Metabolic Syndrome and Sarcopenia

Skeletal muscle is a major organ of insulin-induced glucose metabolism. In addition, loss of muscle mass is closely linked to insulin resistance (IR) and metabolic syndrome (Met-S). Skeletal muscle loss and accumulation of intramuscular fat are associated with a variety of pathologies through a combination of factors, including oxidative stress, inflammatory cytokines, mitochondrial dysfunction, IR, and inactivity. Sarcopenia, defined by a loss of muscle mass and a decline in muscle quality and muscle function, is common in the elderly and is also often seen in patients with acute or chronic muscle-wasting diseases. The relationship between Met-S and sarcopenia has been attracting a great deal of attention these days. Persistent inflammation, fat deposition, and IR are thought to play a complex role in the association between Met-S and sarcopenia. Met-S and sarcopenia adversely affect QOL and contribute to increased frailty, weakness, dependence, and morbidity and mortality. Patients with Met-S and sarcopenia at the same time have a higher risk of several adverse health events than those with either Met-S or sarcopenia. Met-S can also be associated with sarcopenic obesity. In this review, the relationship between Met-S and sarcopenia will be outlined from the viewpoints of molecular mechanism and clinical impact.

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Relationships between insulin sensitivity, skeletal muscle mass and muscle quality in obese adolescent boys

European Journal of Clinical Nutrition ◽

10.1038/ejcn.2012.142 ◽

2012 ◽

Vol 66 (12) ◽

pp. 1366-1368 ◽

Cited By ~ 19

Author(s):

S Lee ◽

Y Kim ◽

D A White ◽

J L Kuk ◽

S Arslanian

Keyword(s):

Skeletal Muscle ◽

Insulin Sensitivity ◽

Muscle Mass ◽

Skeletal Muscle Mass ◽

Muscle Quality ◽

Adolescent Boys ◽

Obese Adolescent

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CNTF genotype is associated with muscular strength and quality in humans across the adult age span

Journal of Applied Physiology ◽

10.1152/jappl.2001.90.4.1205 ◽

2001 ◽

Vol 90 (4) ◽

pp. 1205-1210 ◽

Cited By ~ 61

Author(s):

Stephen M. Roth ◽

Matthew A. Schrager ◽

Robert E. Ferrell ◽

Steven E. Riechman ◽

E. Jeffrey Metter ◽

...

Keyword(s):

Muscle Mass ◽

Body Mass ◽

Muscular Strength ◽

Peak Torque ◽

Fat Free Mass ◽

Muscle Quality ◽

Knee Extensors ◽

Muscular Power ◽

Adult Age ◽

The Relationship

The relationship between ciliary neurotrophic factor (CNTF) genotype and muscle strength was examined in 494 healthy men and women across the entire adult age span (20–90 yr). Concentric (Con) and eccentric (Ecc) peak torque were assessed using a Kin-Com isokinetic dynamometer for the knee extensors (KE) and knee flexors (KF) at slow (0.52 rad/s) and faster (3.14 rad/s) velocities. The results were covaried for age, gender, and body mass or fat-free mass (FFM). Individuals heterozygous for the CNTF null (A allele) mutation (G/A) exhibited significantly higher Con peak torque of the KE and KF at 3.14 rad/s than G/G homozygotes when age, gender, and body mass were covaried ( P < 0.05). When the dominant leg FFM (estimated muscle mass) was used in place of body mass as a covariate, Con peak torque of the KE at 3.14 rad/s was also significantly greater in the G/A individuals ( P < 0.05). In addition, muscle quality of the KE (peak torque at 3.14 rad · s−1 · leg muscle mass−1) was significantly greater in the G/A heterozygotes ( P < 0.05). Similar results were seen in a subanalysis of subjects 60 yr and older, as well as in Caucasian subjects. In contrast, A/A homozygotes demonstrated significantly lower Ecc peak torque at 0.52 rad/s for both KE and KF compared with G/G and G/A groups ( P < 0.05). No significant relationships were observed at 0.52 rad/s between genotype and Con peak torque. These data indicate that individuals exhibiting the G/A genotype possess significantly greater muscular strength and muscle quality at relatively fast contraction speeds than do G/G individuals. Because of high positive correlations between fast-velocity peak torque and muscular power, these findings suggest that further investigations should address the relationship between CNTF genotype and muscular power.

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Skeletal muscle mass at C3 may not be a strong predictor for skeletal muscle mass at L3 in sarcopenic patients with head and neck cancer

PLoS ONE ◽

10.1371/journal.pone.0254844 ◽

2021 ◽

Vol 16 (7) ◽

pp. e0254844

Author(s):

Joon-Kee Yoon ◽

Jeon Yeob Jang ◽

Young-Sil An ◽

Su Jin Lee

Keyword(s):

Skeletal Muscle ◽

Head And Neck Cancer ◽

Diagnostic Accuracy ◽

Prediction Model ◽

Muscle Mass ◽

Skeletal Muscle Mass ◽

Strong Predictor ◽

Healthy Adults ◽

Muscle Area ◽

The Relationship

Purpose To evaluate the feasibility of using skeletal muscle mass (SMM) at C3 (C3 SMM) as a diagnostic marker for sarcopenia in head and neck cancer (HNC) patients. Methods We evaluated 165 HNC patients and 42 healthy adults who underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography scans. The paravertebral muscle area at C3 and skeletal muscle area at L3 were measured by CT. Pearson’s correlation was used to assess the relationship between L3 and C3 SMMs. The prediction model for L3 SMM was developed by multiple linear regression. Then the correlation and the agreement between actual and predicted L3 SMMs were assessed. To evaluate the diagnostic value of C3 SMM for sarcopenia, the receiver operating characteristics (ROC) curves were analyzed. Results Of the 165 HNC patients, 61 (37.0%) were sarcopenic and 104 (63.0%) were non-sarcopenic. A very strong correlation was found between L3 SMM and C3 SMM in both healthy adults (r = 0.864) and non-sarcopenic patients (r = 0.876), while a fair association was found in sarcopenic patients (r = 0.381). Prediction model showed a very strong correlation between actual SMM and predicted L3 SMM in both non-sarcopenic patients and healthy adults (r > 0.9), whereas the relationship was moderate in sarcopenic patients (r = 0.7633). The agreement between two measurements was good for healthy subjects and non-sarcopenic patients, while it was poor for sarcopenic patients. On ROC analysis, predicted L3 SMM showed poor diagnostic accuracy for sarcopenia. Conclusions A correlation between L3 and C3 SMMs was weak in sarcopenic patients. A prediction model also showed a poor diagnostic accuracy. Therefore, C3 SMM may not be a strong predictor for L3 SMM in sarcopenic patients with HNC.

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

Nutrients ◽

10.3390/nu12030755 ◽

2020 ◽

Vol 12 (3) ◽

pp. 755 ◽

Cited By ~ 6

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.

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