scholarly journals Identifying the Structural Adaptations that Drive the Mechanical Load-Induced Growth of Skeletal Muscle: A Scoping Review

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1658 ◽  
Author(s):  
Kent W. Jorgenson ◽  
Stuart M. Phillips ◽  
Troy A. Hornberger
Keyword(s):  
Skeletal Muscle ◽  
Muscle Mass ◽  
Mechanical Loading ◽  
Skeletal Muscle Mass ◽  
Mechanical Load ◽  
Critical Role ◽  
Ultrastructural Changes ◽  
Clear Understanding ◽  
Cross Sectional

The maintenance of skeletal muscle mass plays a critical role in health and quality of life. One of the most potent regulators of skeletal muscle mass is mechanical loading, and numerous studies have led to a reasonably clear understanding of the macroscopic and microscopic changes that occur when the mechanical environment is altered. For instance, an increase in mechanical loading induces a growth response that is mediated, at least in part, by an increase in the cross-sectional area of the myofibers (i.e., myofiber hypertrophy). However, very little is known about the ultrastructural adaptations that drive this response. Even the most basic questions, such as whether mechanical load-induced myofiber hypertrophy is mediated by an increase in the size of the pre-existing myofibrils and/or an increase in the number myofibrils, have not been resolved. In this review, we thoroughly summarize what is currently known about the macroscopic, microscopic and ultrastructural changes that drive mechanical load-induced growth and highlight the critical gaps in knowledge that need to be filled.

scholarly journals Nutrient patterns and the skeletal muscle mass index among Polish women: a cross-sectional study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Anna Danielewicz ◽  
Jakub Morze ◽  
Małgorzata Obara-Gołębiowska ◽  
Mariusz Przybyłowicz ◽  
Katarzyna E. Przybyłowicz
Keyword(s):  
Skeletal Muscle ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Fibre Plant ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Nutrient Patterns ◽  
Skeletal Muscle Mass Index

AbstractAgeing involves significant changes in skeletal muscle mass and its functioning. This study aimed to identify the major nutrient patterns (NPs) present in a sample of adult Polish women and evaluate their associations with the skeletal muscle mass index (SMI). A cross-sectional study initially recruited 527 women, and a final analysis was carried out on 275 women aged 32–60 years. Nutrient intake was assessed using fourteen repetitions of 24-hour dietary recall. NPs were derived using principal component analysis. Associations between adherence to NPs and the SMI were evaluated using linear regression models. Three NPs were identified: ‘Animal Protein-Vitamins’, ‘Fibre-Plant Protein-Minerals’ and ‘Fats’. In the adjusted model, the upper tertile compared to the bottom tertile of the ‘Animal Protein-Vitamins’ NP was related to a higher SMI (β = 0.123 95% CI: 0.019; 0.227; P for 1-SD increase of NP score = 0.009). No associations between the SMI and the ‘Fibre-Plant Protein-Minerals’ and ‘Fats’ NPs were observed. Our results indicate that high adherence to animal product-rich patterns might be related to higher muscle mass in adult women. Research on the influence of dietary and nutrient patterns on the quality of muscle tissue may contribute to the setting of guidelines for nutritional protection of skeletal muscle with ageing and, consequently, dietary recommendations that would improve the quality of women’s lives at the later stage of life.

scholarly journals Body composition and energy intake — skeletal muscle mass is the strongest predictor of food intake in obese adolescents: The HEARTY trial

2016 ◽  
Vol 41 (6) ◽  
pp. 611-617 ◽  
Author(s):  
Jameason D. Cameron ◽  
Ronald J. Sigal ◽  
Glen P. Kenny ◽  
Angela S. Alberga ◽  
Denis Prud’homme ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Body Composition ◽  
Body Weight ◽  
Muscle Mass ◽  
Energy Intake ◽  
Skeletal Muscle Mass ◽  
Fat Free Mass ◽  
Cross Sectional ◽  
Percentage Body Fat ◽  
Obese Adolescents

