The association between sleep parameters and sarcopenia in Japanese community-dwelling older adults

Purpose: This study aimed to examine the association between sleep duration and quality and sarcopenia, assessed by factors such as low muscle mass (LMM), low muscle strength (LMS), and low physical performance (LPP) among older community-dwellers in Japan. Methods: In this cross-sectional study, a total of 2,069 (men, 902; women, 1,167) participants aged 65 to 80 years were included. Sarcopenia and each low physical function were defined using the definitions of the Asian Working Groups of Sarcopenia 2019. Sleep duration was stratified into three categories: short sleep (<6 h), normal sleep (6-8 h), and long sleep (>8 h). Sleep quality was classified into two groups based on 8-item Athens Insomnia Scale score: insomnia (≥6), and non-insomnia (<6). We analyzed the association between sleep parameters and sarcopenia, including low physical functions, by logistic regression analysis. Results: Compared to normal sleepers, long sleepers had a positive association with sarcopenia (odds ratio [OR] 2.11, 95% confidence interval [CI] 1.25-3.58). In particular, long sleep was strongly associated with LMS (OR 1.77, 95%CI 1.07-2.94) and LPP (OR 1.90, 95%CI 1.25-2.88). On the other hand, poor sleep quality was not associated with sarcopenia in long sleepers, but in normal sleepers. Conclusions: Long sleep was associated with sarcopenia, including LMS and LPP. However, in long sleepers, insomnia was not associated with sarcopenia or any of its components.