The role of obesity in sarcopenia and the optimal body composition to prevent against sarcopenia and obesity

Abstract

BackgroundElderly people with low lean and high fat mass, are diagnosed with sarcopenic obesity (SO), and often have poor clinical outcomes. This study aimed to explore the relationship between obesity and sarcopenia, and the optimal proportion of fat and muscle for old individuals.MethodsParticipants aged 60 years or above were instructed to perform bioelectrical impedance analysis to obtain the muscle and fat indicators, and handgrip strength was also performed. Sarcopenia was diagnosed according to predicted appendicular skeletal muscle mass and function. Body mass index (BMI) and body fat percentage (BF%) were used to define obesity. The association of muscle and fat indicators were analyzed by Pearson’s correlation coefficient. Pearson Chi-Square test was utilized to estimate odds ratios (OR) and 95% confidence intervals (CI) on the risk of sarcopenia according to obesity status.Results1637 old subjects (74.8 ± 7.8 years) participated in this study. Not only fat mass, but also muscle indicators were positively correlated to BMI and body weight (p < 0.05). Absolute muscle and fat mass in different positions had positive associations (p < 0.05). Muscle mass and strength were negatively related to appendicular fat mass percentage (p < 0.05). When defined by BMI (OR = 0.69, 95% CI [0.56, 0.86]; p = 0.001), obesity was a protective factor for sarcopenia, whilst it was a risk factor when using BF% (OR = 1.38, 95% CI [1.13, 1.69]; p = 0.002) as the definition. The risk of sarcopenia reduced with the increase of BMI in both genders. It was increased with raised BF% in males but displayed a U-shaped curve for females. BF% 26.0–34.6% in old females and lower than 23.9% in old males are recommended for sarcopenia and obesity prevention.ConclusionSkeletal muscle mass had strong positive relationship with absolute fat mass but negative associations with the percentage of appendicular fat mass. Obesity was a risk factor of sarcopenia when defined by BF% instead of BMI. The management of BF% can accurately help elderly people prevent against both sarcopenia and obesity.

A Comprehensive Risk Factor Exploration: Korean Nationwide Cross-Sectional Study of Sarcopenia Obesity in Young-Old Males—Investigating the Prevalence, Somatometric, Biochemical, and Behavioral Traits

“…Finally, in this study, we did not assess the body fat component by DEXA measurement. Recognizing the potential significance of including this measurement could offer valuable insights into sarcopenic obesity [ 44 , 45 ]. Future studies should prioritize incorporating the measurement of the body fat component for a more comprehensive understanding.…”

Prevalence and factors associated with sarcopenia among older adults in a post-acute hospital in Singapore

“…Thirdly, BMI is likely an inadequate surrogate measure of adiposity in older adults [ 82 , 83 ]. In fact, sarcopenic obesity [SO] prevalence defined with BMI underestimates those defined by body fat percentages in the same cohort in a study [ 78 ]. Interestingly, a higher BMI range, confers a paradoxical survival benefit in older adults [ 84 , 85 ].…”

Prevalence and factors associated with sarcopenia among older adults in a post-acute hospital in Singapore

“…(78, 79) In fact, sarcopenic obesity (SO) prevalence defined with BMI underestimates those defined by body fat percentages in the same cohort in a study. (74) Interestingly, a higher BMI range, confers a paradoxical survival benefit in older adults. (80, 81) A study comparing all-cause mortality within the same cohort between groups with BMI v.s.…”