There has been renewed interest in examining the relationship between specific components of energy expenditure and the overall influence on energy intake (EI). The purpose of this cross-sectional analysis was to determine the strongest metabolic and anthropometric predictors of EI. It was hypothesized that resting metabolic rate (RMR) and skeletal muscle mass would be the strongest predictors of EI in a sample of overweight and obese adolescents. 304 post-pubertal adolescents (91 boys, 213 girls) aged 16.1 (±1.4) years with body mass index at or above the 95th percentile for age and sex OR at or above the 85th percentile plus an additional diabetes risk factor were measured for body weight, RMR (kcal/day) by indirect calorimetry, body composition by magnetic resonance imaging (fat free mass (FFM), skeletal muscle mass, fat mass (FM), and percentage body fat), and EI (kcal/day) using 3 day food records. Body weight, RMR, FFM, skeletal muscle mass, and FM were all significantly correlated with EI (p < 0.005). After adjusting the model for age, sex, height, and physical activity, only FFM (β = 21.9, p = 0.007) and skeletal muscle mass (β = 25.8, p = 0.02) remained as significant predictors of EI. FFM and skeletal muscle mass also predicted dietary protein and fat intake (p < 0.05), but not carbohydrate intake. In conclusion, with skeletal muscle mass being the best predictor of EI, our results support the hypothesis that the magnitude of the body’s lean tissue is related to absolute levels of EI in a sample of inactive adolescents with obesity.

scholarly journals Cutoff values for appendicular skeletal muscle mass and strength in relation to fear of falling among Brazilian older adults: cross-sectional study

2017 ◽  
Vol 135 (5) ◽  
pp. 434-443 ◽  
Author(s):  
Ricardo Aurélio Carvalho Sampaio ◽  
Priscila Yukari Sewo Sampaio ◽  
Luz Albany Arcila Castaño ◽  
João Francisco Barbieri ◽  
Hélio José Coelho Júnior ◽  
...  
Keyword(s):  
Older Adults ◽  
Skeletal Muscle ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Fear Of Falling ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Appendicular Skeletal Muscle ◽  
Appendicular Skeletal Muscle Mass

scholarly journals Relation of serum 25-hydroxyvitamin D status with skeletal muscle mass by sex and age group among Korean adults

2015 ◽  
Vol 114 (11) ◽  
pp. 1838-1844 ◽  
Author(s):  
Min Jung Ko ◽  
Sungha Yun ◽  
Kyungwon Oh ◽  
Kirang Kim
Keyword(s):  
Skeletal Muscle ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Age Groups ◽  
Mean Value ◽  
High Serum ◽  
Cross Sectional ◽  
Mean Values ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D

AbstractThe objective of this study was to examine whether high serum 25-hydroxyvitamin D (25(OH)D) concentration was associated with high skeletal muscle mass, taking into account the effects of sex and age among the participants of the Korea National Health and Nutrition Examination Survey (KNHANES) aged 40 years or older. This was a cross-sectional study using data from the 2009 to 2010 KNHANES; a total of 8406 subjects (3671 men and 4735 women) were included. The appendicular skeletal muscle mass index (ASMMI, kg/m2) was estimated to measure the skeletal muscle mass. Hypovitaminosis was classified when the level of serum 25(OH)D was <20 ng/ml. The general linear model adjusted for confounding factors was used to determine differences in means of ASMMI by 25(OH)D status. The mean values of ASMMI were higher for men when compared with women. Women had a greater proportion of hypovitaminosis (71·1 %) compared with men (53·2 %). After adjusting for multiple factors, men were seen to have significant differences in ASMMI based on 25(OH)D status regardless of age, showing a lower mean value of ASSMI in those with hypovitaminosis. However, there was no difference in ASMMI by 25(OH)D status among women in both younger and older age groups. In conclusion, we found that there might be a positive relationship between 25(OH)D and skeletal muscle mass in men, indicating that interventions to improve 25(OH)D levels that are aimed at increasing muscle mass could be beneficial for men with more rapid decreased rate of skeletal muscle mass.

scholarly journals Alternate Mediterranean diet score is positively associated with skeletal muscle mass index in middle-aged adults

2017 ◽  
Vol 117 (8) ◽  
pp. 1181-1188 ◽  
Author(s):  
Hui-yuan Tian ◽  
Rui Qiu ◽  
Li-peng Jing ◽  
Zhan-yong Chen ◽  
Geng-dong Chen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mediterranean Diet ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
General Information ◽  
Whole Body ◽  
Cross Sectional ◽  
Mediterranean Diet Score ◽  
Skeletal Muscle Mass Index ◽  
Diet Score

