IGF-1 mRNA expression was decreased and Akt/mTOR signalling was not induced after 1 day of recovery. MyoD and myogenin mRNA expression were both induced in WT muscle after 1 day of recovery, but not in IL-6 KO muscle.   Muscle IL-6 expression appears important for the initial growth response during the recovery from disuse. © 2011 The Authors. Acta Physiologica © 2011 Scandinavian Physiological Society.

Ultrasonography to Measure Swallowing Muscle Mass and Quality in Older Patients With Sarcopenic Dysphagia.

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Ogawa, Nami; Mori, Takashi; Fujishima, Ichiro; Wakabayashi, Hidetaka; Itoda, Masataka; Kunieda, Kenjiro; Shigematsu, Takashi; Nishioka, Shinta; Tohara, Haruka; Yamada, Minoru; Ogawa, Sumito

2018-06-01

Sarcopenic dysphagia is characterized by difficulty swallowing due to a loss of whole-body skeletal and swallowing muscle mass and function. However, no study has reported on swallowing muscle mass and quality in patients with sarcopenic dysphagia. To compare the differences in swallowing muscle mass and quality between sarcopenic and nonsarcopenic dysphagia. A cross-sectional study was performed in 55 older patients, who had been recommended to undergo dysphagia assessment and/or rehabilitation. Sarcopenic dysphagia was diagnosed using a diagnostic algorithm for sarcopenic dysphagia. The thickness and area of tongue muscle and geniohyoid muscle (coronal plane and sagittal plane), and the echo-intensity of the tongue and geniohyoid muscles were examined by ultrasound. The study participants included 31 males and 24 females (mean age of 82 ± 7 years), with 14 having possible sarcopenic dysphagia, 22 probable sarcopenic dysphagia, and 19 without sarcopenic dysphagia. The group with sarcopenic dysphagia had a significantly lower cross-sectional area and area of brightness of the tongue muscle than that observed in the group without sarcopenic dysphagia. The most specific factor for identifying the presence of sarcopenic dysphagia was tongue muscle area (sensitivity, 0.389; specificity, 0.947; cut-off value, 1536.0), while the factor with the highest sensitivity was geniohyoid muscle area brightness in sagittal sections (sensitivity, 0.806; specificity, 0.632; cut-off value, 20.1). Multivariate logistic regression analysis showed that the area of the tongue muscle and its area of brightness were independent risk factors for sarcopenic dysphagia. However, geniohyoid sagittal muscle area and area of brightness showed no significant independent association with sarcopenic dysphagia. Tongue muscle mass in patients with sarcopenic dysphagia was smaller than that in patients without the condition. Sarcopenic dysphagia was also associated with increased intensity of the

Correlates of increased lean muscle mass in women with polycystic ovary syndrome.

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Carmina, E; Guastella, E; Longo, R A; Rini, G B; Lobo, R A

2009-10-01

Muscle mass plays an important role in determining cardiovascular and metabolic risks in polycystic ovary syndrome (PCOS). In addition, whether lean mass influences carotid intima-media thickness (IMT) in PCOS has not been assessed. Prospective investigation. Ninety-five women with PCOS were age- and weight-matched to 90 ovulatory controls. All women had dual X-ray absorptiometry for lean, fat and bone mass, and bone mass density (BMD). Serum testosterone, sex hormone-binding globulin, insulin, and glucose and carotid IMT were determined. Free androgen index (FAI) and insulin resistance (by QUICKI) were calculated. In PCOS, waist circumference and insulin were higher and QUICKI lower than in controls (Plean mass were higher in PCOS compared to controls (PPCOS (PPCOS patients had abnormal (> or = 0.9 mm) values. Lean mass correlated with fat parameters, insulin, QUICKI, and FAI, but not with total testosterone; and after adjustments for insulin and QUICKI, lean mass still correlated with fat mass (PLean mass correlated with IMT (Plean mass independently of insulin. Bone mass correlated with lean and fat mass, but not with insulin or androgen. PCOS patients with 'pathological' IMT values had higher % trunk fat, lean mass, and insulin, lower QUICKI, and higher testosterone and FAI compared with those with normal IMT. Lean mass is increased in PCOS, while bone mass is similar to that of matched controls. The major correlates of lean mass are fat mass and insulin but not androgen. Lean mass also correlated with IMT, and although influenced by insulin, small changes in IMT may partially reflect changes in muscle mass, while clearly abnormal values relate to more severe abnormalities of PCOS.

Subclinical hypothyroidism has little influences on muscle mass or strength in elderly people.

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Moon, Min Kyong; Lee, You Jin; Choi, Sung Hee; Lim, Soo; Yang, Eun Joo; Lim, Jae-Young; Paik, Nam-Jong; Kim, Ki Woong; Park, Kyong Soo; Jang, Hak C; Cho, Bo Youn; Park, Young Joo

2010-08-01

Sarcopenia, the age-related decline in muscle mass, affects the muscle strength and muscle quality, and these changes decrease functional capacity. The prevalence of thyroid dysfunction increases with age, and changes in thyroid hormone level lead to neuromuscular deficits. We investigated the effects of subclinical hypothyroidism on the muscle mass, strength or quality in elderly people. One thousand one hundred eighteen subjects aged > or = 65 yr were randomly selected from a local population and classified into a euthyroid (280 men and 358 women), subclinically hypothyroid (61 men and 75 women), or overtly hypothyroid (7 men and 16 women) group. Although women with subclinical hypothyroidism had a higher prevalence of sarcopenia, defined according to the ratio of appendicular skeletal muscle mass to the square of height, muscle mass, strength or quality did not differ in relation to thyroid status in men or in women. Multivariate analysis including age, diabetes, hypertension, acute coronary event, alcohol, smoking, presence of pain, physical activity score, and lipid profile, showed that thyroid-stimulating hormone level was not associated with muscle mass, strength or quality. In conclusion, subclinical hypothyroidism has little influences on muscle mass, strength or quality, and may not be associated with sarcopenia.

Diagnostic ultrasound estimates of muscle mass and muscle quality discriminate between women with and without sarcopenia

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Catheeja eIsmail

2015-10-01

Full Text Available Introduction: Age-related changes in muscle mass and muscle tissue composition contribute to diminished strength in older adults. The objectives of this study are to examine if an assessment method using mobile diagnostic ultrasound augments well-known determinants of lean body mass (LBM to aid sarcopenia staging, and if a sonographic measure of muscle quality is associated with muscle performance.Methods: Twenty community-dwelling female subjects participated in the study (age = 43.4 ±20.9 years; BMI: 23.8, interquartile range: 8.5. Dual energy X-ray absorptiometry (DXA and diagnostic ultrasound morphometry were used to estimate LBM. Muscle tissue quality was estimated via the echogenicity using grayscale histogram analysis. Peak force was measured with grip dynamometry and scaled for body size. Bivariate and multiple regression analyses were used to determine the association of the predictor variables with appendicular lean mass (aLM/ht2, and examine the relationship between scaled peak force values and muscle echogenicity. The sarcopenia LBM cut point value of 6.75 kg/m2 determined participant assignment into the Normal LBM and Low LBM subgroups.Results: The selected LBM predictor variables were body mass index (BMI, ultrasound morphometry, and age. Although BMI exhibited a significant positive relationship with aLM/ht2 (adj. R2 = .61, p < .001, the strength of association improved with the addition of ultrasound morphometry and age as predictor variables (adj. R2 = .85, p < .001. Scaled peak force was associated with age and echogenicity (adj. R2 = .53, p < .001, but not LBM. The Low LBM subgroup of women (n = 10 had higher scaled peak force, lower BMI, and lower echogenicity values in comparison to the Normal LBM subgroup (n = 10; p < .05.Conclusions: Diagnostic ultrasound morphometry values are associated with LBM, and improve the BMI predictive model for aLM/ht2 in women. In addition, ultrasound proxy measures of muscle quality are more

Correlation between Body Mass Index, Gender, and Skeletal Muscle Mass Cut off Point in Bandung

OpenAIRE

Richi Hendrik Wattimena; Vitriana; Irma Ruslina Defi

2017-01-01

Objective: To determine the average skeletal muscle mass (SMM) value in young adults as a reference population; to analyze the correlation of gender, and body mass index to the cut off point; and to determine skeletal muscle mass cut off points of population in Bandung, Indonesia. Methods: This was a cross-sectional study involving 199 participants, 122 females and 77 males. The sampling technique used was the multistage random sampling. The participants were those who lived in four ma...

Muscle hypertrophy: a narrative review on training principles for increasing muscle mass

OpenAIRE

Howe, Louis; Read, Paul; Waldron, Mark

2017-01-01

Developing muscle cross-sectional area has the potential to enhance performance for many athletes. Because emerging evidence challenges traditional beliefs regarding the prescription of hypertrophy-focused training programs, this review provides an overview of the current literature relating, specifically, to programming variables. Evidence-based recommendations are provided for the design of effective resistance-training programs, with the goal of increasing an athlete's skeletal muscle mass.

Relationship between oxidative stress and muscle mass loss in early postmenopause: an exploratory study.

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Zacarías-Flores, Mariano; Sánchez-Rodríguez, Martha A; García-Anaya, Oswaldo Daniel; Correa-Muñoz, Elsa; Mendoza-Núñez, Víctor Manuel

2018-04-09

Endocrine changes due to menopause have been associated to oxidative stress and muscle mass loss. The study objective was to determine the relationship between both variables in early postmenopause. An exploratory, cross-sectional study was conducted in 107 pre- and postmenopausal women (aged 40-57 years). Levels of serum lipid peroxides and uric acid and enzymes superoxide dismutase and glutathione peroxidase, as well as total plasma antioxidant capacity were measured as oxidative stress markers. Muscle mass using bioelectrical impedance and muscle strength using dynamometry were also measured. Muscle mass, skeletal muscle index, fat-free mass, and body mass index were calculated. More than 90% of participants were diagnosed with overweight or obesity. Postmenopausal women had lower values of muscle mass and strength markers, with a negative correlation between lipid peroxide level and skeletal muscle index (r= -0.326, p<.05), and a positive correlation between uric acid and skeletal muscle index (r=0.295, p<.05). A multivariate model including oxidative stress markers, age, and waist circumference showed lipid peroxide level to be the main contributor to explain the decrease in skeletal muscle mass in postmenopause, since for every 0.1μmol/l increase in lipid peroxide level, skeletal muscle index decreases by 3.03 units. Our findings suggest an association between increased oxidative stress and muscle mass loss in early postmenopause. Copyright © 2018 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.

Sex and race/ethnic disparities in the cross-sectional association between depressive symptoms and muscle mass: the Multi-ethnic Study of Atherosclerosis.

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Remigio-Baker, Rosemay A; Allison, Matthew A; Schreiner, Pamela J; Carnethon, Mercedes R; Nettleton, Jennifer A; Mujahid, Mahasin S; Szklo, Moyses; Crum, Rosa M; Leuotsakos, Jeannie-Marie; Franco, Manuel; Jensky, Nicole; Golden, Sherita Hill

2015-09-18

The cross-sectional area of total muscle mass has been reported to decrease by about 40% for those 20-60 years of age. Depressive symptoms may discourage motivation to engage in physical activity such as strength training shown to negate muscle loss. Inflammation related to depressive symptoms may also contribute to muscle atrophy. Physiological differences by sex and race/ethnicity may also modify the association between depression and muscle mass. Evidence on the relationship between depression (or depressive symptoms) and adiposity has been mounting; however, little is known about the depressive symptoms-muscle mass association. We sought to determine the association between elevated depressive symptoms (EDS) and lean muscle mass and whether this varies by sex and race/ethnicity. Evaluating 1605 adults (45-84 years of age) from the Multi-ethnic Study of Atherosclerosis Abdominal Body Composition, Inflammation and Cardiovascular Disease Study, we examined the cross-sectional association between EDS (Center for Epidemiologic Studies for Depression Scale score≥16 and/or antidepressant use) and computed tomography-measured abdominal lean muscle mass using linear regression. Muscles were evaluated as a whole and by functionality (locomotion vs. stabilization/posture). Covariates included height, body mass index, sociodemographics, comorbidities, inflammatory markers and health behaviors (pack-years of smoking, alcohol locomotion compared to men, total intentional exercise, daily caloric intake). Sex and race/ethnicity were assessed as potential modifiers. Statistical significance was at a pdepressive symptoms had 5.9 cm2 lower lean muscle mass for locomotion compared to men without EDS, fully-adjusted (CI=-10.5, -1.4, p=0.011). This was statistically significantly different from the null finding among women (interaction p=0.05). Chinese participants with EDS had 10.2 cm2 lower abdominal lean muscle mass for locomotion compared to those without EDS (fully

Relationship of Muscle Mass Determined by DEXA with Spirometric Results in Healthy Individuals.

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Martín Holguera, Rafael; Turrión Nieves, Ana Isabel; Rodríguez Torres, Rosa; Alonso, María Concepción

2017-07-01

Muscle mass maybe a determining factor in the variability of spirometry results in individuals of the same sex and age who have similar anthropometric characteristics. The aim of this study was to determine the association between spirometric results from healthy individuals and their muscle mass assessed by dual energy X-ray absorptiometry (DEXA). A sample of 161 women and 144 men, all healthy non-smokers, was studied. Ages ranged from18 to77years. For each subject, spirometry results and total and regional lean mass values obtained by full body DEXA were recorded. A descriptive analysis of the variables and a regression analysis were performed to study the relationship between spirometric variables and lean body mass, correcting for age and body mass index (BMI). In both sexes all muscle mass variables correlated positively and significantly with spirometric variables, and to a greater extent in men. After partial adjustment of correlations by age and BMI, the factor which best explains the spirometric variables is the total lean body mass in men, and trunk lean body mass in women. In men, muscle mass in the lower extremities is most closely associated with spirometric results. In women, it is the muscle mass of the trunk. In both sexes muscle mass mainly affects FEV 1 . Copyright © 2016 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

Association between healthy diet and exercise and greater muscle mass in older adults.

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Kim, Jinhee; Lee, Yunhwan; Kye, Seunghee; Chung, Yoon-Sok; Kim, Kwang-Min

2015-05-01

To examine the association between healthy diet and exercise, individually and combined, and low muscle mass in older Korean adults. Population-based cross-sectional study from the Fourth and Fifth Korea National Health and Nutrition Examination Surveys from 2008 to 2011. Community. Nationally representative sample aged 65 and older (1,486 men, 1,799 women) in the Republic of Korea. A food frequency questionnaire was used to determine frequency of food group consumption (meat, fish, eggs, legumes; vegetables; fruits). Participation in exercise (aerobic and resistance) was based on self-report. Combined healthy lifestyle factors were calculated as the number of recommendations met regarding consumption of food groups and exercise performed. Appendicular skeletal muscle mass (ASM) was measured using dual-energy X-ray absorptiometry, and low muscle mass was defined using the variable of ASM adjusted for weight. Logistic regression analysis was performed to examine the association between healthy lifestyle factors and low muscle mass, adjusting for sociodemographic characteristics and health-related variables. In women, after controlling for covariates, vegetable consumption (odds ratio (OR)=0.52, 95% confidence interval (CI)=0.30-0.89) and aerobic exercise (OR=0.62, 95% CI=0.39-1.00) were inversely associated with low muscle mass. Also, the odds of low muscle mass was lower in women with three or more healthy lifestyle factors versus none (OR=0.45, 95% CI=0.23-0.87). In men, there were no associations between food group consumption and exercise and low muscle mass. Older women who exercise and consume a healthy diet have lower odds of low muscle mass. Engaging in multiple healthy behaviors may be important in preventing low muscle mass in late life. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

Fat-Free Mass and Skeletal Muscle Mass Five Years After Bariatric Surgery.

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Davidson, Lance E; Yu, Wen; Goodpaster, Bret H; DeLany, James P; Widen, Elizabeth; Lemos, Thaisa; Strain, Gladys W; Pomp, Alfons; Courcoulas, Anita P; Lin, Susan; Janumala, Isaiah; Thornton, John C; Gallagher, Dympna

2018-07-01

This study investigated changes in fat-free mass (FFM) and skeletal muscle 5 years after surgery in participants from the Longitudinal Assessment of Bariatric Surgery-2 trial. A three-compartment model assessed FFM, and whole-body magnetic resonance imaging (MRI) quantified skeletal muscle mass prior to surgery (T0) and 1 year (T1), 2 years (T2), and 5 years (T5) postoperatively in 93 patients (85% female; 68% Caucasian; age 44.2 ± 11.6 years) who underwent gastric bypass (RYGB), sleeve gastrectomy, or adjustable gastric band. Repeated-measures mixed models were used to analyze the data. Significant weight loss occurred across all surgical groups in females from T0 to T1. FFM loss from T0 to T1 was greater after RYGB (mean ± SE: -6.9 ± 0.6 kg) than adjustable gastric band (-3.5 ± 1.4 kg; P FFM (-3.3 ± 0.7 kg; P FFM loss while maintaining FFM and skeletal muscle from T1 to T5. Between 1 and 5 years following common bariatric procedures, FFM and skeletal muscle are maintained or decrease minimally. The changes observed in FFM and muscle during the follow-up phase may be consistent with aging. © 2018 The Obesity Society.

Increase in relative skeletal muscle mass over time and its inverse association with metabolic syndrome development: a 7-year retrospective cohort study.

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Kim, Gyuri; Lee, Seung-Eun; Jun, Ji Eun; Lee, You-Bin; Ahn, Jiyeon; Bae, Ji Cheol; Jin, Sang-Man; Hur, Kyu Yeon; Jee, Jae Hwan; Lee, Moon-Kyu; Kim, Jae Hyeon

2018-02-05

Skeletal muscle mass was negatively associated with metabolic syndrome prevalence in previous cross-sectional studies. The aim of this study was to investigate the impact of baseline skeletal muscle mass and changes in skeletal muscle mass over time on the development of metabolic syndrome in a large population-based 7-year cohort study. A total of 14,830 and 11,639 individuals who underwent health examinations at the Health Promotion Center at Samsung Medical Center, Seoul, Korea were included in the analyses of baseline skeletal muscle mass and those changes from baseline over 1 year, respectively. Skeletal muscle mass was estimated by bioelectrical impedance analysis and was presented as a skeletal muscle mass index (SMI), a body weight-adjusted appendicular skeletal muscle mass value. Using Cox regression models, hazard ratio for developing metabolic syndrome associated with SMI values at baseline or changes of SMI over a year was analyzed. During 7 years of follow-up, 20.1% of subjects developed metabolic syndrome. Compared to the lowest sex-specific SMI tertile at baseline, the highest sex-specific SMI tertile showed a significant inverse association with metabolic syndrome risk (adjusted hazard ratio [AHR] = 0.61, 95% confidence interval [CI] 0.54-0.68). Furthermore, compared with SMI changes metabolic syndrome development were 0.87 (95% CI 0.78-0.97) for 0-1% changes and 0.67 (0.56-0.79) for > 1% changes in SMI over 1 year after additionally adjusting for baseline SMI and glycometabolic parameters. An increase in relative skeletal muscle mass over time has a potential preventive effect on developing metabolic syndrome, independently of baseline skeletal muscle mass and glycometabolic parameters.

Relationship of interleukin-6 and tumor necrosis factor-alpha with muscle mass and muscle strength in elderly men and women : the Health ABC Study

NARCIS (Netherlands)

Visser, Marjolein; Pahor, Marco; Taaffe, Dennis R; Goodpaster, Bret H; Simonsick, Eleanor M; Newman, Anne B; Nevitt, Michael; Harris, Tamara B

BACKGROUND: A decline in muscle mass and muscle strength characterizes normal aging. As clinical and animal studies show a relationship between higher cytokine levels and low muscle mass, the aim of this study was to investigate whether markers of inflammation are associated with muscle mass and

Appendicular Skeletal Muscle Mass Reference Values and the Peak Muscle Mass to Identify Sarcopenia among Iranian Healthy Population.

Science.gov (United States)

Shafiee, Gita; Ostovar, Afshin; Heshmat, Ramin; Keshtkar, Abbas Ali; Sharifi, Farshad; Shadman, Zhaleh; Nabipour, Iraj; Soltani, Akbar; Larijani, Bagher

2018-01-01

Sacopenia is a common problem in elderly with the adverse outcomes. The objective of this study was to estimate the peak appendicular skeletal muscle mass (ASM) and age of its attainment by sex among the Iranian population. A total of 691 men and women aged 18-94 years participated in this cross-sectional, population-based study in Bushehr, Iran. ASM was measured by dual X-ray absorptiometry. Cutoff points for men and women were established considering two standard deviations (SDs) below the mean values of the skeletal muscle index (SMI) for young reference groups. The relationship between ASM and age was described by the second-degree regression models. Two SDs below the mean SMIs of reference groups were as cutoff values of low muscle mass in Iranian population. The peak ASM values were 21.35 ± 0.12 Kg and 13.68 ± 0.10 Kg, and the age at peak ASM were 26 (24-28) years and 34 (33-35) years for men and women, respectively. Mean and SD of SMI in those ages were 7.01 ± 0.02 Kg/m 2 and 5.44 ± 0.02 Kg/m 2 among men and women, respectively. Calculated cutoff values of low muscle mass among the Iranian population were 7.0 Kg/m 2 and 5.4 Kg/m 2 among men and women, respectively. Iranian reference values of SMI for both genders were similar to Asia Working Group for Sarcopenia recommendation and lower than the United States and European values. Further studies from different nations and the Middle East countries are needed to obtain reference values for populations, enabling the researchers for comparison and also more valid reports on sarcopenia prevalence.

Relative Skeletal Muscle Mass Is Associated with Development of Metabolic Syndrome

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Byung Sam Park

2013-12-01

Full Text Available BackgroundVisceral adiposity is related to insulin resistance. Skeletal muscle plays a central role in insulin-mediated glucose disposal; however, little is known about the association between muscle mass and metabolic syndrome (MS. This study is to clarify the clinical role of skeletal muscle mass in development of MS.MethodsA total of 1,042 subjects were enrolled. Subjects with prior MS and chronic diseases were excluded. After 24 months, development of MS was assessed using NCEP-ATP III criteria. Skeletal muscle mass (SMM; kg, body fat mass (BFM; kg, and visceral fat area (VFA; cm2 were obtained from bioelectrical analysis. Then, the following values were calculated as follows: percent of SMM (SMM%; %: SMM (kg/weight (kg, skeletal muscle index (SMI; kg/m2: SMM (kg/height (m2, skeletal muscle to body fat ratio (MFR: SMM (kg/BFM (kg, and skeletal muscle to visceral fat ratio (SVR; kg/cm2: SMM (kg/VFA (cm2.ResultsAmong 838 subjects, 88 (10.5% were newly diagnosed with MS. Development of MS increased according to increasing quintiles of BMI, SMM, VFA, and SMI, but was negatively associated with SMM%, MFR, and SVR. VFA was positively associated with high waist circumference (WC, high blood pressure (BP, dysglycemia, and high triglyceride (TG. In contrast, MFR was negatively associated with high WC, high BP, dysglycemia, and high TG. SVR was negatively associated with all components of MS.ConclusionRelative SMM ratio to body composition, rather than absolute mass, may play a critical role in development of MS and could be used as a strong predictor.

Impact of low skeletal muscle mass and density on short and long-term outcome after resection of stage I-III colorectal cancer.

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van Vugt, Jeroen L A; Coebergh van den Braak, Robert R J; Lalmahomed, Zarina S; Vrijland, Wietske W; Dekker, Jan W T; Zimmerman, David D E; Vles, Wouter J; Coene, Peter-Paul L O; IJzermans, Jan N M

2018-06-06

Preoperative low skeletal muscle mass and density are associated with increased postoperative morbidity in patients undergoing curative colorectal cancer (CRC) surgery. However, the long-term effects of low skeletal muscle mass and density remain uncertain. Patients with stage I-III CRC undergoing surgery, enrolled in a prospective observational cohort study, were included. Skeletal muscle mass and density were measured on CT. Patients with high and low skeletal muscle mass and density were compared regarding postoperative complications, disease-free survival (DFS), overall survival (OS), and cancer-specific survival (CSS). In total, 816 patients (53.9% males, median age 70) were included; 50.4% had low skeletal muscle mass and 64.1% low density. The severe postoperative complication rate was significantly higher in patients with low versus high skeletal muscle and density (20.9% versus 13.6%, p = 0.006; 20.0% versus 11.8%, p = 0.003). Low skeletal muscle mass (OR 1.91, p = 0.018) and density (OR 1.87, p = 0.045) were independently associated with severe postoperative complications. Ninety-day mortality was higher in patients with low skeletal muscle mass and density compared with patients with high skeletal muscle mass and density (3.6% versus 1.7%, p = 0.091; 3.4% versus 1.0%, p = 0.038). No differences in DFS were observed. After adjustment for covariates such as age and comorbidity, univariate differences in OS and CSS diminished. Low skeletal muscle mass and density are associated with short-term, but not long-term, outcome in patients undergoing CRC surgery. These findings recommend putting more emphasis on preoperative management of patients at risk for surgical complications, but do not support benefit for long-term outcome. Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

[Variation of muscle mass and weight in critical patient].

Science.gov (United States)

Valls-Matarín, J; del Cotillo-Fuente, M; Grané-Mascarell, N; Quintana, S

2015-01-01

Quantify the muscle mass and body weight variation in critically ill patients and to identify associated factors. A descriptive follow-up study. Data for demographic variables, body weight, fluid balance, daily kilocalories, the amount of sedation and muscle relaxants received and motor physiotherapy applied were collected. Three consecutive measurements were performed in the brachial biceps and quadriceps rectus by using ultrasound, upon admission and every 5 days until discharge. 68 patients were included. Average age was of 73.5 [57-78,5] years. The median length of stay was 9.5 [5.5 -15] days. The median 16 (SD=5.7) daily kilocalories per kg/weight, 91.2% received sedation, 44.1% received muscle relaxants and 20% received physiotherapy. The patients presented a muscle wasting of 4.9 (SD=3.9)mm, p <.001 in the brachial biceps and 5.6 (SD=4.8)mm, p <.001 in the quadriceps rectus. Regression analysis selected the length of stay and the muscle relaxants are the most influential variables in the brachial biceps muscle wasting (R2=0.4), and length of stay as the most influential in the quadriceps rectus muscle wasting (R2=0.3). Patient's mean body weight on admission was of 81.1 (SD=15)kg and 81.2 (SD=14.2)kg on discharge, p=.95. The critically ill patient presents a significant muscle waste related with the length of stay and the treatment received with muscle relaxants. Patients are being discharged with a similar body weight to which they were admitted but with a significant reduction of muscle mass. Copyright © 2014 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

High risk of malnutrition is associated with low muscle mass in older hospitalized patients - a prospective cohort study.

Science.gov (United States)

Pierik, Vincent D; Meskers, Carel G M; Van Ancum, Jeanine M; Numans, Siger T; Verlaan, Sjors; Scheerman, Kira; Kruizinga, Roeliene C; Maier, Andrea B

2017-06-05

Malnutrition, low muscle strength and muscle mass are highly prevalent in older hospitalized patients and associated with adverse outcomes. Malnutrition may be a risk factor for developing low muscle mass. We aimed to investigate the association between the risk of malnutrition and 1) muscle strength and muscle mass at admission and 2) the change of muscle strength and muscle mass during hospitalization in older patients. The EMPOWER study included 378 patients aged seventy years or older who were acutely or electively admitted to four different wards of an academic teaching hospital in Amsterdam. Patients were grouped into low risk of malnutrition and high risk of malnutrition based on the Short Nutritional Assessment Questionnaire (SNAQ) score and were assessed for hand grip strength and muscle mass using hand held dynamometry respectively bioelectrical impedance analysis (BIA) within 48 h after admission and at day seven, or earlier at the day of discharge. Muscle mass was expressed as skeletal muscle mass, appendicular lean mass, fat free mass and the skeletal muscle index. The mean age of the patients was 79.7 years (SD 6.39), 48.9% were female. At admission, being at high risk of malnutrition was significantly associated with lower muscle mass (Odds Ratio, 95% CI, 0.90, 0.85-0.96), but not with muscle strength. Muscle strength and muscle mass did not change significantly during hospitalization in both groups. In older hospitalized patients, a high risk of malnutrition is associated with lower muscle mass at admission, but not with muscle strength nor with change of either muscle strength or muscle mass during hospitalization.

Delayed Recovery of Skeletal Muscle Mass following Hindlimb Immobilization in mTOR Heterozygous Mice

OpenAIRE

Lang, Susan M.; Kazi, Abid A.; Hong-Brown, Ly; Lang, Charles H.

2012-01-01

The present study addressed the hypothesis that reducing mTOR, as seen in mTOR heterozygous (+/-) mice, would exaggerate the changes in protein synthesis and degradation observed during hindlimb immobilization as well as impair normal muscle regrowth during the recovery period. Atrophy was produced by unilateral hindlimb immobilization and data compared to the contralateral gastrocnemius. In wild-type (WT) mice, the gradual loss of muscle mass plateaued by day 7. This response was associated ...

Effects of high-intensity exercise and protein supplement on muscle mass in ADL dependent older people with and without malnutrition: a randomized controlled trial.

Science.gov (United States)

Carlsson, M; Littbrand, H; Gustafson, Y; Lundin-Olsson, L; Lindelöf, N; Rosendahl, E; Håglin, L

2011-08-01

Loss of muscle mass is common among old people living in institutions but trials that evaluate interventions aimed at increasing the muscle mass are lacking. Objective, participants and intervention: This randomized controlled trial was performed to evaluate the effect of a high-intensity functional exercise program and a timed protein-enriched drink on muscle mass in 177 people aged 65 to 99 with severe physical or cognitive impairments, and living in residential care facilities. Three-month high-intensity exercise was compared with a control activity and a protein-enriched drink was compared with a placebo drink. A bioelectrical impedance spectrometer (BIS) was used in the evaluation. The amount of muscle mass and body weight (BW) were followed-up at three and six months and analyzed in a 2 x 2 factorial ANCOVA, using the intention to treat principle, and controlling for baseline values. At 3-month follow-up there were no differences in muscle mass and BW between the exercise and the control group or between the protein and the placebo group. No interaction effects were seen between the exercise and nutritional intervention. Long-term negative effects on muscle mass and BW was seen in the exercise group at the 6-month follow-up. A three month high-intensity functional exercise program did not increase the amount of muscle mass and an intake of a protein-enriched drink immediately after the exercise did not induce any additional effect on muscle mass. There were negative long-term effects on muscle mass and BW, indicating that it is probably necessary to compensate for an increased energy demand when offering a high-intensity exercise program.

Measurement of Muscle Protein Fractional Synthetic Rate by Capillary Gas Chromatography/Combustion Isotope Ratio Mass Spectrometry

OpenAIRE

Yarasheski, Kevin E.; Smith, Kenneth; Rennie, Michael J.; Bier, Dennis M.

1992-01-01

The measurement of skeletal muscle protein fractional synthetic rate using an infusion of (1-13C)leucine and measuring the isotopic abundance of the tracer in skeletal muscle protein by preparative gas chromatography (GC)/ninhydrin isotope ratio mass spectrometry (IRMS) is laborious and subject to errors owing to contamination by 12C. The purpose of this study was to compare muscle (13C)leucine enrichment measured with the conventional preparative GC/ninhydrin IRMS approach to a new, continuo...

The Effects of Muscle Mass on Homocyst(e)ine Levels in Plasma and Urine.

Science.gov (United States)

Malinow, M René; Lister, Craig L; DE Crée, Carl

The present study was designed to examine the relationship between homocyst(e)ine (H[e]) levels and muscle mass. Two experimental groups each of 24 Caucasian males, one consisting of higher-muscle mass subjects (HMM) and the other of lower-muscle mass subjects (LMM) participated in this study. Muscle mass was estimated from 24-hour urine collections of creatinine (Crt). Muscle mass was 40.3 ± 15.9 kg in HMM and 37.2 ± 11.4 kg in LMM (P= 0.002). Mean plasma H(e) levels in HMM were 10.29 ± 2.9 nmol/mL, and in LMM were 10.02 ± 2.4 nmol/L (Not significant, [NS]). Urinary H(e) levels (UH[e]) were 9.95 ± 4.3 nmol/mL and 9.22 ± 2.9 nmol/mL for HMM and LMM, respectively (NS). Plasma H(e) levels correlated well with UH(e) (HMM: r= 0.58, P= 0.009; LMM: r= 0.66, P= 0.004). Muscle mass and was not correlated to either plasma H(e) or UH(e). However, in HMM trends were identified for body mass to be correlated with UH(e) (r= 0.39, P= 0.10) and UCrt (r= 0.41, P= 0.08). Surprisingly, in HMM plasma and UCrt were only weakly correlated (r= 0.44, P= 0.06). Our results do not support a causal relationship between the amount of muscle mass and H(e) levels in plasma or urine.

Association of low back pain with muscle stiffness and muscle mass of the lumbar back muscles, and sagittal spinal alignment in young and middle-aged medical workers.

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Masaki, Mitsuhiro; Aoyama, Tomoki; Murakami, Takashi; Yanase, Ko; Ji, Xiang; Tateuchi, Hiroshige; Ichihashi, Noriaki

2017-11-01

Muscle stiffness of the lumbar back muscles in low back pain (LBP) patients has not been clearly elucidated because quantitative assessment of the stiffness of individual muscles was conventionally difficult. This study aimed to examine the association of LBP with muscle stiffness assessed using ultrasonic shear wave elastography (SWE) and muscle mass of the lumbar back muscle, and spinal alignment in young and middle-aged medical workers. The study comprised 23 asymptomatic medical workers [control (CTR) group] and 9 medical workers with LBP (LBP group). Muscle stiffness and mass of the lumbar back muscles (lumbar erector spinae, multifidus, and quadratus lumborum) in the prone position were measured using ultrasonic SWE. Sagittal spinal alignment in the standing and prone positions was measured using a Spinal Mouse. The association with LBP was investigated by multiple logistic regression analysis with a forward selection method. The analysis was conducted using the shear elastic modulus and muscle thickness of the lumbar back muscles, and spinal alignment, age, body height, body weight, and sex as independent variables. Multiple logistic regression analysis showed that muscle stiffness of the lumbar multifidus muscle and body height were significant and independent determinants of LBP, but that muscle mass and spinal alignment were not. Muscle stiffness of the lumbar multifidus muscle in the LBP group was significantly higher than that in the CTR group. The results of this study suggest that LBP is associated with muscle stiffness of the lumbar multifidus muscle in young and middle-aged medical workers. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Regulation of Muscle Mass by Endogenous Glucocorticoids

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Daniel L Marks

2015-02-01

Full Text Available Glucocorticoids are highly conserved fundamental regulators of energy homeostasis. In response to stress in the form of perceived danger or acute inflammation, glucocorticoids are released from the adrenal gland, rapidly mobilizing energy from carbohydrate, fat and protein stores. In the case of inflammation, mobilized protein is critical for the rapid synthesis of acute phase reactants and an efficient immune response to infection. While adaptive in response to infection, chronic mobilization can lead to a p rofound depletion of energy stores. Skeletal muscle represents the major body store of protein, and can become substantially atrophied under conditions of chronic inflammation. Glucocorticoids elicit the atrophy of muscle by increasing the rate of protein degradation by the ubiquitin-proteasome system and autophagy lysosome system. Protein synthesis is also suppressed at the level of translational initiation, preventing the production of new myofibrillar protein. Glucocorticoids also antagonize the action of anabolic regulators such as insulin further exacerbating the loss of protein and muscle mass. The loss of muscle mass in the context of chronic disease is a key feature of cachexia and contributes substantially to morbidity and mortality. A growing body of evidence demonstrates that glucocorticoid signaling is a common mediator of wasting, irrespective of the underlying initiator or disease state. This review will highlight fundamental mechanisms of glucocorticoid signaling and detail the mechanisms of glucocorticoid-induced muscle atrophy. Additionally, the evidence for glucocorticoids as a driver of muscle wasting in numerous disease states will be discussed. Given the burden of wasting diseases and the nodal nature of glucocorticoid signaling, effective anti-glucocorticoid therapy would be a valuable clinical tool. Therefore, the progress and potential pitfalls in the development of glucocorticoid antagonists for muscle wasting will

Total body skeletal muscle mass: estimation by creatine (methyl-d3) dilution in humans

Science.gov (United States)

Walker, Ann C.; O'Connor-Semmes, Robin L.; Leonard, Michael S.; Miller, Ram R.; Stimpson, Stephen A.; Turner, Scott M.; Ravussin, Eric; Cefalu, William T.; Hellerstein, Marc K.; Evans, William J.

2014-01-01

Current methods for clinical estimation of total body skeletal muscle mass have significant limitations. We tested the hypothesis that creatine (methyl-d3) dilution (D3-creatine) measured by enrichment of urine D3-creatinine reveals total body creatine pool size, providing an accurate estimate of total body skeletal muscle mass. Healthy subjects with different muscle masses [n = 35: 20 men (19–30 yr, 70–84 yr), 15 postmenopausal women (51–62 yr, 70–84 yr)] were housed for 5 days. Optimal tracer dose was explored with single oral doses of 30, 60, or 100 mg D3-creatine given on day 1. Serial plasma samples were collected for D3-creatine pharmacokinetics. All urine was collected through day 5. Creatine and creatinine (deuterated and unlabeled) were measured by liquid chromatography mass spectrometry. Total body creatine pool size and muscle mass were calculated from D3-creatinine enrichment in urine. Muscle mass was also measured by magnetic resonance imaging (MRI), dual-energy x-ray absorptiometry (DXA), and traditional 24-h urine creatinine. D3-creatine was rapidly absorbed and cleared with variable urinary excretion. Isotopic steady-state of D3-creatinine enrichment in the urine was achieved by 30.7 ± 11.2 h. Mean steady-state enrichment in urine provided muscle mass estimates that correlated well with MRI estimates for all subjects (r = 0.868, P creatine dose determined by urine D3-creatinine enrichment provides an estimate of total body muscle mass strongly correlated with estimates from serial MRI with less bias than total lean body mass assessment by DXA. PMID:24764133

Phenotype selection reveals coevolution of muscle glycogen and protein and PTEN as a gate keeper for the accretion of muscle mass in adult female mice.

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Mandy Sawitzky

Full Text Available We have investigated molecular mechanisms for muscle mass accretion in a non-inbred mouse model (DU6P mice characterized by extreme muscle mass. This extreme muscle mass was developed during 138 generations of phenotype selection for high protein content. Due to the repeated trait selection a complex setting of different mechanisms was expected to be enriched during the selection experiment. In muscle from 29-week female DU6P mice we have identified robust increases of protein kinase B activation (AKT, Ser-473, up to 2-fold if compared to 11- and 54-week DU6P mice or controls. While a number of accepted effectors of AKT activation, including IGF-I, IGF-II, insulin/IGF-receptor, myostatin or integrin-linked kinase (ILK, were not correlated with this increase, phosphatase and tensin homologue deleted on chromosome 10 (PTEN was down-regulated in 29-week female DU6P mice. In addition, higher levels of PTEN phosphorylation were found identifying a second mechanism of PTEN inhibition. Inhibition of PTEN and activation of AKT correlated with specific activation of p70S6 kinase and ribosomal protein S6, reduced phosphorylation of eukaryotic initiation factor 2α (eIF2α and higher rates of protein synthesis in 29-week female DU6P mice. On the other hand, AKT activation also translated into specific inactivation of glycogen synthase kinase 3ß (GSK3ß and an increase of muscular glycogen. In muscles from 29-week female DU6P mice a significant increase of protein/DNA was identified, which was not due to a reduction of protein breakdown or to specific increases of translation initiation. Instead our data support the conclusion that a higher rate of protein translation is contributing to the higher muscle mass in mid-aged female DU6P mice. Our results further reveal coevolution of high protein and high glycogen content during the selection experiment and identify PTEN as gate keeper for muscle mass in mid-aged female DU6P mice.

The Intriguing Regulators of Muscle Mass in Sarcopenia and Muscular Dystrophy

OpenAIRE

Sakuma, Kunihiro; Aoi, Wataru; Yamaguchi, Akihiko

2014-01-01

Recent advances in our understanding of the biology of muscle have led to new interest in the pharmacological treatment of muscle wasting. Loss of muscle mass and increased intramuscular fibrosis occur in both sarcopenia and muscular dystrophy. Several regulators (mammalian target of rapamycin, serum response factor, atrogin-1, myostatin, etc.) seem to modulate protein synthesis and degradation or transcription of muscle-specific genes during both sarcopenia and muscular dystrophy. This revie...

Muscle mass, BMI, and mortality among adults in the United States: A population-based cohort study.

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Abramowitz, Matthew K; Hall, Charles B; Amodu, Afolarin; Sharma, Deep; Androga, Lagu; Hawkins, Meredith

2018-01-01

The level of body-mass index (BMI) associated with the lowest risk of death remains unclear. Although differences in muscle mass limit the utility of BMI as a measure of adiposity, no study has directly examined the effect of muscle mass on the BMI-mortality relationship. Body composition was measured by dual-energy x-ray absorptiometry in 11,687 participants of the National Health and Nutrition Examination Survey 1999-2004. Low muscle mass was defined using sex-specific thresholds of the appendicular skeletal muscle mass index (ASMI). Proportional hazards models were created to model associations with all-cause mortality. At any level of BMI ≥22, participants with low muscle mass had higher body fat percentage (%TBF), an increased likelihood of diabetes, and higher adjusted mortality than other participants. Increases in %TBF manifested as 30-40% smaller changes in BMI than were observed in participants with preserved muscle mass. Excluding participants with low muscle mass or adjustment for ASMI attenuated the risk associated with low BMI, magnified the risk associated with high BMI, and shifted downward the level of BMI associated with the lowest risk of death. Higher ASMI was independently associated with lower mortality. Effects were similar in never-smokers and ever-smokers. Additional adjustment for waist circumference eliminated the risk associated with higher BMI. Results were unchanged after excluding unintentional weight loss, chronic illness, early mortality, and participants performing muscle-strengthening exercises or recommended levels of physical activity. Muscle mass mediates associations of BMI with adiposity and mortality and is inversely associated with the risk of death. After accounting for muscle mass, the BMI associated with the greatest survival shifts downward toward the normal range. These results provide a concrete explanation for the obesity paradox.

Contraction-induced increases in Na+-K+-ATPase mRNA levels in human skeletal muscle are not amplified by activation of additional muscle mass

DEFF Research Database (Denmark)

Nordsborg, Nikolai; Thomassen, Martin; Lundby, Carsten

2005-01-01

The present study tested the hypothesis that exercise with a large compared with a small active muscle mass results in a higher contraction-induced increase in Na+-K+-ATPase mRNA expression due to greater hormonal responses. Furthermore, the relative abundance of Na+-K+-ATPase subunit a1, a2, a3, a......% of the a2 expression, and no reliable detection of a3 and a4 was possible. In conclusion, activation of additional muscle mass does not result in a higher exercise-induced increase in Na+-K+-ATPase subunit-specific mRNA.......4, ß1, ß2, and ß3 mRNA in human skeletal muscle was investigated. On two occasions, eight subjects performed one-legged knee extension exercise (L) or combined one-legged knee extension and bilateral arm cranking (AL) for 5.00, 4.25, 3.50, 2.75, and 2.00 min separated by 3 min of rest. Leg exercise...

Inflammatory markers and loss of muscle mass (sarcopenia) and strength

NARCIS (Netherlands)

Schaap, Laura A; Pluijm, Saskia M F; Deeg, Dorly J H; Visser, Marjolein

PURPOSE: The objective of this study was to investigate whether high levels of serum interleukin (IL)-6, C-reactive protein (CRP), and alpha1-antichymotrypsin (ACT) were associated with the loss of muscle strength or muscle mass (sarcopenia) in older persons. SUBJECTS: The study included 986 men and

Low muscle mass--tall and obese children a special genre of obesity.

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Ralt, Dina

2007-01-01

The prevalence of over-weight and obesity has increased markedly in the last two decades and vast international resources have been directed toward researching these issues. Obesity would appear to be a problem that is easy to resolve: just eat less and move more. However, this very common condition has turned out to be extremely troublesome, and in some cases even insolvable. A perspective is presented here suggesting that some of the insoluble cases of obesity are the result of an inborn condition of a very low muscle mass. The interplay between less muscle and more fat tissue is discussed from physiological and environmental perspectives with an emphasis on the early years of childhood. It is proposed that these interactions lead to bodily economic decisions sliding between thrift or prodigal strategies. The thrift strategy results not only in obesity and less physical activity but also in other maladies which the body is unable to manage. What leads to obesity (less muscle, more fat) in the medial population will result in morbid obesity when the children are short of muscle tissue from the start. Attempts to lessen the consequences of low muscle mass, which might be very difficult at adulthood, can be more fruitful if initiated at childhood. Early recognition of the ailment is thus crucial. Based on studies demonstrating a 'rivalry' between muscle build-up and height growth at childhood, it is postulated that among the both taller and more obese children the percentage of children with lower muscle mass will be significant. A survey of the height and BMI (Body Mass Index) of Israeli fifth graders supports this postulation. A special, body/muscle-building gymnastics program for children is suggested as a potential early intervention to partially prevent this type of almost irreversible ill progress of obesity.

Creatine Supplementation and Skeletal Muscle Metabolism for Building Muscle Mass- Review of the Potential Mechanisms of Action.

Science.gov (United States)

Farshidfar, Farnaz; Pinder, Mark A; Myrie, Semone B

2017-01-01

Creatine, a very popular supplement among athletic populations, is of growing interest for clinical applications. Since over 90% of creatine is stored in skeletal muscle, the effect of creatine supplementation on muscle metabolism is a widely studied area. While numerous studies over the past few decades have shown that creatine supplementation has many favorable effects on skeletal muscle physiology and metabolism, including enhancing muscle mass (growth/hypertrophy); the underlying mechanisms are poorly understood. This report reviews studies addressing the mechanisms of action of creatine supplementation on skeletal muscle growth/hypertrophy. Early research proposed that the osmotic effect of creatine supplementation serves as a cellular stressor (osmosensing) that acts as an anabolic stimulus for protein synthesis signal pathways. Other reports indicated that creatine directly affects muscle protein synthesis via modulations of components in the mammalian target of rapamycin (mTOR) pathway. Creatine may also directly affect the myogenic process (formation of muscle tissue), by altering secretions of myokines, such as myostatin and insulin-like growth factor-1, and expressions of myogenic regulatory factors, resulting in enhanced satellite cells mitotic activities and differentiation into myofiber. Overall, there is still no clear understanding of the mechanisms of action regarding how creatine affects muscle mass/growth, but current evidence suggests it may exert its effects through multiple approaches, with converging impacts on protein synthesis and myogenesis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Proteome-wide muscle protein fractional synthesis rates predict muscle mass gain in response to a selective androgen receptor modulator in rats.

Science.gov (United States)

Shankaran, Mahalakshmi; Shearer, Todd W; Stimpson, Stephen A; Turner, Scott M; King, Chelsea; Wong, Po-Yin Anne; Shen, Ying; Turnbull, Philip S; Kramer, Fritz; Clifton, Lisa; Russell, Alan; Hellerstein, Marc K; Evans, William J

2016-03-15

Biomarkers of muscle protein synthesis rate could provide early data demonstrating anabolic efficacy for treating muscle-wasting conditions. Androgenic therapies have been shown to increase muscle mass primarily by increasing the rate of muscle protein synthesis. We hypothesized that the synthesis rate of large numbers of individual muscle proteins could serve as early response biomarkers and potentially treatment-specific signaling for predicting the effect of anabolic treatments on muscle mass. Utilizing selective androgen receptor modulator (SARM) treatment in the ovariectomized (OVX) rat, we applied an unbiased, dynamic proteomics approach to measure the fractional synthesis rates (FSR) of 167-201 individual skeletal muscle proteins in triceps, EDL, and soleus. OVX rats treated with a SARM molecule (GSK212A at 0.1, 0.3, or 1 mg/kg) for 10 or 28 days showed significant, dose-related increases in body weight, lean body mass, and individual triceps but not EDL or soleus weights. Thirty-four out of the 94 proteins measured from the triceps of all rats exhibited a significant, dose-related increase in FSR after 10 days of SARM treatment. For several cytoplasmic proteins, including carbonic anhydrase 3, creatine kinase M-type (CK-M), pyruvate kinase, and aldolase-A, a change in 10-day FSR was strongly correlated (r(2) = 0.90-0.99) to the 28-day change in lean body mass and triceps weight gains, suggesting a noninvasive measurement of SARM effects. In summary, FSR of multiple muscle proteins measured by dynamics of moderate- to high-abundance proteins provides early biomarkers of the anabolic response of skeletal muscle to SARM. Copyright © 2016 the American Physiological Society.

Relation between body mass index percentile and muscle strength ...

African Journals Online (AJOL)

Relation between body mass index percentile and muscle strength and endurance. ... Egyptian Journal of Medical Human Genetics ... They were divided into three groups according to their body mass index percentile where group (a) is equal to or more than 5% percentile yet less than 85% percentile, group (b) is equal to ...

Prevalence of skeletal muscle mass loss and its association with swallowing function after cardiovascular surgery.

Science.gov (United States)

Wakabayashi, Hidetaka; Takahashi, Rimiko; Watanabe, Naoko; Oritsu, Hideyuki; Shimizu, Yoshitaka

2017-06-01

The aim of this study was to assess the prevalence of skeletal muscle mass loss and its association with swallowing function in patients with dysphagia after cardiovascular surgery. A retrospective cohort study was performed in 65 consecutive patients with dysphagia after cardiovascular surgery who were prescribed speech therapy. Skeletal muscle index (SMI) was calculated as total psoas muscle area assessed via abdominal computed tomography divided by height squared. Cutoff values were 6.36 cm 2 /m 2 for men and 3.92 cm 2 /m 2 for women. The Food Intake Level Scale (FILS) was used to assess the swallowing function. Univariate and ordered logistic regression analyses were applied to examine the associations between skeletal muscle mass loss and dysphagia. The study included 50 men and 15 women (mean age 73 ± 8 y). The mean SMI was 4.72 ± 1.37 cm 2 /m 2 in men and 3.33 ± 1.42 cm 2 /m 2 in women. Skeletal muscle mass loss was found in 53 (82%) patients. Twelve had tracheostomy cannula. Thirteen were non-oral feeding (FILS levels 1-3), 5 were oral food intake and alternative nutrition (levels 4-6), and 47 were oral food intake alone (levels 7-9) at discharge. The FILS at discharge was significantly lower in patients with skeletal muscle mass loss. Ordered logistic regression analysis of swallowing function showed that skeletal muscle mass loss and tracheostomy cannula were associated independently with the FILS at discharge. The prevalence of skeletal muscle mass loss is very high, and skeletal muscle mass loss is associated with swallowing function. Copyright © 2017 Elsevier Inc. All rights reserved.

