Loneliness, restless sleep, and incident possible or confirmed sarcopenia among middle-aged and older Chinese adults

Abstract Loneliness and sleep problems may mark vulnerability to sarcopenia, but prospective evidence on their co-occurrence is limited. Using 2011 and 2015 CHARLS data, we examined loneliness, restless sleep, and their joint exposure in relation to incident possible or confirmed sarcopenia. The unweighted complete-case analysis included 6,614 participants free of either category at baseline. Loneliness and restless sleep were coded from two CES-D-10 items. During follow-up, 1,067 participants developed the composite outcome. In the most extensively adjusted logistic model, loneliness (OR 1.38, 95% CI 1.18–1.62) and restless sleep (OR 1.20, 95% CI 1.03–1.38) were associated with higher odds. Compared with neither symptom, the OR was 1.32 (95% CI 1.02–1.71) for loneliness only, 1.13 (95% CI 0.95–1.34) for restless sleep only, and 1.53 (95% CI 1.26–1.87) for both symptoms. Modified Poisson analysis was consistent for both symptoms (RR 1.34, 95% CI 1.16–1.54), whereas multiplicative interaction was not supported. Loneliness and restless sleep were associated with the composite outcome, and their co-occurrence identified the highest odds. These observational findings do not establish causality.