Sarcopenic Obesity and Risk of Disability in Community-Dwelling Japanese Older Adults: A 5-Year Longitudinal Study

Abstract

Objectives: Previous studies have indicated that sarcopenic obesity is a risk factor for disability onset. However, these studies had disparities in terms of criteria for sarcopenia, study design, or study population. No longitudinal study has investigated the effect of sarcopenic obesity on disability onset in an Asian population using the Asian Working Group for Sarcopenia 2019 criteria for sarcopenia definition. Herein, we aimed to investigate the longitudinal effect of sarcopenic obesity on disability onset in Japanese older adults and extend the generalizability of results to other populations.

Design: Longitudinal cohort study.

Setting and participants: A total of 4197 Japanese older adults (mean age 74.6 ± 5.0 years, 54.2% women) formed our study population.

Measurements: Sarcopenia was identified using the Asian Working Group for Sarcopenia 2019 algorithm. Obesity was determined when body fat percentage was ≥25%, or when visceral fat content was ≥100 cm² for either sex. Disability onset was defined as a new case of long-term care insurance system certification for 5 years from baseline. Missing values were managed with multi-imputation. Cox proportional hazard regression analysis was used with disability onset as dependent variable and group (nonsarcopenia/nonobesity as a reference, nonsarcopenia/obesity, sarcopenia/non-obesity, possible sarcopenia/obesity, possible sarcopenia/non-obesity, sarcopenic obesity) as explanatory variable, and was adjusted for potential confounding factors.

Results: When the nonsarcopenia/nonobesity group was used as the reference category, other groups such as possible-sarcopenia/nonobesity [hazard ratio (HR) 1.38, 95% confidential interval (95% CI) 1.29‒1.47, P < .028], possible-sarcopenia/obesity (HR 1.54, 95% CI 1.46‒1.62 P < .001), sarcopenia/nonobesity (HR 2.09, 95% CI 1.96‒2.23, P < .001), and sarcopenic obesity (HR 2.48, 95% CI 2.24‒2.75, P < .001) showed significantly increased HRs.

Conclusions and implications: The risk of disability onset because of sarcopenic obesity was exceedingly higher compared with sarcopenia alone among community-dwelling older adults in Japan The health providers should consider assessing the co-existence of sarcopenia and obesity to screen for the risk of disability onset in the community-dwelling population.

Keywords: Asian Working Group for Sarcopenia 2019; Japan; Sarcopenic obesity; disability; longitudinal study.