Muscle mass as a target to reduce fatigue in patients with advanced cancer.

Science.gov (United States)

Neefjes, Elisabeth C W; van den Hurk, Renske M; Blauwhoff-Buskermolen, Susanne; van der Vorst, Maurice J D L; Becker-Commissaris, Annemarie; de van der Schueren, Marian A E; Buffart, Laurien M; Verheul, Henk M W

2017-08-01

Cancer-related fatigue (CRF) reduces quality of life and the activity level of patients with cancer. Cancer related fatigue can be reduced by exercise interventions that may concurrently increase muscle mass. We hypothesized that low muscle mass is directly related to higher CRF. A total of 233 patients with advanced cancer starting palliative chemotherapy for lung, colorectal, breast, or prostate cancer were studied. The skeletal muscle index (SMI) was calculated as the patient's muscle mass on level L3 or T4 of a computed tomography scan, adjusted for height. Fatigue was assessed with the Functional Assessment of Chronic Illness Therapy-fatigue questionnaire (cut-off for fatigue fatigue score was 36 (interquartile range 26-44). A higher SMI on level L3 was significantly associated with less CRF for men (B 0.447, P 0.004) but not for women (B - 0.401, P 0.090). No association between SMI on level T4 and the Functional Assessment of Chronic Illness Therapy-fatigue score was found (n = 82). The association between SMI and CRF may lead to the suggestion that male patients may be able to reduce fatigue by exercise interventions aiming at an increased muscle mass. In women with advanced cancer, CRF is more influenced by other causes, because it is not significantly related to muscle mass. To further reduce CRF in both men and women with cancer, multifactorial assessments need to be performed in order to develop effective treatment strategies. © 2017 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.

Comparative Analysis of Muscle Hypertrophy Models Reveals Divergent Gene Transcription Profiles and Points to Translational Regulation of Muscle Growth through Increased mTOR Signaling

Directory of Open Access Journals (Sweden)

Marcelo G. Pereira

2017-12-01

Full Text Available Skeletal muscle mass is a result of the balance between protein breakdown and protein synthesis. It has been shown that multiple conditions of muscle atrophy are characterized by the common regulation of a specific set of genes, termed atrogenes. It is not known whether various models of muscle hypertrophy are similarly regulated by a common transcriptional program. Here, we characterized gene expression changes in three different conditions of muscle growth, examining each condition during acute and chronic phases. Specifically, we compared the transcriptome of Extensor Digitorum Longus (EDL muscles collected (1 during the rapid phase of postnatal growth at 2 and 4 weeks of age, (2 24 h or 3 weeks after constitutive activation of AKT, and (3 24 h or 3 weeks after overload hypertrophy caused by tenotomy of the Tibialis Anterior muscle. We observed an important overlap between significantly regulated genes when comparing each single condition at the two different timepoints. Furthermore, examining the transcriptional changes occurring 24 h after a hypertrophic stimulus, we identify an important role for genes linked to a stress response, despite the absence of muscle damage in the AKT model. However, when we compared all different growth conditions, we did not find a common transcriptional fingerprint. On the other hand, all conditions showed a marked increase in mTORC1 signaling and increased ribosome biogenesis, suggesting that muscle growth is characterized more by translational, than transcriptional regulation.

Levator claviculae muscle presenting as a hard clavicular mass: imaging study

International Nuclear Information System (INIS)

Ruiz Santiago, F.; Lopez Milena, G.; Tristan Fernandez, J.M.; Chamorro Santos, C.

2001-01-01

We report a case of levator claviculae muscle presenting clinically as a hard mass in the clavicular area due to angular deformity of this bone. To our knowledge, this is the first report where the anomalous muscle shows this clinical presentation. (orig.)

A dietary supplementation with leucine and antioxidants is capable to accelerate muscle mass recovery after immobilization in adult rats.

Directory of Open Access Journals (Sweden)

Isabelle Savary-Auzeloux

Full Text Available Prolonged inactivity induces muscle loss due to an activation of proteolysis and decreased protein synthesis; the latter is also involved in the recovery of muscle mass. The aim of the present work was to explore the evolution of muscle mass and protein metabolism during immobilization and recovery and assess the effect of a nutritional strategy for counteracting muscle loss and facilitating recovery. Adult rats (6-8 months were subjected to unilateral hindlimb casting for 8 days (I0-I8 and then permitted to recover for 10 to 40 days (R10-R40. They were fed a Control or Experimental diet supplemented with antioxidants/polyphenols (AOX (I0 to I8, AOX and leucine (AOX + LEU (I8 to R15 and LEU alone (R15 to R40. Muscle mass, absolute protein synthesis rate and proteasome activities were measured in gastrocnemius muscle in casted and non-casted legs in post prandial (PP and post absorptive (PA states at each time point. Immobilized gastrocnemius protein content was similarly reduced (-37% in both diets compared to the non-casted leg. Muscle mass recovery was accelerated by the AOX and LEU supplementation (+6% AOX+LEU vs. Control, P<0.05 at R40 due to a higher protein synthesis both in PA and PP states (+23% and 31% respectively, Experimental vs. Control diets, P<0.05, R40 without difference in trypsin- and chymotrypsin-like activities between diets. Thus, this nutritional supplementation accelerated the recovery of muscle mass via a stimulation of protein synthesis throughout the entire day (in the PP and PA states and could be a promising strategy to be tested during recovery from bed rest in humans.

Growth hormone mitigates loss of periosteal bone formation and muscle mass in disuse osteopenic rats

DEFF Research Database (Denmark)

Grubbe, M-C; Thomsen, Jesper Skovhus; Nyengaard, J R

2014-01-01

Growth hormone (GH) is a potent anabolic agent capable of increasing both bone and muscle mass. The aim was to investigate whether GH could counteract disuse-induced loss of bone and muscle mass in a rat model. Paralysis was induced by injecting 4 IU Botox (BTX) into the muscles of the right hind...... of periosteal BFR/BS (2-fold increase vs. BTX, Pmuscle mass (+29% vs. BTX, Pmuscle CSA (+11%, P=0.064). In conclusion, GH mitigates disuse......BMD, -13%, Pmuscle mass (-69%, Pmuscle cell cross sectional area (CSA) (-73%, P

Effects of exercise improves muscle strength and fat mass in patients with high fracture risk: A randomized control trial

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Ding-Cheng Chan

2018-07-01

Full Text Available Background: The deterioration of the musculoskeletal system imposes significant impact on physical activity. Exercise is an important strategy which minimizes these changes. It is not clear which type of exercise provides better improvement on low physical performance, low muscle mass and low strength of sarcopenia. We aim to develop an integrated care (IC model and compare its relative efficacy in limb fat free mass, muscle strength, and physical performance with low extremities exercise (LEE in community dwelling older adults with high risk of fractures (Fracture Risk Assessment Tool (FRAX® ≧3% for hip fracture, ≧20% for major osteoporotic fracture or 1-min osteoporosis risk test (≧1 point or fall (≧2 falls in previous year. Methods: Patients were assigned randomized to participate in either IC or LEE group (n = 55 each for 3 months. All participants received education including home-based exercise. The IC group consisted of different modalities of exercise while the LEE group performed machine-based low extremities exercise. Fat free mass, muscle strength, and physical performance were measured at their baseline and 3-months follow-up. Results: Mean age was 73.8 ± 7 years with 69.1% women. Entire cohort demonstrated significant increment in fat free mass, muscle strength (4 indicators and physical performance (3 indicators. However, between group differences were not significant. Conclusion: With regular supervise exercise; both groups are equally effective in decreasing fat mass and increasing physical performance, muscle mass and strength. However, the IC group required fewer resources and thus more financially feasible in a community setting. Keywords: Bone mineral density, Gender differences, Integrated care, Low extremities exercise, Muscle strength

Peak muscle mass in young men and sarcopenia in the ageing male

DEFF Research Database (Denmark)

Nielsen, Morten Frost Munk; Nielsen, T L; Brixen, K

2015-01-01

of sarcopenia in men. INTRODUCTION: The ageing population increases the prevalence of sarcopenia. Estimation of normative data on muscle mass in young men during the peak of anabolic hormones is necessary for the diagnosis of sarcopenia in ageing males. The purposes of this study were to provide population......The prevalence of sarcopenia increases with age. The diagnosis of sarcopenia relies in part on normative data on muscle mass, but these data are lacking. This study provides population-based reference data on muscle mass in young men, and these results may be used clinically for the diagnosis......-based reference data on lean body mass (LBM) in young men during the time of peak levels of GH/IGF-1 and testosterone and further to apply the reference data on a population-based sample of men aged 60-74 years to estimate the prevalence of sarcopenia. METHODS: This is a cross-sectional, population-based single...

Tinetti mobility test is related to muscle mass and strength in non-institutionalized elderly people.

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Curcio, Francesco; Basile, Claudia; Liguori, Ilaria; Della-Morte, David; Gargiulo, Gaetano; Galizia, Gianluigi; Testa, Gianluca; Langellotto, Assunta; Cacciatore, Francesco; Bonaduce, Domenico; Abete, Pasquale

2016-12-01

Elderly people are characterized by a high prevalence of falls and sarcopenia. However, the relationship among Tinetti mobility test (TMT) score, a powerful tool to detect elderly people at risk of falls, and sarcopenia is still not thoroughly investigated. Thus, to determine the relationship between TMT score and muscle mass and strength, 337 elderly participants (mean age 77.1 ± 6.9 years) admitted to comprehensive geriatric assessment were enrolled. TMT score, muscle mass by bioimpedentiometer, and muscle strength by grip strength were evaluated. Muscle mass progressively decreased as TMT score decreased (from 15.3 ± 3.7 to 8.8 ± 1.8 kg/m 2 ; p for trend strength decreased progressively as Tinetti score decreased (from 34.7 ± 8.0 to 23.7 ± 8.7 kg; p for trend 0.001). Linear regression analysis demonstrated that TMT score is linearly related with muscle mass (y = 4.5x + 0.4, r = 0.61; p strength (y = 14.0x + 0.8, r = 0.53; p strength (r = 0.39, p = 0.046). The present study indicates that TMT score is significantly related to muscle mass and strength in non-institutionalized elderly participants. This evidence suggests that TMT score, together with evaluation of muscle mass and strength, may identify sarcopenic elderly participants at high risk of falls.

Reduced bone mass and muscle strength in male 5α-reductase type 1 inactivated mice.

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Sara H Windahl

Full Text Available Androgens are important regulators of bone mass but the relative importance of testosterone (T versus dihydrotestosterone (DHT for the activation of the androgen receptor (AR in bone is unknown. 5α-reductase is responsible for the irreversible conversion of T to the more potent AR activator DHT. There are two well established isoenzymes of 5α-reductase (type 1 and type 2, encoded by separate genes (Srd5a1 and Srd5a2. 5α-reductase type 2 is predominantly expressed in male reproductive tissues whereas 5α-reductase type 1 is highly expressed in liver and moderately expressed in several other tissues including bone. The aim of the present study was to investigate the role of 5α-reductase type 1 for bone mass using Srd5a1⁻/⁻ mice. Four-month-old male Srd5a1⁻/⁻ mice had reduced trabecular bone mineral density (-36%, p<0.05 and cortical bone mineral content (-15%, p<0.05 but unchanged serum androgen levels compared with wild type (WT mice. The cortical bone dimensions were reduced in the male Srd5a1⁻/⁻ mice as a result of a reduced cortical periosteal circumference compared with WT mice. T treatment increased the cortical periosteal circumference (p<0.05 in orchidectomized WT mice but not in orchidectomized Srd5a1⁻/⁻ mice. Male Srd5a1⁻/⁻ mice demonstrated a reduced forelimb muscle grip strength compared with WT mice (p<0.05. Female Srd5a1⁻/⁻ mice had slightly increased cortical bone mass associated with elevated circulating levels of androgens. In conclusion, 5α-reductase type 1 inactivated male mice have reduced bone mass and forelimb muscle grip strength and we propose that these effects are due to lack of 5α-reductase type 1 expression in bone and muscle. In contrast, the increased cortical bone mass in female Srd5a1⁻/⁻ mice, is an indirect effect mediated by elevated circulating androgen levels.

Normal Weight but Low Muscle Mass and Abdominally Obese: Implications for the Cardiometabolic Risk Profile in Chronic Obstructive Pulmonary Disease.

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Beijers, Rosanne J H C G; van de Bool, Coby; van den Borst, Bram; Franssen, Frits M E; Wouters, Emiel F M; Schols, Annemie M W J

2017-06-01

It is well established that low muscle mass affects physical performance in chronic obstructive pulmonary disease (COPD). We hypothesize that combined low muscle mass and abdominal obesity may also adversely influence the cardiometabolic risk profile in COPD, even in those with normal weight. The cardiometabolic risk profile and the responsiveness to 4 months high-intensity exercise training was assessed in normal-weight patients with COPD with low muscle mass stratified by abdominal obesity. This is a cross-sectional study including 81 clinically stable patients with COPD (age 62.5 ± 8.2 years; 50.6% males; forced expiratory volume in 1 second 55.1 ± 19.5 percentage predicted) with fat-free mass index risk profile. Triglycerides showed a significant decrease, while the HOMA-IR increased. Abdominal obesity is highly prevalent in normal-weight patients with COPD with low muscle mass who showed an increased cardiometabolic risk compared with patients without abdominal obesity. This cardiometabolic risk profile was not altered after 4 months of exercise training. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Clinical effectiveness of protein and amino acid supplementation on building muscle mass in elderly people: a meta-analysis.

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Zhe-rong Xu

Full Text Available A major reason for the loss of mobility in elderly people is the gradual loss of lean body mass known as sarcopenia. Sarcopenia is associated with a lower quality of life and higher healthcare costs. The benefit of strategies that include nutritional intervention, timing of intervention, and physical exercise to improve muscle loss unclear as finding from studies investigating this issue have been inconsistent. We have performed a systematic review and meta-analysis to assess the ability of protein or amino acid supplementation to augment lean body mass or strength of leg muscles in elderly patients.Nine studies met the inclusion criteria of being a prospective comparative study or randomized controlled trial (RCT that compared the efficacy of an amino acid or protein supplement intervention with that of a placebo in elderly people (≥ 65 years for the improvement of lean body mass (LBM, leg muscle strength or reduction associated with sarcopenia.The overall difference in mean change from baseline to the end of study in LBM between the treatment and placebo groups was 0.34 kg which was not significant (P = 0.386. The overall differences in mean change from baseline in double leg press and leg extension were 2.14 kg (P = 0.748 and 2.28 kg (P = 0.265, respectively, between the treatment group and the placebo group.These results indicate that amino acid/protein supplements did not increase lean body mass gain and muscle strength significantly more than placebo in a diverse elderly population.

Bio-impedance analysis for appendicular skeletal muscle mass assessment in (pre-) frail elderly people

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Baar, van H.; Hulshof, P.J.M.; Tieland, C.A.B.; Groot, de C.P.G.M.

2015-01-01

Background & aims Screening populations for skeletal muscle mass (SMM) is important for early detection of sarcopenia. Our aim was to develop an age specific bio-impedance (BI) prediction equation for the assessment of appendicular skeletal muscle mass (ASMM) in (pre-) frail elderly people aged

Low muscle mass is associated with metabolic syndrome only in nonobese young adults: the Korea National Health and Nutrition Examination Survey 2008-2010.

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Kim, Byung Chul; Kim, Mee Kyoung; Han, Kyungdo; Lee, Sae-Young; Lee, Seung-Hwan; Ko, Seung-Hyun; Kwon, Hyuk-Sang; Merchant, Anwar T; Yim, Hyeon Woo; Lee, Won-Chul; Park, Yong Gyu; Park, Yong-Moon

2015-12-01

Little is known about the relationship between body composition and metabolic risk factors in young adults. We hypothesized that low muscle mass (LMM) is associated with metabolic syndrome (MetS) and its components in young adults and that the associations vary by obesity. A cross-sectional analysis was conducted using the Korea National Health and Nutrition Examination Survey data. In total, 5300 young adults aged 19 to 39 years were evaluated. Low muscle mass was defined as an appendicular skeletal muscle mass/weight less than 1 SD below the mean for each participant's corresponding sex and age group. Obesity was defined as a body mass index greater than or equal to 25 kg/m2. The prevalence of LMM was higher in obese than nonobese participants (37.6% vs. 9.6%). In the nonobese participants, the prevalence of MetS, high waist circumference, high triglycerides, and high blood pressure was significantly greater in the LMM group than in the high muscle mass group. In the nonobese group, compared with high muscle mass participants, those with LMM had odds ratios for MetS of 3.6 (95% confidence interval, 1.48-8.76; P young adults with LMM may have a high risk of MetS, especially when they are nonobese. Interventions aimed at increasing muscle mass at younger ages may have the potential to reduce MetS. Published by Elsevier Inc.

Time-Course of Muscle Mass Loss, Damage, and Proteolysis in Gastrocnemius following Unloading and Reloading: Implications in Chronic Diseases

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Chacon-Cabrera, Alba; Lund-Palau, Helena; Gea, Joaquim; Barreiro, Esther

2016-01-01

Background Disuse muscle atrophy is a major comorbidity in patients with chronic diseases including cancer. We sought to explore the kinetics of molecular mechanisms shown to be involved in muscle mass loss throughout time in a mouse model of disuse muscle atrophy and recovery following immobilization. Methods Body and muscle weights, grip strength, muscle phenotype (fiber type composition and morphometry and muscle structural alterations), proteolysis, contractile proteins, systemic troponin I, and mitochondrial content were assessed in gastrocnemius of mice exposed to periods (1, 2, 3, 7, 15 and 30 days) of non-invasive hindlimb immobilization (plastic splint, I cohorts) and in those exposed to reloading for different time-points (1, 3, 7, 15, and 30 days, R cohorts) following a seven-day period of immobilization. Groups of control animals were also used. Results Compared to non-exposed controls, muscle weight, limb strength, slow- and fast-twitch cross-sectional areas, mtDNA/nDNA, and myosin content were decreased in mice of I cohorts, whereas tyrosine release, ubiquitin-proteasome activity, muscle injury and systemic troponin I levels were increased. Gastrocnemius reloading following splint removal improved muscle mass loss, strength, fiber atrophy, injury, myosin content, and mtDNA/nDNA, while reducing ubiquitin-proteasome activity and proteolysis. Conclusions A consistent program of molecular and cellular events leading to reduced gastrocnemius muscle mass and mitochondrial content and reduced strength, enhanced proteolysis, and injury, was seen in this non-invasive mouse model of disuse muscle atrophy. Unloading of the muscle following removal of the splint significantly improved the alterations seen during unloading, characterized by a specific kinetic profile of molecular events involved in muscle regeneration. These findings have implications in patients with chronic diseases including cancer in whom physical activity may be severely compromised. PMID

Mechanistic Links Underlying the Impact of C-Reactive Protein on Muscle Mass in Elderly

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Britta Wåhlin-Larsson

2017-11-01

Full Text Available Background/Aims: Mechanisms underlying the relationship between systemic inflammation and age-related decline in muscle mass are poorly defined. The purpose of this work was to investigate the relationship between the systemic inflammatory marker CRP and muscle mass in elderly and to identify mechanisms by which CRP mediates its effects on skeletal muscle, in-vitro. Methods: Muscle mass and serum CRP level were determined in a cohort of 118 older women (67±1.7 years. Human muscle cells were differentiated into myotubes and were exposed to CRP. The size of myotubes was determined after immunofluorescent staining using troponin. Muscle protein synthesis was assessed using stable isotope tracers and key signalling pathways controlling protein synthesis were determined using western-blotting. Results: We observed an inverse relationship between circulating CRP level and muscle mass (β= -0.646 (95% CI: -0.888, -0.405 p<0.05 and demonstrated a reduction (p < 0.05 in the size of human myotubes exposed to CRP for 72 h. We next showed that this morphological change was accompanied by a CRP-mediated reduction (p < 0.05 in muscle protein fractional synthetic rate of human myotubes exposed to CRP for 24 h. We also identified a CRP-mediated increased phosphorylation (p<0.05 of regulators of cellular energy stress including AMPK and downstream targets, raptor and ACC-β, together with decreased phosphorylation of Akt and rpS6, which are important factors controlling protein synthesis. Conclusion: This work established for the first time mechanistic links by which chronic elevation of CRP can contribute to age-related decline in muscle function.

Sarcopenia and Predictors of Skeletal Muscle Mass in Elderly Men With and Without Obesity

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Katja Stoever MA

2017-06-01

Full Text Available Objectives: The aim of this study was to determine the variables which show the highest association with muscle mass and to identify the most important predictors for muscle mass in elderly men with and without sarcopenia. Methods: A total of 71 men participated, aged ≥65 years. Sarcopenia was assessed using the definition of the European Working Group on Sarcopenia in Older People with determining skeletal muscle index (SMI, hand-grip strength (HGS, and Short Physical Performance Battery. In addition, maximum strength at upper and lower extremities and physical activity were measured. Results: Strong correlations existed between SMI and gait speed, HGS, maximum isometric strength at leg and chest press. Physical activity showed low correlations with muscle strength. Regression analysis revealed HGS and gait speed as key predictors for SMI. Discussion: The recommendation is measuring gait speed and HGS in clinical practice at first followed by measuring muscle mass for determining sarcopenia.

Changes in lower limb muscle function and muscle mass following exercise-based interventions in patients with chronic obstructive pulmonary disease: A review of the English-language literature.

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De Brandt, Jana; Spruit, Martijn A; Hansen, Dominique; Franssen, Frits Me; Derave, Wim; Sillen, Maurice Jh; Burtin, Chris

2018-05-01

Chronic obstructive pulmonary disease (COPD) patients often experience lower limb muscle dysfunction and wasting. Exercise-based training has potential to improve muscle function and mass, but literature on this topic is extensive and heterogeneous including numerous interventions and outcome measures. This review uses a detailed systematic approach to investigate the effect of this wide range of exercise-based interventions on muscle function and mass. PUBMED and PEDro databases were searched. In all, 70 studies ( n = 2504 COPD patients) that implemented an exercise-based intervention and reported muscle strength, endurance, or mass in clinically stable COPD patients were critically appraised. Aerobic and/or resistance training, high-intensity interval training, electrical or magnetic muscle stimulation, whole-body vibration, and water-based training were investigated. Muscle strength increased in 78%, muscle endurance in 92%, and muscle mass in 88% of the cases where that specific outcome was measured. Despite large heterogeneity in exercise-based interventions and outcome measures used, most exercise-based trials showed improvements in muscle strength, endurance, and mass in COPD patients. Which intervention(s) is (are) best for which subgroup of patients remains currently unknown. Furthermore, this literature review identifies gaps in the current knowledge and generates recommendations for future research to enhance our knowledge on exercise-based interventions in COPD patients.

Muscle Mass and Weight Gain Nutritional Supplements

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Campbell, Bill

There are numerous sports supplements available that claim to increase lean body mass. However, for these sports supplements to exert any favorable changes in lean body mass, they must influence those factors regulating skeletal muscle hypertrophy (i.e., satellite cell activity, gene transcription, protein translation). If a given sports supplement does favorably influence one of these regulatory factors, the result is a positive net protein balance (in which protein synthesis exceeds protein breakdown). Sports supplement categories aimed at eliciting a positive net protein balance include anabolic hormone enhancers, nutrient timing pre- and postexercise workout supplements, anticatabolic supplements, and nitric oxide boosters. Of all the sports supplements available, only a few have been subject to multiple clinical trials with repeated favorable outcomes relative to increasing lean body mass. This chapter focuses on these supplements and others that have a sound theoretical rationale in relation to increasing lean body mass.

Association between muscle mass and a single measurement of ...

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cause mortality significantly. It is strongly associated with the risk of heart attack, coronary artery disease, cardiovascular disease, stroke and liver disease. The relationship between muscle mass and a diagnosis of hypertension in a sample of ...

Effects of exercise improves muscle strength and fat mass in patients with high fracture risk: A randomized control trial.

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Chan, Ding-Cheng; Chang, Chirn-Bin; Han, Der-Sheng; Hong, Cian-Hui; Hwang, Jawl-Shan; Tsai, Keh-Sung; Yang, Rong-Sen

2017-10-26

The deterioration of the musculoskeletal system imposes significant impact on physical activity. Exercise is an important strategy which minimizes these changes. It is not clear which type of exercise provides better improvement on low physical performance, low muscle mass and low strength of sarcopenia. We aim to develop an integrated care (IC) model and compare its relative efficacy in limb fat free mass, muscle strength, and physical performance with low extremities exercise (LEE) in community dwelling older adults with high risk of fractures (Fracture Risk Assessment Tool (FRAX ® )) ≧3% for hip fracture, ≧20% for major osteoporotic fracture or 1-min osteoporosis risk test (≧1 point) or fall (≧2 falls in previous year). Patients were assigned randomized to participate in either IC or LEE group (n = 55 each) for 3 months. All participants received education including home-based exercise. The IC group consisted of different modalities of exercise while the LEE group performed machine-based low extremities exercise. Fat free mass, muscle strength, and physical performance were measured at their baseline and 3-months follow-up. Mean age was 73.8 ± 7 years with 69.1% women. Entire cohort demonstrated significant increment in fat free mass, muscle strength (4 indicators) and physical performance (3 indicators). However, between group differences were not significant. With regular supervise exercise; both groups are equally effective in decreasing fat mass and increasing physical performance, muscle mass and strength. However, the IC group required fewer resources and thus more financially feasible in a community setting. Copyright © 2017. Published by Elsevier B.V.

Lower Jump Power Rather Than Muscle Mass Itself is Associated with Vertebral Fracture in Community-Dwelling Elderly Korean Women.

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Lee, Eun Young; Lee, Su Jin; Kim, Kyoung Min; Seo, Da Hea; Lee, Seung Won; Choi, Han Sol; Kim, Hyeon Chang; Youm, Yoosik; Kim, Chang Oh; Rhee, Yumie

2017-06-01

Sarcopenia is considered to be a risk factor for osteoporotic fracture, which is a major health problem in elderly women. In this study, we aimed to investigate the association of sarcopenia, with regard to muscle mass and function, with prevalent vertebral fracture in community-dwelling elderly women. We recruited 1281 women aged 64 to 87 years from the Korean Urban Rural Elderly cohort study. Muscle mass and function were measured using bioimpedance analysis and jumping mechanography. Skeletal muscle index (SMI) and jump power were used as an indicator of muscle mass and function, respectively. Among the participants, we observed 282 (18.9%) vertebral fractures and 564 (44.0%) osteoporosis. Although age, body mass index, and prevalence of osteoporosis increased as both SMI and jump power decreased, prevalence of vertebral fracture increased only when jump power decreased. In univariate analysis, compared with the highest quartile of jump power, the lowest quartile had a significant odds ratio of 2.80 (95% CI 1.79-4.36) for vertebral fracture. This association between jump power and vertebral fracture remained significant, with an odds ratio of 3.04 (95% CI 1.77-5.23), even after adjusting for other risk factors including age, bone mineral density, previous fracture, and cognitive function. In contrast, there was no association between SMI and vertebral fracture. Based on our results, low jump power, but not SMI, is associated with vertebral fracture in community-dwelling elderly Korean women. This finding suggests that jump power may have a more important role than muscle mass itself for osteoporotic fracture.

Creatine Loading Does Not Preserve Muscle Mass or Strength During Leg Immobilization in Healthy, Young Males

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Backx, Evelien M.P.; Hangelbroek, Roland; Snijders, Tim; Verscheijden, Marie Louise; Verdijk, Lex B.; Groot, de Lisette C.P.G.M.; Loon, van Luc J.C.

2017-01-01

Background: A short period of leg immobilization leads to rapid loss of muscle mass and strength. Creatine supplementation has been shown to increase lean body mass in active individuals and can be used to augment gains in muscle mass and strength during prolonged resistance-type exercise

Texture-modified diets are associated with decreased muscle mass in older adults admitted to a rehabilitation ward.

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Shimizu, Akio; Maeda, Keisuke; Tanaka, Kei; Ogawa, Mei; Kayashita, Jun

2018-05-01

Texture-modified diets (TMD) have significantly lower energy and protein content than normal diets. Therefore, TMD can cause malnutrition and loss of muscle mass. However, few studies have reported the relationship between TMD and decreased skeletal muscle mass. The aim of the present study was to clarify the association between TMD and decreased skeletal muscle mass. We reviewed data of 188 older adult patients who were admitted to a rehabilitation hospital. TMD were defined based on the Japanese Dysphagia Diet Criteria 2013 proposed by the Japanese Society of Dysphagia Rehabilitation. The Mini Nutritional Assessment-Short Form was used to assess nutritional status; dual-energy X-ray absorptiometry was used to measure the skeletal muscle mass index, and the cut-off values for decreased skeletal muscle mass index were based on the Asian Working Group for Sarcopenia; the Functional Independence Measure was used to evaluate activities of daily living. The patients' mean age was 80.6 ± 7.5 years, and 62% were women. A total of 22 patients (11.7%) consumed TMD. A total of 104 patients (55.3%) had decreased skeletal muscle mass, and approximately 90% of them consumed TMD. Decreased skeletal muscle mass index (odds ratio 7.199, 95% confidence interval 1.489-34.805, P ≤ 0.01) and Functional Independence Measure scores (odds ratio 0.972, 95% confidence interval 0.952-0.992, P ≤ 0.01) were independently related to TMD in the multivariate analysis. The TMD group was associated with decreased skeletal muscle mass. Future, prospective studies are necessary to investigate causality. Geriatr Gerontol Int 2018; 18: 698-704. © 2017 Japan Geriatrics Society.

Muscle mass decline, arterial stiffness, white matter hyperintensity, and cognitive impairment: Japan Shimanami Health Promoting Program study.

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Kohara, Katsuhiko; Okada, Yoko; Ochi, Masayuki; Ohara, Maya; Nagai, Tokihisa; Tabara, Yasuharu; Igase, Michiya

2017-08-01

There is a close association between frailty and cognitive impairment. However, the underlying contribution of sarcopenia to the development of cognitive impairment is unclear. We investigated the possible association between muscle mass decline and cognitive impairment in a cross-sectional study of 1518 subjects aged 55 years or above. We also evaluated arterial stiffness and white matter hyperintensities (WMHs) as possible underlying mechanisms for this association. Two sarcopenic indices were measured: thigh muscle cross-sectional area (CSA; calculated by computed tomography) and skeletal muscle mass (bioelectric impedance). Muscle mass decline was defined as either the bottom 10% or 20% of participants for each sex. Cognitive function was assessed using the Touch Panel-type Dementia Assessment Scale, and brachial-ankle pulse wave velocity was measured as an index of arterial stiffness. Both sarcopenic indices were modestly but significantly associated with brachial-ankle pulse wave velocity in male and female subjects. The presence of WMHs was significantly associated with low thigh muscle CSA in men and with low skeletal muscle mass in women. The Touch Panel-type Dementia Assessment Scale score was modestly but significantly and positively associated with thigh muscle CSA in men and skeletal muscle mass in women. Muscle mass decline in the bottom 10% of participants on both sarcopenic indices was significantly and independently related to cognitive impairment in women. Lower sarcopenic indices are significantly related to lower cognitive scores. Arterial stiffness and WMHs could account, at least in part, for this association. © 2017 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.

Correlation between Body Mass Index, Gender, and Skeletal Muscle Mass Cut off Point in Bandung

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Richi Hendrik Wattimena

2017-09-01

Full Text Available Objective: To determine the average skeletal muscle mass (SMM value in young adults as a reference population; to analyze the correlation of gender, and body mass index to the cut off point; and to determine skeletal muscle mass cut off points of population in Bandung, Indonesia. Methods: This was a cross-sectional study involving 199 participants, 122 females and 77 males. The sampling technique used was the multistage random sampling. The participants were those who lived in four major regions in Bandung, Indonesia: Sukajadi, Cicadas, Buah Batu, and Cibaduyut. Results: The average appendicular skeletal mass index (ASMI in females and males based on body mass index (BMI were identified. The average ASMI values for normal BMI in females was 5.982±0.462 kg/m2 while the average ASMI values normal BMI for males was 7.581±0.744 kg/m2 Conclusions: A correlation between BMI and ASMI that was considered statistically significant was found in females (0.7712; p<0.05 and a very significant correlation was seen in males (0.870; p<0.05. The cut off points were defined by the normal BMI, which were 5.059 for females and 6.093 for males.

Effect of anabolic steroids on skeletal muscle mass during hindlimb suspension

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Tsika, R. W.; Herrick, R. E.; Baldwin, K. M.

1987-01-01

The effect of treatment with an anabolic steroid (nandrolone decanoate) on the muscle mass of plantaris and soleus of a rats in hindlimb suspension, and on the isomyosin expression in these muscles, was investigated in young female rats divided into four groups: normal control (NC), normal steroid (NS), normal suspension (N-sus), and suspension steroid (sus-S). Steroid treatment of suspended animals (sus-S vs N-sus) was found to partially spare body weight and muscle weight, as well as myofibril content of plantaris (but not soleus), but did not modify the isomyosin pattern induced by suspension. In normal rats (NS vs NC), steroid treatment did enhance body weight and plantaris muscle weight; the treatment did not alter isomyosin expression in either muscle type.

Myoglobin plasma level related to muscle mass and fiber composition: a clinical marker of muscle wasting?

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Weber, Marc-André; Kinscherf, Ralf; Krakowski-Roosen, Holger; Aulmann, Michael; Renk, Hanna; Künkele, Annette; Edler, Lutz; Kauczor, Hans-Ulrich; Hildebrandt, Wulf

2007-08-01

Progressive muscle wasting is a central feature of cancer-related cachexia and has been recognized as a determinant of poor prognosis and quality of life. However, until now, no easily assessable clinical marker exists that allows to predict or to track muscle wasting. The present study evaluated the potential of myoglobin (MG) plasma levels to indicate wasting of large locomotor muscles and, moreover, to reflect the loss of MG-rich fiber types, which are most relevant for daily performance. In 17 cancer-cachectic patients (weight loss 22%) and 27 age- and gender-matched healthy controls, we determined plasma levels of MG and creatine kinase (CK), maximal quadriceps muscle cross-sectional area (CSA) by magnetic resonance imaging, muscle morphology and fiber composition in biopsies from the vastus lateralis muscle, body cell mass (BCM) by impedance technique as well as maximal oxygen uptake (VO(2)max). In cachectic patients, plasma MG, muscle CSA, BCM, and VO(2)max were 30-35% below control levels. MG showed a significant positive correlation to total muscle CSA (r = 0.65, p max as an important functional readout. CK plasma levels appear to be less reliable because prolonged increases are observed in even subclinical myopathies or after exercise. Notably, cancer-related muscle wasting was not associated with increases in plasma MG or CK in this study.

Comparison of MRI and DXA to measure muscle size and age-related atrophy in thigh muscles.

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Maden-Wilkinson, T M; Degens, H; Jones, D A; McPhee, J S

2013-09-01

Magnetic resonance imaging (MRI) and dual-energy x-ray absorptiometry (DXA) were used to examine the thigh lean mass in young and old men and women. A whole-body DXA scan was used to estimate thigh lean mass in young (20 men; 22.4±3.1y; 18 women; 22.1±2.0y) and older adults (25 men; 72.3±4.9y; 28 women; 72.0±4.5y). Thigh lean mass determined with a thigh scan on the DXA or full thigh MRI scans were compared. Although the thigh lean mass quantified by DXA and MRI in young and older participants were correlated (R(2)=0.88; polder than young individuals, while the other thigh muscles were only 18% smaller. DXA underestimates the age-related loss of thigh muscle mass in comparison to MRI. The quadriceps muscles were more susceptible to age-related atrophy compared with other thigh muscles.

Alfacalcidol improves muscle power, muscle function and balance in elderly patients with reduced bone mass.

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Schacht, E; Ringe, Johann D

2012-01-01

We investigated the effect of daily therapy with 1 mcg alfacalcidol (Doss(®)-TEVA/AWD-pharma) on muscle power, muscle function, balance performance and fear of falls in an open, multi-centered, uncontrolled, prospective study on a cohort of patients with reduced bone mass. Among the 2,097 participants, 87.1% were post-menopausal women and 12.9% were men. Mean age was 74.8 years and mean body mass index (BMI) 26.3 kg/m². A total of 75.3% of the study population had osteoporosis, 81% a diagnosis of "increased risk of falls" and 70.1% had a creatinine clearance (CrCl) of power tests at onset and after 3 and 6 months: the timed up and go test (TUG) and the chair rising test (CRT). At baseline and after 6 months, participants performed the tandem gait test (TGT) and filled out a questionnaire evaluating fear of falling. Successful performance in the muscle tests is associated with a significantly lower risk of falls and non-vertebral fractures in elderly patients (successful test performance: TUG ≤ 10 s (sec), CRT ≤ 10 s, TGT ≥ 8 steps). A significant improvement in the performance of the two muscle tests was proved already after 3 months of treatment with alfacalcidol and further increased by the end of the therapeutic intervention. There were significant increases in the number of participants able to successfully perform the tests: 24.6% at baseline and 46.3% at the end of trial for the TUG (P balance test (TGT) increased from 36.0% at onset to 58.6% at the end of the trial (P power, muscle function and balance and reduces fear of falls. The significant improvement in the three muscle and balance tests and fear of falls may have a preventative effect on falls and fractures. We suggest that the quantitative risk tests used in this study could be reliable surrogate parameters for the risk of falls and fractures in elderly patients.

A mouse anti-myostatin antibody increases muscle mass and improves muscle strength and contractility in the mdx mouse model of Duchenne muscular dystrophy and its humanized equivalent, domagrozumab (PF-06252616), increases muscle volume in cynomolgus monkeys.

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St Andre, Michael; Johnson, Mark; Bansal, Prashant N; Wellen, Jeremy; Robertson, Andrew; Opsahl, Alan; Burch, Peter M; Bialek, Peter; Morris, Carl; Owens, Jane

2017-11-09

The treatments currently approved for Duchenne muscular dystrophy (DMD), a progressive skeletal muscle wasting disease, address the needs of only a small proportion of patients resulting in an urgent need for therapies that benefit all patients regardless of the underlying mutation. Myostatin is a member of the transforming growth factor-β (TGF-β) family of ligands and is a negative regulator of skeletal muscle mass. Loss of myostatin has been shown to increase muscle mass and improve muscle function in both normal and dystrophic mice. Therefore, myostatin blockade via a specific antibody could ameliorate the muscle weakness in DMD patients by increasing skeletal muscle mass and function, thereby reducing patients' functional decline. A murine anti-myostatin antibody, mRK35, and its humanized analog, domagrozumab, were developed and their ability to inhibit several TGB-β ligands was measured using a cell-based Smad-activity reporter system. Normal and mdx mice were treated with mRK35 to examine the antibody's effect on body weight, lean mass, muscle weights, grip strength, ex vivo force production, and fiber size. The humanized analog (domagrozumab) was tested in non-human primates (NHPs) for changes in skeletal muscle mass and volume as well as target engagement via modulation of circulating myostatin. Both the murine and human antibodies are specific and potent inhibitors of myostatin and GDF11. mRK35 is able to increase body weight, lean mass, and muscle weights in normal mice. In mdx mice, mRK35 significantly increased body weight, muscle weights, grip strength, and ex vivo force production in the extensor digitorum longus (EDL) muscle. Further, tibialis anterior (TA) fiber size was significantly increased. NHPs treated with domagrozumab demonstrated a dose-dependent increase in lean mass and muscle volume and exhibited increased circulating levels of myostatin demonstrating target engagement. We demonstrated that the potent anti-myostatin antibody mRK35 and

Low skeletal muscle mass outperforms the Charlson Comorbidity Index in risk prediction in patients undergoing pancreatic resections.

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Wagner, D; Marsoner, K; Tomberger, A; Haybaeck, J; Haas, J; Werkgartner, G; Cerwenka, H; Bacher, H; Mischinger, H J; Kornprat, P

2018-05-01

Low skeletal muscle mass is a known predictor of morbidity and mortality in patients undergoing major pancreatic surgeries. We sought to combine low skeletal muscle mass with established risk predictors to improve their prognostic capacity for postoperative outcome and morbidity. As established parameters to predict preoperative mortality risk for patients, the ASA classification and the Charlson Comorbidity Index (CCI) were used. The Hounsfield Units Average Calculation (HUAC) was measured to define low skeletal muscle mass in 424 patients undergoing pancreatic resections for malignancies. Patients in the lowest sex-adjusted quartile for HUAC were defined as having low skeletal muscle mass (muscle wasting). Multivariable Cox regression analysis was utilized to identify preoperative risk factors associated with postoperative morbidity. Median patient age was 63 years (19-87), 47.9% patients were male, and half the cohort had multiple comorbidities (Charlson Comorbidity Index [CCI]>6, 63.2%), 30-day mortality was 5.8% (n = 25). Median HUAC was 19.78 HU (IQR: 15.94-23.54) with 145 patients (34.2%) having low skeletal muscle mass. Preoperative frailty defined by low skeletal muscle mass was associated with an increased risk for postoperative complications (OR 1.55, CI 95% 0.98-2.45, p = 0.014), and a higher 30-day mortality (HR 5.17, CI 95% 1.57-16.69, p = 0.004). With an AUC of 0.85 HUAC showed the highest predictability for 30-day mortality (CI 95% 0.78-0.91, p = 0.0001). Patients with CCI ≥6 and low skeletal muscle mass defined by the HUAC had a 9.78 higher risk of dying in the immediate postoperative phase (HR 9.78, CI 95% 2.98-12.2, p = 0.0001). Low skeletal muscle mass predicts postoperative mortality and complications best and it should be incorporated to conventional risk scores to identify high risk patients. Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights

Comparative functional anatomy of hindlimb muscles and bones with reference to aquatic adaptation of the sea otter.

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Mori, Kent; Suzuki, Satoshi; Koyabu, Daisuke; Kimura, Junpei; Han, Sung-Yong; Endo, Hideki

2015-05-01

Although the sea otter (Enhydra lutris) is a complete aquatic species, spending its entire life in the ocean, it has been considered morphologically to be a semi-aquatic animal. This study aimed to clarify the unique hindlimb morphology and functional adaptations of E. lutris in comparison to other Mustelidae species. We compared muscle mass and bone measurements of five Mustelidae species: the sea otter, Eurasian river otter (Lutra lutra), American mink (Neovison vison), Japanese weasel (Mustela itatsi) and Siberian weasel (M. sibirica). In comparison with the other 4 species, E. lutris possessed significantly larger gluteus, popliteus and peroneus muscles, but smaller adductor and ischiopubic muscles. The popliteus muscle may act as a medial rotator of the crus, and the peroneus muscle may act as an abductor of the fifth toe and/or the pronator of the foot. The bundles of the gluteus superficialis muscle of E. lutris were fused with those of the tensor fasciae latae muscle and gluteofemoralis muscles, and they may play a role in femur abduction. These results suggest that E. lutris uses the abducted femur, medially rotated crus, eversion of the ankle and abducted fifth digit or extended interdigital web as a powerful propulsion generator. Therefore, we conclude that E. lutris is a complete aquatic animal, possessing differences in the proportions of the hindlimb muscles compared with those in other semi-aquatic and terrestrial mustelids.

Relative muscle mass and the risk of incident type 2 diabetes: A cohort study.

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Sungwoo Hong

Full Text Available The association between relative muscle mass (RMM and incidence of type 2 diabetes (T2DM is largely unknown. We examined whether RMM predicted development of T2DM in an apparently young healthy population.This cohort study was comprised of 113,913 men and 89,854 women, free of T2DM at baseline, who underwent a health checkup examination and were followed-up annually or biennially for an average of 2.9 years. We used skeletal muscle mass index (SMI as an indicator of RMM. SMI (% [total skeletal muscle mass (kg/body weight (kg×100] was estimated using a bioelectrical impedance analyzer. The study outcome was incident T2DM, defined as fasting serum glucose ≥126 mg/dL, HbA1C ≥6.5%, or use of medication for T2DM.During 589,098.8 person-years of follow-up, 4,264 individuals developed T2DM (incidence rate, 7.2 per 1000 person-years. Median age (range at baseline was 39.1 years (18.1-87.1. RMM was negatively associated with incidence of T2DM in a dose-response manner. The multivariate-adjusted hazard ratios (95% CIs for incident T2DM comparing quartiles 3, 2 and 1 of RMM to the highest quartile were 1.32 (1.14-1.52, 1.63 (1.42-1.86, and 2.21 (1.94-2.51, respectively, for males and 1.18 (0.88-1.58, 1.46 (1.11-1.91, and 1.96 (01.51-2.53 for females (P for trend <0.001; 0.011. This association was stronger in younger or premenopausal subjects.RMM was negatively associated with development of T2DM in a large sample of young and middle-aged Korean adults. Further research is required to determine whether preservation of muscle mass through intervention affects the risk of T2DM.

Loss of mass and performance in skeletal muscle tissue: a continuum model

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Giantesio Giulia

2018-02-01

Full Text Available We present a continuum hyperelastic model which describes the mechanical response of a skeletal muscle tissue when its strength and mass are reduced by aging. Such a reduction is typical of a geriatric syndrome called sarcopenia. The passive behavior of the material is described by a hyperelastic, polyconvex, transversely isotropic strain energy function, and the activation of the muscle is modeled by the so called active strain approach. The loss of ability of activating of an elder muscle is then obtained by lowering of some percentage the active part of the stress, while the loss of mass is modeled through a multiplicative decomposition of the deformation gradient. The obtained stress-strain relations are graphically represented and discussed in order to study some of the effects of sarcopenia.

Decreased Muscle Strength and Quality in Diabetes-Related Dementia

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Akito Tsugawa

2017-12-01

Full Text Available Background/Aims: Diabetes-related dementia (DrD, a dementia subgroup associated with specific diabetes mellitus (DM-related metabolic abnormalities, is clinically and pathophysiologically different from Alzheimer disease (AD and vascular dementia. We determined whether skeletal muscle strength, quality, and mass decrease in individuals with DrD. Methods: We evaluated grip and knee extension strength, muscle mass, and gait speed in 106 patients with probable AD and without type 2 DM (AD[–DM] group, 74 patients with probable AD and with DM (AD[+DM] group, and 36 patients with DrD (DrD group. Muscle quality was defined as the ratio of muscle strength to muscle mass. Results: Both female and male subjects with DrD showed significantly decreased muscle strength and quality in the upper extremities compared with the subjects with AD[–DM] or AD[+DM]. Female subjects with DrD showed significantly decreased muscle quality in the lower extremities compared with the subjects with AD[–DM]. Both female and male subjects with DrD had a significantly lower gait speed compared with the subjects with AD[–DM]. However, there were no significant differences in muscle mass and the prevalence of sarcopenia between the groups. Conclusion: Subjects with DrD showed decreased muscle strength and quality, but not muscle mass, and had a low gait speed.

Alterations in molecular muscle mass regulators after 8 days immobilizing Special Forces mission

DEFF Research Database (Denmark)

Jespersen, J. G.; Mikkelsen, Ulla Ramer; Nedergaard, A.

2015-01-01

In military operations, declined physical capacity can endanger the life of soldiers. During special support and reconnaissance (SSR) missions, Special Forces soldiers sustain 1-2 weeks full-body horizontal immobilization, which impairs muscle strength and performance. Adequate muscle mass and st...

Circulating levels of TNF-alpha and IL-6-relation to truncal fat mass and muscle mass in healthy elderly individuals and in patients with type-2 diabetes

DEFF Research Database (Denmark)

Pedersen, Maria; Bruunsgaard, Helle; Weis, Nina

2003-01-01

The purpose of the current study was to test the hypothesis that an altered fat distribution in elderly healthy subjects and in patients with type-2 diabetes contributes to high circulating levels of interleukin (IL)-6 and tumor necrotic factor (TNF)-alpha, which secondly is related to lower muscle...... mass. Twenty young controls, (20-35 yr), 20 healthy elderly subjects (65-80 yr) and 16 elderly patients with type 2 diabetes (65-80 yr) were included in a cross sectional study. Plasma levels of TNF-alpha and IL-6 were measured after an overnight fast. Dual-energy X-ray absorptiometry and total body...... potassium counting measured truncal fat, appendicular skeletal muscle mass (ASM) and body cell mass (BCM), respectively. TNF-alpha, IL-6 and the relative truncal fat mass were higher in elderly compared with young controls. ASM was lower in diabetic men than in young controls and BCM was lower in elderly...

Does Skeletal Muscle Mass Influence Breast Cancer? Evaluating Mammary Tumorigenesis and Progression Genetically Hyper-Muscular Mice

National Research Council Canada - National Science Library

Zimmers, Teresa

2006-01-01

.... Mice lacking the skeletal muscle-specific muscle growth inhibitor myostatin and mice expressing a dominant negative form of the myostatin receptor, Activin Receptor Type IIB, display heightened muscle mass...

Within-Winter Flexibility in Muscle Masses, Myostatin, and Cellular Aerobic Metabolic Intensity in Passerine Birds.

