Association of depression with sarcopenia and the impact of sleep: the first longitudinal evidence from the CHARLS

Sarcopenia, characterized by age-related declines in muscle mass, strength, and function, shares common risk pathways with depression including chronic inflammation and physical inactivity. Sleep disorders can affect muscle health and emotional state, potentially exacerbating both conditions, but the relationship among the three has not been fully explored. We conducted a longitudinal analysis of 4,067 participants from the China Health and Retirement Longitudinal Study (CHARLS; 2011–2015). Sarcopenia and its components were defined using the Asian Working Group for Sarcopenia (AWGS) 2019 criteria, and depressive symptoms were assessed with the 10-item Center for Epidemiological Studies Depression Scale (CESD-10). Multivariable logistic regression estimated odds ratios (ORs). Stratified analyses were performed by nighttime sleep, total sleep, and daytime napping status, and mediation analyses evaluated sleep duration measured in 2013…. Baseline depressive were associated with incident sarcopenia during follow-up (OR = 1.32, 95% CI 1.08–1.61), low muscle mass (OR = 1.39, 95% CI 1.12–1.72) and low muscle strength (OR = 1.68, 95% CI 1.41–2.00), whereas no statistically significant association was observed for low physical performance (OR = 1.00, 95% CI 0.84–1.20). Stratified analyses suggested that these associations were more evident among individuals reporting shorter sleep duration (particularly < 6 h) and among non-nappers. Mediation analyses indicated a partial indirect association via sleep duration measured in 2013, accounting for approximately 11.8% of the total association. Depressive symptoms were associated with higher odds of incident sarcopenia, primarily through low muscle strength and low muscle mass. Sleep patterns may contribute to heterogeneity in these associations and account for a modest proportion through an indirect pathway, supporting integrated mental health screening and sleep assessment in middle-aged and older adults.