Sleep duration, sarcopenia, and incident depressive symptoms in Chinese middle-aged and older adults: A prospective...

Sarcopenia and depressive symptoms are prevalent health issues in middle-aged and older adults, yet the mechanisms linking them remain unclear. This study aimed to investigate the association between sarcopenia and incident depressive symptoms and to examine the potential mediating role of sleep duration. We conducted a prospective cohort study using data from the China Health and Retirement Longitudinal Study from 2011 to 2015. A total of 5346 participants aged 45 years and older without baseline depressive symptoms were included. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 criteria. Depressive symptoms were assessed using the 10-item Center for Epidemiological Studies Depression Scale, with a cutoff of ≥10 indicating depression. Sleep duration was self-reported. Cox proportional hazards models, restricted cubic spline regression, and bootstrap mediation analysis were employed. During a 4-year follow-up, 1482 participants (27.72%) developed incident depressive symptoms. After adjusting for confounders, both possible sarcopenia and confirmed sarcopenia were significantly associated with an increased risk of depressive symptoms (hazard ratio [HR] = 1.21, 95% confidence interval [CI]:1.02-1.44 and HR = 1.36, 95% CI:1.04-1.78, respectively). Longer sleep duration was independently associated with a lower risk of depression (HR = 0.93, 95% CI: 0.90-0.96). However, the mediating effect of sleep duration became non-significant after covariate adjustment (P = .302). Sarcopenia was independently associated with incident depressive symptoms, but sleep duration did not significantly mediate this association after adjustment. These exploratory findings should be interpreted cautiously. These findings suggest that interventions targeting sarcopenia prevention and management may confer beneficial effects on mental well-being in aging populations.