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Swanson, David L; King, Marisa O; Culver, William; Zhang, Yufeng

Metabolic rates of passerine birds are flexible traits that vary both seasonally and among and within winters. Seasonal variation in summit metabolic rates (M sum = maximum thermoregulatory metabolism) in birds is consistently correlated with changes in pectoralis muscle and heart masses and sometimes with variation in cellular aerobic metabolic intensity, so these traits might also be associated with shorter-term, within-winter variation in metabolic rates. To determine whether these mechanisms are associated with within-winter variation in M sum , we examined the effects of short-term (ST; 0-7 d), medium-term (MT; 14-30 d), and long-term (LT; 30-yr means) temperature variables on pectoralis muscle and heart masses, pectoralis expression of the muscle-growth inhibitor myostatin and its metalloproteinase activators TLL-1 and TLL-2, and pectoralis and heart citrate synthase (CS; an indicator of cellular aerobic metabolic intensity) activities for two temperate-zone resident passerines, house sparrows (Passer domesticus) and dark-eyed juncos (Junco hyemalis). For both species, pectoralis mass residuals were positively correlated with ST temperature variables, suggesting that cold temperatures resulted in increased turnover of pectoralis muscle, but heart mass showed little within-winter variation for either species. Pectoralis mRNA and protein expression of myostatin and the TLLs were only weakly correlated with ST and MT temperature variables, which is largely consistent with trends in muscle masses for both species. Pectoralis and heart CS activities showed weak and variable trends with ST temperature variables in both species, suggesting only minor effects of temperature variation on cellular aerobic metabolic intensity. Thus, neither muscle or heart masses, regulation by the myostatin system, nor cellular aerobic metabolic intensity varied consistently with winter temperature, suggesting that other factors regulate within-winter metabolic variation in these birds.

Insulin Resistance Negatively Influences the Muscle-Dependent IGF-1-Bone Mass Relationship in Premenarcheal Girls.

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Kindler, J M; Pollock, N K; Laing, E M; Jenkins, N T; Oshri, A; Isales, C; Hamrick, M; Lewis, R D

2016-01-01

IGF-1 promotes bone growth directly and indirectly through its effects on skeletal muscle. Insulin and IGF-1 share a common cellular signaling process; thus, insulin resistance may influence the IGF-1-muscle-bone relationship. We sought to determine the effect of insulin resistance on the muscle-dependent relationship between IGF-1 and bone mass in premenarcheal girls. This was a cross-sectional study conducted at a university research center involving 147 girls ages 9 to 11 years. Glucose, insulin, and IGF-1 were measured from fasting blood samples. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated from glucose and insulin. Fat-free soft tissue (FFST) mass and bone mineral content (BMC) were measured by dual-energy x-ray absorptiometry. Our primary outcome was BMC/height. In our path model, IGF-1 predicted FFST mass (b = 0.018; P = .001), which in turn predicted BMC/height (b = 0.960; P IGF-1 predicted BMC/height (b = 0.001; P = .002), but not after accounting for the mediator of this relationship, FFST mass. The HOMA-IR by IGF-1 interaction negatively predicted FFST mass (b = -0.044; P = .034). HOMA-IR had a significant and negative effect on the muscle-dependent relationship between IGF-1 and BMC/height (b = -0.151; P = .047). Lean body mass is an important intermediary factor in the IGF-1-bone relationship. For this reason, bone development may be compromised indirectly via suboptimal IGF-1-dependent muscle development in insulin-resistant children.

Efficacy of a novel formulation of L-Carnitine, creatine, and leucine on lean body mass and functional muscle strength in healthy older adults: a randomized, double-blind placebo-controlled study.

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Evans, Malkanthi; Guthrie, Najla; Pezzullo, John; Sanli, Toran; Fielding, Roger A; Bellamine, Aouatef

2017-01-01

Progressive decline in skeletal muscle mass and function are growing concerns in an aging population. Diet and physical activity are important for muscle maintenance but these requirements are not always met. This highlights the potential for nutritional supplementation. As a primary objective, we sought to assess the effect of a novel combination of L-Carnitine, creatine and leucine on muscle mass and performance in older subjects. Forty-two healthy older adults aged 55-70 years were randomized to receive either a novel L-Carnitine (1500 mg), L-leucine (2000 mg), creatine (3000 mg), Vitamin D3 (10 μg) (L-Carnitine-combination) product ( n  = 14), L-Carnitine (1500 mg) ( n  = 14), or a placebo ( n  = 14) for eight weeks. We evaluated body mass by DXA, upper and lower strength by dynamometry, and walking distance by a 6-min walk test at baseline and after eight weeks of intervention. These measures, reflecting muscle mass, functional strength and mobility have been combined to generate a primary composite score. Quality of life, blood safety markers, and muscle biopsies for protein biomarker analysis were also conducted at baseline and the end of the study. The primary composite outcome improved by 63.5 percentage points in the L-Carnitine-combination group vs. placebo ( P  = 0.013). However, this composite score did not change significantly in the L-Carnitine group ( P =  0.232), and decreased slightly in the placebo group ( P =  0.534). Participants supplemented with the L-Carnitine-combination showed a 1.0 kg increase in total lean muscle mass ( P  = 0.013), leg lean muscle mass (0.35 kg, P =  0.005), and a 1.0 kg increase in lower leg strength ( P  = 0.029) at week 8. In addition, these increases were significant when compared to the placebo group (P =  0.034, P =  0.026, and P =  0.002, respectively). Total mTOR protein expression was increased in participants in the L-Carnitine-combination group at the end of

Signalling pathways regulating muscle mass in ageing skeletal muscle. The role of the IGF1-Akt-mTOR-FoxO pathway

NARCIS (Netherlands)

Sandri, M.; Barberi, L.; Bijlsma, A.Y.; Blaauw, B.; Dyar, K.A.; Milan, G.; Mammucari, C.; Meskers, C.G.M.; Pallafacchina, G.; Paoli, A.; Pion, D.; Roceri, M.; Romanello, V.; Serrano, A.L.; Toniolo, L.; Larsson, L.; Maier, A.B.; Munoz-Canoves, P.; Musaro, A.; Pende, M.; Reggiani, C.; Rizzuto, R.; Schiaffino, S.

2013-01-01

During ageing skeletal muscles undergo a process of structural and functional remodelling that leads to sarcopenia, a syndrome characterized by loss of muscle mass and force and a major cause of physical frailty. To determine the causes of sarcopenia and identify potential targets for interventions

Estimation of thigh muscle mass with magnetic resonance imaging in older adults and people with chronic obstructive pulmonary disease.

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Mathur, Sunita; Takai, Karen Pr; Macintyre, Donna L; Reid, Darlene

2008-02-01

Quantifying muscle mass is an essential part of physical therapy assessment, particularly in older adults and in people with chronic conditions associated with muscle atrophy. The purposes of this study were to examine the relationship between muscle cross-sectional area (CSA) and volume by use of magnetic resonance imaging (MRI) and to compare anthropometric estimations of midthigh CSA with measurements obtained from MRI. Twenty older adults who were healthy and 20 people with chronic obstructive pulmonary disease (COPD), matched for age, sex, and body mass index, underwent MRI to obtain measurements of thigh muscle CSA and volume. Anthropometric measurements (skinfold thickness and thigh circumference) were used to estimate midthigh CSA. Muscle volumes were significantly lower in the people with COPD than in the older adults who were healthy. Moderate to high correlations were found between midthigh CSA and volume in both groups (r=.61-.94). Anthropometric measurements tended to overestimate midthigh CSA in both the people with COPD (estimated CSA=64.9+/-17.8; actual CSA=48.3+/-10.2 cm(2)) and the older adults who were healthy (estimated quadriceps femoris muscle CSA=65.0+/-14.0; actual CSA=56.8+/-13.5 cm(2)). Furthermore, the estimated quadriceps femoris muscle CSAs were not sensitive enough to detect a difference in muscle size between people with COPD and controls. Thigh circumference alone was not different between groups and showed only low to moderate correlations with muscle volume (r=.19-.47). Muscle CSA measured from a single slice provides a good indication of volume, but the most representative slice should be chosen on the basis of the muscle group of interest. Thigh circumference is not correlated with muscle volume and, therefore, should not be used as an indicator of muscle size. The development of population-specific reference equations for estimating muscle CSA from anthropometric measurements is warranted.

Supplementing Breakfast with a Vitamin D and Leucine-Enriched Whey Protein Medical Nutrition Drink Enhances Postprandial Muscle Protein Synthesis and Muscle Mass in Healthy Older Men.

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Chanet, Audrey; Verlaan, Sjors; Salles, Jérôme; Giraudet, Christophe; Patrac, Véronique; Pidou, Véronique; Pouyet, Corinne; Hafnaoui, Nordine; Blot, Adeline; Cano, Noël; Farigon, Nicolas; Bongers, Anke; Jourdan, Marion; Luiking, Yvette; Walrand, Stéphane; Boirie, Yves

2017-12-01

Background: A promising strategy to help older adults preserve or build muscle mass is to optimize muscle anabolism through providing an adequate amount of high-quality protein at each meal. Objective: This "proof of principle" study investigated the acute effect of supplementing breakfast with a vitamin D and leucine-enriched whey protein medical nutrition drink on postprandial muscle protein synthesis and longer-term effect on muscle mass in healthy older adults. Methods: A randomized, placebo-controlled, double-blind study was conducted in 24 healthy older men [mean ± SD: age 71 ± 4 y; body mass index (in kg/m 2 ) 24.7 ± 2.8] between September 2012 and October 2013 at the Unit of Human Nutrition, University of Auvergne, Clermont-Ferrand, France. Participants received a medical nutrition drink [test group; 21 g leucine-enriched whey protein, 9 g carbohydrates, 3 g fat, 800 IU cholecalciferol (vitamin D 3 ), and 628 kJ] or a noncaloric placebo (control group) before breakfast for 6 wk. Mixed muscle protein fractional synthesis rate (FSR) was measured at week 0 in the basal and postprandial state, after study product intake with a standardized breakfast with the use of l-[ 2 H 5 ]-phenylalanine tracer methodology. The longer-term effect of the medical nutrition drink was evaluated by measurement of appendicular lean mass, representing skeletal muscle mass at weeks 0 and 6, by dual-energy X-ray absorptiometry. Results: Postprandial FSR (0-240 min) was higher in the test group than in the control group [estimate of difference (ED): 0.022%/h; 95% CI: 0.010%/h, 0.035%/h; ANCOVA, P = 0.001]. The test group gained more appendicular lean mass than the control group after 6 wk (ED: 0.37 kg; 95% CI: 0.03, 0.72 kg; ANCOVA, P = 0.035), predominantly as leg lean mass (ED: 0.30 kg; 95% CI: 0.03, 0.57 kg; ANCOVA, P = 0.034). Conclusions: Supplementing breakfast with a vitamin D and leucine-enriched whey protein medical nutrition drink stimulated postprandial muscle protein

Depression Is Associated With Muscle Mass And Strength In Patients With End Stage Renal Disease

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Young Rim Song

2012-06-01

Full Text Available Depression is the most common psychiatric complication in patients with end-stage renal disease (ESRD. Sarcopenia, defined as loss of muscle mass and strength, is expected to be associated with depression, because both are closely linked to physical inactivity and functional impairment. We investigated the association of sarcopenia with depression in patients with ESRD. A total of 115 patients undergoing hemodialysis (HD were included in this study. Muscle mass was assessed by lean tissue index (LTI using portable whole body bioimpedance spectroscopy, and muscle strength was measured with handgrip strength (HGS. Depression was defined as Beck Depression Inventory-II (BDI-II score ≥16. About 60% of prevalent HD patients had depression. Compared to subjects without depression, depressed patients had a higher prevalence of sarcopenia (45.5 vs. 8.2%, p<0.001 and significantly increased serum IL-6 and hs-CRP level. However, (prealbumin and body mass index (BMI failed to correlate with BDI-II. HGS and LTI had a consistent negative effect on BDI-II even after adjusting other parameters including inflammation. In multivariate analysis, lower , increased IL-6 and β2-microglobulin,and sarcopenia were significant predictors for depression; sarcopenia was most powerful [odds ratio 9.01, 95% CI 3.60-12.22, p=0.001]. In conclusion, the prevalence of sarcopenia and depression was considerably high and and the presence of sarcopenia was an important predictor for depression.

Pro-inflammatory capacity of classically activated monocytes relates positively to muscle mass and strength.

Science.gov (United States)

Beenakker, Karel G M; Westendorp, Rudi G J; de Craen, Anton J M; Slagboom, Pieternella E; van Heemst, Diana; Maier, Andrea B

2013-08-01

In mice, monocytes that exhibit a pro-inflammatory profile enter muscle tissue after muscle injury and are crucial for clearance of necrotic tissue and stimulation of muscle progenitor cell proliferation and differentiation. The aim of this study was to test if pro-inflammatory capacity of classically activated (M1) monocytes relates to muscle mass and strength in humans. This study included 191 male and 195 female subjects (mean age 64.2 years (SD 6.4) and 61.9 ± 6.4, respectively) of the Leiden Longevity Study. Pro-inflammatory capacity of M1 monocytes was assessed by ex vivo stimulation of whole blood with Toll-like receptor (TLR) 4 agonist lipopolysaccharide (LPS) and TLR-2/1 agonist tripalmitoyl-S-glycerylcysteine (Pam₃Cys-SK₄), both M1 phenotype activators. Cytokines that stimulate M1 monocyte response (IFN-γ and GM-CSF) as well as cytokines that are secreted by M1 monocytes (IL-6, TNF-α, IL-12, and IL-1β) were measured. Analyses were adjusted for age, height, and body fat mass. Upon stimulation with LPS, the cytokine production capacity of INF-γ, GM-CSF, and TNF-α was significantly positively associated with lean body mass, appendicular lean mass and handgrip strength in men, but not in women. Upon stimulation with Pam₃Cys-SK₄, IL-6; TNF-α; and Il-1β were significantly positively associated with lean body mass and appendicular lean in women, but not in men. Taken together, this study shows that higher pro-inflammatory capacity of M1 monocytes upon stimulation is associated with muscle characteristics and sex dependent. © 2013 John Wiley & Sons Ltd and the Anatomical Society.

Preserving Healthy Muscle during Weight Loss123

Science.gov (United States)

Cava, Edda; Yeat, Nai Chien; Mittendorfer, Bettina

2017-01-01

Weight loss is the cornerstone of therapy for people with obesity because it can ameliorate or completely resolve the metabolic risk factors for diabetes, coronary artery disease, and obesity-associated cancers. The potential health benefits of diet-induced weight loss are thought to be compromised by the weight-loss–associated loss of lean body mass, which could increase the risk of sarcopenia (low muscle mass and impaired muscle function). The objective of this review is to provide an overview of what is known about weight-loss–induced muscle loss and its implications for overall physical function (e.g., ability to lift items, walk, and climb stairs). The currently available data in the literature show the following: 1) compared with persons with normal weight, those with obesity have more muscle mass but poor muscle quality; 2) diet-induced weight loss reduces muscle mass without adversely affecting muscle strength; 3) weight loss improves global physical function, most likely because of reduced fat mass; 4) high protein intake helps preserve lean body and muscle mass during weight loss but does not improve muscle strength and could have adverse effects on metabolic function; 5) both endurance- and resistance-type exercise help preserve muscle mass during weight loss, and resistance-type exercise also improves muscle strength. We therefore conclude that weight-loss therapy, including a hypocaloric diet with adequate (but not excessive) protein intake and increased physical activity (particularly resistance-type exercise), should be promoted to maintain muscle mass and improve muscle strength and physical function in persons with obesity. PMID:28507015

Resistance Exercise Impacts Lean Muscle Mass in Women with Polycystic Ovary Syndrome.

Science.gov (United States)

Kogure, Gislaine Satyko; Miranda-Furtado, Cristiana Libardi; Silva, Rafael Costa; Melo, Anderson Sanches; Ferriani, Rui Alberto; De Sá, Marcos Felipe Silva; Dos Reis, Rosana Maria

2016-04-01

This study investigated the effects of progressive resistance training (PRT) on lean muscle mass (LMM) in women with or without polycystic ovary syndrome (PCOS) and its effects on metabolic factors and concentrations of related steroid hormones. This was a nonrandomized, therapeutic, open, single-arm study. All in all, 45 sedentary women with PCOS and 52 without (non-PCOS), 18-37 yr of age, with body mass indexes (BMI) of 18-39.9 kg·m(-2) of all races and social status, performed PRT three times a week for 4 months. Before and after PRT, the concentrations of hormones and metabolic factors and waist circumference were measured. LMM and total body fat percentage were determined using dual-energy x-ray absorptiometry. Clinical characteristics, LMM, and fasting glucose were adjusted for confounding covariables and compared using general linear mixed models. Each patient's menstrual history was taken before study enrollment and after PRT. PRT resulted in reduced plasma testosterone and fasting glucose levels. After PRT, the androstenedione concentration increased and the sex hormone-binding globulin concentration decreased in women with PCOS. The waist circumference was reduced (P lean mass (LM)/height2, increased in women with PCOS (P = 0.04). Women with PCOS showed increased muscle mass indexes of appendicular LM/height2 (P = 0.03) and LM/height2 (P women with PCOS (P = 0.01) at the baseline and after PRT. To our knowledge, this is the first report to show that resistance exercise alone can improve hyperandrogenism, reproductive function, and body composition by decreasing visceral fat and increasing LMM, but it has no metabolic impact on women with PCOS.

High insulin-like growth factor-binding protein-1 (IGFBP-1) is associated with low relative muscle mass in older women

DEFF Research Database (Denmark)

Stilling, Frej; Wallenius, Sara; Michaëlsson, Karl

2017-01-01

. In the present study we investigate the association between serum IGFBP-1 and muscle mass. Design Cross-sectional analysis of 4908 women, between 55 and 85 years old, participating in the Swedish Mammography Cohort-Clinical. Methods We defined low relative muscle mass (LRMM) as an appendicular lean mass divided...... relative muscle mass. High IGFBP-1 may be a marker of a catabolic state.......Objective Skeletal muscles serve several important roles in maintaining good health. Insulin-like growth factor-1 (IGF-1) is a promoter of protein synthesis in skeletal muscle. Its binding protein, Insulin-like growth factor-binding protein-1 (IGFBP-1) can be one determinant of IGF-1 activity...

Protein needs in athletes and dietary-nutrition guidelines to gain muscle mass

Directory of Open Access Journals (Sweden)

Aritz Urdampilleta

2014-05-01

Full Text Available One of the most important effects of strength training is muscular hypertrophy. Athletes should optimize their nutritional management in order to compensate their own genetic limitations. The aim of this review is to analyze the scientific evidence concerning protein intake as a tool to achieve muscle hypertrophy. Depending on the expenditure and energy intake of athlete, a daily protein ranging between 10-15% of total dietary intake is needed. However in sports diets, it is preferable to estimate the amount of protein needed per kilogram of body weight in each individual. In this regard athletes should ingest an amount between 1.2 g and 1.8 g of proteins/kg of body mass/day to maintain their lean mass. In order to increase muscle mass (0.5 kg/week, athletes should take between 1.6 g and 1.8 g of protein/kg/day with an increase of 400-500 kcal in their daily diet. These needs will depend on the sport, muscular catabolic status, the athlete’s lean mass and glycogen stores. Protein needs will increase if muscle and liver glycogen stores are empty. Excess of protein intake (more than 2 g/kg/day, with full glycogen stores, does not benefit the athlete and could cause an increase in circulating ketones and urea, thereby producing an early dehydration.

Assessment of the influence of body composition on bone mass in children and adolescents based on a functional analysis of the muscle-bone relationship.

Science.gov (United States)

Golec, Joanna; Chlebna-Sokół, Danuta

2014-01-01

The functional model of skeletal development considers the mechanical factor to be the most important skeletal modulant. The aim of the study was a functional analysis of the bone-muscle relationship in children with low and normal bone mass. The study involved 149 children with low and 99 children with normal bone mass (control group). All patients underwent a densitometry examination (DXA). Low bone mass was diagnosed if the Z-score was below values of Z-scores for all parameters in children with low bone mass as compared to the control group. Children with low bone mass had lower content of adipose and muscle tissue and a marked deficit of muscle tissue with regard to height (which according to mechanostat theory leads to lower muscle-generated strain on bones). This group of children had also lower TBBMC/LBM Z-scores, which indicates greater fracture susceptibility. 1. Functional analysis, which showed associations between bone and muscle tissues, can be useful for diagnosing and monitoring skeletal system disorders as well as making therapeutic decisions.2. The study emphasizes the role of proper nutrition and physical activities, which contribute to proper body composition, in the prevention of bone mineralization disorders in childhood and adolescence. 3. The study showed the inadequacy of the classic reference ranges used in interpreting DXA data in children and demonstrated the usefulness of continuous variables for that purpose.

Measurement of Muscle Protein Fractional Synthetic Rate by Capillary Gas Chromatography/Combustion Isotope Ratio Mass Spectrometry

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Yarasheski, Kevin E.; Smith, Kenneth; Rennie, Michael J.; Bier, Dennis M.

2014-01-01

The measurement of skeletal muscle protein fractional synthetic rate using an infusion of (1-13C)leucine and measuring the isotopic abundance of the tracer in skeletal muscle protein by preparative gas chromatography (GC)/ninhydrin isotope ratio mass spectrometry (IRMS) is laborious and subject to errors owing to contamination by 12C. The purpose of this study was to compare muscle (13C)leucine enrichment measured with the conventional preparative GC/ninhydrin IRMS approach to a new, continuous-flow technique using capillary GC/combustion IRMS. Quadriceps muscles were removed from four Sprague–Dawley rats after each was infused at a different rate with (1-13C)leucine for 6–8 h. Muscle leucine enrichment (at.% excess) measured by both methods differed by less than 4%, except at low (13C)leucine enrichments (IRMS was used to assess muscle (13C)leucine enrichment and fractional muscle protein synthesis rate in ten normal young men and women infused with (1,2-13C2)leucine for 12–14 h. This approach reduced the variability of the isotope abundance measure and gave estimates of muscle protein synthesis rate (0.050 ± 0.011% h−1 (mean ± SEM); range = 0.023–0.147% h−1) that agree with published values determined using the standard analytical approach. The measurement of (13C)leucine enrichment from skeletal muscle protein by capillary GC/combustion IRMS provides a simple, acceptable and practical alternative to preparative GC/ninhydrin IRMS. PMID:1420371

Locomotion and muscle mass measures in a murine model of collagen-induced arthritis

NARCIS (Netherlands)

Hartog, A.; Hulsman, J.; Garssen, J.

2009-01-01

Background: Rheumatoid arthritis (RA) is characterized by chronic poly-arthritis, synovial hyperplasia, erosive synovitis, progressive cartilage and bone destruction accompanied by a loss of body cell mass. This loss of cell mass, known as rheumatoid cachexia, predominates in the skeletal muscle and

Type VI collagen turnover-related peptides-novel serological biomarkers of muscle mass and anabolic response to loading in young men.

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Nedergaard, Anders; Sun, Shu; Karsdal, Morten A; Henriksen, Kim; Kjær, Michael; Lou, Yunyun; He, Yi; Zheng, Qinlong; Suetta, Charlotte

2013-12-01

Immobilization-induced loss of muscle mass is a complex phenomenon with several parallels to sarcopenic and cachectic muscle loss. Muscle is a large organ with a protein turnover that is orders of magnitude larger than most other tissues. Thus, we hypothesize that muscle loss and regain is reflected by peptide biomarkers derived from type VI collagen processing released in the circulation. In order to test this hypothesis, we set out to develop an ELISA assay against an type VI collagen N-terminal globular domain epitope (IC6) and measured the levels of IC6 and an MMP-generated degradation fragment of collagen 6, (C6M) in a human immobilization-remobilization study setup with young (n = 11) and old (n = 9) men. They were subjected to 2 weeks of unilateral lower limb immobilization followed by 4 weeks of remobilization including thrice weekly resistance training, using the contralateral leg as internal controls. Subjects were sampled for strength, quadriceps muscle volume and blood at baseline (PRE), post-immobilization (2W), and post-remobilization (4W). Blood were subsequently analyzed for levels of the C6M and IC6 biomarkers. We subsequently tested if there was any correlation between C6M, IC6, or the C6M/IC6 ratio and muscle mass or strength at baseline. We also tested whether there was any relation between these biomarkers and changes in muscle mass or strength with immobilization or remobilization. The model produced significant loss of muscle mass and strength in the immobilized leg. This loss was bigger in young subjects than in elderly, but whereas the young recovered almost fully, the elderly had limited regrowth of muscle. We found a significant correlation between IC6 and muscle mass at baseline in young subjects (R (2) = 0.6563, p = 0.0045), but none in the elderly. We also found a significant correlation between C6M measured at the 4W time point and the change in muscle mass during remobilization, again only manifesting in the young

Does Skeletal Muscle Mass Influence Breast Cancer? Evaluating Mammary Tumorigenesis and Progression Genetically Hyper-Muscular Mice

Science.gov (United States)

2006-07-01

the skeletal muscle-specific muscle growth inhibitor myostatin and mice expressing a dominant negative form of the myostatin receptor, Activin...and rates of breast cancer initiation and progression. 15. SUBJECT TERMS Breast cancer, skeletal muscle, myostatin , MPA, DMBA, Activin receptor 16...including interleukins, Insulin-like Growth Factor (IGF) isoforms, IGF-binding proteins and myostatin . To determine the effect of skeletal muscle mass

Is increase in bone mineral content caused by increase in skeletal muscle mass/strength in adult patients with GH-treated GH deficiency?

DEFF Research Database (Denmark)

Klefter, Oliver; Feldt-Rasmussen, Ulla

2009-01-01

to a muscle modulating effect, and if treatment with GH would primarily increase muscle mass and strength with a secondary increase in BMD/BMC, thus supporting the present physiological concept that mass and strength of bones are mainly determined by dynamic loads from the skeletal muscles. METHOD: We...... performed a systematic literature analysis, including 51 clinical trials published between 1996 and 2008, which had studied the development in muscle mass, muscle strength, BMD, and/or BMC in GH-treated adult GHD patients. RESULTS: GH therapy had an anabolic effect on skeletal muscle. The largest increase...... in muscle mass occurred during the first 12 months of therapy. Most trials measuring BMD/BMC reported significant increases from baseline values. The significant increases in BMD/BMC occurred after 12-18 months of treatment, i.e. usually later than the increases in muscle parameters. Only seven trials...

Comparative jaw muscle anatomy in kangaroos, wallabies, and rat-kangaroos (marsupialia: macropodoidea).

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Warburton, Natalie Marina

2009-06-01

The jaw muscles were studied in seven genera of macropodoid marsupials with diets ranging from mainly fungi in Potorous to grass in Macropus. Relative size, attachments, and lamination within the jaw adductor muscles varied between macropodoid species. Among macropodine species, the jaw adductor muscle proportions vary with feeding type. The relative mass of the masseter is roughly consistent, but grazers and mixed-feeders (Macropus and Lagostrophus) had relatively larger medial pterygoids and smaller temporalis muscles than the browsers (Dendrolagus, Dorcopsulus, and Setonix). Grazing macropods show similar jaw muscle proportions to "ungulate-grinding" type placental mammals. The internal architecture of the jaw muscles also varies between grazing and browsing macropods, most significantly, the anatomy of the medial pterygoid muscle. Potoroines have distinctly different jaw muscle proportions to macropodines. The masseter muscle group, in particular, the superficial masseter is enlarged, while the temporalis group is relatively reduced. Lagostrophus fasciatus is anatomically distinct from other macropods with respect to its masticatory muscle anatomy, including enlarged superficial medial pterygoid and deep temporalis muscles, an anteriorly inflected masseteric process, and the shape of the mandibular condyle. The enlarged triangular pterygoid process of the sphenoid bone, in particular, is distinctive of Lagsotrophus. (c) 2009 Wiley-Liss, Inc.

Impaired physical function, loss of muscle mass and assessment of biomechanical properties in critical ill patients

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Poulsen, Jesper Brøndum

2012-01-01

Intensive care unit (ICU) admission is associated with muscle weakness and ICU survivors report sustained limitation of physical capacity for years after discharge. Limited information is available on the underlying biomechanical properties responsible for this muscle function impairment. A plaus......Intensive care unit (ICU) admission is associated with muscle weakness and ICU survivors report sustained limitation of physical capacity for years after discharge. Limited information is available on the underlying biomechanical properties responsible for this muscle function impairment....... A plausible contributor to the accentuated catabolic drive in ICU patients is a synergistic response to inflammation and inactivity leading to loss of muscle mass. As these entities are predominantly present in the early phase of ICU stay, interventions employed during this time frame may exhibit the greatest...... potential to counteract loss of muscle mass. Despite the obvious clinical significance of muscle atrophy for the functional impairment observed in ICU survivors, no preventive therapies have been identified as yet. The overall aim of the present dissertation is to characterize aspects of physical function...

The loss of skeletal muscle strength, mass, and quality in older adults : the health, aging and body composition study

NARCIS (Netherlands)

Goodpaster, Bret H; Park, Seok Won; Harris, Tamara B; Kritchevsky, Steven B; Nevitt, Michael; Schwartz, Ann V; Simonsick, Eleanor M; Tylavsky, Frances A; Visser, Marjolein; Newman, Anne B

2006-01-01

BACKGROUND: The loss of muscle mass is considered to be a major determinant of strength loss in aging. However, large-scale longitudinal studies examining the association between the loss of mass and strength in older adults are lacking. METHODS: Three-year changes in muscle mass and strength were

The Influence of Body Mass Index, Sex, & Muscle Activation on Pressure Distribution During Lateral Falls on the Hip.

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Pretty, Steven P; Martel, Daniel R; Laing, Andrew C

2017-12-01

Hip fracture incidence rates are influenced by body mass index (BMI) and sex, likely through mechanistic pathways that influence dynamics of the pelvis-femur system during fall-related impacts. The goal of this study was to extend our understanding of these impact dynamics by investigating the effects of BMI, sex, and local muscle activation on pressure distribution over the hip region during lateral impacts. Twenty participants underwent "pelvis-release experiments" (which simulate a lateral fall onto the hip), including muscle-'relaxed' and 'contracted' trials. Males and low-BMI individuals exhibited 44 and 55% greater peak pressure, as well as 66 and 56% lower peripheral hip force, compared to females and high-BMI individuals, respectively. Local muscle activation increased peak force by 10%, contact area by 17%, and peripheral hip force by 11% compared to relaxed trials. In summary, males and low-BMI individuals exhibited more concentrated loading over the greater trochanter. Muscle activation increased peak force, but this force was distributed over a larger area, preventing increased localized loading over the greater trochanter. These findings suggest potential value in incorporating sex, gender, and muscle activation-specific force distributions as inputs into computational tissue-level models, and have implications for the design of personalized protective devices including wearable hip protectors.

The association of low muscle mass with soluble receptor for advanced glycation end products (sRAGE): The Korean Sarcopenic Obesity Study (KSOS).

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Kim, Tae Nyun; Park, Man Sik; Lee, Eun Joo; Chung, Hye Soo; Yoo, Hye Jin; Kang, Hyun Joo; Song, Wook; Baik, Sei Hyun; Choi, Kyung Mook

2018-03-01

Advanced glycation end products (AGEs) are accumulated with aging in various tissues of humans. The soluble receptor for AGEs (sRAGE) exerts a protective role against the development of aging-related chronic disorders by neutralizing the action of AGEs. We investigated the implication of sRAGE on low muscle mass in Asian men and women. This cross-sectional study included a 390-participant, nondiabetic subcohort recruited within the framework of the Korean Sarcopenic Obesity Study, an ongoing prospective cohort study. Low muscle mass was defined based on the distribution of appendicular skeletal muscle mass divided by body mass index, as proposed by the Foundation for the National Institutes Sarcopenia Project. Serum sRAGE levels were significantly lower in participants with low muscle mass than in participants without low muscle mass (0.76 [0.60-1.00] ng/mL vs 0.87 [0.67-1.15] ng/mL, P = .005). In age- and sex-adjusted correlation analyses, appendicular skeletal muscle mass divided by body mass index was associated with sRAGE (r = 0.109, P = .037). Furthermore, decreased circulating levels of sRAGE are independently associated with low muscle mass (odds ratio = 0.254, P = .002) after adjusting for confounding factors, including insulin resistance and inflammatory markers. The present study shows that a low circulating level of sRAGE may be an independent risk factor for the presence of low muscle mass. Copyright © 2017 John Wiley & Sons, Ltd.

The Effect of a 12-Week Omega-3 Supplementation on Body Composition, Muscle Strength and Physical Performance in Elderly Individuals with Decreased Muscle Mass

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Roma Krzymińska-Siemaszko

2015-08-01

Full Text Available The aim of the study was to assess the effect of a polyunsaturated omega-3 fatty acids (PUFA supplementation on the parameters of body composition, muscle strength and physical performance in elderly people with decreased muscle mass (DMM. Fifty three elderly people with an ALM index (the ratio of appendicular lean mass to squared height either below (−2SD: low muscle mass-LMM or between (−1SD and −2SD: the risk of LMM-rLMM the ALM index for the young Polish reference population were randomly assigned to PUFA-treated groups (LMM-PUFA, rLMM-PUFA or control groups (LMM-control, rLMM-control. PUFA-treated groups received capsules containing 1.3 g of PUFA and 10 mg of vitamin E, while the control groups received 11 mg of vitamin E daily for 12 weeks. Body composition (BIA analysis, muscle strength (hand grip measured with dynamometer and physical performance (Timed Up and Go test-TUG were assessed before and after supplementation. No statistically significant differences were observed either in muscle mass or in the hand grip and TUG in any group. The post-pre difference (mean ± SD in ALM index was as follows (kg/m2: LMM-PUFA: 0.00 ± 0.30, rLMM-PUFA: 0.00 ± 0.22, LMM-control: 0.03 ± 0.36, rLMM-control: –0.03 ± 0.20. In our study, a 12 week supplementation of PUFA did not affect the evaluated parameters in elderly individuals with DMM.

Low appendicular skeletal muscle mass (ASM) with limited mobility and poor health outcomes in middle-aged African Americans.

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Malmstrom, Theodore K; Miller, Douglas K; Herning, Margaret M; Morley, John E

2013-09-01

Recent efforts to provide a consensus definition propose that sarcopenia be considered a clinical syndrome associated with the loss of both skeletal muscle mass and muscle function that occurs with aging. Validation of sarcopenia definitions that include both low muscle mass and poor muscle function is needed. In the population-based African American Health (AAH) study (N = 998 at baseline/wave 1), muscle mass and mobility were evaluated in a clinical testing center in a subsample of N = 319 persons (ages 52-68) at wave 4 (2004). Muscle mass was measured using dual energy x-ray absorptiometry and mobility by a 6-min walk test and 4-m gait walk test. Height corrected appendicular skeletal mass (ASM; 9.0 ± 1.5 in n = 124 males, 8.3 ± 2.2 in n = 195 females) was computed as total lean muscle mass in arms and legs (kilograms) divided by the square of height (meters). Cross-sectional and longitudinal (6-year) associations of low ASM (bottom 25 % AAH sample; ASM with limited mobility (4-m gait walk ≤1 m/s or 6-min walk ASM with limited mobility was associated with IADL difficulties (p = .008) and frailty (p = .040) but not with ADL difficulties or falls in cross-sectional analyses; and with ADL difficulties (p = .022), IADL difficulties (p = .006), frailty (p = .039), and mortality (p = .003) but not with falls in longitudinal analyses adjusted for age and gender. Low ASM alone was marginally associated with mortality (p = .085) but not with other outcomes in cross-sectional or longitudinal analyses. Low ASM with limited mobility is associated with poor health outcomes among late middle-aged African Americans.

Tissue Selective Androgen Receptor Modulators (SARMs) Increase Pelvic Floor Muscle Mass in Ovariectomized Mice.

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Ponnusamy, Suriyan; Sullivan, Ryan D; Thiyagarajan, Thirumagal; Tillmann, Heather; Getzenberg, Robert H; Narayanan, Ramesh

2017-03-01

Stress urinary incontinence (SUI), a prevalent condition, is represented by an involuntary leakage of urine that results, at least in part, from weakened or damaged pelvic floor muscles and is triggered by physical stress. Current treatment options are limited with no oral therapies available. The pelvic floor is rich in androgen receptor and molecules with anabolic activity including selective androgen receptor modulators (SARMs) may serve as therapeutic options for individuals with SUI. In this study, two SARMs (GTx-024 and GTx-027) were evaluated in a post-menopausal animal model in order to determine their effect on pelvic floor muscles. Female C57BL/6 mice were ovariectomized and their pelvic muscles allowed to regress. The animals were then treated with vehicle or doses of GTx-024 or GTx-027. Animal total body weight, lean body mass, and pelvic floor muscle weights were measured along with the expression of genes associated with muscle catabolism. Treatment with the SARMs resulted in a restoration of the pelvic muscles to the sham-operated weight. Coordinately, the induction of genes associated with muscle catabolism was inhibited. Although a trend was observed towards an increase in total lean body mass in the SARM-treated groups, no significant differences were detected. Treatment of an ovariectomized mouse model with SARMs resulted in an increase in pelvic floor muscles, which may translate to an improvement of symptoms associated with SUI and serves as the basis for evaluating their clinical use. J. Cell. Biochem. 118: 640-646, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Effects of progressive strength training on muscle mass in type 2 diabetes mellitus patients determined by computed tomography

International Nuclear Information System (INIS)

Cauza, E.; Strehblow, C.; Hanusch-Enserer, U.; Fasching, P.; Metz-Schimmerl, S.; Strasser, B.; Kostner, K.; Dunstan, D.; Haber, P.

2009-01-01

To examine the effect of a 4-month progressive strength training program on muscle and fat mass assessed by computed tomography (CT) in type 2 diabetes mellitus (T2DM) patients, and to assess the relationships of changes in muscle cross-section area (CSA) with glycaemic control. Twenty adults (mean age ± SE: 56.4 ± 0.9 a) with T2DM participated in a supervised strength training program for 4 months 3 days/week. Muscle and fat areas of the quadriceps muscle were estimated by CT volumetry before and immediately after the training. Glycaemic (HbA1c) and anthropometric (BMI, skinfolds) measurements were assessed at 0 and 4 months, respectively. After strength training, muscle strength increased significantly in all measured muscle groups. Quadriceps size (CSA of the muscle) was increased by 2.4 % (from 7.99 ± 0.3 cm 3 to 8.18 ± 0.3 cm 3 , p = 0.003) for the right extremity, 3.9 % (from 8.1 ± 0.4 cm 3 to 8.41 ± 0.5 cm 3 , p = 0.04) for the left side. Fat tissue CSA reduced from 0.66 ± 0.1 cm 3 to 0.56 ± 0.12 cm 3 for the right leg (15.3 % reduction) and from 0.58 ± 0.12 cm 3 to 0.37 ± 0.13 cm 3 for the left leg (35.8 % reduction), resulting in a mean fat CSA reduction of 24.8 %. Fat mass assessed by skin folds was significantly reduced and lean body mass was significantly increased. The change in muscle CSA was not correlated with the changes in HbA1c or muscle strength. Strength training significantly improves both muscle mass and the muscle to fat ratio in T2DM. However, changes in muscle observed with computed tomography were not related to changes observed in HbA1c with training. (author) [de

Strong Relation between Muscle Mass Determined by D3-creatine Dilution, Physical Performance and Incidence of Falls and Mobility Limitations in a Prospective Cohort of Older Men.

Science.gov (United States)

Cawthon, Peggy M; Orwoll, Eric S; Peters, Katherine E; Ensrud, Kristine E; Cauley, Jane A; Kado, Deborah M; Stefanick, Marcia L; Shikany, James M; Strotmeyer, Elsa S; Glynn, Nancy W; Caserotti, Paolo; Shankaran, Mahalakshmi; Hellerstein, Marc; Cummings, Steven R; Evans, William J

2018-06-12

Direct assessment of skeletal muscle mass in older adults is clinically challenging. Relationships between lean mass and late-life outcomes have been inconsistent. The D3-creatine dilution method provides a direct assessment of muscle mass. Muscle mass was assessed by D3-creatine (D3Cr) dilution in 1,382 men (mean age, 84.2 yrs). Participants completed the Short Physical Performance Battery (SPPB); usual walking speed (6 meters); and DXA lean mass. Men self-reported mobility limitations (difficulty walking 2-3 blocks or climbing 10 steps); recurrent falls (2+); and serious injurious falls in the subsequent year. Across quartiles of D3Cr muscle mass/body mass, multivariate linear models calculated means for SPPB and gait speed; multivariate logistic models calculated odds ratios for incident mobility limitations or falls. Compared to men in the highest quartile, those in the lowest quartile of D3Cr muscle mass/body mass had slower gait speed (Q1: 1.04 vs Q4: 1.17 m/s); lower SPPB (Q1: 8.4 vs Q4: 10.4 points); greater likelihood of incident serious injurious falls (OR Q1 vs Q4: 2.49, 95% CI: 1.37, 4.54); prevalent mobility limitation (OR Q1 vs Q4,: 6.1, 95%CI: 3.7, 10.3) and incident mobility limitation (OR Q1 vs Q4: 2.15 95% CI: 1.42, 3.26); p for trend strongly related to physical performance, mobility and incident injurious falls in older me.

Identification of skeletal muscle mass depletion across age and BMI groups in health and disease--there is need for a unified definition.

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Bosy-Westphal, A; Müller, M J

2015-03-01

Although reduced skeletal muscle mass is a major predictor of impaired physical function and survival, it remains inconsistently diagnosed to a lack of standardized diagnostic approaches that is reflected by the variable combination of body composition indices and cutoffs. In this review, we summarized basic determinants of a normal lean mass (age, gender, fat mass, body region) and demonstrate limitations of different lean mass parameters as indices for skeletal muscle mass. A unique definition of lean mass depletion should be based on an indirect or direct measure of skeletal muscle mass normalized for height (fat-free mass index (FFMI), appendicular or lumbal skeletal muscle index (SMI)) in combination with fat mass. Age-specific reference values for FFMI or SMI are more advantageous because defining lean mass depletion on the basis of total FFMI or appendicular SMI could be misleading in the case of advanced age due to an increased contribution of connective tissue to lean mass. Mathematical modeling of a normal lean mass based on age, gender, fat mass, ethnicity and height can be used in the absence of risk-defined cutoffs to identify skeletal muscle mass depletion. This definition can be applied to identify different clinical phenotypes like sarcopenia, sarcopenic obesity or cachexia.

The Role of Muscle Mass, Muscle Quality, and Body Composition in Risk for the Metabolic Syndrome and Functional Decline in Older Adults: Topical Collection on Nutrition, Obesity, and Diabetes

NARCIS (Netherlands)

R.T. Mankowski (Robert T.); S.D. Anton (Stephen D.); M. Aubertin-Leheudre (Mylene)

2015-01-01

textabstractAbstract Age-related body composition changes include both loss of muscle mass (sarcopenia) and increase in fat mass, which jointly contribute to a decline in metabolic functions. Muscle quality is positively related to functional capacity and a lower risk for the development of the

Myostatin genotype regulates muscle-specific miRNA expression in mouse pectoralis muscle

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Cheng Ye

2010-11-01

Full Text Available Abstract Background Loss of functional Myostatin results in a dramatic increase in skeletal muscle mass. It is unknown what role miRNAs play in Myostatin mediated repression of skeletal muscle mass. We hypothesized that Myostatin genotype would be associated with the differential expression of miRNAs in skeletal muscle. Findings Loss of functional Myostatin resulted in a significant increase (p .2 on miR-24 expression level. Myostatin genotype did not affect the expression level of MyoD or Myogenin (P > 0.5. Conclusions Myostatin may regulates the expression of miRNAs such as miR-133a, miR-133b, miR-1, and miR-206 in skeletal muscle as it has been observed that the expression of those miRNAs are significantly higher in myostatin null mice compared to wild type and heterozygous mice. In contrast, expression of myogenic factors such as MyoD or Myogenin has not been affected by myostatin in the muscle tissue.

The role of mTOR signaling in the regulation of protein synthesis and muscle mass during immobilization in mice

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You, Jae-Sung; Anderson, Garrett B.; Dooley, Matthew S.; Hornberger, Troy A.

2015-01-01

ABSTRACT The maintenance of skeletal muscle mass contributes substantially to health and to issues associated with the quality of life. It has been well recognized that skeletal muscle mass is regulated by mechanically induced changes in protein synthesis, and that signaling by mTOR is necessary for an increase in protein synthesis and the hypertrophy that occurs in response to increased mechanical loading. However, the role of mTOR signaling in the regulation of protein synthesis and muscle mass during decreased mechanical loading remains largely undefined. In order to define the role of mTOR signaling, we employed a mouse model of hindlimb immobilization along with pharmacological, mechanical and genetic means to modulate mTOR signaling. The results first showed that immobilization induced a decrease in the global rates of protein synthesis and muscle mass. Interestingly, immobilization also induced an increase in mTOR signaling, eIF4F complex formation and cap-dependent translation. Blocking mTOR signaling during immobilization with rapamycin not only impaired the increase in eIF4F complex formation, but also augmented the decreases in global protein synthesis and muscle mass. On the other hand, stimulating immobilized muscles with isometric contractions enhanced mTOR signaling and rescued the immobilization-induced decrease in global protein synthesis through a rapamycin-sensitive mechanism that was independent of ribosome biogenesis. Unexpectedly, the effects of isometric contractions were also independent of eIF4F complex formation. Similar to isometric contractions, overexpression of Rheb in immobilized muscles enhanced mTOR signaling, cap-dependent translation and global protein synthesis, and prevented the reduction in fiber size. Therefore, we conclude that the activation of mTOR signaling is both necessary and sufficient to alleviate the decreases in protein synthesis and muscle mass that occur during immobilization. Furthermore, these results indicate

Impact of fat mass distribution body shapes on muscles strength and the joints pain

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Zerf Mohammed

2016-01-01

Full Text Available Our study focuses on fat mass distribution body shapes type as measured to determine their effect on skeletal muscle strengthening lumbar extensors (upper and lower limbs where our background confirms that every girl has a natural body type of rectangle, apple, pear, or hourglass. It is good for her to know which type of body shape she is, so she can learn what exercises to do, whereas similar studies suggest that it is much better to challenge weight problems with exercise and dietary measures before resorting to figure shaping. For this purpose, our study was carried out with a total of thirty students, females listed in the Institute of Physical Education and Sport, University of Mostaganem, aged between 20 and 23 years; their homogeneity was based on age, sex, and academic specialty, classified based on the body mass index (BMI into two groups (normal and overweight and based on their body shape′s type into three groups (9 pear shape, 10 rectangle shape, and 11 hourglass shape as a protocol experimental to examine the impact of fat mass distribution body shapes type on lumbar extensor strength. Based on our data analysis, we confirm that the pear and the rectangle shape affect the strength lumbar extensors due to body weight distribution which increases the risks relating to the skeletal muscles. Weight gain is a factor contributing to the weakness of skeletal muscles. However, the body shape explains the anomalies of the distribution of fat mass and BMI risk observed in our sample in the lower and upper part of the body recorded by the values of Killy test and endurance of trunk, the case of the pear and the rectangle shape back pain, which are consisting in excess of the body fat distributed in comparison with less percentage of muscle mass. Whereas this difference can affect the pelvic position.

Resistance to rocuronium of rat diaphragm as compared with limb muscles.

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Huang, Lina; Yang, Meirong; Chen, Lianhua; Li, Shitong

2014-12-01

Skeletal muscles are composed of different muscle fiber types. We investigated the different potency to rocuronium among diaphragm (DIA), extensor digitorum longus (EDL), and soleus (SOL) in vitro as well as to investigate the differences of acetylcholine receptors (AChRs) among these three typical kinds of muscles. The isolated left hemidiaphragm nerve-muscle preparations, the EDL sciatic nerve-muscle preparations, and the SOL sciatic nerve-muscle preparations were established to evaluate the potency to rocuronium. Concentration-response curves were constructed and the values of IC50 were obtained. The density of AChRs at the end plate and the number of AChRs per unit fiber cross fiber area (CSA), AChR affinity for muscle relaxants were evaluated. The concentration-twitch tension curves of rocuronium were significantly different. The curves demonstrated a shift to the right of the DIA compared with the EDL and SOL (P  0.05). IC50 was significantly largest in DIA, second largest in SOL, and smallest in EDL (P rocuronium of DIA compared with EDL and SOL was verified. The DIA was characterized by the largest number of AChRs per unit fiber CSA and the lowest affinity of the AChRs. Although compared with SOL, EDL was proved to have larger number of AChRs per unit fiber CSA and the lower affinity of the AChRs. These findings may be the mechanisms of different potency to rocuronium in DIA, EDL, and SOL. The results of the study could help to explain the relationship between different composition of muscle fibers and the potency to muscle relaxants. Extra caution should be taken in clinical practice when monitoring muscle relaxation in anesthetic management using different muscles. Copyright © 2014 Elsevier Inc. All rights reserved.

Muscle quality, aerobic fitness and fat mass predict lower-extremity physical function in community-dwelling older adults.

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Misic, Mark M; Rosengren, Karl S; Woods, Jeffrey A; Evans, Ellen M

2007-01-01

Muscle mass, strength and fitness play a role in lower-extremity physical function (LEPF) in older adults; however, the relationships remain inadequately characterized. This study aimed to examine the relationships between leg mineral free lean mass (MFLM(LEG)), leg muscle quality (leg strength normalized for MFLM(LEG)), adiposity, aerobic fitness and LEPF in community-dwelling healthy elderly subjects. Fifty-five older adults (69.3 +/- 5.5 years, 36 females, 19 males) were assessed for leg strength using an isokinetic dynamometer, body composition by dual energy X-ray absorptiometry and aerobic fitness via a treadmill maximal oxygen consumption test. LEPF was assessed using computerized dynamic posturography and stair ascent/descent, a timed up-and-go task and a 7-meter walk with and without an obstacle. Muscle strength, muscle quality and aerobic fitness were similarly correlated with static LEPF tests (r range 0.27-0.40, p < 0.05); however, the strength of the independent predictors was not robust with explained variance ranging from 9 to 16%. Muscle quality was the strongest correlate of all dynamic LEPF tests (r range 0.54-0.65, p < 0.001). Using stepwise linear regression analysis, muscle quality was the strongest independent predictor of dynamic physical function explaining 29-42% of the variance (p < 0.001), whereas aerobic fitness or body fat mass explained 5-6% of the variance (p < 0.05) depending on performance measure. Muscle quality is the most important predictor, and aerobic fitness and fat mass are secondary predictors of LEPF in community-dwelling older adults. These findings support the importance of exercise, especially strength training, for optimal body composition, and maintenance of strength and physical function in older adults.