AbstractResearches have suggested Mediterranean diet might lower the risk of chronic diseases, but data on skeletal muscle mass (SMM) are limited. This community-based cross-sectional study examined the association between the alternate Mediterranean diet score (aMDS) and SMM in 2230 females and 1059 males aged 40–75 years in Guangzhou, China. General information and habitual dietary information were assessed in face-to-face interviews conducted during 2008–2010 and 3 years later. The aMDS was calculated by summing the dichotomous points for the items of higher intakes of whole grain, vegetables, fruits, legumes, nuts, fish and ratio of MUFA:SFA, lower red meat and moderate ethanol consumption. The SMM of the whole body, limbs, arms and legs were measured using dual-energy X-ray absorptiometry during 2011–2013. After adjusting for potential covariates, higher aMDS was positively associated with skeletal muscle mass index (SMI, SMM/height2, kg/m2) at all of the studied sites in males (all Ptrend<0·05). The multiple covariate-adjusted SMI means were 2·70 % (whole body), 2·65 % (limbs), 2·50 % (arms) and 2·70 % (legs) higher in the high (v. low) category aMDS in males (all P<0·05). In females, the corresponding values were 1·35 % (Ptrend=0·03), 1·05, 0·52 and 1·20 %, (Ptrend>0·05). Age-stratified analyses showed that the favourable associations tended to be more pronounced in the younger subjects aged less than the medians of 59·2 and 62·2 years in females and males (Pinteraction>0·10). In conclusion, the aMDS shows protective associations with SMM in Chinese adults, particularly in male and younger subjects.

scholarly journals Prevalence of Sarcopenia and Association with Lifestyle Patterns in Patients with Type 2 Diabetes Mellitus (P01-025-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Tatiana de Paula ◽  
Mauren de Freitas ◽  
Vanessa Lopes ◽  
Maria Elisa Miller ◽  
Karen Araujo ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Skeletal Muscle ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Meta Analysis ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Logistic Regression Models ◽  
Type 2 Dm

Abstract Objectives The aim of the study was to establish the prevalence of sarcopenia and associated factors in elderly with type 2 diabetes (DM) in southern Brazil. Methods A cross-sectional study was performed in 240 patients with type 2 DM. The diagnosis of sarcopenia was performed according to EWGSOP criteria. Muscle mass was calculated by skeletal muscle mass index (appendicular skeletal muscle mass/height² - Inbody® bioimpendance). Muscle strength was assessed by manual grip strength (Jamar® dynamometer) and physical performance was assessed by the sit and lift test. Patients with type 2 DM with age ≥60 years and with the ability to ambulate were selected. Patients with recent cardiovascular events, serum creatinine >2.0 mg/dl, use of corticosteroids and BMI >40 kg/m² were excluded. The sample size was 240 patients based on meta-analysis who found 17% sarcopenia in elderly patients without DM. Results We included 240 patients aged 68.4 ± 5.5 years, 53.2% were women and the duration of DM was 15 (8–22) years, the BMI was 29.4 ± 4.4 kg/m². The prevalence of sarcopenia was 21% and men had more sarcopenia (75%). Patients with sarcopenia walk less [3541 (2227–4574) vs. 4521 (3037–5678) steps, P = 0.013], drink more alcohol [21 (56.8%) vs. 71 (31.8%); P < 0.034] and have lower total cholesterol levels [146 ± 41 Vs. 168 ± 43; P = 0.007] than the group without sarcopenia. In multivariate logistic regression models, walking < 3760 steps [OR = 2868; CI 95% 1.331–6.181] and male [OR = 5285; CI 95% 2261–12,350], were associated with sarcopenia. Conclusions The prevalence of sarcopenia was 21%, higher than in patients without diabetes (17%). In this group of patients, lower physical activity, and male sex were associated with sarcopenia. Funding Sources FIPE n. 160467; CAPES.

scholarly journals Reference Values for Skeletal Muscle Mass – Current Concepts and Methodological Considerations

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 755 ◽  
Author(s):  
Carina O. Walowski ◽  
Wiebke Braun ◽  
Michael J. Maisch ◽  
Björn Jensen ◽  
Sven Peine ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Mass ◽  
Reference Values ◽  
Skeletal Muscle Mass ◽  
Bioelectrical Impedance ◽  
Reference Population ◽  
Muscle Quality ◽  
Whole Body ◽  
Whole Body Imaging ◽  
Cross Sectional

