Association between sarcopenia and multimorbidity among middle-aged and older adults in China: Findings from the China Health and Retirement Longitudinal Study

Background: Little is known about the association between sarcopenia and multimorbidity among middle-aged and older adults. This study investigated whether sarcopenia is associated with multimorbidity in middle-aged and older Chinese individuals. Materials and methods: A total of 12,760 participants from China Health and Retirement Longitudinal Study (CHARLS) 2015, with data on 14 specified chronic diseases and sarcopenia status were included in the crosssectional analysis. A total of 7345 participants without multimorbidity from the CHARLS 2015 were included and followed up in 2018 in the longitudinal analysis. Logistic regression models were used in a cross-sectional investigation to assess the association between sarcopenia status and multimorbidity. In a longitudinal analysis, the relationships between sarcopenia status and multimorbidity were investigated using Cox proportional hazards models. Results: Multimorbidity was prevalent in the no sarcopenia, possible sarcopenia, and sarcopenia groups at 38.8 % (3765/9713), 56.6 % (1199/2118), and 48.5 % (451/929), respectively. Multivariable regression revealed that both possible sarcopenia (beta = 0.088, P<0.001) and sarcopenia (beta = 0.028, P = 0.009), contributed to the number of chronic diseases. Logistic regression revealed that possible sarcopenia (OR: 1.56, 95 % CI: 1.39-1.76) was associated with multimorbidity. In the longitudinal analysis, participants in the possible sarcopenia group (HR: 1.19, 95 % CI:1.03-1.38) were more prone to experience new onset multimorbidity than did participants in the no sarcopenia group. Conclusions: Possible sarcopenia is associated with the development of multimorbidity in middle-aged and older Chinese populations. Health screening of populations with possible sarcopenia can facilitate early detection of multimorbidity.