Relationship between Handgrip Strength and Muscle Mass in Female Survivors of Breast Cancer: A Mediation Analysis.

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Benavides-Rodríguez, Lorena; García-Hermoso, Antonio; Rodrigues-Bezerra, Diogo; Izquierdo, Mikel; Correa-Bautista, Jorge Enrique; Ramírez-Vélez, Robinson

2017-07-04

This study explored the mediating factors of sarcopenia in a group of women survivors of breast cancer in Bogotá, Colombia. This was a descriptive cross-sectional study with 98 women survivors of breast cancer, who were registered with the SIMMON (Integrated Synergies to Improve Oncological Management in Colombia) Foundation. Body weight, height, and waist circumference (WC) were measured, and body mass index (BMI) was calculated. Body composition (percentage of fat and muscle mass) was evaluated via four-pole bioelectrical impedance analysis. Sarcopenia was defined as low muscle mass plus low grip strength or low gait speed (European Working Group on Sarcopenia in Older People (EWGSOP) criteria). A "causal" mediation analysis with the Baron & Kenny procedure (PROCESS ® macro, Columbus, OH, USA) was used to explore variables related to sarcopenia. Analyses were performed with the IBM SPSS 21 statistical package (SPSS Inc., Chicago, IL, USA). The significance level of the results obtained in the hypothesis contrast was p < 0.05. The mean age of the sample was 65.5 ± 5.9 years, with a BMI of 27.8 ± 4.7 kg/m². The prevalence of sarcopenia was 22.4%. Linear regression models suggest a partial mediation of anthropometric parameters (body mass, body mass index and waist circumference) in the association between handgrip strength and muscle mass. In conclusion, one in every five women survivors of breast cancer had sarcopenia. The findings seem to emphasize the importance of obesity prevention in women survivors of breast cancer, suggesting that high handgrip strength may not relate closely to greater muscle mass and therefore would not exclude the risk of sarcopenia.

Increased Muscular 5α-Dihydrotestosterone in Response to Resistance Training Relates to Skeletal Muscle Mass and Glucose Metabolism in Type 2 Diabetic Rats.

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Naoki Horii

Full Text Available Regular resistance exercise induces skeletal muscle hypertrophy and improvement of glycemic control in type 2 diabetes patients. Administration of dehydroepiandrosterone (DHEA, a sex steroid hormone precursor, increases 5α-dihydrotestosterone (DHT synthesis and is associated with improvements in fasting blood glucose level and skeletal muscle hypertrophy. Therefore, the aim of this study was to investigate whether increase in muscle DHT levels, induced by chronic resistance exercise, can contribute to skeletal muscle hypertrophy and concomitant improvement of muscular glucose metabolism in type 2 diabetic rats. Male 20-week-old type 2 diabetic rats (OLETF were randomly divided into 3 groups: sedentary control, resistance training (3 times a week on alternate days for 8 weeks, or resistance training with continuous infusion of a 5α-reductase inhibitor (n = 8 each group. Age-matched, healthy nondiabetic Long-Evans Tokushima Otsuka (LETO rats (n = 8 were used as controls. The results indicated that OLETF rats showed significant decrease in muscular DHEA, free testosterone, DHT levels, and protein expression of steroidogenic enzymes, with loss of skeletal muscle mass and hyperglycemia, compared to that of LETO rats. However, 8-week resistance training in OLETF rats significantly increased the levels of muscle sex steroid hormones and protein expression of steroidogenic enzymes with a concomitant increase in skeletal muscle mass, improved fasting glucose level, and insulin sensitivity index. Moreover, resistance training accelerated glucose transporter-4 (GLUT-4 translocation and protein kinase B and C-ζ/λ phosphorylation. Administering the 5α-reductase inhibitor in resistance-trained OLETF rats resulted in suppression of the exercise-induced effects on skeletal muscle mass, fasting glucose level, insulin sensitivity index, and GLUT-4 signaling, with a decline in muscular DHT levels. These findings suggest that resistance training

The role of fat mass and skeletal muscle mass in knee osteoarthritis is different for men and women: the NEO study

NARCIS (Netherlands)

Visser, A.W. de; Mutsert, R. de; Loef, M.; Cessie, S. le; Heijer, M. den; Bloem, J.L.; Reijnierse, M.; Rosendaal, F.R.; Kloppenburg, M.; Assendelft, W.J.J.; Smit, J.W.A.; et al.,

2014-01-01

OBJECTIVE: To investigate if the amount of fat mass (FM) or skeletal muscle mass (SMM) is more strongly associated with knee osteoarthritis (OA), in both men and women. METHODS: The Netherlands Epidemiology of Obesity (NEO) study is a population-based cohort aged 45-65 years, including 5313

Relationship between lifting performance and skeletal muscle mass in elite powerlifters.

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Ye, X; Loenneke, J P; Fahs, C A; Rossow, L M; Thiebaud, R S; Kim, D; Bemben, M G; Abe, T

2013-08-01

Aim of the study was to examine the relationship between whole body skeletal muscle mass (SMM) and powerlifting performance in elite powerlifters. Twenty elite male powerlifters, including 4 world champions, volunteered. Muscle thickness (MTH) and subcutaneous fat thickness (FTH) were measured by ultrasound at 9 sites on the anterior and posterior aspects of the body. FTH was used to estimate body fat and fat-free mass and SMM was estimated from ultrasound-derived prediction equations. Best lifting performance in the squat (SQ), bench press (BP), and dead lift (DL) was recorded from competition performance. Significant strong correlations (Pwide range of weight classes (56kg-145kg) and there were no significant correlation between the SMM and those performances (r=0.21 for SQ and r=0.12 for BP). However, the DL/SMM ratio was negatively correlated to DL performance (r=-0.47, P<0.05). SMM is a good predictor of powerlifting performance throughout all weight classes.

Strain in shock-loaded skeletal muscle and the time scale of muscular wobbling mass dynamics.

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Christensen, Kasper B; Günther, Michael; Schmitt, Syn; Siebert, Tobias

2017-10-16

In terrestrial locomotion, muscles undergo damped oscillations in response to limb impacts with the ground. Muscles are also actuators that generate mechanical power to allow locomotion. The corresponding elementary contractile process is the work stroke of an actin-myosin cross-bridge, which may be forcibly detached by superposed oscillations. By experimentally emulating rat leg impacts, we found that full activity and non-fatigue must meet to possibly prevent forcible cross-bridge detachment. Because submaximal muscle force represents the ordinary locomotor condition, our results show that forcible, eccentric cross-bridge detachment is a common, physiological process even during isometric muscle contractions. We also calculated the stiffnesses of the whole muscle-tendon complex and the fibre material separately, as well as Young's modulus of the latter: 1.8 MPa and 0.75 MPa for fresh, fully active and passive fibres, respectively. Our inferred Young's modulus of the tendon-aponeurosis complex suggests that stiffness in series to the fibre material is determined by the elastic properties of the aponeurosis region, rather than the tendon material. Knowing these stiffnesses and the muscle mass, the complex' eigenfrequency for responses to impacts can be quantified, as well as the size-dependency of this time scale of muscular wobbling mass dynamics.

Basic Training of Student’s Outdoor Club Increases Muscle Mass after Five Weeks of Exercise in Males

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Novie Salsabila

2015-03-01

Full Text Available Background: Aerobic and anaerobic exercises, may lead to increase muscle mass. The aim of this study was to determine the change in muscle mass during basic training of students’ outdoor club. Methods: This was an observational analytic study to college students who joined basic training of students’ outdoor club for 19 weeks. Subjects consisted of 17 male and 15 female students, measured five times consecutively by using Body Fat/Hydration monitor scale, with Bioelectrical Impedance Analysis principle. Data collection was performed five times, from February to July 2012 in Bandung. Statistical analysis was processed using Analysis of Variance (ANOVA. Results: The result in males showed the mean 43.35±3.15 on the initial measurement. The muscle mass further increased significantly after five, ten, fifteen, and nineteen weeks of exercise (43.73±3.18 (p0.05; 38.08±1.67 (p>0.05 ; 38.23±1.52 (p>0.05 ; 38.61±1.52 (p<0.05 vs 37.77±2.00 respectively. Conclusion: Basic training of student’s outdoor club increases muscle mass significantly after five weeks of exercise in males, but not in females

Skeletal muscle abnormalities and exercise capacity in adults with a Fontan circulation.

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Cordina, Rachael; O'Meagher, Shamus; Gould, Haslinda; Rae, Caroline; Kemp, Graham; Pasco, Julie A; Celermajer, David S; Singh, Nalin

2013-10-01

The peripheral muscle pump is key in promoting cardiac filling during exercise, especially in subjects who lack a subpulmonary ventricle (the Fontan circulation). A muscle-wasting syndrome exists in acquired heart failure but has not been assessed in Fontan subjects. We sought to investigate whether adults with the Fontan circulation exhibit reduced skeletal muscle mass and/or metabolic abnormalities. Sixteen New York Heart Association Class I/II Fontan adults (30±2 years) underwent cardiopulmonary exercise testing and lean mass quantification with dual x-ray absorptiometry (DXA); eight had calf muscle (31)P magnetic resonance spectroscopy as did eight healthy age-matched and sex-matched controls. DXA results were compared with Australian reference data. Single tertiary referral centre. Peak VO2 was 1.9±0.1 L/min (66±3% of predicted values). Skeletal muscle mass assessed by relative appendicular lean mass index was significantly reduced compared with age-matched and sex-matched reference values (Z-score -1.46±0.22, pskeletal muscle mass correlated with poorer VO2 max (r=0.67, p=0.004). Overall, skeletal muscle mass T-score (derived from comparison with young normal reference mean) was -1.47±0.21; 4/16 Fontan subjects had sarcopenic range muscle wasting (T-score Muscle aerobic capacity, measured by the rate constant (k) of postexercise phosphocreatine resynthesis, was significantly impaired in Fontan adults versus controls (1.48±0.13 vs 2.40±0.33 min(-1), p=0.02). Fontan adults have reduced skeletal muscle mass and intrinsic muscle metabolic abnormalities.

Low vitamin D and high parathyroid hormone levels as determinants of loss of muscle strength and muscle mass (sarcopenia) : the Longitudinal Aging Study Amsterdam

NARCIS (Netherlands)

Visser, Marjolein; Deeg, Dorly J H; Lips, Paul

2003-01-01

The age-related change in hormone concentrations has been hypothesized to play a role in the loss of muscle mass and muscle strength with aging, also called sarcopenia. The aim of this prospective study was to investigate whether low serum 25-hydroxyvitamin D (25-OHD) and high serum PTH

Creatinine excretion rate, a marker of muscle mass, is related to clinical outcome in patients with chronic systolic heart failure

NARCIS (Netherlands)

ter Maaten, Jozine M.; Damman, Kevin; Hillege, Hans L.; Bakker, Stephan J.; Anker, Stefan D.; Navis, Gerjan; Voors, Adriaan A.

2014-01-01

Aims In chronic heart failure (CHF), low body mass as a reflection of low muscle mass has been associated with poor outcome. Urinary creatinine excretion rate (CER) is an established marker of muscle mass, but has not been investigated in CHF. This study aims to evaluate urinary CER as a marker of

The additional value of bioelectrical impedance analysis-derived muscle mass as a screening tool in geriatric assessment for fall prevention.

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Van Puyenbroeck, Karolien; Roelandts, Lieven; Van Deun, Thomas; Van Royen, Paul; Verhoeven, Veronique

2012-01-01

The decline in skeletal muscle in old age is a factor in the development of functional limitations. The objective of this study was to assess if there is a correlation between muscle mass based on bioelectrical impedance analysis (BIA) detection and the fall incidence in nursing home residents and to examine the risk factors for falling in nursing home residents. This prospective cohort study was part of a longitudinal study on nutritional issues in 52 nursing homes in Antwerp (Belgium) from October 2007 to April 2008. Two hundred and seventy-six people aged 65 years and older were included. Each subject was assessed with BIA, the timed get-up-and-go test, the Katz score, the Mini Nutritional Assessment - Short Form and the 36-Item Short Form Health Survey. The primary outcome parameter was fall incidence during the study. The prevalence of sarcopenia varied from 24.3 to 81.5% depending on which definition was used. No association was found between BIA-derived muscle mass and fall incidence. Logistic regression analysis showed that gait speed (odds ratio 1.029; p = 0.003) and mental health (odds ratio 0.981; p = 0.015) are significantly associated with fall incidence in nursing homes. A receiver operating characteristic curve showed that none of the BIA-derived muscle parameters are good predictors of the risk of falling. This study shows that there is no association between sarcopenia based on BIA and fall incidence and that BIA-derived muscle mass has no additional value in predicting fall incidents compared to the timed get-up-and-go test. Copyright © 2012 S. Karger AG, Basel.

Association between muscle mass and adipo-metabolic profile: a cross-sectional study in older subjects

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Perna S

2015-02-01

Full Text Available Simone Perna,1,* Davide Guido,2,* Mario Grassi,2 Mariangela Rondanelli1 1Department of Public Health, Experimental and Forensic Medicine, School of Medicine, Endocrinology and Nutrition Unit, University of Pavia, Azienda di Servizi alla Persona di Pavia, Pavia, Italy; 2Medical and Genomic Statistics Unit, Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy *These authors contributed equally to this work Background: Sarcopenia, the decrease in muscle mass and function, may lead to various negative health outcomes in elderly. The association among sarcopenia with adiposity and metabolic markers has rarely been studied in the elderly population, with controversial results. The aim of this study is to evaluate this relationship in older subjects.Methods: A cross-sectional study was conducted in 290 elderly patients, focusing on the possible association between muscle mass loss, assessed by relative skeletal muscle mass (RSMM, and an adipo-metabolic profile (AMP defined by adiposity and metabolic biochemical markers. Measurements of body composition were assessed by dual energy X-ray absorptiometry. Biochemical parameters, such as albumin, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, total cholesterol, triglycerides, C-reactive protein, and homocysteine and its related markers (folate and vitamin B12 were measured. Using canonical correlation analysis and structural equation modeling, an individual score of AMP was created and correlated with RSMM.Results: The AMP–RSMM correlation was equal to +0.642 (95% confidence interval, +0.512 to +0.773; P<0.001. Hence, a negative association between sarcopenia severity and adiposity/metabolic biochemical markers was highlighted.Conclusion: This study contained a novel way to examine the relationship between the variables of interest based on a composite index of adiposity and metabolic conditions. Results shed light on the orientation and magnitude of

Efficacy of whey protein supplementation on resistance exercise-induced changes in muscle strength, lean mass, and function in mobility-limited older adults

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Whey protein supplementation may augment resistance exercise-induced increases in muscle strength and mass. Further studies are required to determine whether this effect extends to functionally compromised older adults. The objectives of the study were to compare the effects of whey protein concent...

Impact of Weight Loss on Physical Function with Changes in Strength, Muscle Mass, and Muscle Fat Infiltration in Overweight to Moderately Obese Older Adults: A Randomized Clinical Trial

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Adam J. Santanasto

2011-01-01

Full Text Available Purpose. Evaluate the effects of weight loss on muscle mass and area, muscle fat infiltration, strength, and their association with physical function. Methods. Thirty-six overweight to moderately obese, sedentary older adults were randomized into either a physical activity plus weight loss (PA+WL or physical activity plus successful aging health education (PA+SA program. Measurements included body composition by dual-energy X-ray absorptiometry, computerized tomography, knee extensor strength, and short physical performance battery (SPPB. Results. At 6 months, PA+WL lost greater thigh fat and muscle area compared to PA+SA. PA+WL lost 12.4% strength; PA+SA lost 1.0%. Muscle fat infiltration decreased significantly in PA+WL and PA+SA. Thigh fat area decreased 6-fold in comparison to lean area in PA+WL. Change in total SPPB score was strongly inversely correlated with change in fat but not with change in lean or strength. Conclusion. Weight loss resulted in additional improvements in function over exercise alone, primarily due to loss of body fat.

Electrically Stimulated Antagonist Muscle Contraction Increased Muscle Mass and Bone Mineral Density of One Astronaut - Initial Verification on the International Space Station.

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Shiba, Naoto; Matsuse, Hiroo; Takano, Yoshio; Yoshimitsu, Kazuhiro; Omoto, Masayuki; Hashida, Ryuki; Tagawa, Yoshihiko; Inada, Tomohisa; Yamada, Shin; Ohshima, Hiroshi

2015-01-01

Musculoskeletal atrophy is one of the major problems of extended periods of exposure to weightlessness such as on the International Space Station (ISS). We developed the Hybrid Training System (HTS) to maintain an astronaut's musculoskeletal system using an electrically stimulated antagonist to resist the volitional contraction of the agonist instead of gravity. The present study assessed the system's orbital operation capability and utility, as well as its preventative effect on an astronaut's musculoskeletal atrophy. HTS was attached to the non-dominant arm of an astronaut staying on the ISS, and his dominant arm without HTS was established as the control (CTR). 10 sets of 10 reciprocal elbow curls were one training session, and 12 total sessions of training (3 times per week for 4 weeks) were performed. Pre and post flight ground based evaluations were performed by Biodex (muscle performance), MRI (muscle volume), and DXA (BMD, lean [muscle] mass, fat mass). Pre and post training inflight evaluations were performed by a hand held dynamometer (muscle force) and a measuring tape (upper arm circumference). The experiment was completed on schedule, and HTS functioned well without problems. Isokinetic elbow extension torque (Nm) changed -19.4% in HTS, and -21.7% in CTR. Isokinetic elbow flexion torque changed -23.7% in HTS, and there was no change in CTR. Total Work (Joule) of elbow extension changed -8.3% in HTS, and +0.3% in CTR. For elbow flexion it changed -23.3% in HTS and -32.6% in CTR. Average Power (Watts) of elbow extension changed +22.1% in HTS and -8.0% in CTR. For elbow flexion it changed -6.5% in HTS and -4.8% in CTR. Triceps muscle volume according to MRI changed +11.7% and that of biceps was +2.1% using HTS, however -0.1% and -0.4% respectively for CTR. BMD changed +4.6% in the HTS arm and -1.2% for CTR. Lean (muscle) mass of the arm changed only +10.6% in HTS. Fat mass changed -12.6% in HTS and -6.4% in CTR. These results showed the orbital operation

Electrically Stimulated Antagonist Muscle Contraction Increased Muscle Mass and Bone Mineral Density of One Astronaut - Initial Verification on the International Space Station.

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Naoto Shiba

Full Text Available Musculoskeletal atrophy is one of the major problems of extended periods of exposure to weightlessness such as on the International Space Station (ISS. We developed the Hybrid Training System (HTS to maintain an astronaut's musculoskeletal system using an electrically stimulated antagonist to resist the volitional contraction of the agonist instead of gravity. The present study assessed the system's orbital operation capability and utility, as well as its preventative effect on an astronaut's musculoskeletal atrophy.HTS was attached to the non-dominant arm of an astronaut staying on the ISS, and his dominant arm without HTS was established as the control (CTR. 10 sets of 10 reciprocal elbow curls were one training session, and 12 total sessions of training (3 times per week for 4 weeks were performed. Pre and post flight ground based evaluations were performed by Biodex (muscle performance, MRI (muscle volume, and DXA (BMD, lean [muscle] mass, fat mass. Pre and post training inflight evaluations were performed by a hand held dynamometer (muscle force and a measuring tape (upper arm circumference.The experiment was completed on schedule, and HTS functioned well without problems. Isokinetic elbow extension torque (Nm changed -19.4% in HTS, and -21.7% in CTR. Isokinetic elbow flexion torque changed -23.7% in HTS, and there was no change in CTR. Total Work (Joule of elbow extension changed -8.3% in HTS, and +0.3% in CTR. For elbow flexion it changed -23.3% in HTS and -32.6% in CTR. Average Power (Watts of elbow extension changed +22.1% in HTS and -8.0% in CTR. For elbow flexion it changed -6.5% in HTS and -4.8% in CTR. Triceps muscle volume according to MRI changed +11.7% and that of biceps was +2.1% using HTS, however -0.1% and -0.4% respectively for CTR. BMD changed +4.6% in the HTS arm and -1.2% for CTR. Lean (muscle mass of the arm changed only +10.6% in HTS. Fat mass changed -12.6% in HTS and -6.4% in CTR.These results showed the orbital

Age associated declines in muscle mass, strength, power, and physical performance: impact on fear of falling and quality of life

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SUMMARY: This 3 year longitudinal study among older adults showed that declining muscle mass, strength, power, and physical performance are independent contributing factors to increased fear of falling, while declines of muscle mass and physical performance contribute to deterioration of quality of ...

Comparing trapezius muscle activity in the different planes of shoulder elevation.

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Ishigaki, Tomonobu; Ishida, Tomoya; Samukawa, Mina; Saito, Hiroshi; Hirokawa, Motoki; Ezawa, Yuya; Sugawara, Makoto; Tohyama, Harukazu; Yamanaka, Masanori

2015-05-01

[Purpose] The purpose of this study was to compare the upper, middle, and lower trapezius muscles' activity in the different planes of shoulder elevation. [Subjects] Twenty male subjects volunteered for this study. [Methods] Surface electromyographic (EMG) activity for each of the three regions of the trapezius muscles in the three different planes of elevation were collected while the participants maintained 30, 60, and 90 degrees of elevation in each plane. The EMG data were normalized with maximum voluntary isometric contraction (%MVIC), and compared among the planes at each angle of elevation. [Results] There were significantly different muscle activities among the elevation planes at each angle. [Conclusion] This study found that the three regions of the trapezius muscles changed their activity depending on the planes of shoulder elevation. These changes in the trapezius muscles could induce appropriate scapular motion to face the glenoid cavity in the correct directions in different planes of shoulder elevation.

Comparative Statistical Mechanics of Muscle and Non-Muscle Contractile Systems: Stationary States of Near-Equilibrium Systems in A Linear Regime

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Yves Lecarpentier

2017-10-01

Full Text Available A. Huxley’s equations were used to determine the mechanical properties of muscle myosin II (MII at the molecular level, as well as the probability of the occurrence of the different stages in the actin–myosin cycle. It was then possible to use the formalism of statistical mechanics with the grand canonical ensemble to calculate numerous thermodynamic parameters such as entropy, internal energy, affinity, thermodynamic flow, thermodynamic force, and entropy production rate. This allows us to compare the thermodynamic parameters of a non-muscle contractile system, such as the normal human placenta, with those of different striated skeletal muscles (soleus and extensor digitalis longus as well as the heart muscle and smooth muscles (trachea and uterus in the rat. In the human placental tissues, it was observed that the kinetics of the actin–myosin crossbridges were considerably slow compared with those of smooth and striated muscular systems. The entropy production rate was also particularly low in the human placental tissues, as compared with that observed in smooth and striated muscular systems. This is partly due to the low thermodynamic flow found in the human placental tissues. However, the unitary force of non-muscle myosin (NMII generated by each crossbridge cycle in the myofibroblasts of the human placental tissues was similar in magnitude to that of MII in the myocytes of both smooth and striated muscle cells. Statistical mechanics represents a powerful tool for studying the thermodynamics of all contractile muscle and non-muscle systems.

Pre-hospital dietary intake correlates with muscle mass at the time of fracture in older hip fractured patients

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Riccardo eCalvani

2014-11-01

Full Text Available Background. Failure to meet an adequate dietary intake is involved in the pathogenesis of sarcopenia and osteoporosis, which in turn increase the risk for falls and fractures, respectively. Older people with hip fracture are often protein-malnourished at hospitalization. Whether low protein-energy intake is associated with muscle atrophy in hip fractured patients is presently unknown. This information is necessary for the development of novel strategies to manage this especially vulnerable patient population. The aim of this study was therefore to explore the relationship between dietary intake and muscle mass in older hip fractured patients.Methods. Analyses were conducted in hip fractured elderly admitted to an orthopedic and trauma surgery ward (University Hospital. Muscle mass was estimated by bioelectrical impedance analysis within 24 h from admission. Dietary information was collected via 24-h dietary recall and nutrient intakes calculated by a nutrition software.Results. Among 62 hip fractured patients (mean age 84.6±7.6 years, 84% women, the average energy intake was 929.2±170.3 Kcal/day, with higher values reported by men (1.046.8±231.4 Kcal/day relative to women (906.5±148.3 Kcal/day; p=0.01. Absolute and normalized protein intake was 50.0±13.5 g/day and 0.88±0.27 g/kg (body weight/day, respectively, with no gender differences. A positive correlation was determined between total energy intake and muscle mass (r=0.384; p=0.003. Similarly, protein and leucine consumption was positively correlated with muscle mass (r=0.367 and 0.311, respectively; p=0.005 for both.Conclusions. A low intake of calories, protein and leucine is associated with reduced muscle mass in hip fractured elderly. Given the relevance of sarcopenia as a risk factor for adverse outcomes in this patient population, our findings highlight the importance of a comprehensive dietary assessment for the detection of nutritional deficits predisposing to or aggravating

Leg blood flow is impaired during small muscle mass exercise in patients with COPD

DEFF Research Database (Denmark)

Iepsen, Ulrik Winning; Munch, Gregers Druedal Wibe; Rugbjerg, Mette

2017-01-01

to both endothelium-independent (SNP) and endothelium-dependent (ACh) stimulation. The results suggests that leg muscle blood flow is impaired during small muscle mass exercise in patients with COPD possibly due to impaired formation of prostacyclin and increased levels of endothelin-1.......Skeletal muscle blood flow is regulated to match the oxygen demand and dysregulation could contribute to exercise intolerance in patients with COPD. We measured leg hemodynamics and metabolites from vasoactive compounds in muscle interstitial fluid and plasma at rest, during one-legged knee...... the formation of interstitial prostacyclin (vasodilator) was only increased in the controls. There was no difference between groups in the nitrite/nitrate levels (vasodilator) in plasma or interstitial fluid during exercise. Moreover, patients and controls showed similar vasodilatory capacity in response...

Genetic variations in the androgen receptor are associated with steroid concentrations and anthropometrics but not with muscle mass in healthy young men.

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Hélène De Naeyer

Full Text Available OBJECTIVE: The relationship between serum testosterone (T levels, muscle mass and muscle force in eugonadal men is incompletely understood. As polymorphisms in the androgen receptor (AR gene cause differences in androgen sensitivity, no straightforward correlation can be observed between the interindividual variation in T levels and different phenotypes. Therefore, we aim to investigate the relationship between genetic variations in the AR, circulating androgens and muscle mass and function in young healthy male siblings. DESIGN: 677 men (25-45 years were recruited in a cross-sectional, population-based sibling pair study. METHODS: Relations between genetic variation in the AR gene (CAGn, GGNn, SNPs, sex steroid levels (by LC-MS/MS, body composition (by DXA, muscle cross-sectional area (CSA (by pQCT, muscle force (isokinetic peak torque, grip strength and anthropometrics were studied using linear mixed-effect modelling. RESULTS: Muscle mass and force were highly heritable and related to age, physical activity, body composition and anthropometrics. Total T (TT and free T (FT levels were positively related to muscle CSA, whereas estradiol (E2 and free E2 (FE2 concentrations were negatively associated with muscle force. Subjects with longer CAG repeat length had higher circulating TT, FT, and higher E2 and FE2 concentrations. Weak associations with TT and FT were found for the rs5965433 and rs5919392 SNP in the AR, whereas no association between GGN repeat polymorphism and T concentrations were found. Arm span and 2D:4D finger length ratio were inversely associated, whereas muscle mass and force were not associated with the number of CAG repeats. CONCLUSIONS: Age, physical activity, body composition, sex steroid levels and anthropometrics are determinants of muscle mass and function in young men. Although the number of CAG repeats of the AR are related to sex steroid levels and anthropometrics, we have no evidence that these variations in the AR

Expression of androgen receptor target genes in skeletal muscle

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Kesha Rana

2014-10-01

Full Text Available We aimed to determine the mechanisms of the anabolic actions of androgens in skeletal muscle by investigating potential androgen receptor (AR-regulated genes in in vitro and in vivo models. The expression of the myogenic regulatory factor myogenin was significantly decreased in skeletal muscle from testosterone-treated orchidectomized male mice compared to control orchidectomized males, and was increased in muscle from male AR knockout mice that lacked DNA binding activity (ARΔZF2 versus wildtype mice, demonstrating that myogenin is repressed by the androgen/AR pathway. The ubiquitin ligase Fbxo32 was repressed by 12 h dihydrotestosterone treatment in human skeletal muscle cell myoblasts, and c-Myc expression was decreased in testosterone-treated orchidectomized male muscle compared to control orchidectomized male muscle, and increased in AR∆ZF2 muscle. The expression of a group of genes that regulate the transition from myoblast proliferation to differentiation, Tceal7 , p57 Kip2, Igf2 and calcineurin Aa, was increased in AR∆ZF2 muscle, and the expression of all but p57 Kip2 was also decreased in testosterone-treated orchidectomized male muscle compared to control orchidectomized male muscle. We conclude that in males, androgens act via the AR in part to promote peak muscle mass by maintaining myoblasts in the proliferative state and delaying the transition to differentiation during muscle growth and development, and by suppressing ubiquitin ligase-mediated atrophy pathways to preserve muscle mass in adult muscle.

Role of Protein Carbonylation in Skeletal Muscle Mass Loss Associated with Chronic Conditions

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Esther Barreiro

2016-05-01

Full Text Available Muscle dysfunction, characterized by a reductive remodeling of muscle fibers, is a common systemic manifestation in highly prevalent conditions such as chronic heart failure (CHF, chronic obstructive pulmonary disease (COPD, cancer cachexia, and critically ill patients. Skeletal muscle dysfunction and impaired muscle mass may predict morbidity and mortality in patients with chronic diseases, regardless of the underlying condition. High levels of oxidants may alter function and structure of key cellular molecules such as proteins, DNA, and lipids, leading to cellular injury and death. Protein oxidation including protein carbonylation was demonstrated to modify enzyme activity and DNA binding of transcription factors, while also rendering proteins more prone to proteolytic degradation. Given the relevance of protein oxidation in the pathophysiology of many chronic conditions and their comorbidities, the current review focuses on the analysis of different studies in which the biological and clinical significance of the modifications induced by reactive carbonyls on proteins have been explored so far in skeletal muscles of patients and animal models of chronic conditions such as COPD, disuse muscle atrophy, cancer cachexia, sepsis, and physiological aging. Future research will elucidate the specific impact and sites of reactive carbonyls on muscle protein content and function in human conditions.

LOW MID-UPPER ARM CIRCUMFERENCE AND MORTALITY IN OLDER PERSONS: THE INFLUENCE OF FAT AND MUSCLE MASS

NARCIS (Netherlands)

Delmonico, M.J.; Harris, T.B.; Visser, M.; Park, S.W.; Conroy, M.B.; Velasquez-Mieyer, P.; Boudreau, R.; Manini, T.M.; Nevitt, M.; Newman, A.B.; Goodpaster, B.H.

2009-01-01

Background: Sarcopenia is thought to be accompanied by increased muscle fat infiltration. However, no longitudinal studies have examined concomitant changes in muscle mass, strength, or fat infiltration in older adults. Objective: We present longitudinal data on age-related changes in leg

Associations between lower extremity muscle mass and metabolic parameters related to obesity in Japanese obese patients with type 2 diabetes

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Hidetaka Hamasaki

2015-05-01

Full Text Available Background. Age-related loss of muscle mass (sarcopenia increases the incidence of obesity in the elderly by reducing physical activity. This sarcopenic obesity may become self-perpetuating, increasing the risks for metabolic syndrome, disability, and mortality. We investigated the associations of two sarcopenic indices, the ratio of lower extremity muscle mass to body weight (L/W ratio and the ratio of lower extremity muscle mass to upper extremity muscle mass (L/U ratio, with metabolic parameters related to obesity in patients with type 2 diabetes and obesity.Methods. Of 148 inpatients with type 2 diabetes treated between October 2013 and April 2014, we recruited 26 with obesity but no physical disability. Daily physical activity was measured by a triaxial accelerometer during a period of hospitalization, and which was also evaluated by our previously reported non-exercise activity thermogenesis questionnaire. We measured body composition by bioelectrical impedance and investigated the correlations of L/W and L/U ratios with body weight, body mass index (BMI, waist circumference (WC, waist-to-hip ratio (WHR, visceral fat area, subcutaneous fat area, serum lipid profile, and daily physical activity.Results. The L/W ratio was significantly and negatively correlated with BMI, WC, WHR, body fat mass, body fat percentage, subcutaneous fat area, and serum free fatty acid concentration, was positively correlated with daily physical activity: the locomotive non-exercise activity thermogenesis score, but was not correlated with visceral fat area. The L/U ratio was significantly and positively correlated with serum high-density lipoprotein cholesterol.Conclusions. High L/W and L/U ratios, indicative of relatively preserved lower extremity muscle mass, were predictive of improved metabolic parameters related to obesity. Preserved muscle fitness in obesity, especially of the lower extremities, may prevent sarcopenic obesity and lower associated risks for

Type VI collagen turnover-related peptides—novel serological biomarkers of muscle mass and anabolic response to loading in young men

DEFF Research Database (Denmark)

Nedergaard, Anders; Sun, Shu; Karsdal, Morten A

2013-01-01

Immobilization-induced loss of muscle mass is a complex phenomenon with several parallels to sarcopenic and cachectic muscle loss. Muscle is a large organ with a protein turnover that is orders of magnitude larger than most other tissues. Thus, we hypothesize that muscle loss and regain is reflec...

Skeletal muscle mass and quality as risk factors for postoperative outcome after open colon resection for cancer

NARCIS (Netherlands)

Boer, B. C.; de Graaff, F.; Brusse-Keizer, M.; Bouman, D. E.; Slump, C. H.; Slee-Valentijn, M.; Klaase, J. M.

The prevalence of colorectal cancer in the elderly is increasing and, therefore, surgical interventions with a risk of potential complications are more frequently performed. This study investigated the role of low skeletal muscle mass (sarcopenia), muscle quality, and the sarcopenic obesity as

Comparison of different mass spectrometry techniques in the measurement of L-[ring-13C6]phenylalanine incorporation into mixed muscle proteins

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Zabielski, Piotr; Ford, G. Charles; Persson, X. Mai; Jaleel, Abdul; Dewey, Jerry D.; Nair, K Sreekumaran

2013-01-01

Precise measurement of low enrichment of stable isotope labeled amino-acid tracers in tissue samples is a prerequisite in measuring tissue protein synthesis rates. The challenge of this analysis is augmented when small sample size is a critical factor. Muscle samples from human participants following an 8 hour intravenous infusion of L-[ring-13C6]phenylalanine and a bolus dose of L-[ring-13C6]phenylalanine in a mouse were utilized. Liquid Chromatography tandem mass spectrometry (LC/MS/MS), Gas Chromatography tandem mass spectrometry (GC/MS/MS) and Gas Chromatography/Mass spectrometry (GC/MS) were compared to the Gas Chromatography-Combustion-Isotope Ratio mass spectrometry (GC/C/IRMS), to measure mixed muscle protein enrichment of [ring13C6]phenylalanine enrichment. The sample isotope enrichment ranged from 0.0091 to 0.1312 Molar Percent excess (MPE). As compared with GC/C/IRMS, LC/MS/MS, GC/MS/MS and GC/MS showed coefficients of determination of R2 = 0.9962 and R2 = 0.9942, and 0.9217 respectively. However, the precision of measurements (coefficients of variation) for intra-assay are 13.0%, 1.7%, 6.3% and 13.5% and for inter-assay are 9.2%, 3.2%, 10.2% and 25% for GC/C/IRMS, LC/MS/MS, GC/MS/MS and GC/MS respectively. The muscle sample sizes required to obtain these results were 8μg, 0.8μg, 3μg and 3μg for GC/C/IRMS, LC/MS/MS, GC/MS/MS, and GC/MS respectively. We conclude that LC/MS/MS is optimally suited for precise measurements of L-[ring-13C6]phenylalanine tracer enrichment in low abundance and in small quantity samples. PMID:23378099

Effect of Body Mass Index on Postural Balance and Muscle Strength in Children Aged 8-10 years

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Lucky Prasetiowati

2017-04-01

Full Text Available Background:Childhood overweight and obesity, which are considered as global epidemic, can be assessed using Body Mass Index (BMI. BMI difference can lead to anatomic changes due to an increased body load. This increase might also affect motor performance, including changes in postural balance and muscle strength. Aims and Objectives: to explain the influence of BMI on postural balance and lower limb muscle strength and to assess the correlation between those two variables in children aged 8-10 years. Material and methods:The sample consisted of 63 children aged 8-10 years, which were divided in 3 groups: BMI-normal, BMI-overweight, and BMI-obese. The postural balance was assessed using single leg balance test on MatScan and the Center Of Pressure (COP area was recorded. Isometric muscle strength of hip extensor and knee extensor were measured using a hand-held dynamometer. Results: Obese children had significantly largerCOP area than overweight (p = 0.004 and normal weight children (p = 0.000.There were no significant differences in hip extensor muscle strength between obese children with overweight and normal weight children (p=0.527. The absolute knee extensor muscle strength in obese group was significantly higher than the overweight and normal group (p = 0.003. However the relative muscle strength of lower limb for obese children was significantly lower than for normal weight. There was no significant correlation between absolute hip extensor and knee extensor muscles strength with COP area. Conclusion: Obese children have decreased postural balance and increased absolute knee extensormuscle strength significantly when compared to overweight and normal children. There is no significant correlation between postural balance and muscle strength.

Is increase in bone mineral content caused by increase in skeletal muscle mass/strength in adult patients with GH-treated GH deficiency? A systematic literature analysis

DEFF Research Database (Denmark)

Klefter, O.; Feldt-Rasmussen, U.

2009-01-01

to a muscle modulating effect, and if treatment with GH would primarily increase muscle mass and strength with a secondary increase in BMD/BMC, thus supporting the present physiological concept that mass and strength of bones are mainly determined by dynamic loads from the skeletal muscles. METHOD: We...... performed a systematic literature analysis, including 51 clinical trials published between 1996 and 2008, which had studied the development in muscle mass, muscle strength, BMD, and/or BMC in GH-treated adult GHD patients. RESULTS: GH therapy had an anabolic effect on skeletal muscle. The largest increase...... in muscle mass occurred during the first 12 months of therapy. Most trials measuring BMD/BMC reported significant increases from baseline values. The significant increases in BMD/BMC occurred after 12-18 months of treatment, i.e. usually later than the increases in muscle parameters. Only seven trials...

Genes Whose Gain or Loss-Of-Function Increases Skeletal Muscle Mass in Mice: A Systematic Literature Review

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Sander A. J. Verbrugge

2018-05-01

Full Text Available Skeletal muscle mass differs greatly in mice and humans and this is partially inherited. To identify muscle hypertrophy candidate genes we conducted a systematic review to identify genes whose experimental loss or gain-of-function results in significant skeletal muscle hypertrophy in mice. We found 47 genes that meet our search criteria and cause muscle hypertrophy after gene manipulation. They are from high to small effect size: Ski, Fst, Acvr2b, Akt1, Mstn, Klf10, Rheb, Igf1, Pappa, Ppard, Ikbkb, Fstl3, Atgr1a, Ucn3, Mcu, Junb, Ncor1, Gprasp1, Grb10, Mmp9, Dgkz, Ppargc1a (specifically the Ppargc1a4 isoform, Smad4, Ltbp4, Bmpr1a, Crtc2, Xiap, Dgat1, Thra, Adrb2, Asb15, Cast, Eif2b5, Bdkrb2, Tpt1, Nr3c1, Nr4a1, Gnas, Pld1, Crym, Camkk1, Yap1, Inhba, Tp53inp2, Inhbb, Nol3, Esr1. Knock out, knock down, overexpression or a higher activity of these genes causes overall muscle hypertrophy as measured by an increased muscle weight or cross sectional area. The mean effect sizes range from 5 to 345% depending on the manipulated gene as well as the muscle size variable and muscle investigated. Bioinformatical analyses reveal that Asb15, Klf10, Tpt1 are most highly expressed hypertrophy genes in human skeletal muscle when compared to other tissues. Many of the muscle hypertrophy-regulating genes are involved in transcription and ubiquitination. Especially genes belonging to three signaling pathways are able to induce hypertrophy: (a Igf1-Akt-mTOR pathway, (b myostatin-Smad signaling, and (c the angiotensin-bradykinin signaling pathway. The expression of several muscle hypertrophy-inducing genes and the phosphorylation of their protein products changes after human resistance and high intensity exercise, in maximally stimulated mouse muscle or in overloaded mouse plantaris.

Loss of Muscle Mass During Chemotherapy Is Predictive for Poor Survival of Patients With Metastatic Colorectal Cancer

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Blauwhoff-Buskermolen, Susanne; Versteeg, Kathelijn S.; de van der Schueren, Marian A. E.; den Braver, Nicole R.; Berkhof, Johannes; Langius, Jacqueline A. E.; Verheul, Henk M. W.

2016-01-01

Low muscle mass is present in approximately 40% of patients with metastatic colorectal cancer (mCRC) and may be associated with poor outcome. We studied change in skeletal muscle during palliative chemotherapy in patients with mCRC and its association with treatment modifications and overall

Butyryl-cholinesterase is related to muscle mass and strength. A new biomarker to identify elderly subjects at risk of sarcopenia.

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Cacciatore, Francesco; Della-Morte, David; Basile, Claudia; Curcio, Francesco; Liguori, Ilaria; Roselli, Mario; Gargiulo, Gaetano; Galizia, Gianluigi; Bonaduce, Domenico; Abete, Pasquale

2015-01-01

To determine the relationship between Butyryl-cholinesterase (α-glycoprotein synthesized in the liver, b-CHE) and muscle mass and strength. Muscle mass by bioimpedentiometer and muscle strength by grip strength were evaluated in 337 elderly subjects (mean age: 76.2 ± 6.7 years) admitted to comprehensive geriatric assessment. b-CHE levels were lower in sarcopenic than in nonsarcopenic elderly subjects (p elderly subjects. Thus, b-CHE may be considered to be a fair biomarker for identifying elderly subjects at risk of sarcopenia.

Altered fibre types in gastrocnemius muscle of high wheel-running selected mice with mini-muscle phenotypes.

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Guderley, Helga; Joanisse, Denis R; Mokas, Sophie; Bilodeau, Geneviève M; Garland, Theodore

2008-03-01

Selective breeding of mice for high voluntary wheel running has favoured characteristics that facilitate sustained, aerobically supported activity, including a "mini-muscle" phenotype with markedly reduced hind limb muscle mass, increased mass-specific activities of oxidative enzymes, decreased % myosin heavy chain IIb, and, in the medial gastrocnemius, reduced twitch speed, reduced mass-specific isotonic power, and increased fatigue resistance. To evaluate whether selection has altered fibre type expression in mice with either "mini" or normal muscle phenotypes, we examined fibre types of red and white gastrocnemius. In both the medial and lateral gastrocnemius, the mini-phenotype increased activities of oxidative enzymes and decreased activities of glycolytic enzymes. In red muscle samples, the mini-phenotype markedly changed fibre types, with the % type I and type IIA fibres and the surface area of type IIA fibres increasing; in addition, mice from selected lines in general had an increased % type IIA fibres and larger type I fibres as compared with mice from control lines. White muscle samples from mini-mice showed dramatic structural alterations, with an atypical distribution of extremely small, unidentifiable fibres surrounded by larger, more oxidative fibres than normally present in white muscle. The increased proportion of oxidative fibres and these atypical small fibres together may explain the reduced mass and increased mitochondrial enzyme activities in mini-muscles. These and previous results demonstrate that extension of selective breeding beyond the time when the response of the selected trait (i.e. distance run) has levelled off can still modify the mechanistic underpinnings of this behaviour.

Hormonal and lifestyle determinants of appendicular skeletal muscle mass in men: the MINOS study.

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Szulc, Pawel; Duboeuf, François; Marchand, François; Delmas, Pierre D

2004-08-01

Aging-related sarcopenia is characterized by a loss of muscle mass and strength and increased fatigability. However, studies of its determinants in elderly men are scarce. We investigated risk factors for sarcopenia in a large cohort of men. We analyzed 845 men aged 45-85 y who belonged to the MINOS cohort. Lifestyle factors (physical activity, tobacco smoking, alcohol intake, caffeine intake) were evaluated by using a standardized questionnaire. Appendicular skeletal muscle mass (ASM) was estimated by using dual-energy X-ray absorptiometry. The relative appendicular skeletal muscle mass index (RASM) was calculated as ASM/body height(2.3). Apparent free testosterone concentration (AFTC) and free testosterone index (FTI) were calculated on the basis of concentrations of total testosterone and sex hormone-binding globulin. RASM decreased with age (r = -0.29, P values for AFTC, FTI, or 25-hydroxycholecalciferol [25(OH)D] were >2 SDs below the mean for young men had significantly lower RASM than did men with higher values. Men with sarcopenia, defined as the lowest quartile of RASM in the studied cohort (normal RASM, weighed significantly less, smoked more, and spent significantly less time on leisure-time activities. Sarcopenic men also had lower values for testosterone, AFTC, FTI, and 25(OH)D. In elderly men, low physical activity, tobacco smoking, thinness, low testosterone (AFTC and FTI), and decreased 25(OH)D concentrations are risk factors for sarcopenia.

Ultrasonographic evaluation of the calf muscle mass and architecture in elderly patients with and without sarcopenia.

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Kuyumcu, Mehmet Emin; Halil, Meltem; Kara, Özgür; Çuni, Bledjan; Çağlayan, Gökhan; Güven, Serdar; Yeşil, Yusuf; Arık, Güneş; Yavuz, Burcu Balam; Cankurtaran, Mustafa; Özçakar, Levent

2016-01-01

To sonographically assess the muscle mass and architecture of sarcopenic elderly subjects, and to explore the utility of ultrasound (US) measurements in predicting sarcopenia. One hundred elderly subjects were enrolled in this cross-sectional study. Mean age value of our study population was 73.08±6.18years. The diagnosis of sarcopenia was confirmed by measuring fat-free mass index (using bioelectrical impedance analysis) and handgrip strength. Calf circumference was measured and US evaluations comprised bilateral gastrocnemius muscle (MG) thickness, fascicle length and pennate angles; subcutaneous fat and dermis thicknesses in the calf. Bilateral muscle thickness and fascicle length values were significantly lower in patients with sarcopenia (both psarcopenia (all values>76.92%). Gastrocnemius muscle thickness and fascicle length values are lower in sarcopenic elderly and these two parameters can serve as alternative measurements for predicting/quantifying sarcopenia. Calf circumference measurements alone may not be appropriate for assessing sarcopenia. Instead, US imaging can conveniently be used to evaluate different compartments of the musculoskelal system in (sarcopenic) elderly. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Ratio of dietary ω-3 and ω-6 fatty acids-independent determinants of muscle mass-in hemodialysis patients with diabetes.

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Wong, Te-Chih; Chen, Yu-Tong; Wu, Pei-Yu; Chen, Tzen-Wen; Chen, Hsi-Hsien; Chen, Tso-Hsiao; Hsu, Yung-Ho; Yang, Shwu-Huey

2016-09-01

ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) are essential nutrients in the human diet and possibly affect muscle mass. We evaluated the association between the dietary ratios of ω-3 and ω-6 PUFAs and muscle mass, indicated as skeletal muscle mass (SMM) and appendicular skeletal muscle mass (ASM), in patients with diabetes undergoing hemodialysis (HD). In this cross-sectional study, data on 69 patients with diabetes who underwent standard HD therapy were analyzed. For estimating muscle mass, anthropometric and bioelectrical impedance analyses were conducted following dialysis. In addition, routine laboratory and 3-d dietary data were obtained. The adequate intake (AI) cut-off for ω-3 PUFAs was 1.6 g/d and 1.1 g/d for male and female patients, respectively. The average age of the participants was 63.0 ± 10.4 y. The mean ratios of ω-3/ω-6 PUFA intake, ω-6/ω-3 PUFA intake, SMM, and ASM of the patients were 0.13 ± 0.07, 9.4 ± 6.4, 24.6 ± 5.4 kg, and 18.3 ± 4.6 kg, respectively. Patients who had AI of ω-3 PUFAs had significantly higher SMM and ASM than did their counterparts. Linear and stepwise multivariable adjustment analyses revealed that insulin resistance and the ω-6/ω-3 PUFA ratio were the independent deleterious determinants of ASM normalized to height in HD patients. Patients with AI of ω-3 PUFAs had total-body SMM and ASM that were more appropriate. A higher dietary ratio of ω-6/ω-3 PUFAs was associated with reduced muscle mass in HD patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Low relative skeletal muscle mass (sarcopenia) in older persons is associated with functional impairment and physical disability.

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Janssen, Ian; Heymsfield, Steven B; Ross, Robert

2002-05-01

To establish the prevalence of sarcopenia in older Americans and to test the hypothesis that sarcopenia is related to functional impairment and physical disability in older persons. Cross-sectional survey. Nationally representative cross-sectional survey using data from the Third National Health and Nutrition Examination Survey (NHANES III). Fourteen thousand eight hundred eighteen adult NHANES III participants aged 18 and older. The presence of sarcopenia and the relationship between sarcopenia and functional impairment and disability were examined in 4,504 adults aged 60 and older. Skeletal muscle mass was estimated from bioimpedance analysis measurements and expressed as skeletal muscle mass index (SMI = skeletal muscle mass/body mass x 100). Subjects were considered to have a normal SMI if their SMI was greater than -one standard deviation above the sex-specific mean for young adults (aged 18-39). Class I sarcopenia was considered present in subjects whose SMI was within -one to -two standard deviations of young adult values, and class II sarcopenia was present in subjects whose SMI was below -two standard deviations of young adult values. The prevalence of class I and class II sarcopenia increased from the third to sixth decades but remained relatively constant thereafter. The prevalence of class I (59% vs 45%) and class II (10% vs 7%) sarcopenia was greater in the older (> or = 60 years) women than in the older men (P normal SMI, respectively. Some of the associations between class II sarcopenia and functional impairment remained significant after adjustment for age, race, body mass index, health behaviors, and comorbidity. Reduced relative skeletal muscle mass in older Americans is a common occurrence that is significantly and independently associated with functional impairment and disability, particularly in older women. These observations provide strong support for the prevailing view that sarcopenia may be an important and potentially reversible cause of

Age-associated declines in muscle mass, strength, power, and physical performance: impact on fear of falling and quality of life.