Assessment of a low skeletal muscle mass (SM) is important for diagnosis of ageing and disease-associated sarcopenia and is hindered by heterogeneous methods and terminologies that lead to differences in diagnostic criteria among studies and even among consensus definitions. The aim of this review was to analyze and summarize previously published cut-offs for SM applied in clinical and research settings and to facilitate comparison of results between studies. Multiple published reference values for discrepant parameters of SM were identified from 64 studies and the underlying methodological assumptions and limitations are compared including different concepts for normalization of SM for body size and fat mass (FM). Single computed tomography or magnetic resonance imaging images and appendicular lean soft tissue by dual X-ray absorptiometry (DXA) or bioelectrical impedance analysis (BIA) are taken as a valid substitute of total SM because they show a high correlation with results from whole body imaging in cross-sectional and longitudinal analyses. However, the random error of these methods limits the applicability of these substitutes in the assessment of individual cases and together with the systematic error limits the accurate detection of changes in SM. Adverse effects of obesity on muscle quality and function may lead to an underestimation of sarcopenia in obesity and may justify normalization of SM for FM. In conclusion, results for SM can only be compared with reference values using the same method, BIA- or DXA-device and an appropriate reference population. Limitations of proxies for total SM as well as normalization of SM for FM are important content-related issues that need to be considered in longitudinal studies, populations with obesity or older subjects.

scholarly journals Role of PDK1 in skeletal muscle hypertrophy induced by mechanical load

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Naoki Kuramoto ◽  
Kazuhiro Nomura ◽  
Daisuke Kohno ◽  
Tadahiro Kitamura ◽  
Gerard Karsenty ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Muscle Hypertrophy ◽  
Mechanical Load ◽  
Static Condition ◽  
Ribosomal Protein S6 ◽  
Pi3k Signaling Pathway ◽  
Induced Changes

AbstractPhosphatidylinositol 3-kinase (PI3K) plays an important role in protein metabolism and cell growth. We here show that mice (M-PDK1KO mice) with skeletal muscle–specific deficiency of 3′-phosphoinositide–dependent kinase 1 (PDK1), a key component of PI3K signaling pathway, manifest a reduced skeletal muscle mass under the static condition as well as impairment of mechanical load–induced muscle hypertrophy. Whereas mechanical load-induced changes in gene expression were not affected, the phosphorylation of ribosomal protein S6 kinase (S6K) and S6 induced by mechanical load was attenuated in skeletal muscle of M-PDK1KO mice, suggesting that PDK1 regulates muscle hypertrophy not through changes in gene expression but through stimulation of kinase cascades such as the S6K-S6 axis, which plays a key role in protein synthesis. Administration of the β2-adrenergic receptor (AR) agonist clenbuterol activated the S6K-S6 axis in skeletal muscle and induced muscle hypertrophy in mice. These effects of clenbuterol were attenuated in M-PDK1KO mice, and mechanical load–induced activation of the S6K-S6 axis and muscle hypertrophy were inhibited in mice with skeletal muscle–specific deficiency of β2-AR. Our results suggest that PDK1 regulates skeletal muscle mass under the static condition and that it contributes to mechanical load–induced muscle hypertrophy, at least in part by mediating signaling from β2-AR.

Effects of 6 months of abiraterone acetate (AA) on muscle and adipose mass in men with metastatic castration-resistant prostate cancer (mCRPC).

2012 ◽  
Vol 30 (5_suppl) ◽  
pp. 222-222 ◽  
Author(s):  
Samuel Craig Brondfield ◽  
Vivian K. Weinberg ◽  
Kathryn M. Koepfgen ◽  
Arturo Molina ◽  
Charles J. Ryan ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Muscle Wasting ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Adipose Mass

