Skeletal Muscle Mass Index Change Research Articles

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

BackgroundSkeletal 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.MethodsA 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.ResultsDuring 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 < 0% over a year, multivariate-AHRs for 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.ConclusionsAn 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.

Combining Amino Acid and Vitamin D Supplementation with Exercise Training Increases Skeletal Muscle Mass and Prevent Bone Mineral Density Loss in Participants with Low Muscle Mass

This study evaluated the impact of exercise training with amino acid and vitamin D supplementation on muscle and bone mass in participants with low muscle volume. Twenty-nine Japanese participants (56-84 years old) were enrolled and assigned into the supplement (n=15) and non-supplement (n=14) groups. All participants underwent a 6-month exercise program. Supplements and nutrition support were provided to the participants in the supplement group for 12 weeks. Body composition and whole bone mineral density (BMD) were measured using dual energy x-ray absorptiometry. The outcomes, including body composition, whole BMD, and skeletal muscle mass index (SMI), were evaluated twice: pre- and post-intervention. The SMI was 6.51(6.28; 7.14) and 5.58 (5.24; 6.05) (kg/m2) in men and women, respectively. The average SMI change was 0.13% (-0.05%; 0.31%) and 2.33% (-0.88%; 5.48%); [mean (lower; upper quartile)]. The average BMD loss in the non-supplement group was -2.78%, and the BMD increased in the supplement group by 4.34%; there was an absolute difference between the two groups (p&lt;0.05). After the intervention, serum myostatin was changed (p=0.001, non-supplement&gt;supplement), serum vitamin D was increased (p=0.03; supplement&gt;non-supplement), and BMD was maintained (p=0.03, supplement&gt;non-supplement). There was a significant difference in the serum myostatin level at baseline and at 6-month in the non-supplement group, with a mean difference of 483.78 ng/ml (p=0.01). There was no significant improvement in the total lean mass, and handgrip strength. Resistance exercise combined with an amino acid supplement affects muscle and bone mass in the short-term intervention.

Relationship between skeletal muscle mass and cardiac function during exercise in community-dwelling older adults.

AimsThis study aimed to investigate the relationship between skeletal muscle mass and cardiac functional parameters in older adults during cardiopulmonary exercise testing (CPET).Methods and resultsSixty‐three Japanese community‐dwelling older adults were enrolled (20 men and 43 women; mean age 80 years, range 65–97 years). Cardiac functional parameters during exercise were assessed using CPET. Skeletal muscle mass index (SMI) was calculated by dividing the appendicular lean mass (measured using dual‐energy X‐ray absorptiometry) by height in metres squared. Subjects were divided into two groups: men with SMI ≥ 7.0 kg/m2 and women with SMI ≥ 5.4 kg/m2 (non‐sarcopenic group); or men with SMI < 7.0 kg/m2 and women with SMI < 5.4 kg/m2 (sarcopenic group). There were significant positive correlations between SMI and peak oxygen uptake (VO2) (r = 0.631, P < 0.001), and between SMI and peak VO2/heart rate (HR) (r = 0.683, P < 0.001). However, only peak VO2/HR significantly differed between groups in both sexes. Multiple linear regression analyses with peak VO2/HR as a dependent variable showed that SMI was the only independent determinant after adjusting for potential confounders. After 4 month follow‐up of 47 participants, there was still a significant positive correlation between SMI and peak VO2/HR (r = 0.567, P < 0.001), and between percent change of SMI and percent change of peak VO2/HR (r = 0.305, P < 0.05).ConclusionsPeak VO2/HR, an index of stroke volume at peak exercise, was associated with SMI. This indicates that skeletal muscle mass might affect cardiac function during exercise.

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

BackgroundThe 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. Methodsduring 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. ResultsThe 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%, (p<0.001)]. High successful agers had better rates in ASM (p=0.01), SMI (p<0.001) and BF% (p<0.001), compared with the medium and low successful ones. Changes in SMI [b-coefficient (95% CI):2.14 (1.57 to 2.71)] were positively associated with successful ageing, 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. ConclusionsBody composition changes seem to be associated with lower quality of life in the older adults, as measured through successful ageing.