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Trombetti, A; Reid, K F; Hars, M; Herrmann, F R; Pasha, E; Phillips, E M; Fielding, R A

2016-02-01

This 3-year longitudinal study among older adults showed that declining muscle mass, strength, power, and physical performance are independent contributing factors to increased fear of falling, while declines of muscle mass and physical performance contribute to deterioration of quality of life. Our findings reinforce the importance of preserving muscle health with advancing age. The age-associated loss of skeletal muscle quantity and function are critical determinants of independent physical functioning in later life. Longitudinal studies investigating how decrements in muscle components of sarcopenia impact fear of falling (FoF) and quality of life (QoL) in older adults are lacking. Twenty-six healthy older subjects (age, 74.1 ± 3.7; Short Physical Performance Battery (SPPB) score ≥10) and 22 mobility-limited older subjects (age, 77.2 ± 4.4; SPPB score ≤9) underwent evaluations of lower extremity muscle size and composition by computed tomography, strength and power, and physical performance at baseline and after 3-year follow-up. The Falls Efficacy Scale (FES) and Short Form-36 questionnaire (SF-36) were also administered at both timepoints to assess FoF and QoL, respectively. At 3-year follow-up, muscle cross-sectional area (CSA) (p < 0.013) and power decreased (p < 0.001), while intermuscular fat infiltration increased (p < 0.001). These decrements were accompanied with a longer time to complete 400 m by 22 ± 46 s (p < 0.002). Using linear mixed-effects regression models, declines of muscle CSA, strength and power, and SPPB score were associated with increased FES score (p < 0.05 for each model). Reduced physical component summary score of SF-36 over follow-up was independently associated with decreased SPPB score (p < 0.020), muscle CSA (p < 0.046), and increased 400 m walk time (p < 0.003). In older adults with and without mobility limitations, declining muscle mass, strength, power, and physical

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

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

Dexamethasone and BCAA Failed to Modulate Muscle Mass and mTOR Signaling in GH-Deficient Rats.

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Nishida, Hikaru; Ikegami, Ayaka; Kaneko, Chiaki; Kakuma, Hitomi; Nishi, Hisano; Tanaka, Noriko; Aoyama, Michiko; Usami, Makoto; Okimura, Yasuhiko

2015-01-01

Branched-chain amino acids (BCAAs) and IGF-I, the secretion of which is stimulated by growth hormone (GH), prevent muscle atrophy. mTOR plays a pivotal role in the protective actions of BCAA and IGF-1. The pathway by which BCAA activates mTOR is different from that of IGF-1, which suggests that BCAA and GH work independently. We tried to examine whether BCAA exerts a protective effect against dexamethasone (Dex)-induced muscle atrophy independently of GH using GH-deficient spontaneous dwarf rats (SDRs). Unexpectedly, Dex did not induce muscle atrophy assessed by the measurement of cross-sectional area (CSA) of the muscle fibers and did not increase atrogin-1, MuRF1 and REDD1 expressions, which are activated during protein degradation. Glucocorticoid (GR) mRNA levels were higher in SDRs compared to GH-treated SDRs, indicating that the low expression of GR is not the reason of the defect of Dex's action in SDRs. BCAA did not stimulate the phosphorylation of p70S6K or 4E-BP1, which stimulate protein synthesis. BCAA did not decrease the mRNA level of atrogin-1 or MuRF1. These findings suggested that Dex failed to modulate muscle mass and that BCAA was unable to activate mTOR in SDRs because these phosphorylations of p70S6K and 4E-BP1 and the reductions of these mRNAs are regulated by mTOR. In contrast, after GH supplementation, these responses to Dex were normalized and muscle fiber CSA was decreased by Dex. BCAA prevented the Dex-induced decrease in CSA. BCAA increased the phosphorylation of p70S6K and decreased the Dex-induced elevations of atrogin-1 and Bnip3 mRNAs. However, the amount of mTORC1 components including mTOR was not decreased in the SDRs compared to the normal rats. These findings suggest that GH increases mTORC1 activity but not its content to recover the action of BCAA in SDRs and that GH is required for actions of Dex and BCAA in muscles.

Dexamethasone and BCAA Failed to Modulate Muscle Mass and mTOR Signaling in GH-Deficient Rats.

Directory of Open Access Journals (Sweden)

Hikaru Nishida

Full Text Available Branched-chain amino acids (BCAAs and IGF-I, the secretion of which is stimulated by growth hormone (GH, prevent muscle atrophy. mTOR plays a pivotal role in the protective actions of BCAA and IGF-1. The pathway by which BCAA activates mTOR is different from that of IGF-1, which suggests that BCAA and GH work independently. We tried to examine whether BCAA exerts a protective effect against dexamethasone (Dex-induced muscle atrophy independently of GH using GH-deficient spontaneous dwarf rats (SDRs. Unexpectedly, Dex did not induce muscle atrophy assessed by the measurement of cross-sectional area (CSA of the muscle fibers and did not increase atrogin-1, MuRF1 and REDD1 expressions, which are activated during protein degradation. Glucocorticoid (GR mRNA levels were higher in SDRs compared to GH-treated SDRs, indicating that the low expression of GR is not the reason of the defect of Dex's action in SDRs. BCAA did not stimulate the phosphorylation of p70S6K or 4E-BP1, which stimulate protein synthesis. BCAA did not decrease the mRNA level of atrogin-1 or MuRF1. These findings suggested that Dex failed to modulate muscle mass and that BCAA was unable to activate mTOR in SDRs because these phosphorylations of p70S6K and 4E-BP1 and the reductions of these mRNAs are regulated by mTOR. In contrast, after GH supplementation, these responses to Dex were normalized and muscle fiber CSA was decreased by Dex. BCAA prevented the Dex-induced decrease in CSA. BCAA increased the phosphorylation of p70S6K and decreased the Dex-induced elevations of atrogin-1 and Bnip3 mRNAs. However, the amount of mTORC1 components including mTOR was not decreased in the SDRs compared to the normal rats. These findings suggest that GH increases mTORC1 activity but not its content to recover the action of BCAA in SDRs and that GH is required for actions of Dex and BCAA in muscles.

Specific Adaptations in Performance and Muscle Architecture After Weighted Jump-Squat vs. Body Mass Squat Jump Training in Recreational Soccer Players.

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Coratella, Giuseppe; Beato, Marco; Milanese, Chiara; Longo, Stefano; Limonta, Eloisa; Rampichini, Susanna; Cè, Emiliano; Bisconti, Angela V; Schena, Federico; Esposito, Fabio

2018-04-01

Coratella, G, Beato, M, Milanese, C, Longo, S, Limonta, E, Rampichini, S, Cè, E, Bisconti, AV, Schena, F, and Esposito, F. Specific adaptations in performance and muscle architecture after weighted jump-squat vs. body mass squat jump training in recreational soccer players. J Strength Cond Res 32(4): 921-929, 2018-The aim of the present study was to compare the effects of weighted jump-squat training (WJST) vs. body mass squat jump training (BMSJT) on quadriceps' muscle architecture, lower-limb lean-mass (LM) and muscle strength, performance in change of direction (COD), and sprint and jump in recreational soccer players. Forty-eight healthy soccer players participated in an offseason randomized controlled trial. Before and after an 8-week training intervention, vastus lateralis pennation angle, fascicle length, muscle thickness, LM, squat 1RM, quadriceps and hamstrings isokinetic peak torque, agility T-test, 10-and 30-m sprints, and squat-jump (SJ) were measured. Although similar increases were observed in muscle thickness, fascicle length increased more in WJST (Effect size [ES] = 1.18, 0.82-1.54) than in BMSJT (ES = 0.54, 0.40-0.68), and pennation angle increased only in BMSJT (ES = 1.03, 0.78-1.29). Greater increases in LM were observed in WJST (ES = 0.44, 0.29-0.59) than in BMSJT (ES = 0.21, 0.07-0.37). The agility T-test (ES = 2.95, 2.72-3.18), 10-m (ES = 0.52, 0.22-0.82), and 30-m sprints (ES = 0.52, 0.23-0.81) improved only in WJST, whereas SJ improved in BMSJT (ES = 0.89, 0.43-1.35) more than in WJST (ES = 0.30, 0.03-0.58). Similar increases in squat 1RM and peak torque occurred in both groups. The greater inertia accumulated within the landing phase in WJST vs. BMSJT has increased the eccentric workload, leading to specific eccentric-like adaptations in muscle architecture. The selective improvements in COD in WJST may be related to the increased braking ability generated by the enhanced eccentric workload.

Influence of muscle strength, physical activity and weight on bone mass in a population-based sample of 1004 elderly women.

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Gerdhem, P; Ringsberg, K A M; Akesson, K; Obrant, K J

2003-09-01

High physical activity level has been associated with high bone mass and low fracture risk and is therefore recommended to reduce fractures in old age. The aim of this study was to estimate the effect of potentially modifiable variables, such as physical activity, muscle strength, muscle mass and weight, on bone mass in elderly women. The influence of isometric thigh muscle strength, self-estimated activity level, body composition and weight on bone mineral density (dual energy X-ray absorptiometry; DXA) in total body, hip and spine was investigated. Subjects were 1004 women, all 75 years old, taking part in the Malmö Osteoporosis Prospective Risk Assessment (OPRA) study. Physical activity and muscle strength accounted for 1-6% of the variability in bone mass, whereas weight, and its closely associated variables lean mass and fat mass, to a much greater extent explained the bone mass variability. We found current body weight to be the variable with the most substantial influence on the total variability in bone mass (15-32% depending on skeletal site) in a forward stepwise regression model. Our findings suggest that in elderly women, the major fracture-preventive effect of physical activity is unlikely to be mediated through increased bone mass. Retaining or even increasing body weight is likely to be beneficial to the skeleton, but an excess body weight increase may have negative effects on health. Nevertheless, training in elderly women may have advantages by improving balance, co-ordination and mobility and therefore decreasing the risk of fractures.

Clinical Outcomes of Living Liver Transplantation According to the Presence of Sarcopenia as Defined by Skeletal Muscle Mass, Hand Grip, and Gait Speed.

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Harimoto, N; Yoshizumi, T; Izumi, T; Motomura, T; Harada, N; Itoh, S; Ikegami, T; Uchiyama, H; Soejima, Y; Nishie, A; Kamishima, T; Kusaba, R; Shirabe, K; Maehara, Y

2017-11-01

Sarcopenia is an independent predictor of death after living-donor liver transplantation (LDLT). However, the ability of the Asian Working Group for Sarcopenia criteria for sarcopenia (defined as reduced skeletal muscle mass plus low muscle strength) to predict surgical outcomes in patients who have undergone LDLT has not been determined. This study prospectively enrolled 366 patients who underwent LDLT at Kyushu University Hospital. Skeletal muscle area (determined by computed tomography), hand-grip strength, and gait speed were measured in 102 patients before LDLT. We investigated the relationship between sarcopenia and surgical outcomes after LDLT performed in three time periods. The number of patients with lower skeletal muscle area has increased to 52.9% in recent years. The incidence of sarcopenia according to the Asian Working Group for Sarcopenia criteria was 23.5% (24/102). Patients with sarcopenia (defined by skeletal muscle area and functional parameters) had significantly lower skeletal muscle area and weaker hand-grip strength than did those without sarcopenia. Compared with non-sarcopenic patients, patients with sarcopenia also had significantly worse liver function, greater estimated blood loss, greater incidence of postoperative complications of Clavien-Dindo grade IV or greater (including amount of ascites on postoperative day 14, total bilirubin on postoperative day 14, and postoperative sepsis), and longer postoperative hospital stay. Multiple logistic regression analysis revealed sarcopenia as a significant predictor of 6-month mortality. The combination of skeletal muscle mass and function can predict surgical outcomes in LDLT patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Age-related differences in lean mass, protein synthesis and skeletal muscle markers of proteolysis after bed rest and exercise rehabilitation.

Science.gov (United States)

Tanner, Ruth E; Brunker, Lucille B; Agergaard, Jakob; Barrows, Katherine M; Briggs, Robert A; Kwon, Oh Sung; Young, Laura M; Hopkins, Paul N; Volpi, Elena; Marcus, Robin L; LaStayo, Paul C; Drummond, Micah J

2015-09-15

Bed rest-induced muscle loss and impaired muscle recovery may contribute to age-related sarcopenia. It is unknown if there are age-related differences in muscle mass and muscle anabolic and catabolic responses to bed rest. A secondary objective was to determine if rehabilitation could reverse bed rest responses. Nine older and fourteen young adults participated in a 5-day bed rest challenge (BED REST). This was followed by 8 weeks of high intensity resistance exercise (REHAB). Leg lean mass (via dual-energy X-ray absorptiometry; DXA) and strength were determined. Muscle biopsies were collected during a constant stable isotope infusion in the postabsorptive state and after essential amino acid (EAA) ingestion on three occasions: before (PRE), after bed rest and after rehabilitation. Samples were assessed for protein synthesis, mTORC1 signalling, REDD1/2 expression and molecular markers related to muscle proteolysis (MURF1, MAFBX, AMPKα, LC3II/I, Beclin1). We found that leg lean mass and strength decreased in older but not younger adults after bedrest (P protein synthesis increased before bed rest in both age groups (P protein synthesis rates and increased MAFBX mRNA, p-AMPKα and the LC3II/I ratio (P protein synthesis and a marginal increase in proteolytic markers. Finally, rehabilitation restored bed rest-induced deficits in lean mass and strength in older adults. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

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.

Brain and muscle Arnt-like 1 promotes skeletal muscle regeneration through satellite cell expansion

Energy Technology Data Exchange (ETDEWEB)

Chatterjee, Somik [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Yin, Hongshan [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Department of Cardiovascular Medicine, Third Affiliated Hospital, Hebei Medical University, Shijiazhuang 050051, Hebei (China); Nam, Deokhwa [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Li, Yong [Department of Pediatric Surgery, Center for Stem Cell Research and Regenerative Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030 (United States); Ma, Ke, E-mail: kma@houstonmethodist.org [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States)

2015-02-01

Circadian clock is an evolutionarily conserved timing mechanism governing diverse biological processes and the skeletal muscle possesses intrinsic functional clocks. Interestingly, although the essential clock transcription activator, Brain and muscle Arnt-like 1 (Bmal1), participates in maintenance of muscle mass, little is known regarding its role in muscle growth and repair. In this report, we investigate the in vivo function of Bmal1 in skeletal muscle regeneration using two muscle injury models. Bmal1 is highly up-regulated by cardiotoxin injury, and its genetic ablation significantly impairs regeneration with markedly suppressed new myofiber formation and attenuated myogenic induction. A similarly defective regenerative response is observed in Bmal1-null mice as compared to wild-type controls upon freeze injury. Lack of satellite cell expansion accounts for the regeneration defect, as Bmal1{sup −/−} mice display significantly lower satellite cell number with nearly abolished induction of the satellite cell marker, Pax7. Furthermore, satellite cell-derived primary myoblasts devoid of Bmal1 display reduced growth and proliferation ex vivo. Collectively, our results demonstrate, for the first time, that Bmal1 is an integral component of the pro-myogenic response that is required for muscle repair. This mechanism may underlie its role in preserving adult muscle mass and could be targeted therapeutically to prevent muscle-wasting diseases. - Highlights: • Bmal1 is highly inducible by muscle injury and myogenic stimuli. • Genetic ablation of Bmal1 significantly impairs muscle regeneration. • Bmal1 promotes satellite cell expansion during muscle regeneration. • Bmal1-deficient primary myoblasts display attenuated growth and proliferation.

Brain and muscle Arnt-like 1 promotes skeletal muscle regeneration through satellite cell expansion

International Nuclear Information System (INIS)

Chatterjee, Somik; Yin, Hongshan; Nam, Deokhwa; Li, Yong; Ma, Ke

2015-01-01

Circadian clock is an evolutionarily conserved timing mechanism governing diverse biological processes and the skeletal muscle possesses intrinsic functional clocks. Interestingly, although the essential clock transcription activator, Brain and muscle Arnt-like 1 (Bmal1), participates in maintenance of muscle mass, little is known regarding its role in muscle growth and repair. In this report, we investigate the in vivo function of Bmal1 in skeletal muscle regeneration using two muscle injury models. Bmal1 is highly up-regulated by cardiotoxin injury, and its genetic ablation significantly impairs regeneration with markedly suppressed new myofiber formation and attenuated myogenic induction. A similarly defective regenerative response is observed in Bmal1-null mice as compared to wild-type controls upon freeze injury. Lack of satellite cell expansion accounts for the regeneration defect, as Bmal1 −/− mice display significantly lower satellite cell number with nearly abolished induction of the satellite cell marker, Pax7. Furthermore, satellite cell-derived primary myoblasts devoid of Bmal1 display reduced growth and proliferation ex vivo. Collectively, our results demonstrate, for the first time, that Bmal1 is an integral component of the pro-myogenic response that is required for muscle repair. This mechanism may underlie its role in preserving adult muscle mass and could be targeted therapeutically to prevent muscle-wasting diseases. - Highlights: • Bmal1 is highly inducible by muscle injury and myogenic stimuli. • Genetic ablation of Bmal1 significantly impairs muscle regeneration. • Bmal1 promotes satellite cell expansion during muscle regeneration. • Bmal1-deficient primary myoblasts display attenuated growth and proliferation

Lean body mass and muscle function in head and neck cancer patients and healthy individuals - results from the DAHANCA 25 study

DEFF Research Database (Denmark)

Lønbro, Simon; Dalgas, Ulrik; Primdahl, Hanne

2013-01-01

Abstract Introduction. Loss of lean body mass is common following radiotherapy in patients with head and neck squamous cell carcinoma (HNSCC) and may reduce maximal muscle strength and functional performance. However, the associations between lean body mass, muscle strength and functional...... m max gait speed, 30 s chair rise, 30 s arm curl, stair climb) from HNSCC patients from the DAHANCA 25 trials and data from 24 healthy individuals were included. Results. Lean body mass and maximal muscle strength were significantly associated according to the gender and age-adjusted linear...... regression model (p regression analyses showed that HNSCC patients expressed significant lower levels of the investigated variables after radiotherapy...

The effects of dietary protein intake on appendicular lean mass and muscle function in elderly men

DEFF Research Database (Denmark)

Mitchell, Cameron J; Milan, Amber M; Mitchell, Sarah M

2017-01-01

Background: The Recommended Daily Allowance (RDA) for protein intake in the adult population is widely promoted as 0.8 g · kg-1 · d-1 Aging may increase protein requirements, particularly to maintain muscle mass.Objective: We investigated whether controlled protein consumption at the current RDA...... or twice the RDA (2RDA) affects skeletal muscle mass and physical function in elderly men.Design: In this parallel-group randomized trial, 29 men aged >70 y [mean ± SD body mass index (in kg/m2): 28.3 ± 4.2] were provided with a complete diet containing either 0.8 (RDA) or 1.6 (2RDA) g protein · kg-1 · d-1...... energy balance (mean ± SD RDA: 209 ± 213 kcal/d; 2RDA 145 ± 214 kcal/d; P= 0.427 for difference between the groups). In comparison with RDA, whole-body lean mass increased in 2RDA (P = 0.001; 1.49 ± 1.30 kg, P

Influence of Nordic Walking Training on Muscle Strength and the Electromyographic Activity of the Lower Body in Women With Low Bone Mass

Directory of Open Access Journals (Sweden)

Ossowski Zbigniew

2016-06-01

Full Text Available Introduction. Osteoporosis and osteopenia are related to changes in the quantity and quality of skeletal muscle and contribute to a decreased level of muscle strength. The purpose of this study was to evaluate the impact of Nordic walking training on muscle strength and the electromyographic (EMG activity of the lower body in women with low bone mass. Material and methods. The participants of the study were 27 women with low bone mass. The sample was randomly divided into two groups: a control group and an experimental group. Women from the experimental group participated in 12 weeks of regular Nordic walking training. Functional strength was assessed with a 30-second chair stand test. The EMG activities of the gluteus maximus (GMax, rectus femoris (RF, biceps femoris (BF, soleus (SOL, and lumbar (LB muscles were measured using a surface electromyogram. Results. Nordic walking training induced a significant increase in the functional strength (p = 0.006 of the lower body and activity of GMax (p = 0.013 and a decrease in body mass (p = 0.006 in women with reduced bone mass. There was no statistically significant increase in the EMG activities of the RF, BF, SOL, or LB muscles. The study did not indicate any significant changes in functional muscle strength, the EMG activity of the lower body, or anthropometry in women from the control group. Conclusions. Nordic walking training induces positive changes in lower body strength and the electromyographic activity of the gluteus maximus as well as a decrease in body mass in women with low bone mass.

Impaired Bronchoprotection Is Not Induced by Increased Smooth Muscle Mass in Chronic Treatment In Vivo with Formoterol in Asthmatic Mouse Model

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W Luo

2014-09-01

Full Text Available Objective: Inhaling β2-adrenoceptor agonist is first-line asthma treatment, which is used for both acute relief and prevention of bronchoconstriction. However, chronic use of β-agonists results in impaired bronchoprotection and increasing occurrences of severe asthma exacerbation, even death in clinical practice. The mechanism of β-adrenoceptor hyposensitivity has not been thoroughly elucidated thus far. Bronchial smooth muscle contraction induces airway narrowing and also mediates airway inflammation. Moreover, bronchial smooth muscle mass significantly increases in asthmatics. We aimed to establish an asthmatic model that demonstrated that formoterol induced impaired bronchoprotection and to see whether increased smooth muscle mass played a role in it. Methods: We combined routine allergen challenging (seven weeks with repeated application of formoterol, formoterol plus budesonide or physiological saline in allergen-sensitized BALB/c mouse. The bronchoprotection mediated by β-agonist was measured in five consecutive weeks. Smooth muscle mass was shown by morphometric analysis, and α-actin expression was detected by western blot. Results: The trend of bronchoprotection was wavy in drug interventional groups, which initially increased and then decreased. Chronic treatment with formoterol significantly impaired bronchoprotection. According to the morphometric analysis and α-actin expression, no significant difference was detected in smooth muscle mass in all groups. Conclusion: This experiment successfully established that a chronic asthmatic mouse model, which manifested typical features of asthmatic patients, with chronic use of formoterol, results in a loss of bronchoprotection. No significant difference was detected in smooth muscle mass in all groups, which implied some subcellular signalling changes may be the key points.

The effect of individualized nutritional counseling on muscle mass and treatment outcome in patients with metastatic colorectal cancer undergoing chemotherapy: a randomized controlled trial protocol

NARCIS (Netherlands)

van der Werf, Anne; Blauwhoff-Buskermolen, Susanne; Langius, Jacqueline A. E.; Berkhof, Johannes; Verheul, Henk M. W.; de van der Schueren, Marian A. E.

2015-01-01

A low muscle mass is prevalent in patients with metastatic colorectal cancer (mCRC) and has been associated with poor treatment outcome. Chemotherapeutic treatment has an additional unfavorable effect on muscle mass. Sufficient protein intake and physical activity are known to induce muscle protein

Hypertrophy Stimulation at the Onset of Type I Diabetes Maintains the Soleus but Not the EDL Muscle Mass in Wistar Rats

Science.gov (United States)

Fortes, Marco A. S.; Scervino, Maria V. M.; Marzuca-Nassr, Gabriel N.; Vitzel, Kaio F.; da Justa Pinheiro, Carlos H.; Curi, Rui

2017-01-01

Diabetes mellitus induces a reduction in skeletal muscle mass and strength. Strength training is prescribed as part of treatment since it improves glycemic control and promotes increase of skeletal muscle mass. The mechanisms involved in overload-induced muscle hypertrophy elicited at the establishment of the type I diabetic state was investigated in Wistar rats. The purpose was to examine whether the overload-induced hypertrophy can counteract the hypotrophy associated to the diabetic state. The experiments were performed in oxidative (soleus) or glycolytic (EDL) muscles. PI3K/Akt/mTOR protein synthesis pathway was evaluated 7 days after overload-induced hypertrophy of soleus and of EDL muscles. The mRNA expression of genes associated with different signaling pathways that control muscle hypertrophy was also evaluated: mechanotransduction (FAK), Wnt/β-catenin, myostatin, and follistatin. The soleus and EDL muscles when submitted to overload had similar hypertrophic responses in control and diabetic animals. The increase of absolute and specific twitch and tetanic forces had the same magnitude as muscle hypertrophic response. Hypertrophy of the EDL muscle from diabetic animals mostly involved mechanical loading-stimulated PI3K/Akt/mTOR pathway besides the reduced activation of AMP-activated protein kinase (AMPK) and decrease of myostatin expression. Hypertrophy was more pronounced in the soleus muscle of diabetic animals due to a more potent activation of rpS6 and increased mRNA expression of insulin-like growth factor-1 (IGF-1), mechano-growth factor (MGF) and follistatin, and decrease of myostatin, MuRF-1 and atrogin-1 contents. The signaling changes enabled the soleus muscle mass and force of the diabetic rats to reach the values of the control group. PMID:29123487

Creatine monohydrate supplementation does not increase muscle strength, lean body mass, or muscle phosphocreatine in patients with myotonic dystrophy type 1.

Science.gov (United States)

Tarnopolsky, Mark; Mahoney, Douglas; Thompson, Terry; Naylor, Heather; Doherty, Timothy J

2004-01-01

Creatine monohydrate (CrM) supplementation may increase strength in some types of muscular dystrophy. A recent study in myotonic muscular dystrophy type 1 (DM1) did not find a significant treatment effect, but measurements of muscle phosphocreatine (PCr) were not performed. We completed a randomized, double-blind, cross-over trial using 34 genetically confirmed adult DM1 patients without significant cognitive impairment. Participants received CrM (5 g, approximately 0.074 g/kg daily) and a placebo for each 4-month phase with a 6-week wash-out. Spirometry, manual muscle testing, quantitative isometric strength testing of handgrip, foot dorsiflexion, and knee extension, handgrip and foot dorsiflexion endurance, functional tasks, activity of daily living scales, body composition (total, bone, and fat-free mass), serum creatine kinase activity, serum creatinine concentration and clearance, and liver function tests were completed before and after each intervention, and muscle PCr/beta-adenosine triphosphate (ATP) ratios of the forearm flexor muscles were completed at the end of each phase. CrM supplementation did not increase any of the outcome measurements except for plasma creatinine concentration (but not creatinine clearance). Thus, CrM supplementation at 5 g daily does not have any effects on muscle strength, body composition, or activities of daily living in patients with DM1, perhaps because of a failure of the supplementation to increase muscle PCr/beta-ATP content.

Comparative anatomy of the cheek muscles within the Centromochlinae subfamily (Ostariophysi, Siluriformes, Auchenipteridae).

Science.gov (United States)

Sarmento-Soares, Luisa Maria; Porto, Marcovan

2006-02-01

Glanidium melanopterum Miranda Ribeiro, a typical representative of the subfamily Centromochlinae (Siluriformes: Auchenipteridae), is herein described myologically and compared to other representative species within the group, Glanidium ribeiroi, G. leopardum, Tatia neivai, T. intermedia, T. creutzbergi, Centromochlus heckelii, and C. existimatus. The structure of seven pairs of striated cephalic muscles was compared anatomically: adductor mandibulae, levator arcus palatini, dilatator operculi, adductor arcus palatini, extensor tentaculi, retractor tentaculi, and levator operculi. We observed broad adductor mandibulae muscles in both Glanidium and Tatia, catfishes with depressed heads and smaller eyes. Similarities between muscles were observed: the presence of a large aponeurotic insertion for the levator arcus palatini muscle; an adductor arcus palatini muscle whose origin spread over the orbitosphenoid, pterosphenoid, and parasphenoid; and the extensor tentaculi muscle broadly attached to the autopalatine. There is no retractor tentaculi muscle in either the Glanidium or Tatia species. On the other hand, in Centromochlus, with forms having large eyes and the tallest head, the adductor mandibulae muscles are slim; there is a thin aponeurotic or muscular insertion for the levator arcus palatini muscle; the adductor arcus palatini muscle originates from a single osseous process, forming a keel on the parasphenoid; the extensor tentaculi muscle is loosely attached to the autopalatine, permitting exclusive rotating and sliding movements between this bone and the maxillary. The retractor tentaculi muscle is connected to the maxilla through a single tendon, so that both extensor and retractor tentaculi muscles contribute to a wide array of movements of the maxillary barbels. A discussion on the differences in autopalatine-maxillary movements among the analyzed groups is given. (c) 2005 Wiley-Liss, Inc.

Slow movement resistance training using body weight improves muscle mass in the elderly: A randomized controlled trial.

Science.gov (United States)

Tsuzuku, S; Kajioka, T; Sakakibara, H; Shimaoka, K

2018-04-01

To examine the effect of a 12-week slow movement resistance training using body weight as a load (SRT-BW) on muscle mass, strength, and fat distribution in healthy elderly people. Fifty-three men and 35 women aged 70 years old or older without experience in resistance training participated, and they were randomly assigned to a SRT-BW group or control group. The control group did not receive any intervention, but participants in this group underwent a repeat measurement 12 weeks later. The SRT-BW program consisted of 3 different exercises (squat, tabletop push-up, and sit-up), which were designed to stimulate anterior major muscles. Initially, these exercises were performed by 2 sets of 10 repetitions, and subsequently, the number of repetitions was increased progressively by 2 repetitions every 4 weeks. Participants were instructed to perform each eccentric and concentric phase of movement slowly (spending 4 seconds on each movement), covering the full range of motion. We evaluated muscle mass, strength, and fat distribution at baseline and after 12 weeks of training. Changes over 12 weeks were significantly greater in the SRT-BW group than in the control group, with a decrease in waist circumference, hip circumference, and abdominal preperitoneal and subcutaneous fat thickness, and an increase in thigh muscle thickness, knee extension strength, and hip flexion strength. In conclusion, relatively short-term SRT-BW was effective in improving muscle mass, strength, and fat distribution in healthy elderly people. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparison between body mass index, triceps skin fold thickness and mid-arm muscle circumference in Saudi adolescents

International Nuclear Information System (INIS)

Abdalkhail, B.; Shawky, S.

2002-01-01

Adolescence is an important period in an individual's life. Overweight and obesity are fraught with several health problems even late in life. The objective of this study was estimate the overweight, obesity, body fat and muscle content of Saudi adolescents as compared to a recognized reference population. Data were collected from a sample of Saudi adolescents in Jeddah from 42 boys' and 42 girls' school during the month of April 2000. Data collection was done by personal interviews to collect sociodemograhic factors and by direct measurement of weight, height, triceps skin fold thickness (TSF) and mid-arm circumference (MAC). The 50th, 85th and 95th percentiles(P50, P85 and P95) for body mass index (BMI) and triceps skin fold thickness (TSF) were taken, then the 50th, 90th, and 95th percentiles (P50, P90 and P95) for the mid-arm muscle circumference (MAMC) were calculated. These measurements were compared with corresponding values of the National Health and Nutrition Examination Survey I (NHANES I). The P85 and P95 for the BMI and TSF were higher for Saudi adolescents than the NHANES I and the difference was wider for P95. Conversely, there was a lower MAMC at P90 and P95thane the NHANES I reference population curves. The lower MAMC curves were less marked in girls than in boys. On the other hand Saudi boys and girls showed on average similar body mass index indicated by MBI at P50, which was misleading, since those adolescents showing similar body mass index had more fatness than of average reference population indicated by TSF and P50, and less muscularity on average than reference population indicated MAMC at P-50. Overweight and obesity with increased body fat content and decreased body muscle content appear to be widespread among Saudi adolescents even among those adolescents showing average body index. Public health interventions are required to improve quality of food, encourage physical, activity and exercise, as well as correct the perception of

Predictors Associated with Increase in Skeletal Muscle Mass after Sustained Virological Response in Chronic Hepatitis C Treated with Direct Acting Antivirals

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Kazunori Yoh

2017-10-01

Full Text Available Aims: We aimed to examine changes in skeletal muscle mass in chronic hepatitis C (CHC patients undergoing interferon (IFN-free direct acting antivirals (DAAs therapy who achieved sustained virological response (SVR. Patients and methods: A total of 69 CHC patients treated with DAAs were analyzed. We compared the changes in skeletal muscle index (SMI using bio-impedance analysis at baseline and SMI at SVR. SMI was calculated as the sum of skeletal muscle mass in upper and lower extremities divided by height squared (cm2/m2. Further, we identified pretreatment parameters contributing to the increased SMI at SVR. Results: SMI in males at baseline ranged from 6.73 to 9.08 cm2/m2 (median, 7.65 cm2/m2, while that in females ranged from 4.45 to 7.27 cm2/m2 (median, 5.81 cm2/m2. At SVR, 36 patients (52.2% had increased SMI as compared with baseline. In the univariate analysis, age (p = 0.0392, hyaluronic acid (p = 0.0143, and branched-chain amino acid to tyrosine ratio (BTR (p = 0.0024 were significant pretreatment factors linked to increased SMI at SVR. In the multivariate analysis, only BTR was an independent predictor linked to the increased SMI at SVR (p = 0.0488. Conclusion: Pretreatment BTR level can be helpful for predicting increased SMI after SVR in CHC patients undergoing IFN-free DAAs therapy.

Comparative anatomy of the extraocular muscles in four Myliobatoidei rays (Batoidea, Myliobatiformes).

Science.gov (United States)

Cunha, Carlo M; Oliveira, Luciano E; Kfoury, José R

2016-05-01

Extraocular muscles are classically grouped as four rectus and two oblique muscles. However, their description and potential associations with species behavior are limited. The objective was to characterize extraocular muscles in four Myliobatoidei rays from diverse habitats with divergent behaviors. Heads (10 per species) of Dasyatis hypostigma, Gymnura altavela, Mobula thurstoni and Pteroplatytrygon violacea were decalcified and dissected to characterize and describe extraocular muscles. Principal component analysis (PCA) was used to evaluate relationships between muscle length and species; for P. violacea, D. hypostigma and G. altavela, these were qualitatively and quantitatively consistent with the general pattern of extraocular muscles in vertebrates. In contrast, for M. thurstoni, the two oblique muscles were completely fused and there was a seventh extraocular muscle, named m. lateral rectus β (both were apparently novel findings in this species). There were also significant differences in eye disposition in the chondrocranium. The PCA axis 1 (rectus muscles) and PCA axis 2 (oblique muscles) accounted for 98.47% of data variability. Extraocular muscles had significant differences in length and important anatomical differences among sampled species that facilitated grouping species according to their life history. In conclusion, extraocular muscles are not uniform in all vertebrate species, thereby providing another basis for comparative studies. © 2016 Anatomical Society.

Muscle function-dependent sarcopenia and cut-off values of possible predictors in community-dwelling Turkish elderly: calf circumference, midarm muscle circumference and walking speed.

Science.gov (United States)

Akın, S; Mucuk, S; Öztürk, A; Mazıcıoğlu, M; Göçer, Ş; Arguvanlı, S; Şafak, E D

2015-10-01

The aim of this study was to determine the prevalence of muscle strength-based sarcopenia and to determine possible predictors. This is a cross-sectional population-based study in the community-dwelling Turkish elderly. Anthropometric measurements, namely body height, weight, triceps skin fold (TSF), mid upper arm circumference (MUAC), waist circumference (WC) and calf circumference (CC), were noted. The midarm muscle circumference (MAMC) was calculated by using MUAC and TSF measurement. Sarcopenia was assessed, adjusted for body mass index (BMI) and gender, according to muscle strength. Physical performance was determined by 4 m walking speed (WS; m/s). The receiver operating curve analysis was performed to determine cut-offs of CC, MAMC and 4 m WS. A total of 879 elderly subjects, 50.1% of whom were female, were recruited. The mean handgrip strength (HGS) and s.d. was 24.2 (8.8) kg [17.9 (4.8) female, 30.6 (7.1) male]. The muscle function-dependent sarcopenia was 63.4% (female 73.5%, male 53.2%). The muscle mass-dependent sarcopenia for CC (sarcopenia. An adequate muscle mass may not mean a reliable muscle function. Muscle function may describe sarcopenia better compared with muscle mass. The CC, MAMC and 4 m WS cut-offs may be used to assess sarcopenia in certain age groups.

Long-term outcome of muscle strength in ulnar and median nerve injury: Comparing manual muscle strength testing, grip and pinch strength dynamometers and a new intrinsic muscle strength dynamometer

NARCIS (Netherlands)

A.R. Schreuders (Ton); M.E. Roebroeck (Marij); J.B. Jaquet (Jean); S.E.R. Hovius (Steven); H.J. Stam (Henk)

2004-01-01

textabstractObjective: To compare the outcome of muscle strength with manual muscle strength testing grip and pinch strength measurements and a dynamometer which allows for measurements of the intrinsic muscles of the hand in isolation (the Rotterdam Intrinsic Hand Myometer, RIHM). Methods:

The effect of protein intake and resistance training on muscle mass in acutely ill old medical patients - A randomized controlled trial

DEFF Research Database (Denmark)

Buhl, Sussi F; Andersen, Aino L; Andersen, Jens Rikardt

2016-01-01

admission and a daily protein supplement (18.8 g protein) and resistance training 3 times per week the 12 weeks following discharge. Muscle mass was assessed by Dual-energy X-ray Absorptiometry. Muscle strength was assessed by Hand Grip Strength and Chair Stand Test. Functional ability was assessed...... mass (unadjusted: β-coefficient = -1.28 P = 0.32, adjusted for gender: β-coefficient = -0.02 P = 0.99, adjusted for baseline lean mass: β-coefficient = -0.31 P = 0.80). The de Morton Mobility Index significantly increased in the Control Group (β-coefficient = -11.43 CI: 0.72-22.13, P = 0.04). No other...... differences were found. CONCLUSION: No significant effect on muscle mass was observed in this group of acutely ill old medical patients. High compliance was achieved with the dietary intervention, but resistance training was challenging. Clinical trials identifier NCT02077491....

Hypertrophy Stimulation at the Onset of Type I Diabetes Maintains the Soleus but Not the EDL Muscle Mass in Wistar Rats

Directory of Open Access Journals (Sweden)

Marco A. S. Fortes

2017-10-01

Full Text Available Diabetes mellitus induces a reduction in skeletal muscle mass and strength. Strength training is prescribed as part of treatment since it improves glycemic control and promotes increase of skeletal muscle mass. The mechanisms involved in overload-induced muscle hypertrophy elicited at the establishment of the type I diabetic state was investigated in Wistar rats. The purpose was to examine whether the overload-induced hypertrophy can counteract the hypotrophy associated to the diabetic state. The experiments were performed in oxidative (soleus or glycolytic (EDL muscles. PI3K/Akt/mTOR protein synthesis pathway was evaluated 7 days after overload-induced hypertrophy of soleus and of EDL muscles. The mRNA expression of genes associated with different signaling pathways that control muscle hypertrophy was also evaluated: mechanotransduction (FAK, Wnt/β-catenin, myostatin, and follistatin. The soleus and EDL muscles when submitted to overload had similar hypertrophic responses in control and diabetic animals. The increase of absolute and specific twitch and tetanic forces had the same magnitude as muscle hypertrophic response. Hypertrophy of the EDL muscle from diabetic animals mostly involved mechanical loading-stimulated PI3K/Akt/mTOR pathway besides the reduced activation of AMP-activated protein kinase (AMPK and decrease of myostatin expression. Hypertrophy was more pronounced in the soleus muscle of diabetic animals due to a more potent activation of rpS6 and increased mRNA expression of insulin-like growth factor-1 (IGF-1, mechano-growth factor (MGF and follistatin, and decrease of myostatin, MuRF-1 and atrogin-1 contents. The signaling changes enabled the soleus muscle mass and force of the diabetic rats to reach the values of the control group.

Deficiency of heat shock transcription factor 1 suppresses heat stress-associated increase in slow soleus muscle mass of mice.

Science.gov (United States)

Ohno, Y; Egawa, T; Yokoyama, S; Nakai, A; Sugiura, T; Ohira, Y; Yoshioka, T; Goto, K

2015-12-01

Effects of heat shock transcription factor 1 (HSF1) deficiency on heat stress-associated increase in slow soleus muscle mass of mice were investigated. Both HSF1-null and wild-type mice were randomly assigned to control and heat-stressed groups. Mice in heat-stressed group were exposed to heat stress (41 °C for 60 min) in an incubator without anaesthesia. Significant increase in wet and dry weights, and protein content of soleus muscle in wild-type mice was observed seven days after the application of the heat stress. However, heat stress had no impact on soleus muscle mass in HSF1-null mice. Neither type of mice exhibited much effect of heat stress on HSF mRNA expression (HSF1, HSF2 and HSF4). On the other hand, heat stress upregulated heat shock proteins (HSPs) at the mRNA (HSP72) and protein (HSP72 and HSP110) levels in wild-type mice, but not in HSF1-null mice. The population of Pax7-positive nuclei relative to total myonuclei of soleus muscle in wild-type mice was significantly increased by heat stress, but not in HSF1-null mice. Furthermore, the absence of HSF1 gene suppressed heat stress-associated phosphorylation of Akt and p70 S6 kinase (p-p70S6K) in soleus muscle. Heat stress-associated increase in skeletal muscle mass may be induced by HSF1 and/or HSF1-mediated stress response that activates muscle satellite cells and Akt/p70S6K signalling pathway. © 2015 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Morphological analysis of the hindlimb in apes and humans. I. Muscle architecture.

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Payne, R C; Crompton, R H; Isler, K; Savage, R; Vereecke, E E; Günther, M M; Thorpe, S K S; D'Août, K

2006-06-01

We present quantitative data on the hindlimb musculature of Pan paniscus, Gorilla gorilla gorilla, Gorilla gorilla graueri, Pongo pygmaeus abelii and Hylobates lar and discuss the findings in relation to the locomotor habits of each. Muscle mass and fascicle length data were obtained for all major hindlimb muscles. Physiological cross-sectional area (PCSA) was estimated. Data were normalized assuming geometric similarity to allow for comparison of animals of different size/species. Muscle mass scaled closely to (body mass)(1.0) and fascicle length scaled closely to (body mass)(0.3) in most species. However, human hindlimb muscles were heavy and had short fascicles per unit body mass when compared with non-human apes. Gibbon hindlimb anatomy shared some features with human hindlimbs that were not observed in the non-human great apes: limb circumferences tapered from proximal-to-distal, fascicle lengths were short per unit body mass and tendons were relatively long. Non-human great ape hindlimb muscles were, by contrast, characterized by long fascicles arranged in parallel, with little/no tendon of insertion. Such an arrangement of muscle architecture would be useful for locomotion in a three dimensionally complex arboreal environment.

Leg muscle mass and composition in relation to lower extremity performance in men and women aged 70 to 79 : the health, aging and body composition study

NARCIS (Netherlands)

Visser, Marjolein; Kritchevsky, Stephen B; Goodpaster, Bret H; Newman, Anne B; Nevitt, Michael; Stamm, Elizabeth; Harris, Tamara B

OBJECTIVES: The loss of muscle mass with aging, or sarcopenia, is hypothesized to be associated with the deterioration of physical function. Our aim was to determine whether low leg muscle mass and greater fat infiltration in the muscle were associated with poor lower extremity performance (LEP).

Body mass in comparative primatology.

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Smith, R J; Jungers, W L

1997-06-01

Data are presented on adult body mass for 230 of 249 primate species, based on a review of the literature and previously unpublished data. The issues involved in collecting data on adult body mass are discussed, including the definition of adults, the effects of habitat and pregnancy, the strategy for pooling data on single species from multiple studies, and use of an appropriate number of significant figures. An analysis of variability in body mass indicates that the coefficient of variation for body mass increases with increasing species mean mass. Evaluation of several previous body mass reviews reveals a number of shortcomings with data that have been used often in comparative studies.

Skeletal Muscle Regeneration, Repair and Remodelling in Aging: The Importance of Muscle Stem Cells and Vascularization.

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Joanisse, Sophie; Nederveen, Joshua P; Snijders, Tim; McKay, Bryon R; Parise, Gianni

2017-01-01

Sarcopenia is the age-related loss of skeletal muscle mass and strength. Ultimately, sarcopenia results in the loss of independence, which imposes a large financial burden on healthcare systems worldwide. A critical facet of sarcopenia is the diminished ability for aged muscle to regenerate, repair and remodel. Over the years, research has focused on elucidating underlying mechanisms of sarcopenia and the impaired ability of muscle to respond to stimuli with aging. Muscle-specific stem cells, termed satellite cells (SC), play an important role in maintaining muscle health throughout the lifespan. It is well established that SC are essential in skeletal muscle regeneration, and it has been hypothesized that a reduction and/or dysregulation of the SC pool, may contribute to accelerated loss of skeletal muscle mass that is observed with advancing age. The preservation of skeletal muscle tissue and its ability to respond to stimuli may be impacted by reduced SC content and impaired function observed with aging. Aging is also associated with a reduction in capillarization of skeletal muscle. We have recently demonstrated that the distance between type II fibre-associated SC and capillaries is greater in older compared to younger adults. The greater distance between SC and capillaries in older adults may contribute to the dysregulation in SC activation ultimately impairing muscle's ability to remodel and, in extreme circumstances, regenerate. This viewpoint will highlight the importance of optimal SC activation in addition to skeletal muscle capillarization to maximize the regenerative potential of skeletal muscle in older adults. © 2016 S. Karger AG, Basel.

Initial Presentation of Renal Cell Carcinoma as a Metastatic Mass within the Masseter Muscle: A Case Report and Literature Review

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Bae, Kyung Eun; Lee, Han Bee; Cho, Woo Ho; Kim, Jae Hyung; Lee, Ji Hae; Kang, Min Jin [Dept. of Radiology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of); Kim, Hyun Jung [Dept. of Pathology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of)

2012-02-15

Renal cell carcinoma (RCC) is often concomitant with distant metastasis, and these metastases are the first sign of an otherwise occult primary. Whereas metastasis of RCC to the head and neck has been reported, metastasis to the masseter muscle, which is composed of skeletal muscle, is quite rare. We now report the case of a 66-year-old man who had a past history of pulmonary tuberculosis, with RCC metastasis of a well-defined intensely enhancing hypervascular mass in the masseter muscle as the initial presentation. We present the imaging findings of this case and a literature review about radiologic differential diagnosis of intramasseteric masses.

Comparative proteomic profiling of soleus, extensor digitorum longus, flexor digitorum brevis and interosseus muscles from the mdx mouse model of Duchenne muscular dystrophy.

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Carberry, Steven; Brinkmeier, Heinrich; Zhang, Yaxin; Winkler, Claudia K; Ohlendieck, Kay

2013-09-01

Duchenne muscular dystrophy is due to genetic abnormalities in the dystrophin gene and represents one of the most frequent genetic childhood diseases. In the X-linked muscular dystrophy (mdx) mouse model of dystrophinopathy, different subtypes of skeletal muscles are affected to a varying degree albeit the same single base substitution within exon 23 of the dystrophin gene. Thus, to determine potential muscle subtype-specific differences in secondary alterations due to a deficiency in dystrophin, in this study, we carried out a comparative histological and proteomic survey of mdx muscles. We intentionally included the skeletal muscles that are often used for studying the pathomechanism of muscular dystrophy. Histological examinations revealed a significantly higher degree of central nucleation in the soleus and extensor digitorum longus muscles compared with the flexor digitorum brevis and interosseus muscles. Muscular hypertrophy of 20-25% was likewise only observed in the soleus and extensor digitorum longus muscles from mdx mice, but not in the flexor digitorum brevis and interosseus muscles. For proteomic analysis, muscle protein extracts were separated by fluorescence two-dimensional (2D) gel electrophoresis. Proteins with a significant change in their expression were identified by mass spectrometry. Proteomic profiling established an altered abundance of 24, 17, 19 and 5 protein species in the dystrophin-deficient soleus, extensor digitorum longus, flexor digitorum brevis and interosseus muscle, respectively. The key proteomic findings were verified by immunoblot analysis. The identified proteins are involved in the contraction-relaxation cycle, metabolite transport, muscle metabolism and the cellular stress response. Thus, histological and proteomic profiling of muscle subtypes from mdx mice indicated that distinct skeletal muscles are differentially affected by the loss of the membrane cytoskeletal protein, dystrophin. Varying degrees of perturbed protein

Exercise quantity-dependent muscle hypertrophy in adult zebrafish (Danio rerio).

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Hasumura, Takahiro; Meguro, Shinichi

2016-07-01

Exercise is very important for maintaining and increasing skeletal muscle mass, and is particularly important to prevent and care for sarcopenia and muscle disuse atrophy. However, the dose-response relationship between exercise quantity, duration/day, and overall duration and muscle mass is poorly understood. Therefore, we investigated the effect of exercise duration on skeletal muscle to reveal the relationship between exercise quantity and muscle hypertrophy in zebrafish forced to exercise. Adult male zebrafish were exercised 6 h/day for 4 weeks, 6 h/day for 2 weeks, or 3 h/day for 2 weeks. Flow velocity was adjusted to maximum velocity during continual swimming (initial 43 cm/s). High-speed consecutive photographs revealed that zebrafish mainly drove the caudal part. Additionally, X-ray micro computed tomography measurements indicated muscle hypertrophy of the mid-caudal half compared with the mid-cranial half part. The cross-sectional analysis of the mid-caudal half muscle revealed that skeletal muscle (red, white, or total) mass increased with increasing exercise quantity, whereas that of white muscle and total muscle increased only under the maximum exercise load condition of 6 h/day for 4 weeks. Additionally, the muscle fiver size distributions of exercised fish were larger than those from non-exercised fish. We revealed that exercise quantity, duration/day, and overall duration were correlated with skeletal muscle hypertrophy. The forced exercise model enabled us to investigate the relationship between exercise quantity and skeletal muscle mass. These results open up the possibility for further investigations on the effects of exercise on skeletal muscle in adult zebrafish.