222 Background: AA, an inhibitor of androgen biosynthesis, has been shown to prolong overall survival in patients with mCRPC who have previously been treated with chemotherapy. Androgen deprivation therapy (ADT) has been shown to result in muscle wasting in prostate cancer pts. The effects of AA on progression of muscle and fat wasting have not been characterized. We evaluated whether 6 months of AA therapy altered total skeletal muscle mass or adipose mass. Methods: 10 sequential pts who responded to AA therapy for at least 6 months and had available computed tomography (CT) scans were retrospectively selected from the phase I-II COU-AA-002 study. CT image analysis was used to quantify change from baseline in total skeletal muscle and adipose tissue after 6 months of AA treatment. Skeletal muscle and adipose tissue cross-sectional area were calculated at the L3 level using Slice-O-Matic software V4.3. Previously published regression models were used to estimate fat-free mass, fat mass and skeletal muscle mass. Paired t-tests were performed to determine the change in measurements. Results: At baseline, 7 of 10 pts were overweight or obese (body mass index [BMI] > 25 kg/m2), and none were underweight. Advanced muscle wasting (sarcopenia, previously defined as the ratio of skeletal muscle cross-sectional area at L3 level to height < 52.4 cm2/m2) was present at baseline and 6 months in 9 of 10 pts. Over 6 months of AA treatment, pts lost an average of 1.9 kg ± 1.9 kg (p = 0.13). Mean changes (kg) (±standard deviation) in total skeletal muscle mass (−0.80 ± 1.71, p = 0.18) and total non-adipose mass (−1.44 ± 3.09, p = 0.17) were not significant. A significant decrease in total adipose mass (−0.61 ± 0.84, p = 0.048) was observed. Conclusions: Sarcopenia is prevalent in pts with mCRPC. AA was not related to significantly worsening sarcopenia or overall weight loss during the first 6 months of treatment; however, this may reflect a relatively short duration of therapy and/or small sample size. A significant loss of adipose tissue was observed, which is unexpected given the known effects of ADT, which increases adipose mass. Evaluation of additional AA treated patients is ongoing.

Body composition as a predictor of sunitinib toxicity in patients with renal cell carcinoma.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e15566-e15566
Author(s):  
Samantha Cushen ◽  
Aoife M Ryan ◽  
MinYuen Teo ◽  
Peter MacEneaney ◽  
Patrick McLaughlin ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Body Composition ◽  
Muscle Mass ◽  
Renal Cell ◽  
Skeletal Muscle Mass ◽  
Cell Cancer ◽  
Drug Dose ◽  
Fat Free Mass ◽  
Cross Sectional ◽  
Overweight Group

e15566 Background: Sunitinib is a standard first-line option for metastatic renal cell cancer (mRCC). Identification of biomarkers associated with outcome or toxicity is a challenge. Body composition is a prognostic factor in cancer and sarcopenia is associated with treatment toxicity and survival. We investigated if body composition by CT scan predicted dose limiting toxicity (DLT) from sunitinib in mRCC. Methods: Patients (pts) with mRCC receiving sunitinib 50mg as 1stline therapy between 2007-2012 were included. Ethical approval was obtained and prospectively maintained databases analysed. Skeletal muscle cross-sectional area at L3 was measured by CT. Sarcopenia was defined using published cut offs. Toxicity was assessed after 4 cycles of drug (CTCAE, v4.0). Results: 55 pts (43 male), mean age 64yrs (±10.6) were included. 67% were overweight/obese (BMI>25kg/m2). Sarcopenia was present in 33% (56% of normal BMI, 44% overweight group). Overall 40 pts (73%) experienced DLT (51% M, 100% F, p<0.016). DLT occurred in <6 months in 53% (44% M vs 83% F, p<0.016) and these pts were older (mean 68 yrs vs 60 yrs, p<0.01), had lower skeletal muscle mass (51.8 cm2/m2 vs 59.4 cm2/m2, p<0.012), and fat free mass (FFM) (51.4kg vs 57.7kg, p<0.03), and received higher drug dose in mg/kg FFM (1.01 vs 0.89, p<0.02). Common toxicities were GI (65%) and fatigue (47%). Of pts <25th percentile skeletal muscle mass 92% experienced DLT, higher than pts >75th percentile (p<0.05). Pts <25th percentile had an average of 5 toxicities vs 2 in those >75th percentile (p<0.003). All toxicities were more common in muscle wasted patients (p<0.05). 77% (n=10) of pts receiving a drug dose >75th percentile (1.105mg/FFM) experienced DLT in <6 months vs 44% (n=17) receiving a dose <75thpercentile (<1.099mg/FFM; p<0.037). Conclusions: Sarcopenia is prevalent in patients with mRCC, is easily measured, is an occult condition in pts with normal/high BMI, and is a significant predictor of DLT in pts receiving 1st line sunitinib. Our results highlight the potential use of baseline body composition to predict toxicity. The role of sarcopenia in targeted therapy is evolving and its potential to predict toxicity should be further studied.

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