Abstract / Summary
Abstract Background Both depression and sarcopenia are common in older adults and have individually been linked to functional decline and mortality. Whether their co-occurrence confers excess risk beyond independent effects remains unclear, particularly in Chinese populations. Methods We included 4,161 community-dwelling adults aged ≥ 60 years from the China Health and Retirement Longitudinal Study (CHARLS, 2011–2018) who were free of activities of daily living (ADL) disability at baseline. Depressive symptoms were defined as a 10-item Center for Epidemiologic Studies Depression Scale (CESD-10) score ≥ 10. Sarcopenia was ascertained using the Asian Working Group for Sarcopenia (AWGS) 2019 algorithm, integrating low handgrip strength, slow gait speed, and low estimated appendicular skeletal muscle mass. Participants were categorized into four groups: no depression/no sarcopenia, sarcopenia only, depression only, and depression plus sarcopenia. The primary outcome was incident ADL disability at any follow-up wave (2013, 2015, or 2018); the secondary outcome was all-cause mortality, ascertained through CHARLS death-tracking records with follow-up censored at 2018. Cox proportional hazards models with progressive covariate adjustment and multiple imputation by chained equations (10 datasets, Rubin's rules) were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results Over a median follow-up of 7.0 years, 1,651 (39.7%) participants developed ADL disability and 521 (12.5%) died. Compared with the no depression/no sarcopenia group, the fully adjusted HRs for ADL disability were 1.01 (95% CI 0.87–1.18) for sarcopenia only, 1.37 (1.23–1.53) for depression only, and 1.40 (1.15–1.70) for depression plus sarcopenia. For all-cause mortality, the corresponding HRs were 1.19 (0.92–1.53), 1.03 (0.84–1.25), and 1.27 (0.91–1.77). Depression independently predicted ADL disability, and low grip strength—a core component of sarcopenia—was independently associated with higher all-cause mortality (HR 1.44, 1.15–1.79), whereas the overall sarcopenia diagnosis was not. The co-occurrence of depression and sarcopenia conferred the highest relative risks for both outcomes, with the strongest association for ADL disability among adults aged 60–69 years (HR 2.02, 1.54–2.65), and associations with mortality were most pronounced in participants with fewer than two chronic conditions. Conclusions Depression and sarcopenia contribute additively to the risk of ADL disability and mortality in Chinese older adults. Adults aged 60–69 years with co-occurring depression and sarcopenia represent a high-risk population that may benefit from integrated screening and early intervention.