Mechanisms of cisplatin-induced muscle atrophy

International Nuclear Information System (INIS)

Sakai, Hiroyasu; Sagara, Atsunobu; Arakawa, Kazuhiko; Sugiyama, Ryoto; Hirosaki, Akiko; Takase, Kazuhide; Jo, Ara; Sato, Ken; Chiba, Yoshihiko; Yamazaki, Mitsuaki; Matoba, Motohiro; Narita, Minoru

2014-01-01

Fatigue is the most common side effect of chemotherapy. However, the mechanisms of “muscle fatigue” induced by anti-cancer drugs are not fully understood. We therefore investigated the muscle-atrophic effect of cisplatin, a platinum-based anti-cancer drug, in mice. C57BL/6J mice were treated with cisplatin (3 mg/kg, i.p.) or saline for 4 consecutive days. On Day 5, hindlimb and quadriceps muscles were isolated from mice. The loss of body weight and food intake under the administration of cisplatin was the same as those in a dietary restriction (DR) group. Under the present conditions, the administration of cisplatin significantly decreased not only the muscle mass of the hindlimb and quadriceps but also the myofiber diameter, compared to those in the DR group. The mRNA expression levels of muscle atrophy F-box (MAFbx), muscle RING finger-1 (MuRF1) and forkhead box O3 (FOXO3) were significantly and further increased by cisplatin treated group, compared to DR. Furthermore, the mRNA levels of myostatin and p21 were significantly upregulated by the administration of cisplatin, compared to DR. On the other hand, the phosphorylation of Akt and FOXO3a, which leads to the blockade of the upregulation of MuRF1 and MAFbx, was significantly and dramatically decreased by cisplatin. These findings suggest that the administration of cisplatin increases atrophic gene expression, and may lead to an imbalance between protein synthesis and protein degradation pathways, which would lead to muscle atrophy. This phenomenon could, at least in part, explain the mechanism of cisplatin-induced muscle fatigue. - Highlights: • Cisplatin decreased mass and myofiber diameter in quadriceps muscle. • The mRNA of MAFbx, MuRF1 and FOXO3 were increased by the cisplatin. • The mRNA of myostatin and p21 were upregulated by cisplatin. • The phosphorylation of Akt and FOXO3a was decreased by cisplatin

Mechanisms of cisplatin-induced muscle atrophy

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Sakai, Hiroyasu, E-mail: sakai@hoshi.ac.jp [Department of Pharmacology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Division of Pharmacy Professional Development and Research, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Sagara, Atsunobu; Arakawa, Kazuhiko; Sugiyama, Ryoto; Hirosaki, Akiko; Takase, Kazuhide; Jo, Ara [Department of Pharmacology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Sato, Ken [Department of Pharmacology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Division of Pharmacy Professional Development and Research, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Chiba, Yoshihiko [Department of Biology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Yamazaki, Mitsuaki [Department of Anesthesiology, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, 2630 Sugitani, Toyama-shi, Toyama 9300194 (Japan); Matoba, Motohiro [Department of Palliative Medicine and Psychooncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 1040045 (Japan); Narita, Minoru, E-mail: narita@hoshi.ac.jp [Department of Pharmacology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan)

2014-07-15

Fatigue is the most common side effect of chemotherapy. However, the mechanisms of “muscle fatigue” induced by anti-cancer drugs are not fully understood. We therefore investigated the muscle-atrophic effect of cisplatin, a platinum-based anti-cancer drug, in mice. C57BL/6J mice were treated with cisplatin (3 mg/kg, i.p.) or saline for 4 consecutive days. On Day 5, hindlimb and quadriceps muscles were isolated from mice. The loss of body weight and food intake under the administration of cisplatin was the same as those in a dietary restriction (DR) group. Under the present conditions, the administration of cisplatin significantly decreased not only the muscle mass of the hindlimb and quadriceps but also the myofiber diameter, compared to those in the DR group. The mRNA expression levels of muscle atrophy F-box (MAFbx), muscle RING finger-1 (MuRF1) and forkhead box O3 (FOXO3) were significantly and further increased by cisplatin treated group, compared to DR. Furthermore, the mRNA levels of myostatin and p21 were significantly upregulated by the administration of cisplatin, compared to DR. On the other hand, the phosphorylation of Akt and FOXO3a, which leads to the blockade of the upregulation of MuRF1 and MAFbx, was significantly and dramatically decreased by cisplatin. These findings suggest that the administration of cisplatin increases atrophic gene expression, and may lead to an imbalance between protein synthesis and protein degradation pathways, which would lead to muscle atrophy. This phenomenon could, at least in part, explain the mechanism of cisplatin-induced muscle fatigue. - Highlights: • Cisplatin decreased mass and myofiber diameter in quadriceps muscle. • The mRNA of MAFbx, MuRF1 and FOXO3 were increased by the cisplatin. • The mRNA of myostatin and p21 were upregulated by cisplatin. • The phosphorylation of Akt and FOXO3a was decreased by cisplatin.

Ratio of muscle mass to fat mass assessed by bioelectrical impedance analysis is significantly correlated with liver fat accumulation in patients with type 2 diabetes mellitus.

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Kurinami, Noboru; Sugiyama, Seigo; Morita, Ayami; Yoshida, Akira; Hieshima, Kunio; Miyamoto, Fumio; Kajiwara, Keizo; Jinnouch, Katsunori; Jinnouchi, Tomio; Jinnouchi, Hideaki

2018-05-01

Obesity and ectopic fat accumulation are important conditions of type 2 diabetes mellitus (T2DM). Our aim was to determine whether bioelectrical impedance body composition analysis combined with blood test results could estimate liver ectopic fat accumulation in patients with treatment-naïve T2DM. Subjects were 119 untreated T2DM patients. Computed tomography scans were performed to calculate the liver to spleen attenuation ratio (L/S ratio) as a measure of liver fat accumulation, with excess liver fat accumulation defined as an L/S ratio analysis using InBody770. The Nagelkerke R 2 test showed that the muscle mass/fat mass ratio (muscle/fat ratio) was the most suitable variable among anthropometric factors and body component indexes for estimating liver fat accumulation. The muscle/fat ratio was significantly correlated with the L/S ratio (ρ = 0.4386, P analysis showed that the muscle/fat ratio (odds ratio 0.40, 95% confidence interval 0.22-0.73, P ratio 1.06, 95% confidence interval 1.02-1.10, P analysis, the cutoff value of the muscle/fat ratio for excess liver fat accumulation was 2.34. In patients with treatment-naïve T2DM, the muscle/fat ratio and ALT are useful for estimating the presence of excess liver fat accumulation in daily clinical practice. Copyright © 2018. Published by Elsevier B.V.

Effect of strength training and short-term detraining on muscle mass in women aged over 50 years old

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Maryam Delshad

2013-01-01

Full Text Available Background: The loss of muscle mass is associated with aging. The aim of this study was to determine the effects of resistance training and detraining on muscle mass in elderly women. Methods: Twenty post-menopausal women aged ≥50 years old were enrolled. Matching for age, they were randomly assigned into control and resistance training group (RT. The intervention consisted of three sets of 10 repetitions for 10 movements with Thera-Band tubing (based on 80-100% 10-RM, three times a week, for 12 weeks and thereafter, four weeks detraining. Skinfold thickness was determined by caliper. Percentage of body fat was estimated from skinfold thickness (triceps and subscapular by McArdle method. Fat mass (FM and fat-free mass (FFM were calculated. Range of motion for trunk flexion and extension was determined. Results: During 12 weeks of intervention, significant increases were observed in 1-RM of biceps curl, FFM, trunk flexion and extension and significant decreases during four weeks detraining in RT group. The RT group demonstrated significant decreases during resistance training and increases during detraining in skinfold thickness. FFM, trunk flexion, and extension decreased and skinfold thickness, %FM, and weight of body fat increased in the control group (P < 0.05. Conclusions: Resistance training with Thera-Band enhanced strength and muscle endurance in elderly women and a 4-week detraining period had an adverse effect on muscle power. This suggests that a strength training program is an effective intervention to prevent functional reductions, and can contribute to improve neuromuscular function in older adults.

Jaw-muscle fiber architecture in tufted capuchins favors generating relatively large muscle forces without compromising jaw gape

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Taylor, Andrea B.; Vinyard, Christopher J.

2009-01-01

Cebus apella is renowned for its dietary flexibility and capacity to exploit hard and tough objects. Cebus apella differs from other capuchins in displaying a suite of craniodental features that have been functionally and adaptively linked to their feeding behavior, particularly the generation and dissipation of relatively large jaw forces. We compared fiber architecture of the masseter and temporalis muscles between the tufted capuchin (C. apella; n = 12 ) and two “untufted” capuchins (C. capuchinus, n = 3; C. albifrons, n = 5). These three species share broadly similar diets, but tufted capuchins occasionally exploit mechanically challenging tissues. We tested the hypothesis that C. apella exhibits architectural properties of their jaw muscles that facilitate relatively large forces, including relatively greater physiologic cross-sectional areas (PCSA), more pinnate fibers, and lower ratios of mass to tetanic tension (Mass/P0). Results show some evidence supporting these predictions, as C. apella has relatively greater superficial masseter, whole masseter, and temporalis PCSAs, significantly so only for the temporalis following Bonferroni adjustment. Capuchins did not differ in pinnation angle or Mass/P0. As an architectural trade-off between maximizing muscle force and muscle excursion/contraction velocity, we also tested the hypothesis that C. apella exhibits relatively shorter muscle fibers. Contrary to our prediction, there are no significant differences in relative fiber lengths between tufted and untufted capuchins. Therefore, we attribute the relatively greater PCSAs in C. apella primarily to their larger muscle masses. These findings suggest that relatively large jaw-muscle PCSAs can be added to the suite of masticatory features that have been functionally linked to the exploitation of a more resistant diet by C. apella. By enlarging jaw-muscle mass to increase PCSA, rather than reducing fiber lengths and increasing pinnation, tufted capuchins appear

The Association between Total Protein and Vegetable Protein Intake and Low Muscle Mass among the Community-Dwelling Elderly Population in Northern Taiwan

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Ru-Yi Huang

2016-06-01

Full Text Available Sarcopenia, highly linked with fall, frailty, and disease burden, is an emerging problem in aging society. Higher protein intake has been suggested to maintain nitrogen balance. Our objective was to investigate whether pre-sarcopenia status was associated with lower protein intake. A total of 327 community-dwelling elderly people were recruited for a cross-sectional study. We adopted the multivariate nutrient density model to identify associations between low muscle mass and dietary protein intake. The general linear regression models were applied to estimate skeletal muscle mass index across the quartiles of total protein and vegetable protein density. Participants with diets in the lowest quartile of total protein density (<13.2% were at a higher risk for low muscle mass (odds ratio (OR 3.03, 95% confidence interval (CI 1.37–6.72 than those with diets in the highest quartile (≥17.2%. Similarly, participants with diets in the lowest quartile of vegetable protein density (<5.8% were at a higher risk for low muscle mass (OR 2.34, 95% CI 1.14–4.83 than those with diets in the highest quartile (≥9.4%. Furthermore, the estimated skeletal muscle mass index increased significantly across the quartiles of total protein density (p = 0.023 and vegetable protein density (p = 0.025. Increasing daily intakes of total protein and vegetable protein densities appears to confer protection against pre-sarcopenia status.

Linear pneumatic motors – a comparative study

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Deaconescu Tudor

2017-01-01

Full Text Available The paper presents a comparative study of the performance of single-acting cylinders, diaphragm cylinders and pneumatic muscles, and offers users information that allows the selection of an optimum technical solution. Such a study was necessary, in view of the numerous papers on pneumatic muscle applications found in literature, that assert the superiority of pneumatic muscles over other pneumatic linear motors in relation to quantities like dimensions, mass, developed force or energy-to-mass ratios, however without offering concrete data.

Muscle fibre type composition and body composition in hammer throwers.

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Terzis, Gerasimos; Spengos, Konstantinos; Kavouras, Stavros; Manta, Panagiota; Georgiadis, Giorgos

2010-01-01

Aim of the present study was to describe the muscle fibre type composition and body composition of well-trained hammer throwers. Six experienced hammer throwers underwent the following measurements: one repetition maximum in squat, snatch, and clean, standing broad jump, backward overhead shot throw and the hammer throw. Dual x-ray absorptiometry was used for body composition analysis. Fibre type composition and cross sectional area was determined in muscle biopsy samples of the right vastus lateralis. Eight physical education students served as a control group. One repetition maximum in squat, snatch and clean for the hammer throwers was 245 ± 21, 132 ± 13 and 165 ± 12kg, respectively. Lean body mass was higher in hammer throwers (85.9 ± 3. 9kg vs. 62.7 ± 5.1kg (p hammer throwers and 51 ± 8% in the control group (p Hammer throwers had significantly larger type IIA fibres (7703 ± 1171 vs. 5676 ± 1270μm(2), p Hammer throwing performance correlated significantly with lean body mass (r = 0.81, p hammer throwers have larger lean body mass and larger muscular areas occupied by type II fibres, compared with relatively untrained subjects. Moreover, it seems that the enlarged muscle mass of the hammer throwers contributes significantly to the hammer throwing performance. Key pointsWell-trained hammer throwers had increased lean body mass, higher type IIA muscle fibres cross sectional areas, as well as higher bone mineral density, compared to controls.Increased lean body mass was closely related with hammer throwing performance.The relative high percentage of type IIX muscle fibres in vastus lateralis in hammer throwers warrants further investigation.

Quantitative analysis of veterinary drugs in bovine muscle and milk by liquid chromatography quadrupole time-of-flight mass spectrometry.

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Saito-Shida, Shizuka; Sakai, Takatoshi; Nemoto, Satoru; Akiyama, Hiroshi

2017-07-01

A simple and reliable multiresidue method for quantitative determination of veterinary drugs in bovine muscle and milk using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) was developed. Critical MS parameters such as capillary voltage, cone voltage, collision energy, desolvation gas temperature and extraction mass window were carefully optimised to obtain the best possible sensitivity. Analytical samples were prepared using extraction with acetonitrile and hexane in the presence of anhydrous sodium sulphate and acetic acid, followed by ODS cartridge clean-up. The developed method was validated for 82 veterinary drugs in bovine muscle and milk at spike levels of 0.01 and 0.1 mg kg - 1 . With the exception of cefoperazone and phenoxymethylpenicillin, all these compounds exhibited sufficient signal intensity at 0.01 μg ml -1 (equivalent to 0.01 mg kg - 1 ), indicating the high sensitivity of the developed method. For most targets, the determined accuracies were within 70-120%, with repeatability and reproducibility being below 20% at both levels. Except for sulfathiazole in bovine muscle, no interfering peaks at target compound retention times were detected in the blank extract, indicating that the developed method is highly selective. The absence of sulfathiazole in bovine muscle was confirmed by simultaneous acquisition at low and high collision energies to afford exact masses of molecular adduct and fragment ions. Satisfactory linearity was observed for all compounds, with matrix effects being negligible for most targets in bovine muscle and milk at both spike levels. Overall, the results suggest that the developed LC-QTOF-MS method is suitable for routine regulatory-purpose analysis of veterinary drugs in bovine muscle and milk.

Usefulness of circuit training at home for improving bone mass and muscle mass while losing fat mass in undergraduate female students.

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Takahata, Yoko

2018-05-09

The purpose of this study was to determine whether or not circuit training at home affects the calcaneus quantitative ultrasound status as well as other indices of body composition among undergraduate female students. Forty-one adolescents were recruited (18.5 ± 0.6 years old). The stiffness index of the calcaneus, broadband ultrasound attenuation of the calcaneus, speed of sound of the calcaneus, and body frame index. This was a three-month intervention study, so the measurements were conducted at baseline, 2 months later, and 3 months later while the subjects underwent circuit training at home. The subjects were divided into two groups: namely, the exercising group and non-exercising group. In the exercising group, broadband ultrasound attenuation of the calcaneus was higher 2 months later (p = 0.033) as well as 3 months later (p = 0.036), and the speed of sound of the calcaneus was higher 3 months later (p = 0.018). In addition, the muscle mass was strongly positively correlated with the calcaneus QUS-SOS (p = 0.004), while the body fat percentage was a strongly negatively correlated with the calcaneus QUS-BUA (p = 0.043). In the non-exercising group, the stiffness index of the calcaneus was higher 2 months later (p = 0.002) as well as 3 months later (p = 0.002). Furthermore, the body percentage was strongly positively correlated with the calcaneus QUS-SI (p = 0.009). These findings suggest that the calcaneus quantitative ultrasound status and muscle mass while losing fat mass may be improved by means of a simple exercise regimen within a short period among undergraduate female students.

Ratio of Dietary n-6/n-3 Polyunsaturated Fatty Acids Independently Related to Muscle Mass Decline in Hemodialysis Patients.

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Te-Chih Wong

Full Text Available n-3 polyunsaturated fatty acids (PUFAs might be useful nutritional strategy for treating patients with sarcopenia. We evaluated the effect of the intake of dietary n-3 PUFAs on the skeletal muscle mass (SMM, appendicular skeletal muscle mass (ASM, and its determinants in patients receiving standard hemodialysis (HD treatment for the management of end stage renal disease.In this cross-sectional study, data of 111 HD patients were analyzed. Anthropometric and bioelectrical impedance measurements used to estimate the muscle mass were performed the day of dialysis immediately after the dialysis session. Routine laboratory and 3-day dietary data were also collected. The cutoff value of adequate intake (AI for both n-3 PUFAs and alpha-linolenic acid (ALA was 1.6 g/day and 1.1 g/day for men and women, respectively.The mean age, mean dietary n-3 PUFAs intake, ALA intake, ratio of n-6/n-3 PUFAs intake, SMM, and ASM of patients were 61.4 ± 10.4 years, 2.0 ± 1.3 g/day, 1.5 ± 1.0 g/day, 9.5 ± 6.7 g/day, 23.9 ± 5.5 kg, and 17.5 ± 4.5 kg, respectively. A higher SMM and ASM significantly observed in patients who achieved an AI of n-3 PUFAs. Similar trends appeared to be observed among those patients who achieved the AI of ALA, but the difference was not significantly, except for ASM (P = 0.047. No relevant differences in demographics, laboratory and nutritional parameters were observed, regardless of whether the patients achieved an AI of n-3 PUFAs. Multivariate analysis showed that the BMI and equilibrated Kt/V were independent determinants of the muscle mass. Moreover, the ratio of n-6/n-3 PUFAs was an independent risk determinant of reduced ASM in HD patients.Patients with an AI of n-3 PUFAs had better total-body SMM and ASM. A higher dietary ratio of n-6/n-3 PUFAs seemed to be associated with a reduced muscle mass in HD patients.

Ratio of Dietary n-6/n-3 Polyunsaturated Fatty Acids Independently Related to Muscle Mass Decline in Hemodialysis Patients.

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Wong, Te-Chih; Chen, Yu-Tong; Wu, Pei-Yu; Chen, Tzen-Wen; Chen, Hsi-Hsien; Chen, Tso-Hsiao; Yang, Shwu-Huey

2015-01-01

n-3 polyunsaturated fatty acids (PUFAs) might be useful nutritional strategy for treating patients with sarcopenia. We evaluated the effect of the intake of dietary n-3 PUFAs on the skeletal muscle mass (SMM), appendicular skeletal muscle mass (ASM), and its determinants in patients receiving standard hemodialysis (HD) treatment for the management of end stage renal disease. In this cross-sectional study, data of 111 HD patients were analyzed. Anthropometric and bioelectrical impedance measurements used to estimate the muscle mass were performed the day of dialysis immediately after the dialysis session. Routine laboratory and 3-day dietary data were also collected. The cutoff value of adequate intake (AI) for both n-3 PUFAs and alpha-linolenic acid (ALA) was 1.6 g/day and 1.1 g/day for men and women, respectively. The mean age, mean dietary n-3 PUFAs intake, ALA intake, ratio of n-6/n-3 PUFAs intake, SMM, and ASM of patients were 61.4 ± 10.4 years, 2.0 ± 1.3 g/day, 1.5 ± 1.0 g/day, 9.5 ± 6.7 g/day, 23.9 ± 5.5 kg, and 17.5 ± 4.5 kg, respectively. A higher SMM and ASM significantly observed in patients who achieved an AI of n-3 PUFAs. Similar trends appeared to be observed among those patients who achieved the AI of ALA, but the difference was not significantly, except for ASM (P = 0.047). No relevant differences in demographics, laboratory and nutritional parameters were observed, regardless of whether the patients achieved an AI of n-3 PUFAs. Multivariate analysis showed that the BMI and equilibrated Kt/V were independent determinants of the muscle mass. Moreover, the ratio of n-6/n-3 PUFAs was an independent risk determinant of reduced ASM in HD patients. Patients with an AI of n-3 PUFAs had better total-body SMM and ASM. A higher dietary ratio of n-6/n-3 PUFAs seemed to be associated with a reduced muscle mass in HD patients.

Integrative Analyses of miRNA-mRNA Interactions Reveal let-7b, miR-128 and MAPK Pathway Involvement in Muscle Mass Loss in Sex-Linked Dwarf Chickens

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Luo, Wen; Lin, Shumao; Li, Guihuan; Nie, Qinghua; Zhang, Xiquan

2016-01-01

The sex-linked dwarf (SLD) chicken is an ideal model system for understanding growth hormone (GH)-action and growth hormone receptor (GHR) function because of its recessive mutation in the GHR gene. Skeletal muscle mass is reduced in the SLD chicken with a smaller muscle fiber diameter. Our previous study has presented the mRNA and miRNA expression profiles of the SLD chicken and normal chicken between embryo day 14 and seven weeks of age. However, the molecular mechanism of GHR-deficient induced muscle mass loss is still unclear, and the key molecules and pathways underlying the GHR-deficient induced muscle mass loss also remain to be illustrated. Here, by functional network analysis of the differentially expressed miRNAs and mRNAs between the SLD and normal chickens, we revealed that let-7b, miR-128 and the MAPK pathway might play key roles in the GHR-deficient induced muscle mass loss, and that the reduced cell division and growth are potential cellular processes during the SLD chicken skeletal muscle development. Additionally, we also found some genes and miRNAs involved in chicken skeletal muscle development, through the MAPK, PI3K-Akt, Wnt and Insulin signaling pathways. This study provides new insights into the molecular mechanism underlying muscle mass loss in the SLD chickens, and some regulatory networks that are crucial for chicken skeletal muscle development. PMID:26927061

Age- and gender-dependent values of skeletal muscle mass in healthy children and adolescents

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Webber, Colin E.; Barr, Ronald D.

2011-01-01

Background Skeletal muscle mass (SMM) can be extracted from whole-body scans obtained by X-ray-based dual-photon absorptiometry (DXA). There is a need to establish expected age-dependent values for children and adolescents. Methods Appendicular lean tissue mass (ALM) was extracted from whole-body DXA scans in 140 healthy children and adolescents (68 females and 72 males). Whole-body SMM was calculated from ALM using equations developed by Kim et al. (Am J Clin Nutr 84:1014–1020, 2006). Age-de...

Comparisons of predictive values of sarcopenia with different muscle mass indices in Korean rural older adults: a longitudinal analysis of the Aging Study of PyeongChang Rural Area

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Jang IY

2018-01-01

Full Text Available Il-Young Jang,1,2,* Hee-Won Jung,3,4,* Chang Ki Lee,5 Sang Soo Yu,2 Young Soo Lee,1 Eunju Lee1 1Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 2PyeongChang Health Center & County Hospital, Gangwon-Do, 3Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST, Daejeon, 4Geriatric Center, Seoul National University Bundang Hospital, Gyeonggi-Do, 5Goldman Urology Clinic, Seoul, Republic of Korea *These authors contributed equally to this work Purpose: It is important to define lean muscle mass when diagnosing sarcopenia, but there is still controversy on the clinical implication of sarcopenia derived by height, weight, and body mass index (BMI adjusted muscle mass indices. We aimed to evaluate the longitudinal clinical relevance of 3 sarcopenia definitions in the Korean population. Patients and methods: We conducted comprehensive geriatric assessments for 1,379 community-dwelling older participants in the Aging Study of PyeongChang Rural Area (ASPRA cohort and followed them up prospectively for death, institutionalization, and disability every 3 months. Sarcopenia was defined using the Asian Working Group consensus algorithm, combining grip strength, gait speed, and muscle mass.Results: Among 1,343 participants (mean age: 76 years, 741 women analyzed, there were 29 deaths and 89 institutionalizations during 22.0 ± 8.3 months follow-up (mean ± SD. All three muscle indices correlated to age and sex. All sarcopenia criteria with muscle mass indices of height, weight, and body mass index (BMI adjustment significantly predicted death or institutionalization. However, when adjusted for age and sex, only the sarcopenia criteria with muscle mass index of height adjustment were significantly associated with major adverse health outcomes.Conclusion: Adjusting age and gender, the sarcopenia definition from the quintile-based muscle index of height

Comparative Analyses between Skeletal Muscle miRNAomes from Large White and Min Pigs Revealed MicroRNAs Associated with Postnatal Muscle Hypertrophy.

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Sheng, Xihui; Wang, Ligang; Ni, Hemin; Wang, Lixian; Qi, Xiaolong; Xing, Shuhan; Guo, Yong

2016-01-01

The molecular mechanism regulated by microRNAs (miRNAs) that underlies postnatal hypertrophy of skeletal muscle is complex and remains unclear. Here, the miRNAomes of longissimus dorsi muscle collected at five postnatal stages (60, 120, 150, 180, and 210 days after birth) from Large White (commercial breed) and Min pigs (indigenous breed of China) were analyzed by Illumina sequencing. We identified 734 miRNAs comprising 308 annotated miRNAs and 426 novel miRNAs, of which 307 could be considered pig-specific. Comparative analysis between two breeds suggested that 60 and 120 days after birth were important stages for skeletal muscle hypertrophy and intramuscular fat accumulation. A total of 263 miRNAs were significantly differentially expressed between two breeds at one or more developmental stages. In addition, the differentially expressed miRNAs between every two adjacent developmental stages in each breed were determined. Notably, ssc-miR-204 was significantly more highly expressed in Min pig skeletal muscle at all postnatal stages compared with its expression in Large White pig skeletal muscle. Based on gene ontology and KEGG pathway analyses of its predicted target genes, we concluded that ssc-miR-204 may exert an impact on postnatal hypertrophy of skeletal muscle by regulating myoblast proliferation. The results of this study will help in elucidating the mechanism underlying postnatal hypertrophy of skeletal muscle modulated by miRNAs, which could provide valuable information for improvement of pork quality and human myopathy.

Effect of experimental hyperthyroidism on protein turnover in skeletal and cardiac muscle.

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Carter, W J; Van Der Weijden Benjamin, W S; Faas, F H

1980-10-01

Since experimental hyperthyroidism reduces skeletal muscle mass while simultaneously increasing cardiac muscle mass, the effect of hyperthyroidism on muscle protein degradation was compared in skeletal and cardiac muscle. Pulse-labeling studies using (3H) leucine and (14C) carboxyl labeled aspartate and glutamate were carried out. Hyperthyroidism caused a 25%-29% increase in protein breakdown in both sarcoplasmic and myofibrillar fractions of skeletal muscle. Increased muscle protein degradation may be a major factor in the development of skeletal muscle wasting and weakness in hyperthyroidism. In contrast, protein breakdown appeared to be reduced 22% in the sarcoplasmic fraction of hyperthyroid heart muscle and was unchanged in the myofibrillar fraction. Possible reasons for the contrasting effects of hyperthyroidism on skeletal and cardiac muscle include increased sensitivity of the hyperthyroid heart to catecholamines, increased cardiac work caused by the hemodynamic effects of hyperthyroidism, and a different direct effect of thyroid hormone at the nuclear level in cardiac as opposed to skeletal muscle.

Role of protein and amino acids in promoting lean mass accretion with resistance exercise and attenuating lean mass loss during energy deficit in humans.

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Churchward-Venne, Tyler A; Murphy, Caoileann H; Longland, Thomas M; Phillips, Stuart M

2013-08-01

Amino acids are major nutrient regulators of muscle protein turnover. After protein ingestion, hyperaminoacidemia stimulates increased rates of skeletal muscle protein synthesis, suppresses muscle protein breakdown, and promotes net muscle protein accretion for several hours. These acute observations form the basis for strategized protein intake to promote lean mass accretion, or prevent lean mass loss over the long term. However, factors such as protein dose, protein source, and timing of intake are important in mediating the anabolic effects of amino acids on skeletal muscle and must be considered within the context of evaluating the reported efficacy of long-term studies investigating protein supplementation as part of a dietary strategy to promote lean mass accretion and/or prevent lean mass loss. Current research suggests that dietary protein supplementation can augment resistance exercise-mediated gains in skeletal muscle mass and strength and can preserve skeletal muscle mass during periods of diet-induced energy restriction. Perhaps less appreciated, protein supplementation can augment resistance training-mediated gains in skeletal muscle mass even in individuals habitually consuming 'adequate' (i.e., >0.8 g kg⁻¹ day⁻¹) protein. Additionally, overfeeding energy with moderate to high-protein intake (15-25 % protein or 1.8-3.0 g kg⁻¹ day⁻¹) is associated with lean, but not fat mass accretion, when compared to overfeeding energy with low protein intake (5 % protein or ~0.68 g kg⁻¹ day⁻¹). Amino acids represent primary nutrient regulators of skeletal muscle anabolism, capable of enhancing lean mass accretion with resistance exercise and attenuating the loss of lean mass during periods of energy deficit, although factors such as protein dose, protein source, and timing of intake are likely important in mediating these effects.

Molecular regulation of high muscle mass in developing Blonde d'Aquitaine cattle foetuses

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Isabelle Cassar-Malek

2017-10-01

Full Text Available The Blonde d'Aquitaine (BA is a French cattle breed with enhanced muscularity, partly attributable to a MSTN mutation. The BA m. Semitendinosus has a faster muscle fibre isoform phenotype comprising a higher proportion of fast type IIX fibres compared to age-matched Charolais (CH. To better understand the molecular network of modifications in BA compared to CH muscle, we assayed the transcriptomes of the m. Semitendinosus at 110, 180, 210 and 260 days postconception (dpc. We used a combination of differential expression (DE and regulatory impact factors (RIF to compare and contrast muscle gene expression between the breeds. Prominently developmentally regulated genes in both breeds reflected the replacement of embryonic myosin isoforms (MYL4, MYH3 with adult isoforms (MYH1 and the upregulation of mitochondrial metabolism (CKMT2, AGXT2L1 in preparation for birth. However, the transition to a fast, glycolytic muscle phenotype in the MSTN mutant BA is detectable through downregulation of various slow twitch subunits (TNNC1, MYH7, TPM3, CSRP3 beyond 210 dpc, and a small but consistent genome-wide reduction in mRNA encoding the mitoproteome. Across the breeds, NRIP2 is the regulatory gene possessing a network change most similar to that of MSTN.

An herbal medicine, Go-sha-jinki-gan (GJG, increases muscle weight in severe muscle dystrophy model mice

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Yusei Takemoto

2017-12-01

Full Text Available Go-sha-jinki-gan (GJG, a traditional Japanese herbal medicine has a clinical implication to alleviate age-related symptoms, especially in some motor disorders. However, the scientific evidence is limited, and there is a possibility to expand the medical application range of GJG. Using senescence-accelerated mice, our group showed that GJG exerted an effect to prevent sarcopenia, the aged-related loss of skeletal muscle. Because muscular dystrophy is characterized by a progressive loss of skeletal muscle, we examined the effects of GJG on a mouse model of muscular dystrophy. Using a newly established mouse model for Duchenne muscular dystrophy (DMD, DBA/2-mdx, we showed that GJG significantly increased the body and skeletal muscle weights in comparison to the control DBA/2-mdx mice, regardless of gender. The increased skeletal muscle mass resulted from an increment in the myofiber size, but not from the myofiber number. Both the skeletal muscle regenerative ability and the accumulation of fibrosis (the dystrophic pathology in GJG-fed DBA/2-mdx mice were comparable to those in control DBA/2-mdx mice, suggesting that the cellular target of GJG is myofibers, with no contribution from the muscle satellite cells neither in an direct nor in an indirect manner. Taken together, GJG increased the skeletal muscle mass in a mouse model of muscular dystrophy, in addition to our previously tested sarcopenia mouse model.

Comparative study of a muscle stiffness sensor and electromyography and mechanomyography under fatigue conditions.

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Han, Hyonyoung; Jo, Sungho; Kim, Jung

2015-07-01

This paper proposes the feasibility of a stiffness measurement for muscle contraction force estimation under muscle fatigue conditions. Bioelectric signals have been widely studied for the estimation of the contraction force for physical human-robot interactions, but the correlation between the biosignal and actual motion is decreased under fatigue conditions. Muscle stiffness could be a useful contraction force estimator under fatigue conditions because it measures the same physical quantity as the muscle contraction that generates the force. Electromyography (EMG), mechanomyography (MMG), and a piezoelectric resonance-based active muscle stiffness sensor were used to analyze the biceps brachii under isometric muscle fatigue conditions with reference force sensors at the end of the joint. Compared to EMG and MMG, the change in the stiffness signal was smaller (p fatigue condition changed fatigue conditions. This result indicates that the muscle stiffness signal is less sensitive to muscle fatigue than other biosignals. This investigation provides insights into methods of monitoring and compensating for muscle fatigue.

Development of the Muscle Appearance Satisfaction Scale: a self-report measure for the assessment of muscle dysmorphia symptoms.

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Mayville, Stephen B; Williamson, Donald A; White, Marney A; Netemeyer, Richard G; Drab, Danae L

2002-12-01

Muscle dysmorphia has recently been described as a variant of body dysmorphic disorder that involves an intense preoccupation with one's perceived lack of muscle size. Currently, no assessment measures specific to the cognitive, affective, and behavioral dimensions of the construct of muscle dysmorphia have been published. To address this need, the authors developed the Muscle Appearance Satisfaction Scale (MASS), a brief 19-item self-report measure for the assessment of muscle dysmorphia symptoms. Psychometric evaluation of the MASS across two samples of male weight lifting participants (total N = 372) revealed a stable five-factor structure. An evaluation of factor content resulted in the following factor labels: Bodybuilding Dependence, Muscle Checking, Substance Use, Injury, and Muscle Satisfaction. Internal consistency, test-retest reliability, and construct validity were established with the MASS total score and its subscales. The authors believe the MASS will be a useful measure for research and applied work relating to muscle dysmorphia.

Vitamin D and muscle trophicity.

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Domingues-Faria, Carla; Boirie, Yves; Walrand, Stéphane

2017-05-01

We review recent findings on the involvement of vitamin D in skeletal muscle trophicity. Vitamin D deficiencies are associated with reduced muscle mass and strength, and its supplementation seems effective to improve these parameters in vitamin D-deficient study participants. Latest investigations have also evidenced that vitamin D is essential in muscle development and repair. In particular, it modulates skeletal muscle cell proliferation and differentiation. However, discrepancies still exist about an enhancement or a decrease of muscle proliferation and differentiation by the vitamin D. Recently, it has been demonstrated that vitamin D influences skeletal muscle cell metabolism as it seems to regulate protein synthesis and mitochondrial function. Finally, apart from its genomic and nongenomic effects, recent investigations have demonstrated a genetic contribution of vitamin D to muscle functioning. Recent studies support the importance of vitamin D in muscle health, and the impact of its deficiency in regard to muscle mass and function. These 'trophic' properties are of particular importance for some specific populations such as elderly persons and athletes, and in situations of loss of muscle mass or function, particularly in the context of chronic diseases.

Congenital muscle dystrophy and diet consistency affect mouse skull shape differently.

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Spassov, Alexander; Toro-Ibacache, Viviana; Krautwald, Mirjam; Brinkmeier, Heinrich; Kupczik, Kornelius

2017-11-01

The bones of the mammalian skull respond plastically to changes in masticatory function. However, the extent to which muscle function affects the growth and development of the skull, whose regions have different maturity patterns, remains unclear. Using muscle dissection and 3D landmark-based geometric morphometrics we investigated the effect of changes in muscle function established either before or after weaning, on skull shape and muscle mass in adult mice. We compared temporalis and masseter mass and skull shape in mice with a congenital muscle dystrophy (mdx) and wild type (wt) mice fed on either a hard or a soft diet. We found that dystrophy and diet have distinct effects on the morphology of the skull and the masticatory muscles. Mdx mice show a flattened neurocranium with a more dorsally displaced foramen magnum and an anteriorly placed mandibular condyle compared with wt mice. Compared with hard diet mice, soft diet mice had lower masseter mass and a face with more gracile features as well as labially inclined incisors, suggesting reduced bite strength. Thus, while the early-maturing neurocranium and the posterior portion of the mandible are affected by the congenital dystrophy, the late-maturing face including the anterior part of the mandible responds to dietary differences irrespective of the mdx mutation. Our study confirms a hierarchical, tripartite organisation of the skull (comprising neurocranium, face and mandible) with a modular division based on development and function. Moreover, we provide further experimental evidence that masticatory loading is one of the main environmental stimuli that generate craniofacial variation. © 2017 Anatomical Society.

Comparative anatomy, evolution, and homologies of tetrapod hindlimb muscles, comparison with forelimb muscles, and deconstruction of the forelimb-hindlimb serial homology hypothesis.

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Diogo, Rui; Molnar, Julia

2014-06-01

For more than two centuries, the idea that the forelimb and hindlimb are serially homologous structures has been accepted without serious question. This study presents the first detailed analysis of the evolution and homologies of all hindlimb muscles in representatives of each major tetrapod group and proposes a unifying nomenclature for these muscles. These data are compared with information obtained previously about the forelimb muscles of tetrapods and the muscles of other gnathostomes in order to address one of the most central and enigmatic questions in evolutionary and comparative anatomy: why are the pelvic and pectoral appendages of gnathostomes generally so similar to each other? An integrative analysis of the new myological data, combined with a review of recent paleontological, developmental, and genetic works and of older studies, does not support serial homology between the structures of these appendages. For instance, many of the strikingly similar forelimb and hindlimb muscles found in each major extant tetrapod taxon were acquired at different geological times and/or have different embryonic origins. These similar muscles are not serial homologues, but the result of evolutionary parallelism/convergence due to a complex interplay of ontogenetic, functional, topological, and phylogenetic constraints/factors. Copyright © 2014 Wiley Periodicals, Inc.

Muscle wasting and resistance of muscle anabolism: the "anabolic threshold concept" for adapted nutritional strategies during sarcopenia.

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Dardevet, Dominique; Rémond, Didier; Peyron, Marie-Agnès; Papet, Isabelle; Savary-Auzeloux, Isabelle; Mosoni, Laurent

2012-01-01

Skeletal muscle loss is observed in several physiopathological situations. Strategies to prevent, slow down, or increase recovery of muscle have already been tested. Besides exercise, nutrition, and more particularly protein nutrition based on increased amino acid, leucine or the quality of protein intake has generated positive acute postprandial effect on muscle protein anabolism. However, on the long term, these nutritional strategies have often failed in improving muscle mass even if given for long periods of time in both humans and rodent models. Muscle mass loss situations have been often correlated to a resistance of muscle protein anabolism to food intake which may be explained by an increase of the anabolic threshold toward the stimulatory effect of amino acids. In this paper, we will emphasize how this anabolic resistance may affect the intensity and the duration of the muscle anabolic response at the postprandial state and how it may explain the negative results obtained on the long term in the prevention of muscle mass. Sarcopenia, the muscle mass loss observed during aging, has been chosen to illustrate this concept but it may be kept in mind that it could be extended to any other catabolic states or recovery situations.

Comparative morphology of the muscles of mastication in the giant panda and the Asiatic black bear.

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Endo, Hideki; Taru, Hajime; Yamamoto, Masako; Arishima, Kazuyoshi; Sasaki, Motoki

2003-06-01

The morphological differences in the muscles of mastication between the giant panda (Ailuropoda melanoleuca) and the Asiatic black bear (Ursus thibetanus) were sought to confirm the adaptational strategy of these muscles in the giant panda. We measured some skull characteristics and weighed the muscles of mastication, and macroscopically observed the muscles of mastication in the two species. The noticeable differences between the two species are classified as follows: (1) The size ratio of the zygomatic width was much larger in the giant panda than in the Asiatic black bear. (2) The weight ratio of the two pterygoid muscles was also much larger in the giant panda than in the Asiatic black bear. (3) The lateral slips of the temporal muscles are thicker and stronger in the Asiatic black bear than in the giant panda. (4) The deep layer of the masseter muscle was rostrocaudally divided, and a complicated running of tendons is observed in the giant panda. (5) The two pterygoid muscles were much larger and well-developed in the giant panda than in the Asiatic black bear. The points (1) and (4) may be related to the generation of the force necessary to chew the bamboo in the giant panda. We thought that the large mass of the masseter and temporal muscles are needed in this species. In the points of (2) and (5), the two pterygoid muscles were obviously different in form and weight ratio between the two species. We suggest that the two pterygoid muscles may act as an additional force generator to dorsoventrally press and crush bamboo stems.

Association between Thigh Muscle Volume and Leg Muscle Power in Older Women.

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Ulrich Lindemann

Full Text Available The construct of sarcopenia is still discussed with regard to best appropriate measures of muscle volume and muscle function. The aim of this post-hoc analysis of a cross-sectional experimental study was to investigate and describe the hierarchy of the association between thigh muscle volume and measurements of functional performance in older women. Thigh muscle volume of 68 independently living older women (mean age 77.6 years was measured via magnetic resonance imaging. Isometric strength was assessed for leg extension in a movement laboratory in sitting position with the knee flexed at 90° and for hand grip. Maximum and habitual gait speed was measured on an electronic walk way. Leg muscle power was measured during single leg push and during sit-to-stand performance. Thigh muscle volume was associated with sit-to-stand performance power (r = 0.628, leg push power (r = 0.550, isometric quadriceps strength (r = 0.442, hand grip strength (r = 0.367, fast gait speed (r = 0.291, habitual gait speed (r = 0.256, body mass index (r = 0.411 and age (r = -0.392. Muscle power showed the highest association with thigh muscle volume in healthy older women. Sit-to-stand performance power showed an even higher association with thigh muscle volume compared to single leg push power.

Protein-containing nutrient supplementation following strength training enhances the effect on muscle mass, strength, and bone formation in postmenopausal women

DEFF Research Database (Denmark)

Holm, Lars; Olesen, Jens L; Matsumoto, Keitaro

2008-01-01

.0 +/- 1.4%); nutrient group: 0.953 +/- 0.051 to 0.978 +/- 0.043 g/mm(3) (3.8 +/- 3.4%)] when adjusted for age, body mass index, and BMD at inclusion. Bone formation displayed an interaction (P increased osteocalcin at 24 wk in the nutrient group. In conclusion, we report...... that nutrient supplementation results in superior improvements in muscle mass, muscle strength, femoral neck BMD, and bone formation during 24 wk of strength training. The observed differences following such a short intervention emphasize the significance of postexercise nutrient supply on musculoskeletal......We evaluated the response of various muscle and bone adaptation parameters with 24 wk of strength training in healthy, early postmenopausal women when a nutrient supplement (protein, carbohydrate, calcium, and vitamin D) or a placebo supplement (a minimum of energy) was ingested immediately...

Postoperative loss of skeletal muscle mass, complications and quality of life in patients undergoing cardiac surgery

NARCIS (Netherlands)

van Venrooij, Lenny M. W.; Verberne, Hein J.; de Vos, Rien; Borgmeijer-Hoelen, Mieke M. M. J.; van Leeuwen, Paul A. M.; de Mol, Bas A. J. M.

2012-01-01

Objective: The objective of this study was to describe postoperative undernutrition in terms of postoperative losses of appendicular skeletal muscle mass (ASMM) with respect to complications, quality of life, readmission, and 1-y mortality after cardiac surgery. Methods: Patients undergoing cardiac

Middle cerebral artery blood velocity depends on cardiac output during exercise with a large muscle mass

NARCIS (Netherlands)

Ide, K.; Pott, F.; van Lieshout, J. J.; Secher, N. H.

1998-01-01

We tested the hypothesis that pharmacological reduction of the increase in cardiac output during dynamic exercise with a large muscle mass would influence the cerebral blood velocity/perfusion. We studied the relationship between changes in cerebral blood velocity (transcranial Doppler), rectus

Assessment of muscle mass, risk of falls and fear of falling in elderly people with diabetic neuropathy

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Hudson Azevedo Pinheiro

Full Text Available Abstract Objective : To assess muscle mass, risk of falls and fear of falling in elderly adults with diabetic neuropathy (DNP. Methods : 50 elderly patients with diabetes mellitus (DM and diabetic neuropathy (NPD participated in this study. Risk of falling was assessed using the Berg Balance Scale (BBS. Fear of falling was assessed by means of the Falls Efficacy Scale-International (FES-I. Muscle mass was assessed by tetrapolar bioimpedance analysis (BIA and Janssen's equation. Subjects were divided into two groups: one with a history of falls in the six months before study enrollment (G1 and the other without history of falls (G2. Results : There were statistically significant differences between G1 and G2 regarding lean body mass (p < 0.05, risk of falls as measured by the BBS (p < 0.01, and fear of falling as measured by the FES-I (p < 0.01. In addition, there was a significant correlation between the BBS and BIA (r = 0.45 and p < 0.01, showing that the greater the lean body mass, the lower the risk of falling. Conclusions : We found an association between lean mass, risk of falls and fear of falling in elderly adults with DNP and a history of falls from own height.

Mechanical muscle function and lean body mass during supervised strength training and testosterone therapy in aging men with low-normal testosterone levels

DEFF Research Database (Denmark)

Kvorning, Thue; Christensen, Louise L; Madsen, Klavs

2013-01-01

To examine the effect of strength training and testosterone therapy on mechanical muscle function and lean body mass (LBM) in aging men with low-normal testosterone levels in a randomized, double-blind, placebo-controlled 24-week study.......To examine the effect of strength training and testosterone therapy on mechanical muscle function and lean body mass (LBM) in aging men with low-normal testosterone levels in a randomized, double-blind, placebo-controlled 24-week study....

Skeletal muscles of hibernating brown bears are unusually resistant to effects of denervation.

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Lin, David C; Hershey, John D; Mattoon, John S; Robbins, Charles T

2012-06-15

Hibernating bears retain most of their skeletal muscle strength despite drastically reduced weight-bearing activity. Regular neural activation of muscles is a potential mechanism by which muscle atrophy could be limited. However, both mechanical loading and neural activity are usually necessary to maintain muscle size. An alternative mechanism is that the signaling pathways related to the regulation of muscle size could be altered so that neither mechanical nor neural inputs are needed for retaining strength. More specifically, we hypothesized that muscles in hibernating bears are resistant to a severe reduction in neural activation. To test this hypothesis, we unilaterally transected the common peroneal nerve, which innervates ankle flexor muscles, in hibernating and summer-active brown bears (Ursus arctos). In hibernating bears, the long digital extensor (LDE) and cranial tibial (CT) musculotendon masses on the denervated side decreased after 11 weeks post-surgery by 18 ± 11 and 25 ± 10%, respectively, compared with those in the intact side. In contrast, decreases in musculotendon masses of summer-active bears after denervation were 61 ± 4 and 58 ± 5% in the LDE and CT, respectively, and significantly different from those of hibernating bears. The decrease due to denervation in summer-active bears was comparable to that occurring in other mammals. Whole-muscle cross-sectional areas (CSAs) measured from ultrasound images and myofiber CSAs measured from biopsies decreased similarly to musculotendon mass. Thus, hibernating bears alter skeletal muscle catabolic pathways regulated by neural activity, and exploration of these pathways may offer potential solutions for disuse atrophy of muscles.

Imaging mass spectrometry reveals fiber-specific distribution of acetylcarnitine and contraction-induced carnitine dynamics in rat skeletal muscles.

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Furuichi, Yasuro; Goto-Inoue, Naoko; Manabe, Yasuko; Setou, Mitsutoshi; Masuda, Kazumi; Fujii, Nobuharu L

2014-10-01

Carnitine is well recognized as a key regulator of long-chain fatty acyl group translocation into the mitochondria. In addition, carnitine, as acetylcarnitine, acts as an acceptor of excess acetyl-CoA, a potent inhibitor of pyruvate dehydrogenase. Here, we provide a new methodology for accurate quantification of acetylcarnitine content and determination of its localization in skeletal muscles. We used matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) to visualize acetylcarnitine distribution in rat skeletal muscles. MALDI-IMS and immunohistochemistry of serial cross-sections showed that acetylcarnitine was enriched in the slow-type muscle fibers. The concentration of ATP was lower in muscle regions with abundant acetylcarnitine, suggesting a relationship between acetylcarnitine and metabolic activity. Using our novel method, we detected an increase in acetylcarnitine content after muscle contraction. Importantly, this increase was not detected using traditional biochemical assays of homogenized muscles. We also demonstrated that acetylation of carnitine during muscle contraction was concomitant with glycogen depletion. Our methodology would be useful for the quantification of acetylcarnitine and its contraction-induced kinetics in skeletal muscles. Copyright © 2014 Elsevier B.V. All rights reserved.

Activated protein synthesis and suppressed protein breakdown signaling in skeletal muscle of critically ill patients

DEFF Research Database (Denmark)

Jespersen, Jakob G; Nedergaard, Anders; Reitelseder, Søren

2011-01-01

Skeletal muscle mass is controlled by myostatin and Akt-dependent signaling on mammalian target of rapamycin (mTOR), glycogen synthase kinase 3β (GSK3β) and forkhead box O (FoxO) pathways, but it is unknown how these pathways are regulated in critically ill human muscle. To describe factors invol...... involved in muscle mass regulation, we investigated the phosphorylation and expression of key factors in these protein synthesis and breakdown signaling pathways in thigh skeletal muscle of critically ill intensive care unit (ICU) patients compared with healthy controls....

Activated protein synthesis and suppressed protein breakdown signaling in skeletal muscle of critically ill patients

DEFF Research Database (Denmark)

Jespersen, Jakob G; Nedergaard, Anders; Reitelseder, Søren

2011-01-01

Skeletal muscle mass is controlled by myostatin and Akt-dependent signaling on mammalian target of rapamycin (mTOR), glycogen synthase kinase 3ß (GSK3ß) and forkhead box O (FoxO) pathways, but it is unknown how these pathways are regulated in critically ill human muscle. To describe factors invol...... involved in muscle mass regulation, we investigated the phosphorylation and expression of key factors in these protein synthesis and breakdown signaling pathways in thigh skeletal muscle of critically ill intensive care unit (ICU) patients compared with healthy controls....

Low vitamin D status is associated with reduced muscle mass and impaired physical performance in frail elderly people.

Science.gov (United States)

Tieland, M; Brouwer-Brolsma, E M; Nienaber-Rousseau, C; van Loon, L J C; De Groot, L C P G M

2013-10-01

Serum 25-hydroxyvitamin D (25(OH)D) status has been associated with muscle mass, strength and physical performance in healthy elderly people. Yet, in pre-frail and frail elderly people this association has not been studied. The objective of this study was to explore the association between vitamin D intake and serum 25(OH)D status with muscle mass, strength and physical performance in a pre-frail and frail elderly population. This cross-sectional study included 127 pre-frail and frail elderly people in The Netherlands. Whole body and appendicular lean mass (ALM) (dual energy X-ray absorptiometry), leg strength (one repetition maximum), handgrip strength and physical performance (short physical performance battery) were measured, and blood samples were collected for the assessment of serum 25(OH)D status (liquid chromatography-tandem mass spectrometry). In addition, habitual dietary intake (3-day food records) and physical activity data (accelerometers) were collected. In total, 53% of the participants had a serum 25(OH)D level below 50  nmol/l. After adjustment for confounding factors, 25(OH)D status was associated with ALM (β=0.012, P=0.05) and with physical performance (β=0.020, PVitamin D intake was associated with physical performance (β=0.18, P0.05). In this frail elderly population, 25(OH)D status is low and suggests a modest association with reduced ALM and impaired physical performance. In addition, vitamin D intake tended to be associated with impaired physical performance. Our findings highlight the need for well-designed intervention trials to assess the impact of vitamin D supplementation on 25(OH)D status, muscle mass and physical performance in pre-frail and frail elderly people.

Association of chronic kidney disease with muscle deficits in children.

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Foster, Bethany J; Kalkwarf, Heidi J; Shults, Justine; Zemel, Babette S; Wetzsteon, Rachel J; Thayu, Meena; Foerster, Debbie L; Leonard, Mary B

2011-02-01

The effect of chronic kidney disease (CKD) on muscle mass in children, independent of poor growth and delayed maturation, is not well understood. We sought to characterize whole body and regional lean mass (LM) and fat mass (FM) in children and adolescents with CKD and to identify correlates of LM deficits in CKD. We estimated LM and FM from dual energy x-ray absorptiometry scans in 143 children with CKD and 958 controls at two pediatric centers. We expressed whole body, trunk, and leg values of LM and FM as Z-scores relative to height, sitting height, and leg length, respectively, using the controls as the reference. We used multivariable regression models to compare Z-scores in CKD and controls, adjusted for age and maturation, and to identify correlates of LM Z-scores in CKD. Greater CKD severity associated with greater leg LM deficits. Compared with controls, leg LM Z-scores were similar in CKD stages 2 to 3 (difference: 0.02 [95% CI: -0.20, 0.24]; P = 0.8), but were lower in CKD stages 4 to 5 (-0.41 [-0.66, -0.15]; P = 0.002) and dialysis (-1.03 [-1.33, -0.74]; P normal leg FM, compared with controls. In conclusion, advanced CKD associates with significant deficits in leg lean mass, indicating skeletal muscle wasting. These data call for prospective studies of interventions to improve muscle mass among children with CKD.

Protein-containing nutrient supplementation following strength training enhances the effect on muscle mass, strength, and bone formation in postmenopausal women

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Holm, Lars; Olesen, J.L.; Matsumoto, K.

2008-01-01

.4%); nutrient group: 0.953 ± 0.051 to 0.978 ± 0.043 g/mm3 (3.8 ± 3.4%)] when adjusted for age, body mass index, and BMD at inclusion. Bone formation displayed an interaction (P increased osteocalcin at 24 wk in the nutrient group. In conclusion, we report that nutrient supplementation...... results in superior improvements in muscle mass, muscle strength, femoral neck BMD, and bone formation during 24 wk of strength training. The observed differences following such a short intervention emphasize the significance of postexercise nutrient supply on musculoskeletal maintenance.......We evaluated the response of various muscle and bone adaptation parameters with 24 wk of strength training in healthy, early postmenopausal women when a nutrient supplement (protein, carbohydrate, calcium, and vitamin D) or a placebo supplement (a minimum of energy) was ingested immediately...

Effects of Long Term Supplementation of Anabolic Androgen Steroids on Human Skeletal Muscle

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Yu, Ji-Guo; Bonnerud, Patrik; Eriksson, Anders; Stål, Per S.; Tegner, Yelverton; Malm, Christer

2014-01-01

The effects of long-term (over several years) anabolic androgen steroids (AAS) administration on human skeletal muscle are still unclear. In this study, seventeen strength training athletes were recruited and individually interviewed regarding self-administration of banned substances. Ten subjects admitted having taken AAS or AAS derivatives for the past 5 to 15 years (Doped) and the dosage and type of banned substances were recorded. The remaining seven subjects testified to having never used any banned substances (Clean). For all subjects, maximal muscle strength and body composition were tested, and biopsies from the vastus lateralis muscle were obtained. Using histochemistry and immunohistochemistry (IHC), muscle biopsies were evaluated for morphology including fiber type composition, fiber size, capillary variables and myonuclei. Compared with the Clean athletes, the Doped athletes had significantly higher lean leg mass, capillary per fibre and myonuclei per fiber. In contrast, the Doped athletes had significantly lower absolute value in maximal squat force and relative values in maximal squat force (relative to lean body mass, to lean leg mass and to muscle fiber area). Using multivariate statistics, an orthogonal projection of latent structure discriminant analysis (OPLS-DA) model was established, in which the maximal squat force relative to muscle mass and the maximal squat force relative to fiber area, together with capillary density and nuclei density were the most important variables for separating Doped from the Clean athletes (regression  =  0.93 and prediction  =  0.92, p<0.0001). In Doped athletes, AAS dose-dependent increases were observed in lean body mass, muscle fiber area, capillary density and myonuclei density. In conclusion, long term AAS supplementation led to increases in lean leg mass, muscle fiber size and a parallel improvement in muscle strength, and all were dose-dependent. Administration of AAS may induce sustained

The obesity paradox in men with coronary heart disease and heart failure: the role of muscle mass and leptin.

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Wannamethee, S Goya; Shaper, A Gerald; Whincup, Peter H; Lennon, Lucy; Papacosta, Olia; Sattar, Naveed

2014-01-15

We have investigated the role of muscle mass, natriuretic peptides and adipokines in explaining the obesity paradox. The obesity paradox relates to the association between obesity and increased survival in patients with coronary heart disease (CHD) or heart failure (HF). Prospective study of 4046 men aged 60-79 years followed up for a mean period of 11 years, during which 1340 deaths occurred. The men were divided according to the presence of doctor diagnosed CHD and HF: (i) no CHD or HF ii), with CHD (no HF) and (iii) with HF. Overweight (BMI 25-9.9 kg/m(2)) and obesity (BMI ≥ 30 kg/m(2)) were associated with lower mortality risk compared to men with normal weight (BMI 18.5-24.9 kg/m(2)) in those with CHD [hazards ratio (HR) 0.71 (0.56,0.91) and 0.77 (0.57,1.04); p=0.04 for trend] and in those with HF [HR 0.57 (0.28,1.16) and 0.41 (0.16,1.09; p=0.04 for trend). Adjustment for muscle mass and NT-proBNP attenuated the inverse association in those with CHD (no HF) [HR 0.78 (0.61,1.01) and 0.96 (0.68,1.36) p=0.60 for trend) but made minor differences to those with HF [p=0.05]. Leptin related positively to mortality in men without HF but inversely to mortality in those with HF; adjustment for leptin abolished the BMI mortality association in men with HF [HR 0.82 (0.31,2.20) and 0.99 (0.27,3.71); p=0.98 for trend]. The lower mortality risk associated with excess weight in men with CHD without HF may be due to higher muscle mass. In men with HF, leptin (possibly reflecting cachexia) explain the inverse association. Copyright © 2013. Published by Elsevier Ireland Ltd.

A new approach to assess the gastrocnemius muscle volume in rodents using ultrasound; comparison with the gastrocnemius muscle index.

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Tim H J Nijhuis

Full Text Available INTRODUCTION: The purpose of this study was to determine the reliability and validity of a new non-invasive ultrasound technique to measure gastrocnemius muscle atrophy after nerve denervation in an animal model. METHODS: In sixteen rodents an eight mm sciatic nerve gap was created. In the following 8 weeks, each week, two rodents were euthanized and the gastrocnemius muscle was examined using two different ultrasound systems and two investigators. The standardized ultrasound measurement protocol consisted of identifying pre-defined anatomical landmarks: 1 the fibula, 2 the fibular nerve, and 3 the junction between the most distal point of the semitendinosus muscle and gastrocnemius muscle. Consequently, we measured the muscle thickness as the length of the line between the fibula and the junction between the two muscles, perpendicular to the fibular nerve. After the ultrasound recording, the muscle mass was determined. RESULTS: A steep decline of muscle weight of 24% was observed after one week. In the following weeks, the weight further decreased and then remained stable from 6 weeks onwards, resulting in a maximal muscle weight decrease of 82%. The correlation coefficient was >0.96 between muscle diameter and weight using both ultrasound systems. The inter-rater reliability was excellent for both devices on the operated side (ICC of 0.99 for both ultrasound systems and good for the non-operated site (ICC's: 0.84 & 0.89. The difference between the muscle mass ratio and the muscle thickness ratio was not more than 5% with two outliers of approximately 13%. DISCUSSION: We have developed an innovative, highly reliable technique for quantifying muscle atrophy after nerve injury. This technique allows serial measurements in the same animal over time. This is a significant advantage compared to the conventional technique for quantifying muscle atrophy, which requires sacrificing the animal.

Effect of pretreatment psoas muscle mass on survival for patients with unresectable pancreatic cancer undergoing systemic chemotherapy.

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Ishii, Noriko; Iwata, Yoshinori; Nishikawa, Hiroki; Enomoto, Hirayuki; Aizawa, Nobuhiro; Ishii, Akio; Miyamoto, Yuho; Yuri, Yukihisa; Hasegawa, Kunihiro; Nakano, Chikage; Nishimura, Takashi; Yoh, Kazunori; Sakai, Yoshiyuki; Ikeda, Naoto; Takashima, Tomoyuki; Takata, Ryo; Iijima, Hiroko; Nishiguchi, Shuhei

2017-11-01

To the best of our knowledge, there are few previous studies that have investigated the effect of decreased skeletal muscle mass (DSMM) on survival in patients with unresectable advanced pancreatic cancer (APC) who are undergoing systemic chemotherapy. Thus, the present study aimed to investigate the impact of DSMM, as determined by the psoas muscle index (PMI) following computed tomography and prior to systemic chemotherapy, on the outcomes of patients with unresectable APC (n=61). The primary endpoint used was the overall survival (OS) rate. The OS rates in the PMI-High group (exceeds the median PMI value in each gender) were retrospectively compared with those in the PMI-Low group (below the median PMI value in each gender), and factors associated with OS were investigated using univariate and multivariate analyses. The study cohort included 31 male and 30 female patients with a median age of 72 years, 13 of whom were stage IVA, and 48 were stage IVB. The median PMI in males was 4.3 cm 2 /m 2 (range, 1.6-8.2 cm 2 /m 2 ), while that in females was 2.3 cm 2 /m 2 (range, 0.7-6.1 cm 2 /m 2 ). The proportion of patients with performance status 0 in the PMI-High group was significantly high, compared with that in the PMI-Low group [83.3% (25/30) vs. 58.1% (18/31); P=0.0486]. Body mass index in the PMI-High group was significantly higher compared with that in the PMI-Low group (P=0.0154). The 1-year cumulative survival rate was 43.3% in the PMI-High group and 12.9% in the PMI-Low group (P=0.0027). Following multivariate analysis, PMI (P=0.0036), prothrombin time (P=0.0044) and carbohydrate antigen 19-9 (P=0.0451) were identified to be significant predictors of OS. In conclusion, DSMM, as determined by the PMI, could be a significant predictor of prognosis in patients with unresectable APC who are receiving systemic chemotherapy.

Physiological effects beyond the significant gain in muscle mass in sarcopenic elderly men: evidence from a randomized clinical trial using a protein-rich food

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Alemán-Mateo H

2012-07-01

Full Text Available Heliodoro Alemán-Mateo,1 Liliana Macías,1 Julián Esparza-Romero,1 Humberto Astiazaran-García,1 Ana Luz Blancas21Coordinación de Nutrición, Centro de Investigación en Alimentación y Desarrollo, AC, Hermosillo, Sonora, México; 2Dirección General de Servicios de Salud a la Persona, Hermosillo, Sonora, MéxicoBackground: Sarcopenia is strongly associated with an inadequate intake of dietary protein. Dietary protein supplementation boosts muscle-protein synthesis and increases muscle mass in the elderly. This study tested whether adding a protein-rich food, ricotta cheese, to the habitual diet increased total appendicular skeletal muscle mass and strength in elderly people.Methods: Participants (n = 40, were sarcopenic elderly men and women over 60 years of age. Two comparison groups were formed at random and followed for 3 months: the intervention group received 210 g/day of ricotta cheese plus the habitual diet, while the control group followed the habitual diet with no additional intervention. Total appendicular skeletal muscle (TASM was assessed by dual-energy X-ray absorptiometry, while strength was measured using a handheld dynamometer at baseline and after the intervention period. The primary outcomes were the percentage of relative change in TASM and strength.Results: The percentage of relative change in TASM was not significant between the groups after the intervention period. Muscle strength improved in the intervention group, but showed only a tendency towards significance (P = 0.06. Secondary analysis showed that the men in the intervention group gained 270 g in TASM compared to those in the control group, and improved their fasting insulin levels (P = 0.05, muscle strength, lean body mass in the arms, and body weight variables.Conclusion: The results of this study indicate that a nutritional intervention using a high-quality protein food, specifically ricotta cheese, in order to increase the amount of protein intake might not

Exercise Promotes Healthy Aging of Skeletal Muscle.

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Cartee, Gregory D; Hepple, Russell T; Bamman, Marcas M; Zierath, Juleen R

2016-06-14

Primary aging is the progressive and inevitable process of bodily deterioration during adulthood. In skeletal muscle, primary aging causes defective mitochondrial energetics and reduced muscle mass. Secondary aging refers to additional deleterious structural and functional age-related changes caused by diseases and lifestyle factors. Secondary aging can exacerbate deficits in mitochondrial function and muscle mass, concomitant with the development of skeletal muscle insulin resistance. Exercise opposes deleterious effects of secondary aging by preventing the decline in mitochondrial respiration, mitigating aging-related loss of muscle mass and enhancing insulin sensitivity. This review focuses on mechanisms by which exercise promotes "healthy aging" by inducing modifications in skeletal muscle. Copyright © 2016 Elsevier Inc. All rights reserved.

Whole-body electromyostimulation as a means to impact muscle mass and abdominal body fat in lean, sedentary, older female adults: subanalysis of the TEST-III trial

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Kemmler W

2013-10-01

Full Text Available Wolfgang Kemmler, Simon von StengelInstitute of Medical Physics, University of Erlangen-Nürnberg, Erlangen, GermanyBackground: The primary aim of this study was to determine the effect of 12 months of whole-body electromyostimulation (WB-EMS exercise on appendicular muscle mass and abdominal fat mass in subjects specifically at risk for sarcopenia and abdominal obesity, but unable or unwilling to exercise conventionally.Methods: Forty-six lean, nonsportive (<60 minutes of exercise per week, elderly women (aged 75 ± 4 years with abdominal obesity according to International Diabetes Federation criteria were randomly assigned to either a WB-EMS group (n=23 which performed 18 minutes of intermittent, bipolar WB-EMS (85 Hz three sessions in 14 days or an "active" control group (n=23. Whole-body and regional body composition was assessed by dual energy X-ray absorptiometry to determine appendicular muscle mass, upper leg muscle mass, abdominal fat mass, and upper leg fat mass. Maximum strength of the leg extensors was determined isometrically by force plates.Results: After 12 months, significant intergroup differences were detected for the primary endpoints of appendicular muscle mass (0.5% ± 2.0% for the WB-EMS group versus −0.8% ± 2.0% for the control group, P=0.025 and abdominal fat mass (−1.2% ± 5.9% for the WB-EMS group versus 2.4% ± 5.8% for the control group, P=0.038. Further, upper leg lean muscle mass changed favorably in the WB-EMS group (0.5% ± 2.5% versus −0.9% ± 1.9%, in the control group, P=0.033, while effects for upper leg fat mass were borderline nonsignificant (−0.8% ± 3.5% for the WB-EMS group versus 1.0% ± 2.6% for the control group, P=0.050. With respect to functional parameters, the effects for leg extensor strength were again significant, with more favorable changes in the WB-EMS group (9.1% ± 11.2% versus 1.0% ± 8.1% in the control group, P=0.010.Conclusion: In summary, WB-EMS showed positive effects on the

Enhancement of adipogenesis and fibrogenesis in skeletal muscle of Wagyu compared with Angus cattle.

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Duarte, M S; Paulino, P V R; Das, A K; Wei, S; Serão, N V L; Fu, X; Harris, S M; Dodson, M V; Du, M

2013-06-01

Intramuscular fat and collagen content are major factors affecting beef quality, but mechanisms regulating intramuscular adipose and connective tissue deposition are far from clear. Japanese Wagyu cattle are well known for their extremely high marbling. The objective of this study was to evaluate intramuscular fat (IMF) and collagen deposition in the muscle of Wagyu compared with Angus cattle. Animals were managed under the same condition and slaughtered at an averaging 585 ± 12.1 kg of BW. Samples of sternomandibularis muscle were collected from Wagyu (n = 3) and Angus (n = 3) for molecular and histological investigations of adipogenesis and fibrogenesis. With exception of C/EBPβ (P = 0.2864), the expression of the adipogenic markers C/EBPα (P = 0.008), PPARγ (P = 0.028), and zip finger protein 423 (Zfp423; P = 0.047) in Wagyu were greater than in Angus muscle, which was consistent with greater IMF deposition in Wagyu (P Angus cattle. These results clearly show that both IMF and collagen contents are enhanced in Wagyu cattle and more adipogenic cells are detected in Wagyu muscle, indicating intramuscular adipogenesis is enhanced in Wagyu compared with Angus muscle.

A comparative study of charge movement in rat and frog skeletal muscle fibres.

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Hollingworth, S; Marshall, M W

1981-12-01

1. The middle of the fibre voltage--clamp technique (Adrian & Marshall, 1977), modified where necessary for electrically short muscle fibres, has been used to measure non-linear charge movements in mammalian fast twitch (rat extensor digitorum longus), mammalian slow twitch (rat soleus) and frog (sartorius) muscles. 2. The maximum amount of charge moved in mammalian fast twitch muscle at 2 degrees C in hypertonic solution, was 3--5 times greater than in slow twitch muscle. The voltage distribution of fast twitch charge was 10--15 mV more positive when compared to slow twitch. 3. In both mammalian muscle types hypertonic Ringer solution negatively shifted the voltage distribution of charge some 6 mV. The steepness of charge moved around mechanical threshold was unaffected by hypertonicity. 4. The amount of charge in frog sartorius fibres at 2 degrees C in hypertonic solution was about half of that in rat fast twitch muscle; the voltage distribution of the frog charge was similar to rat soleus muscle. 5. Warming between 2 and 15 degrees C had no effect on either the amount of steady-state distribution of charge in mammalian or frog muscles. 6. At 2 degrees C, the kinetics of charge movement in fast and slow twitch mammalian muscles were similar and 2--3 times faster than frog muscle at the same temperature. In fast and slow mammalian fibres at 2 degrees C similar times were taken to shift the same fractions of the total amount of charge. The Q10 of charge movement kinetics was between 1.2 and 2.0 in the three muscles studied.

IGF-I treatment improves the functional properties of fast- and slow-twitch skeletal muscles from dystrophic mice.

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Lynch, G S; Cuffe, S A; Plant, D R; Gregorevic, P

2001-04-01

Although insulin-like growth factor-I (IGF-I) has been proposed for use by patients suffering from muscle wasting conditions, few studies have investigated the functional properties of dystrophic skeletal muscle following IGF-I treatment. 129P1 ReJ-Lama2(dy) (129 ReJ dy/dy) dystrophic mice suffer from a deficiency in the structural protein, laminin, and exhibit severe muscle wasting and weakness. We tested the hypothesis that 4 weeks of IGF-I treatment ( approximately 2 mg/kg body mass, 50 g/h via mini-osmotic pump, subcutaneously) would increase the mass and force producing capacity of skeletal muscles from dystrophic mice. IGF-I treatment increased the mass of the extensor digitorum longus (EDL) and soleus muscles of dystrophic mice by 20 and 29%, respectively, compared with untreated dystrophic mice (administered saline-vehicle only). Absolute maximum force (P(o)) of the EDL and soleus muscle was increased by 40 and 32%, respectively, following IGF-I treatment. Specific P(o) (sP(o)) was increased by 23% in the EDL muscles of treated compared with untreated mice, but in the soleus muscle sP(o) was unchanged. IGF-I treatment increased the proportion of type IIB and type IIA fibres and decreased the proportion of type I fibres in the EDL muscles of dystrophic mice. In the soleus muscles of dystrophic mice, IGF-I treatment increased the proportion of type IIA fibres and decreased the proportion of type I fibres. Average fibre cross-sectional area was increased in the EDL and soleus muscles of treated compared with untreated mice. We conclude that IGF-I treatment ameliorates muscle wasting and improves the functional properties of skeletal muscles of dystrophic mice. The findings have important implications for the role of IGF-I in ameliorating muscle wasting associated with the muscular dystrophies.

Multiple skeletal muscle metastases revealing a cardiac intimal sarcoma

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Crombe, Amandine [Institut Bergonie, Department of Radiology, Bordeaux (France); Lintingre, Pierre-Francois; Dallaudiere, Benjamin [Clinique du Sport de Bordeaux-Merignac, Department of Musculoskeletal Radiology, Merignac (France); Le Loarer, Francois [Institut Bergonie, Department of Pathology, Bordeaux (France); Lachatre, Denis [Dupuytren University Hospital, Department of Radiology, Limoges (France)

2018-01-15

We report the case of a 59-year-old female with progressive bilateral painful swelling of the thighs. MRI revealed multiple intramuscular necrotic masses with similar morphologic patterns. Whole-body CT and 18-FDG PET-CT scans demonstrated additional hypermetabolic muscular masses and a lobulated lesion within the left atrial cavity. As biopsy of a muscular mass was compatible with a poorly differentiated sarcoma with MDM2 oncogene amplification, two diagnoses were discussed: a dedifferentiated liposarcoma with muscle and heart metastases or a primary cardiac sarcoma, mainly a cardiac intimal sarcoma, with muscular metastases, which was finally confirmed by array-comparative genomic hybridization (aCGH) in a sarcoma reference center. This case emphasizes the potential for intimal sarcoma to disseminate in skeletal muscle prior to any other organ and the need for a genomic approach in addition to classical radiopathologic analyses to distinguish primary from secondary locations facing simultaneous tumors of the heart and skeletal muscles with MDM2 amplification. (orig.)

Muscle Wasting and Resistance of Muscle Anabolism: The “Anabolic Threshold Concept” for Adapted Nutritional Strategies during Sarcopenia

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Dominique Dardevet

2012-01-01

Full Text Available Skeletal muscle loss is observed in several physiopathological situations. Strategies to prevent, slow down, or increase recovery of muscle have already been tested. Besides exercise, nutrition, and more particularly protein nutrition based on increased amino acid, leucine or the quality of protein intake has generated positive acute postprandial effect on muscle protein anabolism. However, on the long term, these nutritional strategies have often failed in improving muscle mass even if given for long periods of time in both humans and rodent models. Muscle mass loss situations have been often correlated to a resistance of muscle protein anabolism to food intake which may be explained by an increase of the anabolic threshold toward the stimulatory effect of amino acids. In this paper, we will emphasize how this anabolic resistance may affect the intensity and the duration of the muscle anabolic response at the postprandial state and how it may explain the negative results obtained on the long term in the prevention of muscle mass. Sarcopenia, the muscle mass loss observed during aging, has been chosen to illustrate this concept but it may be kept in mind that it could be extended to any other catabolic states or recovery situations.

A robust neuromuscular system protects rat and human skeletal muscle from sarcopenia.

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Pannérec, Alice; Springer, Margherita; Migliavacca, Eugenia; Ireland, Alex; Piasecki, Mathew; Karaz, Sonia; Jacot, Guillaume; Métairon, Sylviane; Danenberg, Esther; Raymond, Frédéric; Descombes, Patrick; McPhee, Jamie S; Feige, Jerome N

2016-04-01

Declining muscle mass and function is one of the main drivers of loss of independence in the elderly. Sarcopenia is associated with numerous cellular and endocrine perturbations, and it remains challenging to identify those changes that play a causal role and could serve as targets for therapeutic intervention. In this study, we uncovered a remarkable differential susceptibility of certain muscles to age-related decline. Aging rats specifically lose muscle mass and function in the hindlimbs, but not in the forelimbs. By performing a comprehensive comparative analysis of these muscles, we demonstrate that regional susceptibility to sarcopenia is dependent on neuromuscular junction fragmentation, loss of motoneuron innervation, and reduced excitability. Remarkably, muscle loss in elderly humans also differs in vastus lateralis and tibialis anterior muscles in direct relation to neuromuscular dysfunction. By comparing gene expression in susceptible and non-susceptible muscles, we identified a specific transcriptomic signature of neuromuscular impairment. Importantly, differential molecular profiling of the associated peripheral nerves revealed fundamental changes in cholesterol biosynthetic pathways. Altogether our results provide compelling evidence that susceptibility to sarcopenia is tightly linked to neuromuscular decline in rats and humans, and identify dysregulation of sterol metabolism in the peripheral nervous system as an early event in this process.

Metabolomic Analysis of Oxidative and Glycolytic Skeletal Muscles by Matrix-Assisted Laser Desorption/IonizationMass Spectrometric Imaging (MALDI MSI)

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Tsai, Yu-Hsuan; Garrett, Timothy J.; Carter, Christy S.; Yost, Richard A.

2015-06-01

Skeletal muscles are composed of heterogeneous muscle fibers that have different physiological, morphological, biochemical, and histological characteristics. In this work, skeletal muscles extensor digitorum longus, soleus, and whole gastrocnemius were analyzed by matrix-assisted laser desorption/ionization mass spectrometry to characterize small molecule metabolites of oxidative and glycolytic muscle fiber types as well as to visualize biomarker localization. Multivariate data analysis such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were performed to extract significant features. Different metabolic fingerprints were observed from oxidative and glycolytic fibers. Higher abundances of biomolecules such as antioxidant anserine as well as acylcarnitines were observed in the glycolytic fibers, whereas taurine and some nucleotides were found to be localized in the oxidative fibers.

Skeletal muscle mass and body fat in relation to successful ageing of older adults: The multi-national MEDIS study.

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Tyrovolas, Stefanos; Haro, Josep-Maria; Mariolis, Anargiros; Piscopo, Suzanne; Valacchi, Giuseppe; Bountziouka, Vassiliki; Anastasiou, Foteini; Zeimbekis, Akis; Tyrovola, Dimitra; Foscolou, Alexandra; Gotsis, Efthimios; Metallinos, George; Tur, Josep-Antoni; Matalas, Antonia; Lionis, Christos; Polychronopoulos, Evangelos; Panagiotakos, Demosthenes

2016-01-01

The determinants that promote successful ageing still remain unknown. The aim of the present work was to evaluate the role of skeletal muscle mass and body fat percentage (BF%), in the level of successful ageing. during 2005-2011, 2663 older (aged 65-100 years) from 21 Mediterranean islands and the rural Mani region (Peloponnesus) of Greece were voluntarily enrolled in the study. Appendicular skeletal muscle mass (ASM), skeletal muscle mass index (SMI) and BF% were calculated using population formulas. Dietary habits, energy intake, expenditure and energy balance were derived throughout standard procedures. A successful ageing index ranging from 0 to 10 was used. The mean ASM mass was 24±6.0kg, the SMI was 0.84±0.21 and the BF% was 44%. Females had lower SMI and higher BF% in comparison with males, respectively [(SMI: 0.66±0.09 vs. 1.03±0.11; BF%: 51% vs. 34%, (pageing, while changes in BF% [b-coefficient (95% CI): -0.04 (-0.05 to -0.03)] were inversely associated with successful ageing. Results from sensitivity analysis showed that the effects of variations on body composition were consistent, less pronounced in the positive energy balance group and more pronounced among the oldest old. Body composition changes seem to be associated with lower quality of life in the older adults, as measured through successful ageing. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Recumbent vs. upright bicycles: 3D trajectory of body centre of mass, limb mechanical work, and operative range of propulsive muscles.

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Telli, Riccardo; Seminati, Elena; Pavei, Gaspare; Minetti, Alberto Enrico

2017-03-01

Recumbent bicycles (RB) are high performance, human-powered vehicles. In comparison to normal/upright bicycles (NB) the RB may allow individuals to reach higher speeds due to aerodynamic advantages. The purpose of this investigation was to compare the non-aerodynamic factors that may potentially influence the performance of the two bicycles. 3D body centre of mass (BCoM) trajectory, its symmetries, and the components of the total mechanical work necessary to sustain cycling were assessed through 3D kinematics and computer simulations. Data collected at 50, 70, 90 110 rpm during stationary cycling were used to drive musculoskeletal modelling simulation and estimate muscle-tendon length. Results demonstrated that BCoM trajectory, confined in a 15-mm side cube, changed its orientation, maintaining a similar pattern across all cadences in both bicycles. RB displayed a reduced additional mechanical external power (16.1 ± 9.7 W on RB vs. 20.3 ± 8.8 W on NB), a greater symmetry on the progression axis, and no differences in the internal mechanical power compared to NB. Simulated muscle activity revealed small significant differences for only selected muscles. On the RB, quadriceps and gluteus demonstrated greater shortening, while biceps femoris, iliacus, and psoas exhibited greater stretch; however, aerodynamics still remains the principal benefit.

Semimembranosus muscle herniation: a rare case with emphasis on muscle biomechanics

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Naffaa, Lena [American University of Beirut, Department of Diagnostic Radiology, P.O. Box 11-0236, Riad El-Solh, Beirut (Lebanon); Moukaddam, Hicham [Saint Rita Medical Center, Lima, OH (United States); Samim, Mohammad [New York University, Department of Radiology, Hospital for Joint Disease, New York, NY (United States); Lemieux, Aaron [University of California, San Diego School of Medicine, La Jolla, CA (United States); Smitaman, Edward [University of California, San Diego, Teleradiology and Education Center, San Diego, CA (United States)

2017-03-15

Muscle herniations are rare and most reported cases involve muscles of the lower leg. We use a case of muscle herniation involving the semimembranosus muscle, presenting as a painful mass in an adolescent male after an unspecified American football injury, to highlight a simple concept of muscle biomechanics as it pertains to muscle hernia(s): decreased traction upon muscle fibers can increase conspicuity of muscle herniation(s) - this allows a better understanding of the apt provocative maneuvers to employ, during dynamic ultrasound or magnetic resonance imaging, in order to maximize diagnostic yield and, thereby, limit patient morbidity related to any muscle herniation. Our patient subsequently underwent successful decompressive fasciotomy and has since returned to his normal daily activities. (orig.)

Semimembranosus muscle herniation: a rare case with emphasis on muscle biomechanics

International Nuclear Information System (INIS)

Naffaa, Lena; Moukaddam, Hicham; Samim, Mohammad; Lemieux, Aaron; Smitaman, Edward

2017-01-01

Muscle herniations are rare and most reported cases involve muscles of the lower leg. We use a case of muscle herniation involving the semimembranosus muscle, presenting as a painful mass in an adolescent male after an unspecified American football injury, to highlight a simple concept of muscle biomechanics as it pertains to muscle hernia(s): decreased traction upon muscle fibers can increase conspicuity of muscle herniation(s) - this allows a better understanding of the apt provocative maneuvers to employ, during dynamic ultrasound or magnetic resonance imaging, in order to maximize diagnostic yield and, thereby, limit patient morbidity related to any muscle herniation. Our patient subsequently underwent successful decompressive fasciotomy and has since returned to his normal daily activities. (orig.)

The impact of obesity on skeletal muscle strength and structure through adolescence to old age.

Science.gov (United States)

Tomlinson, D J; Erskine, R M; Morse, C I; Winwood, K; Onambélé-Pearson, Gladys

2016-06-01

Obesity is associated with functional limitations in muscle performance and increased likelihood of developing a functional disability such as mobility, strength, postural and dynamic balance limitations. The consensus is that obese individuals, regardless of age, have a greater absolute maximum muscle strength compared to non-obese persons, suggesting that increased adiposity acts as a chronic overload stimulus on the antigravity muscles (e.g., quadriceps and calf), thus increasing muscle size and strength. However, when maximum muscular strength is normalised to body mass, obese individuals appear weaker. This relative weakness may be caused by reduced mobility, neural adaptations and changes in muscle morphology. Discrepancies in the literature remain for maximal strength normalised to muscle mass (muscle quality) and can potentially be explained through accounting for the measurement protocol contributing to muscle strength capacity that need to be explored in more depth such as antagonist muscle co-activation, muscle architecture, a criterion valid measurement of muscle size and an accurate measurement of physical activity levels. Current evidence demonstrating the effect of obesity on muscle quality is limited. These factors not being recorded in some of the existing literature suggest a potential underestimation of muscle force either in terms of absolute force production or relative to muscle mass; thus the true effect of obesity upon skeletal muscle size, structure and function, including any interactions with ageing effects, remains to be elucidated.

Effect of modified fasting therapy on body weight, fat and muscle mass, and blood chemistry in patients with obesity.

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Kim, Koh-Woon; Song, Mi-Yeon; Chung, Seok-Hee; Chung, Won-Seok

2016-02-01

The aim of this study was to investigate the effects and safety of modified fasting therapy using fermented medicinal herbs and exercise on body weight, fat and muscle mass, and blood chemistry in obese subjects. Twenty-six patients participated in a 14-day fast, during which they ingested a supplement made from fermented medicinal herbs and carbohydrates (intake: 400-600 kcal/d). The schedule included 7 prefasting relief days and 14 days of stepwise reintroduction of food. The patients also took part in an exercise program that incorporated Qigong, weight training, and walking exercises. The efficacy of treatments was observed by assessing body fat mass and muscle mass, and alanine aminotransferase (ALT), aspartate aminotransferase (AST), cholesterol, and triglycerides in each study period. Specific symptoms or side effects were reported. Body weight and body fat mass both decreased significantly by (5.16 ± 0.95) and (3.89 ± 0.79) kg (both P fasting therapy using fermented medicinal herbs and exercise could be effective and safe on obese patients.

Comparative profiling of sarcoplasmic phosphoproteins in ovine muscle with different color stability.

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Li, Meng; Li, Zheng; Li, Xin; Xin, Jianzeng; Wang, Ying; Li, Guixia; Wu, Liguo; Shen, Qingwu W; Zhang, Dequan

2018-02-01

The phosphorylation of sarcoplasmic proteins in postmortem muscles was investigated in relationship to color stability in the present study. Although no difference was observed in the global phosphorylation level of sarcoplasmic proteins, difference was determined in the phosphorylation levels of individual protein bands from muscles with different color stability. Correlation analysis and liquid chromatography - tandem mass spectrometry (LC-MS/MS) identification of phosphoproteins showed that most of the color stability-related proteins were glycolytic enzymes. Interestingly, the phosphorylation level of myoglobin was inversely related to meat color stability. As the phosphorylation of myoglobin increased, color stability based on a ∗ value decreased and metMb content increased. In summary, the study revealed that protein phosphorylation might play a role in the regulation of meat color stability probably by regulating glycolysis and the redox stability of myoglobin, which might be affected by the phosphorylation of myoglobin. Copyright © 2017 Elsevier Ltd. All rights reserved.

Protein supplementation increases muscle mass gain during prolonged resistance-type exercise training in frail elderly people: a randomized double-blind, placebo-controlled trial

NARCIS (Netherlands)

Tieland, C.A.B.; Dirks, M.L.; Zwaluw, van der N.L.; Verdijk, L.; Rest, van de O.; Groot, de C.P.G.M.; Loon, van L.C.

2012-01-01

Objectives Protein supplementation has been proposed as an effective dietary strategy to augment the skeletal muscle adaptive response to prolonged resistance-type exercise training in elderly people. Our objective was to assess the impact of protein supplementation on muscle mass, strength, and

Comparison of the prevalence of sarcopenia using skeletal muscle mass index and calf circumference applying the European consensus definition in elderly Mexican women.

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Velazquez-Alva, Maria Consuelo; Irigoyen Camacho, Maria Esther; Lazarevich, Irina; Delgadillo Velazquez, Jaime; Acosta Dominguez, Patricia; Zepeda Zepeda, Marco A

2017-01-01

To compare the prevalence of sarcopenia using two indicators: skeletal muscle mass index (SMI) and calf circumference (CC) used in the algorithm proposed by the European Working Group on Sarcopenia in Mexican elderly women. This was a cross-sectional study. Lean body mass was determined by dual-energy X-ray absorptiometry. To define sarcopenia, the SMI was obtained using a cut-off value of 5.5 kg/m 2 , and the CC cut-off was 31 cm. For gait speed and handgrip strength, the cut-off values were 0.8 m/s and 20 kg, respectively. A total of 137 women (mean age 73.8 ± 6.7 years) participated in the study. The prevalence of sarcopenia was 14.6% using SMI and 11.0% using CC (P = 0.009). Body mass index was associated with a lower probability of sarcopenia applying SMI or CC (OR 0.75, P = 0.002 for SMI and OR 0.71, P = 0.004 for CC). Sarcopenia evaluated either with dual-energy X-ray absorptiometry or CC was not associated with physical performance, such as five times chair stand test, timed up and go test and short physical performance battery. Additionally, SMI was not associated with physical performance, five times chair stand test (P = 0.775) and timed up-and-go test (P = 0.341). The prevalence of sarcopenia in active elderly women was low. A higher prevalence of sarcopenia was detected using SMI compared with CC. It is important to identify the best methods to assess skeletal muscle mass to obtain a reliable diagnosis of sarcopenia. Geriatr Gerontol Int 2017; 17: 161-170. © 2015 Japan Geriatrics Society.

The impact of dietary protein or amino acid supplementation on muscle mass and strength in elderly people

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Tieland, M.; Franssen, R.; Dullemeijer, C.; Dronkelaar, van C.; Kim, H.K.; Ispoglou, T.; Zhu, K.; Prince, R.L.; Loon, van L.J.C.; Groot, de Lisette C.P.G.M.

2017-01-01

Objectives: Increasing protein or amino acid intake has been promoted as a promising strategy to increase muscle mass and strength in elderly people, however, long-term intervention studies show inconsistent findings. Therefore, we aim to determine the impact of protein or amino acid

Prioritization of skeletal muscle growth for emergence from hibernation.

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Hindle, Allyson G; Otis, Jessica P; Epperson, L Elaine; Hornberger, Troy A; Goodman, Craig A; Carey, Hannah V; Martin, Sandra L

2015-01-15

Mammalian hibernators provide an extreme example of naturally occurring challenges to muscle homeostasis. The annual hibernation cycle is characterized by shifts between summer euthermy with tissue anabolism and accumulation of body fat reserves, and winter heterothermy with fasting and tissue catabolism. The circannual patterns of skeletal muscle remodelling must accommodate extended inactivity during winter torpor, the motor requirements of transient winter active periods, and sustained activity following spring emergence. Muscle volume in thirteen-lined ground squirrels (Ictidomys tridecemlineatus) calculated from MRI upper hindlimb images (n=6 squirrels, n=10 serial scans) declined from hibernation onset, reaching a nadir in early February. Paradoxically, mean muscle volume rose sharply after February despite ongoing hibernation, and continued total body mass decline until April. Correspondingly, the ratio of muscle volume to body mass was steady during winter atrophy (October-February) but increased (+70%) from February to May, which significantly outpaced changes in liver or kidney examined by the same method. Generally stable myocyte cross-sectional area and density indicated that muscle remodelling is well regulated in this hibernator, despite vastly altered seasonal fuel and activity levels. Body composition analysis by echo MRI showed lean tissue preservation throughout hibernation amid declining fat mass by the end of winter. Muscle protein synthesis was 66% depressed in early but not late winter compared with a summer fasted baseline, while no significant changes were observed in the heart, liver or intestine, providing evidence that could support a transition in skeletal muscle regulation between early and late winter, prior to spring emergence and re-feeding. © 2015. Published by The Company of Biologists Ltd.

The Promotion of a Functional Fibrosis in Skeletal Muscle with Volumetric Muscle Loss Injury Following the Transplantation of Muscle-ECM

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2013-02-04

Zou K, Boppart MD. Eccentric exercise facil- itates mesenchymal stem cell appearance in skeletal muscle. PLoS One 2012; 7:e29760. [40] Matziolis G...remaining muscle mass leading to additional improvements in functional capacity; how- ever, no study has explicitly studied these effects . The purpose of...muscles were isolated from donor Lewis rats. The tendon and fascia were removed and TA muscle decellularization was performed using an enzymatic and

Hip flexor muscle size, strength and recruitment pattern in patients with acetabular labral tears compared to healthy controls.

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Mendis, M Dilani; Wilson, Stephen J; Hayes, David A; Watts, Mark C; Hides, Julie A

2014-10-01

Acetabular labral tears are a source of hip pain and are considered to be a precursor to hip osteoarthritis. Hip flexor muscles contribute to hip joint stability and function but it is unknown if their size and function is altered in the presence of labral pathology. This study aimed to investigate hip flexor muscle size, strength and recruitment pattern in patients with hip labral pathology compared to control subjects. 12 subjects diagnosed with an unilateral acetabular labral tear were compared to 12 control subjects matched for age and gender. All subjects underwent magnetic resonance imaging (MRI) of their lumbo-pelvic region. Average muscle cross-sectional area (CSA) of the iliacus, psoas, iliopsoas, sartorius, tensor fascia latae and rectus femoris muscles were measured. Hip flexion strength was measured by an externally fixed dynamometer. Individual muscle recruitment pattern during a resisted hip flexion exercise task was measured by muscle functional MRI. Hip flexor muscle strength was found to be decreased in patients with labral pathology compared to control subjects (p muscle size (all p > 0.17) and recruitment pattern (all p > 0.53). Decreased hip flexor muscle strength may affect physical function in patients with hip labral pathology by contributing to altered gait patterns and functional tasks. Clinical rehabilitation of these patients may need to include strengthening exercises for the hip flexor muscles. Copyright © 2014 Elsevier Ltd. All rights reserved.

Administration of soluble activin receptor 2B increases bone and muscle mass in a mouse model of osteogenesis imperfecta

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DiGirolamo, Douglas J.; Singhal, Vandana; Chang, Xiaoli; Lee, Se-Jin; Germain-Lee, Emily L.

2015-01-01

Osteogenesis imperfecta (OI) comprises a group of heritable connective tissue disorders generally defined by recurrent fractures, low bone mass, short stature and skeletal fragility. Beyond the skeletal complications of OI, many patients also report intolerance to physical activity, fatigue and muscle weakness. Indeed, recent studies have demonstrated that skeletal muscle is also negatively affected by OI, both directly and indirectly. Given the well-established interdependence of bone and skeletal muscle in both physiology and pathophysiology and the observations of skeletal muscle pathology in patients with OI, we investigated the therapeutic potential of simultaneous anabolic targeting of both bone and skeletal muscle using a soluble activin receptor 2B (ACVR2B) in a mouse model of type III OI (oim). Treatment of 12-week-old oim mice with ACVR2B for 4 weeks resulted in significant increases in both bone and muscle that were similar to those observed in healthy, wild-type littermates. This proof of concept study provides encouraging evidence for a holistic approach to treating the deleterious consequences of OI in the musculoskeletal system. PMID:26161291

Exercise Promotes Healthy Aging of Skeletal Muscle

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Cartee, Gregory D; Hepple, Russell T; Bamman, Marcas M

2016-01-01

caused by diseases and lifestyle factors. Secondary aging can exacerbate deficits in mitochondrial function and muscle mass, concomitant with the development of skeletal muscle insulin resistance. Exercise opposes deleterious effects of secondary aging by preventing the decline in mitochondrial...... respiration, mitigating aging-related loss of muscle mass and enhancing insulin sensitivity. This review focuses on mechanisms by which exercise promotes "healthy aging" by inducing modifications in skeletal muscle....

Changes in contractile properties of muscles receiving repeat injections of botulinum toxin (Botox).

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Fortuna, Rafael; Vaz, Marco Aurélio; Youssef, Aliaa Rehan; Longino, David; Herzog, Walter

2011-01-04

Botulinum toxin type A (BTX-A) is a frequently used therapeutic tool to denervate muscles in the treatment of neuromuscular disorders. Although considered safe by the US Food and Drug Administration, BTX-A can produce adverse effects in target and non-target muscles. With an increased use of BTX-A for neuromuscular disorders, the effects of repeat injections of BTX-A on strength, muscle mass and structure need to be known. Therefore, the purpose of this study was to investigate the changes in strength, muscle mass and contractile material in New Zealand White (NZW) rabbits. Twenty NZW rabbits were divided into 4 groups: control and 1, 3 and 6 months of unilateral, repeat injections of BTX-A into the quadriceps femoris. Outcome measures included knee extensor torque, muscle mass and the percentage of contractile material in the quadriceps muscles of the target and non-injected contralateral hindlimbs. Strength in the injected muscles was reduced by 88%, 89% and 95% in the 1, 3 and 6 months BTX-A injected hindlimbs compared to controls. Muscle mass was reduced by 50%, 42% and 31% for the vastus lateralis (VL), rectus femoris (RF) and vastus medialis (VM), respectively, at 1 month, by 68%, 51% and 50% at 3 months and by 76%, 44% and 13% at 6 months. The percentage of contractile material was reduced for the 3 and 6 months animals to 80-64%, respectively, and was replaced primarily by fat. Similar, but less pronounced results were also observed for the quadriceps muscles of the contralateral hindlimbs, suggesting that repeat BTX-A injections cause muscle atrophy and loss of contractile tissue in target muscles and also in non-target muscles that are far removed from the injection site. Copyright © 2010 Elsevier Ltd. All rights reserved.

Electrical Stimulation of Denervated Rat Skeletal Muscle Retards Capillary and Muscle Loss in Early Stages of Disuse Atrophy

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Kouki Nakagawa

2017-01-01

Full Text Available The purpose of the present study is to investigate the effects of low-frequency electrical muscle stimulation (ES on the decrease in muscle mass, fiber size, capillary supply, and matrix metalloproteinase (MMP immunoreactivity in the early stages of denervation-induced limb disuse. Direct ES was performed on the tibialis anterior muscle following denervation in seven-week-old male rats. The rats were divided into the following groups: control (CON, denervation (DN, and denervation with direct ES (DN + ES. Direct ES was performed at an intensity of 16 mA and a frequency of 10 Hz for 30 min per day, six days a week, for one week. We performed immunohistochemical staining to determine the expression of dystrophin, CD34, and MMP-2 in transverse sections of TA muscles. The weight, myofiber cross-sectional area (FCSA, and capillary-to-fiber (C/F ratio of the tibialis anterior (TA muscle were significantly reduced in the DN group compared to the control and DN + ES groups. The MMP-2 positive area was significantly greater in DN and DN + ES groups compared to the control group. These findings suggest beneficial effects of direct ES in reducing muscle atrophy and capillary regression without increasing MMP-2 immunoreactivity in the early stages of DN-induced muscle disuse in rat hind limbs.

Electrical Stimulation of Denervated Rat Skeletal Muscle Retards Capillary and Muscle Loss in Early Stages of Disuse Atrophy

Science.gov (United States)

Nakagawa, Kouki; Hayao, Keishi; Yotani, Kengo; Ogita, Futoshi; Yamamoto, Noriaki; Onishi, Hideaki

2017-01-01

The purpose of the present study is to investigate the effects of low-frequency electrical muscle stimulation (ES) on the decrease in muscle mass, fiber size, capillary supply, and matrix metalloproteinase (MMP) immunoreactivity in the early stages of denervation-induced limb disuse. Direct ES was performed on the tibialis anterior muscle following denervation in seven-week-old male rats. The rats were divided into the following groups: control (CON), denervation (DN), and denervation with direct ES (DN + ES). Direct ES was performed at an intensity of 16 mA and a frequency of 10 Hz for 30 min per day, six days a week, for one week. We performed immunohistochemical staining to determine the expression of dystrophin, CD34, and MMP-2 in transverse sections of TA muscles. The weight, myofiber cross-sectional area (FCSA), and capillary-to-fiber (C/F) ratio of the tibialis anterior (TA) muscle were significantly reduced in the DN group compared to the control and DN + ES groups. The MMP-2 positive area was significantly greater in DN and DN + ES groups compared to the control group. These findings suggest beneficial effects of direct ES in reducing muscle atrophy and capillary regression without increasing MMP-2 immunoreactivity in the early stages of DN-induced muscle disuse in rat hind limbs. PMID:28497057

Novel biomarkers of changes in muscle mass or muscle pathology

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Arvanitidis, Athanasios

healthy individuals and patients with different myopathy diseases, describe the underlying mechanisms of muscle conditions and possibly putative response to an intervention. There were three different studies where biomarkers were applied in this thesis. Study I involved 51 myositis patients (28...

Assessment of respiratory muscle strength in children according to the classification of body mass index

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George Jung da Rosa

2014-06-01

Full Text Available OBJECTIVE: To assess and compare the respiratory muscle strength among eutrophic, overweight and obese school children, as well as to identify anthropometric and respiratory variables related to the results.METHODS: Cross-sectional survey with healthy schoolchildren aged 7-9 years old, divided into three groups: Normal weight, Overweight and Obese. The International Study of Asthma and Allergies in Childhood (ISAAC questionnaire was applied. The body mass index (BMI was evaluated, as well as the forced expiratory volume in one second (FEV1 with a portable digital device. The maximal inspiratory and expiratory pressures (MIP and MEP were measured by a digital manometer. Comparisons between the groups were made by Kruskal-Wallis test. Spearman's correlation coefficient was used to analyze the correlations among the variables.RESULTS: MIP of eutrophic school children was higher than MIP found in overweight (p=0.043 and obese (p=0.013 children. MIP was correlated with BMI percentile and weight classification (r=-0.214 and r=-0.256 and MEP was correlated with height (r=0.328. Both pressures showed strong correlation with each other in all analyses (r≥0.773, and less correlation with FEV1 (MIP - r=0.362 and MEP - r=0.494. FEV1 correlated with MEP in all groups (r: 0.429 - 0.569 and with MIP in Obese Group (r=0.565. Age was correlated with FEV1 (r=0.578, MIP (r=0.281 and MEP (r=0.328.CONCLUSIONS: Overweight and obese children showed lower MIP values, compared to eutrophic ones. The findings point to the influence of anthropometric variables on respiratory muscle strength in children.

Case report 376: Accessory (anomalous) soleus muscle

International Nuclear Information System (INIS)

Apple, J.S.; Khoury, M.B.; Martinez, S.; Nunley, J.A.

1986-01-01

In summary, a case has been presented of a 24-year-old woman who developed pain in the left lower extremity while jogging. Physical examination showed a soft, palpable mass medial and anterior to the Achilles tendon in the left lower extremity. Although a lipoma was suspected, plain films and CT studies indicated clearly that the mass was not of fatty density. In fact, the density of the mass was equivalent to adjacent muscles. The mass itself was lying in the soft tissues of the left ankle tissue. An open biopsy showed a normal muscle which represented an accessory soleus muscle - a muscle known to be anomalous on accoasion and reported as being symptomatic or asymptomatic in different individuals. (orig./SHA)

Muscle size, neuromuscular activation, and rapid force characteristics in elderly men and women

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Suetta, C; Aagaard, P; Magnusson, S P

2007-01-01

quadriceps muscle cross-sectional area (LCSA), contractile rate of force development (RFD, Delta force/Delta time), impulse (integral force dt), muscle activation deficit (interpolated twitch technique), maximal neuromuscular activity [electromyogram (EMG)], and antagonist muscle coactivation in elderly men......%), contractile RFD (W: 17-26%; M: 15-24%), impulse (W: 10-19%, M: 19-20%), maximal EMG amplitude (W: 22-25%, M: 22-28%), and an increased muscle activation deficit (-18%) compared with UN. Furthermore, women were less strong (AF: 40%; UN: 39%), had less muscle mass (AF: 33%; UN: 34%), and had a lower RFD (AF: 38......-50%; UN: 41-48%) compared with men. Similarly, maximum EMG amplitude was smaller for both agonists (AF: 51-63%; UN: 35-61%) and antagonist (AF: 49-64%; UN: 36-56%) muscles in women compared with men. However, when MVC and RFD were normalized to LCSA, there were no differences between genders. The present...

Primary non-Hodgkin lymphoma of skeletal muscle: imaging findings

International Nuclear Information System (INIS)

Zhou Liangping; Peng Weijun; Tang Feng; Mao Jian; Yang Wentao

2006-01-01

Objective: To analyze the imaging manifestations of primary non-Hodgkin lymphoma of skeletal muscle and improve the recognition of this rare disease. Methods: Five cases of primary non- Hodgkin lymphoma of skeletal muscle proved pathologically underwent imaging exam, including MRI and CT in 3 cases, only MRI in 1 case, only CT in 1 case, X-ray in 2 cases and bone scintigraphy in 2 cases. Results: Diffuse enlargements of involved muscle with presentation of overall configuration were observed in all five cases. All 4 cases manifested as homogeneous soft masses, which is isoattenuating to normal muscle on unenhanced CT images. After intravenous injection of contrast media, the masses enhanced homogeneously and slightly (2 cases) or moderately (1 case) on CT images. The lesions were homogenous and had isointense or slightly low signal intensity compared with that of uninvolved muscle on T 1 -weighted images and high signal intensity on T 2 -weighted images. After intravenous injection of contrast media, all 2 cases enhanced homogeneously and moderately with the enhanced signal intensity of involved muscle greatly higher than that of uninvolved muscle on MR images. Two cases of X-ray plain showed no destruction of bone and 2 cases of bone scintigraphy exams showed increased radiotracer uptake of involved muscle with no infiltration of bone marrow. Conclusion: There are several characteristics on the imaging of primary non-Hodgkin lymphoma of skeletal muscle. MRI is the optimal imaging method for the diagnosis of this disease. (authors)

Beyond Body Mass Index. Is the Body Cell Mass Index (BCMI) a useful prognostic factor to describe nutritional, inflammation and muscle mass status in hospitalized elderly?: Body Cell Mass Index links in elderly.

Science.gov (United States)

Rondanelli, Mariangela; Talluri, Jacopo; Peroni, Gabriella; Donelli, Chiara; Guerriero, Fabio; Ferrini, Krizia; Riggi, Emilia; Sauta, Elisabetta; Perna, Simone; Guido, Davide

2018-06-01

The aim of this study was to establish the effectiveness of Body Cell Mass Index (BCMI) as a prognostic index of (mal)nutrition, inflammation and muscle mass status in the elderly. A cross-sectional observational study has been conducted on 114 elderly patients (80 women and 34 men), with mean age equal to 81.07 ± 6.18 years. We performed a multivariate regression model by Structural Equation Modelling (SEM) framework. We detected the effects over a Mini Nutritional Assessment (MNA) stratification, by performing a multi-group multivariate regression model (via SEM) in two MNA nutritional strata, less and bigger (or equal) than 17. BCMI had a significant effect on albumin (β = +0.062, P = 0.001), adjusting for the other predictors of the model as Body Mass Index (BMI), age, sex, fat mass and cognitive condition. An analogous result is maintained in MNAelderly patients. Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Concurrent Label-Free Mass Spectrometric Analysis of Dystrophin Isoform Dp427 and the Myofibrosis Marker Collagen in Crude Extracts from mdx-4cv Skeletal Muscles

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Murphy, Sandra; Zweyer, Margit; Mundegar, Rustam R.; Henry, Michael; Meleady, Paula; Swandulla, Dieter; Ohlendieck, Kay

2015-01-01

The full-length dystrophin protein isoform of 427 kDa (Dp427), the absence of which represents the principal abnormality in X-linked muscular dystrophy, is difficult to identify and characterize by routine proteomic screening approaches of crude tissue extracts. This is probably related to its large molecular size, its close association with the sarcolemmal membrane, and its existence within a heterogeneous glycoprotein complex. Here, we used a careful extraction procedure to isolate the total protein repertoire from normal versus dystrophic mdx-4cv skeletal muscles, in conjunction with label-free mass spectrometry, and successfully identified Dp427 by proteomic means. In contrast to a considerable number of previous comparative studies of the total skeletal muscle proteome, using whole tissue proteomics we show here for the first time that the reduced expression of this membrane cytoskeletal protein is the most significant alteration in dystrophinopathy. This agrees with the pathobiochemical concept that the almost complete absence of dystrophin is the main defect in Duchenne muscular dystrophy and that the mdx-4cv mouse model of dystrophinopathy exhibits only very few revertant fibers. Significant increases in collagens and associated fibrotic marker proteins, such as fibronectin, biglycan, asporin, decorin, prolargin, mimecan, and lumican were identified in dystrophin-deficient muscles. The up-regulation of collagen in mdx-4cv muscles was confirmed by immunofluorescence microscopy and immunoblotting. Thus, this is the first mass spectrometric study of crude tissue extracts that puts the proteomic identification of dystrophin in its proper pathophysiological context. PMID:28248273

Structural and biochemical characteristics of locomotory muscles of emperor penguins, Aptenodytes forsteri.

Science.gov (United States)

Ponganis, P J; Costello, M L; Starke, L N; Mathieu-Costello, O; Kooyman, G L

1997-07-01

Structural and biochemical characteristics of the primary muscles used for swimming (pectoralis, PEC and supracoracoideus, SC) were compared to those of leg muscles in emperor penguins (Aptenodytes forsteri). The mass of PEC-SC was four times that of the leg musculature, and mitochondrial volume density in PEC and SC (4%) was two-thirds that in sartorius (S) and gastrocnemius. The differences in muscle mass and mitochondrial density yielded a 2.2-fold greater total mitochondrial content in PEC-SC than leg muscles, which appears to account for the 1.8-fold greater whole-body highest oxygen consumption previously recorded in emperor penguins during swimming compared to walking. Calculation of maximal mitochondrial O2 consumption in PEC-SC and leg muscle yielded value of 5.8-6.9 ml O2 ml-1 min-1, which are similar to those in locomotory muscles of most mammals and birds. A distinct feature of emperor penguin muscle was its myoglobin content, with concentrations in PEC-SC (6.4 g 100 g-1 among the highest measured in any species. This resulted in a PEC-SC O2 store greater than that of the entire blood. In addition, ratios of myoglobin content to mitochondrial volume density and to citrate synthase activity were 4.4 and 2.5 times greater in PEC than in S, indicative of the significant role of myoglobin in the adaptation of muscle to cardiovascular adjustments during diving.

Comparative molecular analysis of early and late cancer cachexia-induced muscle wasting in mouse models.

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Sun, Rulin; Zhang, Santao; Lu, Xing; Hu, Wenjun; Lou, Ning; Zhao, Yan; Zhou, Jia; Zhang, Xiaoping; Yang, Hongmei

2016-12-01

Cancer-induced muscle wasting, which commonly occurs in cancer cachexia, is characterized by impaired quality of life and poor patient survival. To identify an appropriate treatment, research on the mechanism underlying muscle wasting is essential. Thus far, studies on muscle wasting using cancer cachectic models have generally focused on early cancer cachexia (ECC), before severe body weight loss occurs. In the present study, we established models of ECC and late cancer cachexia (LCC) and compared different stages of cancer cachexia using two cancer cachectic mouse models induced by colon-26 (C26) adenocarcinoma or Lewis lung carcinoma (LLC). In each model, tumor-bearing (TB) and control (CN) mice were injected with cancer cells and PBS, respectively. The TB and CN mice, which were euthanized on the 24th day or the 36th day after injection, were defined as the ECC and ECC-CN mice or the LCC and LCC-CN mice. In addition, the tissues were harvested and analyzed. We found that both the ECC and LCC mice developed cancer cachexia. The amounts of muscle loss differed between the ECC and LCC mice. Moreover, the expression of some molecules was altered in the muscles from the LCC mice but not in those from the ECC mice compared with their CN mice. In conclusion, the molecules with altered expression in the muscles from the ECC and LCC mice were not exactly the same. These findings may provide some clues for therapy which could prevent the muscle wasting in cancer cachexia from progression to the late stage.

The Comparing the Leg Muscles Electromyography during Single Leg Drop Landing in Pesplanus and Normal Men

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mostafa bazvand

2016-03-01

Full Text Available Objective: pesplanus is one of the changes that brings about changes in muscle activation patterns. Being aware of muscles activity changes in various standing positions among pesplanus patients provides insights into preventing lower extremity injuries in this population. The aim of this study was to compare leg muscles electromyography during various standing positions in pesplanus and normal subjects. Methods: 60 healthy male university students, 30 subjects with pesplanus deformity (with average age 23/54±3/57 year, average height 175/34±7/62 cm, average weight 74/87±10/72 kg and 30 normal subjects (with average age 22/97±2/38 year, average height 176/6±5/59 cm, average weight 73/58±8/36 kg participated in this comparative study. Deformity of pesplanus was assessed with navicular drop test. Each subject performed single-leg landing dropping from 30cm height onto a force platform where muscles activity was recorded with EMG device. For data analysis, Matlab and Spss softwares were used and independent sample t-test was used to compare the dependent variables at a significance level of P &le 0/05. Results: Significant differences were observed between the two groups for the activities of the longus peroneus and anterior tibialis muscles ( p&le0/05 while no significant differences were observed in other muscles. Conclusion: The changes in the normal structure of the foot might affect muscle activities during standing, which can cause changes in the injury patterns. Therefore, it is proposed that focusing on corrective exercises and therapy plan can reduce these risks.

Muscle function and postural balance in lifelong trained male footballers compared with sedentary elderly men and youngsters

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Sundstrup, Emil; Jakobsen, Markus D.; Andersen, Lars Juel

2010-01-01

The present study investigated whether elderly subjects exposed to lifelong football training have better rapid muscle force characteristics, body composition and postural stability in comparison with untrained elderly. Ten elderly men exposed to lifelong football training (FTE; 69.6 ± 1.4 years....../s), higher total lean body mass (56.9 ± 0.8 vs 52.7 ± 2.2 kg) and better postural stability (Flamingo test: 15 ± 1 vs 33 ± 2 falls) compared with UE (P... in UE (Ppostural stability were consistently higher in elderly subjects exposed to lifelong football training, providing an enhanced ability to counteract unexpected perturbations in postural balance. The superior RFD and balance in elderly footballers were...

Regulation of Akt-mTOR, ubiquitin-proteasome and autophagy-lysosome pathways in locomotor and respiratory muscles during experimental sepsis in mice.

Science.gov (United States)

Morel, Jérome; Palao, Jean-Charles; Castells, Josiane; Desgeorges, Marine; Busso, Thierry; Molliex, Serge; Jahnke, Vanessa; Del Carmine, Peggy; Gondin, Julien; Arnould, David; Durieux, Anne Cécile; Freyssenet, Damien

2017-09-07

Sepsis induced loss of muscle mass and function contributes to promote physical inactivity and disability in patients. In this experimental study, mice were sacrificed 1, 4, or 7 days after cecal ligation and puncture (CLP) or sham surgery. When compared with diaphragm, locomotor muscles were more prone to sepsis-induced muscle mass loss. This could be attributed to a greater activation of ubiquitin-proteasome system and an increased myostatin expression. Thus, this study strongly suggests that the contractile activity pattern of diaphragm muscle confers resistance to atrophy compared to the locomotor gastrocnemius muscle. These data also suggest that a strategy aimed at preventing the activation of catabolic pathways and preserving spontaneous activity would be of interest for the treatment of patients with sepsis-induced neuromyopathy.

Effect of restriction vegan diet's on muscle mass, oxidative status, and myocytes differentiation: A pilot study.

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Vanacore, Daniela; Messina, Giovanni; Lama, Stefania; Bitti, Giuseppe; Ambrosio, Pasqualina; Tenore, Giancarlo; Messina, Antonietta; Monda, Vincenzo; Zappavigna, Silvia; Boccellino, Mariarosaria; Novellino, Ettore; Monda, Marcellino; Stiuso, Paola

2018-01-10

This study was conceived to evaluate the effects of three different diets on body composition, metabolic parameters, and serum oxidative status. We enrolled three groups of healthy men (omnivores, vegetarians, and vegans) with similar age, weight and BMI, and we observed a significant decrease in muscle mass index and lean body mass in vegan compared to vegetarian and omnivore groups, and higher serum homocysteine levels in vegetarians and vegans compared to omnivores. We studied whether serum from omnivore, vegetarian, and vegan subjects affected oxidative stress, growth and differentiation of both cardiomyoblast cell line H9c2 and H-H9c2 (H9c2 treated with H 2 O 2 to induce oxidative damage). We demonstrated that vegan sera treatment of both H9c2 and H-H9c2 cells induced an increase of TBARS values and cell death and a decrease of free NO 2- compared to vegetarian and omnivorous sera. Afterwards, we investigated the protective effects of vegan, vegetarian, and omnivore sera on the morphological changes induced by H 2 O 2 in H9c2 cell line. We showed that the omnivorous sera had major antioxidant and differentiation properties compared to vegetarian and vegan sera. Finally, we evaluated the influence of the three different groups of sera on MAPKs pathway and our data suggested that ERK expression increased in H-H9c2 cells treated with vegetarian and vegan sera and could promote cell death. The results obtained in this study demonstrated that restrictive vegan diet could not prevent the onset of metabolic and cardiovascular diseases nor protect by oxidative damage. © 2018 Wiley Periodicals, Inc.

Adiposity, muscle mass and muscle strength in relation to functional decline in older persons.

NARCIS (Netherlands)

Schaap, L.A.; Koster, A.; Visser, M.

2013-01-01

Aging is associated with changes in body composition and muscle strength. This review aimed to determine the relation between different body composition measures and muscle strength measures and functional decline in older men and women. By use of relevant databases (PubMed, Embase, and CINAHL) and

Agonist muscle adaptation accompanied by antagonist muscle atrophy in the hindlimb of mice following stretch-shortening contraction training.

Science.gov (United States)

Rader, Erik P; Naimo, Marshall A; Ensey, James; Baker, Brent A

2017-02-02

The vast majority of dynamometer-based animal models for investigation of the response to chronic muscle contraction exposure has been limited to analysis of isometric, lengthening, or shortening contractions in isolation. An exception to this has been the utilization of a rat model to study stretch-shortening contractions (SSCs), a sequence of consecutive isometric, lengthening, and shortening contractions common during daily activity and resistance-type exercise. However, the availability of diverse genetic strains of rats is limited. Therefore, the purpose of the present study was to develop a dynamometer-based SSC training protocol to induce increased muscle mass and performance in plantarflexor muscles of mice. Young (3 months old) C57BL/6 mice were subjected to 1 month of plantarflexion SSC training. Hindlimb muscles were analyzed for muscle mass, quantitative morphology, myogenesis/myopathy relevant gene expression, and fiber type distribution. The main aim of the research was achieved when training induced a 2-fold increase in plantarflexion peak torque output and a 19% increase in muscle mass for the agonist plantaris (PLT) muscle. In establishing this model, several outcomes emerged which raised the value of the model past that of being a mere recapitulation of the rat model. An increase in the number of muscle fibers per transverse muscle section accounted for the PLT muscle mass gain while the antagonist tibialis anterior (TA) muscle atrophied by 30% with preferential atrophy of type IIb and IIx fibers. These alterations were accompanied by distinct gene expression profiles. The findings confirm the development of a stretch-shortening contraction training model for the PLT muscle of mice and demonstrate that increased cross-sectional fiber number can occur following high-intensity SSC training. Furthermore, the TA muscle atrophy provides direct evidence for the concept of muscle imbalance in phasic non-weight bearing muscles, a concept largely

Does metabosensitive afferent fibers activity differ from slow- and fast-twitch muscles?

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Caron, Guillaume; Decherchi, Patrick; Marqueste, Tanguy

2015-09-01

This study was designed to investigate the metabosensitive afferent response evoked by electrically induced fatigue (EIF), lactic acid (LA) and potassium chloride (KCl) in three muscle types. We recorded the activity of groups III-IV afferents originating from soleus, gastrocnemius and tibialis anterior muscles. Our data showed a same pattern of response in the three muscles after chemical injections, i.e., a bell curve with maximal discharge rate at 1 mM for LA injections and a linear relationship between KCl concentrations and the afferent discharge rate. Furthermore, a stronger response was recorded after EIF in the gastrocnemius muscle compared to the two other muscles. The change in afferent discharge after 1 mM LA injection was higher for the gastrocnemius muscle compared to the response obtained with the corresponding concentration applied in the two other muscles, whereas changes to KCl injections did not dramatically differ between the three muscles. We conclude that anatomical (mass, phenotype, vascularization, receptor and afferent density…) and functional (flexor vs. extensor) differences between muscles could explain the amplitude of these responses.

Injectable skeletal muscle matrix hydrogel promotes neovascularization and muscle cell infiltration in a hindlimb ischemia model

Directory of Open Access Journals (Sweden)

JA DeQuach

2012-06-01

Full Text Available Peripheral artery disease (PAD currently affects approximately 27 million patients in Europe and North America, and if untreated, may progress to the stage of critical limb ischemia (CLI, which has implications for amputation and potential mortality. Unfortunately, few therapies exist for treating the ischemic skeletal muscle in these conditions. Biomaterials have been used to increase cell transplant survival as well as deliver growth factors to treat limb ischemia; however, existing materials do not mimic the native skeletal muscle microenvironment they are intended to treat. Furthermore, no therapies involving biomaterials alone have been examined. The goal of this study was to develop a clinically relevant injectable hydrogel derived from decellularized skeletal muscle extracellular matrix and examine its potential for treating PAD as a stand-alone therapy by studying the material in a rat hindlimb ischemia model. We tested the mitogenic activity of the scaffold’s degradation products using an in vitro assay and measured increased proliferation rates of smooth muscle cells and skeletal myoblasts compared to collagen. In a rat hindlimb ischemia model, the femoral artery was ligated and resected, followed by injection of 150 µL of skeletal muscle matrix or collagen 1 week post-injury. We demonstrate that the skeletal muscle matrix increased arteriole and capillary density, as well as recruited more desmin-positive and MyoD-positive cells compared to collagen. Our results indicate that this tissue-specific injectable hydrogel may be a potential therapy for treating ischemia related to PAD, as well as have potential beneficial effects on restoring muscle mass that is typically lost in CLI.

Comparing electro- and mechano-myographic muscle activation patterns in self-paced pediatric gait.

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Plewa, Katherine; Samadani, Ali; Chau, Tom

2017-10-01

Electromyography (EMG) is the standard modality for measuring muscle activity. However, the convenience and availability of low-cost accelerometer-based wearables makes mechanomyography (MMG) an increasingly attractive alternative modality for clinical applications. Literature to date has demonstrated a strong association between EMG and MMG temporal alignment in isometric and isokinetic contractions. However, the EMG-MMG relationship has not been studied in gait. In this study, the concurrence of EMG- and MMG-detected contractions in the tibialis anterior, lateral gastrocnemius, vastus lateralis, and biceps femoris muscles were investigated in children during self-paced gait. Furthermore, the distribution of signal power over the gait cycle was statistically compared between EMG-MMG modalities. With EMG as the reference, muscular contractions were detected based on MMG with balanced accuracies between 88 and 94% for all muscles except the gastrocnemius. MMG signal power differed from that of EMG during certain phases of the gait cycle in all muscles except the biceps femoris. These timing and power distribution differences between the two modalities may in part be related to muscle fascicle length changes that are unique to muscle motion during gait. Our findings suggest that the relationship between EMG and MMG appears to be more complex during gait than in isometric and isokinetic contractions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Retardation of muscle growth in castrated male mice: further ...

African Journals Online (AJOL)

Retardation of muscle growth in castrated male mice was studied as an evidence for the influence of hormones on the development of muscle mass. Male albino mice were castrated at 28days of age by open castration method. The weights and the muscle mass indices (mg muscle weight per gram body weight) of the ...

Feasibility of resistance training in adult McArdle patients: clinical outcomes and muscle strength and mass benefits.

Science.gov (United States)

Santalla, Alfredo; Munguía-Izquierdo, Diego; Brea-Alejo, Lidia; Pagola-Aldazábal, Itziar; Díez-Bermejo, Jorge; Fleck, Steven J; Ara, Ignacio; Lucia, Alejandro

2014-01-01

We analyzed the effects of a 4-month resistance (weight lifting) training program followed by a 2-month detraining period in 7 adult McArdle patients (5 female) on: muscle mass (assessed by DXA), strength, serum creatine kinase (CK) activity and clinical severity. Adherence to training was ≥84% in all patients and no major contraindication or side effect was noted during the training or strength assessment sessions. The training program had a significant impact on total and lower extremities' lean mass (P training by +855 g (95% confidence interval (CI): 30, 1679) and +547 g (95%CI: 116, 978), respectively, and significantly decreasing with detraining. Body fat showed no significant changes over the study period. Bench press and half-squat performance, expressed as the highest value of average muscle power (W) or force (N) in the concentric-repetition phase of both tests showed a consistent increase over the 4-month training period, and decreased with detraining. Yet muscle strength and power detraining values were significantly higher than pre-training values, indicating that a training effect was still present after detraining. Importantly, all the participants, with no exception, showed a clear gain in muscle strength after the 4-month training period, e.g., bench press: +52 W (95% CI: 13, 91); half-squat: +173 W (95% CI: 96, 251). No significant time effect (P > 0.05) was noted for baseline or post strength assessment values of serum CK activity, which remained essentially within the range reported in our laboratory for McArdle patients. All the patients changed to a lower severity class with training, such that none of them were in the highest disease severity class (3) after the intervention and, as such, they did not have fixed muscle weakness after training. Clinical improvements were retained, in all but one patient, after detraining, such that after detraining all patients were classed as class 1 for disease severity.

Skeletal muscle adaptation to immobilization and subsequent retraining in elderly men

DEFF Research Database (Denmark)

Dideriksen, K; Boesen, A P; Kristiansen, J F

2016-01-01

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) may enhance resistance training induced gain in skeletal muscle mass and strength, but it is unknown if NSAIDs affects muscle loss during periods of inactivity in elderly individuals. Thus, we studied the influence of NSAID treatment on h...... weeks of retraining and whey protein supplementation. After 6weeks of retraining and whey protein supplementation, muscle mass and strength increased beyond baseline levels, and NSAID treatment did not significantly influence this in elderly.......BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) may enhance resistance training induced gain in skeletal muscle mass and strength, but it is unknown if NSAIDs affects muscle loss during periods of inactivity in elderly individuals. Thus, we studied the influence of NSAID treatment...... isolate was ingested (2×20g/d) throughout the whole study period. Plasma inflammatory markers, quadriceps muscle mass and strength, and muscle gene expression were investigated. RESULTS: Muscle mass and strength decreased after 2weeks of immobilization (P

Cycle ergometer and inspiratory muscle training offer modest benefit compared with cycle ergometer alone: a comprehensive assessment in stable COPD patients

Directory of Open Access Journals (Sweden)

Wang K

2017-09-01

Full Text Available Kai Wang,1,* Guang-qiao Zeng,2,* Rui Li,1,* Yu-wen Luo,1 Mei Wang,1 Yu-he Hu,1 Wen-hui Xu,1 Lu-qian Zhou,2 Rong-chang Chen,2 Xin Chen1 1Department of Respiratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China; 2Department of Respiratory Medicine, The State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China *These authors contributed equally to this work Background: Cycle ergometer training (CET has been shown to improve exercise performance of the quadriceps muscles in patients with COPD, and inspiratory muscle training (IMT may improve the pressure-generating capacity of the inspiratory muscles. However, the effects of combined CET and IMT remain unclear and there is a lack of comprehensive assessment.Materials and methods: Eighty-one patients with COPD were randomly allocated to three groups: 28 received 8 weeks of CET + IMT (combined training group, 27 received 8 weeks of CET alone (CET group, and 26 only received 8 weeks of free walking (control group. Comprehensive assessment including respiratory muscle strength, exercise capacity, pulmonary function, dyspnea, quality of life, emotional status, nutritional status, and body mass index, airflow obstruction, and exercise capacity index were measured before and after the pulmonary rehabilitation program.Results: Respiratory muscle strength, exercise capacity, inspiratory capacity, dyspnea, quality of life, depression and anxiety, and nutritional status were all improved in the combined training and CET groups when compared with that in the control group (P<0.05 after pulmonary rehabilitation program. Inspiratory muscle strength increased significantly in the combined training group when compared with that in the CET group (ΔPImax [maximal inspiratory pressure] 5.20±0.89 cmH2O vs 1.32±0.91 cmH2O

A comparative study of different amniotic membrane orientations during extraocular muscle surgery in rabbits.

Science.gov (United States)

Kassem, Rehab Rashad; El-Mofty, Randa Mohamed Abdel-Moneim; Khodeir, Mustafa Mahmoud; Hamza, Wael Mostafa

2018-03-01

To histopathologically compare the effect of different orientations of cryopreserved human amniotic membrane (AM) transplant during extraocular muscle surgery in rabbits. Fifty-two albino rabbit eyes underwent 4-mm resection of the superior rectus. Eyes were randomly divided into four groups. In Group C (Control group, 16 eyes) the muscle was not wrapped with amniotic membrane. In the three AM groups, cryopreserved AM was wrapped around the muscle, oriented with either its stroma (Group S, 15 eyes) or epithelium (Group E, nine eyes) towards the muscle, or folded on itself with the epithelium externally (Group F, 12 eyes). The rabbits were sacrificed and the eyes were enucleated 6 weeks after surgery. Histopathological examination was conducted for periamniotic, foreign body, scleral, and conjunctival inflammation, conjunctival vascularity, adhesions and muscle fibrosis. In all AM eyes, the AM was surrounded by periamniotic inflammation, with no adhesions detected between the muscle and surrounding tissues in the segment where the AM was present, but detected elsewhere. Adhesions were detected in all group C eyes. Foreign body inflammation was significantly less in Group C than in each of the AM groups (p  .05). Scleral inflammation was absent in all specimens. No significant differences were noted among all groups in terms of conjunctival vascularity, conjunctival inflammation, or muscle fibrosis (p > .05). All AM orientations were equally effective in preventing the development of postoperative adhesions between the extraocular muscle and surrounding tissues.

Influence of aging on isometric muscle strength, fat-free mass and electromyographic signal power of the upper and lower limbs in women

Science.gov (United States)

Amaral, Josária F.; Alvim, Felipe C.; Castro, Eliane A.; Doimo, Leonice A.; Silva, Marcus V.; Novo, José M.

2014-01-01

Background Aging is a multifactorial process that leads to changes in the quantity and quality of skeletal muscle and contributes to decreased levels of muscle strength. Objective This study sought to investigate whether the isometric muscle strength, fat-free mass (FFM) and power of the electromyographic (EMG) signal of the upper and lower limbs of women are similarly affected by aging. Method The sample consisted of 63 women, who were subdivided into three groups (young (YO) n=33, 24.7±3.5 years; middle age (MA) n=15, 58.6±4.2 years; and older adults (OA). n=15, 72.0±4.2 years). Isometric strength was recorded simultaneously with the capture of the electrical activity of the flexor muscles of the fingers and the vastus lateralis during handgrip and knee extension tests, respectively. FFM was assessed using dual-energy X-ray absorptiometry. Results The handgrip strength measurements were similar among groups (p=0.523), whereas the FFM of the upper limbs was lower in group OA compared to group YO (p=0.108). The RMSn values of the hand flexors were similar among groups (p=0.754). However, the strength of the knee extensors, the FFM of the lower limbs and the RMSn values of the vastus lateralis were lower in groups MA (p=0.014, p=0.006 and p=0.013, respectively) and OA (p=0.000, p=0.000 and pisometric muscle strength in MLG and electromyographic activity of the lower limbs are more pronounced with the aging process of the upper limb. PMID:24676705

Muscle strength in patients with acromegaly at diagnosis and during long-term follow-up.

Science.gov (United States)

Füchtbauer, Laila; Olsson, Daniel S; Bengtsson, Bengt-Åke; Norrman, Lise-Lott; Sunnerhagen, Katharina S; Johannsson, Gudmundur

2017-08-01

Patients with acromegaly have decreased body fat (BF) and increased extracellular water (ECW) and muscle mass. Although there is a lack of systematic studies on muscle function, it is believed that patients with acromegaly may suffer from proximal muscle weakness despite their increased muscle mass. We studied body composition and muscle function in untreated acromegaly and after biochemical remission. Prospective observational study. Patients with acromegaly underwent measurements of muscle strength (dynamometers) and body composition (four-compartment model) at diagnosis ( n  = 48), 1 year after surgery ( n  = 29) and after long-term follow-up (median 11 years) ( n  = 24). Results were compared to healthy subjects. Untreated patients had increased body cell mass (113 ± 9% of predicted) and ECW (110 ± 20%) and decreased BF (67 ± 7.6%). At one-year follow-up, serum concentration of IGF-I was reduced and body composition had normalized. At baseline, isometric muscle strength in knee flexors and extensors was normal and concentric strength was modestly increased whereas grip strength and endurance was reduced. After one year, muscle strength was normal in both patients with still active disease and patients in remission. At long-term follow-up, all patients were in remission. Most muscle function tests remained normal, but isometric flexion and the fatigue index were increased to 153 ± 42% and 139 ± 28% of predicted values, respectively. Patients with untreated acromegaly had increased body cell mass and normal or modestly increased proximal muscle strength, whereas their grip strength was reduced. After biochemical improvement and remission, body composition was normalized, hand grip strength was increased, whereas proximal muscle fatigue increased. © 2017 European Society of Endocrinology.

Low vitamin D status is associated with reduced muscle mass and impaired physical performance in frail elderly people

NARCIS (Netherlands)

Tieland, C.A.B.; Brouwer, E.M.; Nienaber-Rousseau, C.; Loon, van L.J.C.; Groot, de C.P.G.M.

2013-01-01

Background/Objectives: Serum 25-hydroxyvitamin D (25(OH)D) status has been associated with muscle mass, strength and physical performance in healthy elderly people. Yet, in pre-frail and frail elderly people this association has not been studied. The objective of this study was to explore the

The Human Skeletal Muscle Proteome Project

DEFF Research Database (Denmark)

Gonzalez-Freire, Marta; Semba, Richard D.; Ubaida-Mohien, Ceereena

2017-01-01

Skeletal muscle is a large organ that accounts for up to half the total mass of the human body. A progressive decline in muscle mass and strength occurs with ageing and in some individuals configures the syndrome of ‘sarcopenia’, a condition that impairs mobility, challenges autonomy, and is a ri...

Low skeletal muscle mass is associated with increased hospital expenditure in patients undergoing cancer surgery of the alimentary tract

NARCIS (Netherlands)

J.L.A. van Vugt (Jeroen); S. Büttner (Stefan); S. Levolger (S.); R.R.J. Coebergh van den Braak (Robert); M. Suker (Mustafa); M.P. Gaspersz (Marcia); R.W.F. de Bruin (Ron); C. Verhoef (Kees); Van Eijck, C.H.C. (Casper H. C.); Bossche, N. (Niek); B. Groot Koerkamp (Bas); J.N.M. IJzermans (Jan)

2017-01-01

textabstractBackground: Low skeletal muscle mass is associated with poor postoperative outcomes in cancer patients. Furthermore, it is associated with increased healthcare costs in the United States. We investigated its effect on hospital expenditure in a Western-European healthcare system, with

Per meal dose and frequency of protein consumption is associated with lean mass and muscle performance.

Science.gov (United States)

Loenneke, Jeremy P; Loprinzi, Paul D; Murphy, Caoileann H; Phillips, Stuart M

2016-12-01

It has been hypothesized that for older adults evenly distributing consumption of protein at 30-40 g per meal throughout the day may result in more favorable retention of lean mass and muscular strength. Such a thesis has not, to our knowledge, been tested outside of short-term studies or acute measures of muscle protein synthesis. To examine whether the number of times an individual consumed a minimum of 30 g of protein at a meal is associated with leg lean mass and knee extensor strength. Data from the 1999-2002 NHANES were used, with 1081 adults (50-85 y) constituting the analytic sample. A "multiple pass" 24-h dietary interview format was used to collect detailed information about the participants' dietary intake. Knee extensor strength was assessed objectively using the Kin Com MP dynamometer. Leg lean mass was estimated from whole-body dual-energy X-ray absorptiometry (DXA) scans. Participants with 1 vs. 0 (β adjusted  = 23.6, p = 0.002) and 2 vs. 0 (β adjusted  = 51.1, p = 0.001) meals of ≥30 g protein/meal had greater strength and leg lean mass (1 vs. 0, β adjusted  = 1160, p frequency with leg lean mass and strength plateaued at ∼45 g protein/meal for those consuming 2 vs. 0 meals above the evaluated protein/meal threshold. However, for those with only 1 meal at or above the evaluated threshold, the response plateaued at 30 g/meal. Leg lean mass mediated the relationship between protein frequency and strength, with the proportion of the total effect mediated being 64%. We found that more frequent consumption of meals containing between 30 and 45 g protein/meal produced the greatest association with leg lean mass and strength. Thus, the consumption of 1-2 daily meals with protein content from 30 to 45 g may be an important strategy for increasing and/or maintaining lean body mass and muscle strength with aging. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Feasibility of resistance training in adult McArdle patients: Clinical outcomes and muscle strength and mass benefits

Directory of Open Access Journals (Sweden)

Alfredo eSantalla

2014-12-01

Full Text Available We analyzed the effects of a 4-month resistance (weight lifting training program followed by a 2-month detraining period in 7 adult McArdle patients (5 female on: muscle mass (assessed by DXA, strength, serum creatine kinase (CK activity and clinical severity. Adherence to training was ≥ 84% in all patients and no major contraindication or side effect was noted during the training or strength assessment sessions. The training program had a significant impact on total and lower extremities’ lean mass (P0.05 was noted for baseline or post strength assessment values of serum CK activity, which remained essentially within the range reported in our laboratory for McArdle patients. All the patients changed to a lower severity class with training, such that none of them were in the highest disease severity class (3 after the intervention and, as such, they did not have fixed muscle weakness after training. Clinical improvements were retained, in all but one patient, after detraining, such that after detraining all patients were classed as class 1 for

Leucine incorporation into mixed skeletal muscle protein in humans

International Nuclear Information System (INIS)

Nair, K.S.; Halliday, D.; Griggs, R.C.

1988-01-01

Fractional mixed skeletal muscle protein synthesis (FMPS) was estimated in 10 postabsorptive healthy men by determining the increment in the abundance of [ 13 C]-leucine in quadriceps muscle protein during an intravenous infusion of L-[1- 13 C]leucine. Whole-body muscle protein synthesis (MPS) was calculated based on the estimation of muscle mass from creatinine excretion and compared with whole-body protein synthesis (WBPS) calculated from the nonoxidative portion of leucine flux. A significant correlation was found between MPS. The contribution of MPS to WBPS was 27 ± 1%, which is comparable to the reports in other species. Morphometric analyses of adjacent muscle samples in eight subjects demonstrated that the biopsy specimens consisted of 86.5 ± 2% muscular as opposed to other tissues. Because fiber type composition varies between biopsies, the authors examined the relationship between proportions of each fiber type and FMPS. Variation in the composition of biopsies and in fiber-type proportion did not affect the estimation of muscle protein synthesis rate. They conclude that stable isotope techniques using serial needle biopsies permit the direct measurement of FMPS in humans and that this estimation is correlated with an indirect estimation of WBPS

Lower limb asymmetry in mechanical muscle function

DEFF Research Database (Denmark)

Jordan, M J; Aagaard, Per; Herzog, W

2015-01-01

.05), and the final phase of the SJ (P AI in the CMJ concentric phase (r = 0.57, P Future research is required to assess the role of the CMJ and SJ phase-specific kinetic impulse AI......-R). Elite alpine skiers with ACL-R (n = 9; 26.2 ± 11.8 months post-op) and uninjured skiers (n = 9) participated in neuromuscular screening. Vertical ground reaction force during the CMJ and SJ was assessed using dual force plate methodology to obtain phase-specific bilateral asymmetry indices (AIs......) for kinetic impulse (CMJ and SJ phase-specific kinetic impulse AI). Dual x-ray absorptiometry scanning was used to assess asymmetry in lower body muscle mass. Compared with controls, ACL-R skiers had increased AI in muscle mass (P AI in the CMJ concentric phase (P 

Cellular and molecular mechanisms of muscle atrophy

Directory of Open Access Journals (Sweden)

Paolo Bonaldo

2013-01-01

Full Text Available Skeletal muscle is a plastic organ that is maintained by multiple pathways regulating cell and protein turnover. During muscle atrophy, proteolytic systems are activated, and contractile proteins and organelles are removed, resulting in the shrinkage of muscle fibers. Excessive loss of muscle mass is associated with poor prognosis in several diseases, including myopathies and muscular dystrophies, as well as in systemic disorders such as cancer, diabetes, sepsis and heart failure. Muscle loss also occurs during aging. In this paper, we review the key mechanisms that regulate the turnover of contractile proteins and organelles in muscle tissue, and discuss how impairments in these mechanisms can contribute to muscle atrophy. We also discuss how protein synthesis and degradation are coordinately regulated by signaling pathways that are influenced by mechanical stress, physical activity, and the availability of nutrients and growth factors. Understanding how these pathways regulate muscle mass will provide new therapeutic targets for the prevention and treatment of muscle atrophy in metabolic and neuromuscular diseases.

Comparative study on conjoint fascial sheath suspension and levator muscle resection for moderate or severe congenital ptosis

Directory of Open Access Journals (Sweden)

Wei Lin

2016-06-01

Full Text Available AIM:To compare the curative effect of conjoint fascial sheath(CSFsuspension and levator muscle resection for moderate or severe congenital ptosis. METHODS: Forty-three patients(74 eyeswith moderate or severe ptosis were treated by CSF suspension or levator muscle resection randomly, and followed up for 6mo. The normalization rates of the two operations were then compared by statistical method, and the complications of the two operations were analyzed.RESULTS: The two operations appeared no significant difference on the normalization rate for moderate congenital ptosis(P>0.05, while the normalization rate of CSF suspension on severe congenital ptosis was significantly higher than that of levator muscle resection(PCONCLUSION: CSF suspension is more effective on the treatment of severe congenital ptosis than levator muscle resection, and has advantages such as less trauma, repeatable, and less complication.

Immobilization/remobilization and the regulation of muscle mass

Science.gov (United States)

Almon, R. R.

1983-01-01

The relationship between animal body weight and the wet and dry weights of the soleus and EDL muscles was derived. Procedures were examined for tissue homogenization, fractionation, protein determination and DNA determination. A sequence of procedures and buffers were developed to carry out all analyses on one small muscle. This would yield a considerable increase in analytical strength associated with paired statistics. The proposed casting procedure which was to be used for immobilization was reexamined.

Development of a bedside viable ultrasound protocol to quantify appendicular lean tissue mass.

Science.gov (United States)

Paris, Michael T; Lafleur, Benoit; Dubin, Joel A; Mourtzakis, Marina

2017-10-01

Ultrasound is a non-invasive and readily available tool that can be prospectively applied at the bedside to assess muscle mass in clinical settings. The four-site protocol, which images two anatomical sites on each quadriceps, may be a viable bedside method, but its ability to predict musculature has not been compared against whole-body reference methods. Our primary objectives were to (i) compare the four-site protocol's ability to predict appendicular lean tissue mass from dual-energy X-ray absorptiometry; (ii) optimize the predictability of the four-site protocol with additional anatomical muscle thicknesses and easily obtained covariates; and (iii) assess the ability of the optimized protocol to identify individuals with low lean tissue mass. This observational cross-sectional study recruited 96 university and community dwelling adults. Participants underwent ultrasound scans for assessment of muscle thickness and whole-body dual-energy X-ray absorptiometry scans for assessment of appendicular lean tissue. Ultrasound protocols included (i) the nine-site protocol, which images nine anterior and posterior muscle groups in supine and prone positions, and (ii) the four-site protocol, which images two anterior sites on each quadriceps muscle group in a supine position. The four-site protocol was strongly associated (R 2  = 0.72) with appendicular lean tissue mass, but Bland-Altman analysis displayed wide limits of agreement (-5.67, 5.67 kg). Incorporating the anterior upper arm muscle thickness, and covariates age and sex, alongside the four-site protocol, improved the association (R 2  = 0.91) with appendicular lean tissue and displayed narrower limits of agreement (-3.18, 3.18 kg). The optimized protocol demonstrated a strong ability to identify low lean tissue mass (area under the curve = 0.89). The four-site protocol can be improved with the addition of the anterior upper arm muscle thickness, sex, and age when predicting appendicular lean tissue mass

Lack of independent effect of type 2 diabetes beyond characteristic comorbidities and medications on small muscle mass exercising muscle blood flow and exercise tolerance.

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Poitras, Veronica J; Bentley, Robert F; Hopkins-Rosseel, Diana H; LaHaye, Stephen A; Tschakovsky, Michael E

2015-08-01

Persons with type 2 diabetes (T2D) are believed to have reduced exercise tolerance; this may be partly due to impaired exercising muscle blood flow (MBF). Whether there is an impact of T2D on exercising MBF within the typical constellation of comorbidities (hypertension, dyslipidemia, obesity) and their associated medications has not been investigated. We tested the hypothesis that small muscle mass exercise tolerance is reduced in persons with T2D versus Controls (matched for age, body mass index, fitness, comorbidities, non-T2D medications) and that this is related to blunted MBF. Eight persons with T2D and eight controls completed a forearm critical force (fCFimpulse) test as a measure of exercise tolerance (10-min intermittent maximal effort forearm contractions; the average contraction impulse in the last 30 sec quantified fCFimpulse). Forearm blood flow (FBF; ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured; forearm vascular conductance (FVK) was calculated. Data are means ± SD, T2D versus Control. fCFimpulse was not different between groups (136.9 ± 47.3  N·sec vs. 163.1 ± 49.7 N·sec, P = 0.371) nor was the ∆FBF from rest to during exercise at fCFimpulse (502.9 ± 144.6 vs. 709.1 ± 289.2 mL/min, P = 0.092), or its determinants ∆FVK and ∆MAP (both P > 0.05), although there was considerable interindividual variability. ∆FBF was strongly related to fCFimpulse (r = 0.727, P = 0.002), providing support for the relationship between oxygen delivery and exercise tolerance. We conclude that small muscle mass exercising MBF and exercise tolerance are not impaired in representative persons with T2D versus appropriately matched controls. This suggests that peripheral vascular control impairment does not contribute to reduced exercise tolerance in this population. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and

A comparative analysis of the encapsulated end-organs of mammalian skeletal muscles and of their sensory nerve endings.

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Banks, R W; Hulliger, M; Saed, H H; Stacey, M J

2009-06-01

The encapsulated sensory endings of mammalian skeletal muscles are all mechanoreceptors. At the most basic functional level they serve as length sensors (muscle spindle primary and secondary endings), tension sensors (tendon organs), and pressure or vibration sensors (lamellated corpuscles). At a higher functional level, the differing roles of individual muscles in, for example, postural adjustment and locomotion might be expected to be reflected in characteristic complements of the various end-organs, their sensory endings and afferent nerve fibres. This has previously been demonstrated with regard to the number of muscle-spindle capsules; however, information on the other types of end-organ, as well as the complements of primary and secondary endings of the spindles themselves, is sporadic and inconclusive regarding their comparative provision in different muscles. Our general conclusion that muscle-specific variability in the provision of encapsulated sensory endings does exist demonstrates the necessity for the acquisition of more data of this type if we are to understand the underlying adaptive relationships between motor control and the structure and function of skeletal muscle. The present quantitative and comparative analysis of encapsulated muscle afferents is based on teased, silver-impregnated preparations. We begin with a statistical analysis of the number and distribution of muscle-spindle afferents in hind-limb muscles of the cat, particularly tenuissimus. We show that: (i) taking account of the necessity for at least one primary ending to be present, muscles differ significantly in the mean number of additional afferents per spindle capsule; (ii) the frequency of occurrence of spindles with different sensory complements is consistent with a stochastic, rather than deterministic, developmental process; and (iii) notwithstanding the previous finding, there is a differential distribution of spindles intramuscularly such that the more complex ones tend

GH/IGF-I Transgene Expression on Muscle Homeostasis

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Schwartz, Robert J.

1999-01-01

We propose to test the hypothesis that the growth hormone/ insulin like growth factor-I axis through autocrine/paracrine mechanisms may provide long term muscle homeostasis under conditions of prolonged weightlessness. As a key alternative to hormone replacement therapy, ectopic production of hGH, growth hormone releasing hormone (GHRH), and IGF-I will be studied for its potential on muscle mass impact in transgenic mice under simulated microgravity. Expression of either hGH or IGF-I would provide a chronic source of a growth-promoting protein whose biosynthesis or secretion is shut down in space. Muscle expression of the IGF-I transgene has demonstrated about a 20% increase in hind limb muscle mass over control nontransgenic litter mates. These recent experiments, also establish the utility of hind-limb suspension in mice as a workable model to study atrophy in weight bearing muscles. Thus, transgenic mice will be used in hind-limb suspension models to determine the role of GH/IGF-I on maintenance of muscle mass and whether concentric exercises might act in synergy with hormone treatment. As a means to engineer and ensure long-term protein production that would be workable in humans, gene therapy technology will be used by to monitor muscle mass preservation during hind-limb suspension, after direct intramuscular injection of a genetically engineered muscle-specific vector expressing GHRH. Effects of this gene-based therapy will be assessed in both fast twitch (medial gastrocnemius) and slow twitch muscle (soleus). End-points include muscle size, ultrastructure, fiber type, and contractile function, in normal animals, hind limb suspension, and reambutation.

"Nutraceuticals" in relation to human skeletal muscle and exercise.

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Deane, Colleen S; Wilkinson, Daniel J; Phillips, Bethan E; Smith, Kenneth; Etheridge, Timothy; Atherton, Philip J

2017-04-01

Skeletal muscles have a fundamental role in locomotion and whole body metabolism, with muscle mass and quality being linked to improved health and even lifespan. Optimizing nutrition in combination with exercise is considered an established, effective ergogenic practice for athletic performance. Importantly, exercise and nutritional approaches also remain arguably the most effective countermeasure for muscle dysfunction associated with aging and numerous clinical conditions, e.g., cancer cachexia, COPD, and organ failure, via engendering favorable adaptations such as increased muscle mass and oxidative capacity. Therefore, it is important to consider the effects of established and novel effectors of muscle mass, function, and metabolism in relation to nutrition and exercise. To address this gap, in this review, we detail existing evidence surrounding the efficacy of a nonexhaustive list of macronutrient, micronutrient, and "nutraceutical" compounds alone and in combination with exercise in relation to skeletal muscle mass, metabolism (protein and fuel), and exercise performance (i.e., strength and endurance capacity). It has long been established that macronutrients have specific roles and impact upon protein metabolism and exercise performance, (i.e., protein positively influences muscle mass and protein metabolism), whereas carbohydrate and fat intakes can influence fuel metabolism and exercise performance. Regarding novel nutraceuticals, we show that the following ones in particular may have effects in relation to 1 ) muscle mass/protein metabolism: leucine, hydroxyl β-methylbutyrate, creatine, vitamin-D, ursolic acid, and phosphatidic acid; and 2 ) exercise performance: (i.e., strength or endurance capacity): hydroxyl β-methylbutyrate, carnitine, creatine, nitrates, and β-alanine. Copyright © 2017 the American Physiological Society.

FMAj: a tool for high content analysis of muscle dynamics in Drosophila metamorphosis.