Abnormal Sleep Duration and Sarcopenia are Jointly Associated with Adverse Depressive Trajectories in Adults Aged ≥45: Evidence from A Longitudinal Cohort Study

Abnormal sleep duration (ASD) and sarcopenia are highly prevalent. However, their combined effects on dynamic depressive trajectories remain unclear. This study aimed to explore the associations of coexisting ASD and sarcopenia with first-onset depressive symptoms and depressive symptom trajectories in adults aged ≥45 years. Data were derived from the China Health and Retirement Longitudinal Study. A total of 11295 and 6739 participants were included in cross-sectional, cohort studies and trajectory analysis. Sarcopenia was diagnosed based on the AWGS 2025 criteria, and ASD was defined as sleep duration <6 h or >8 h. Depressive symptoms were assessed using the CES-D-10 scale. Latent class growth model was used to identify depressive trajectories, and multinomial logistic regression was applied to analyze the relationship. ASD combined with sarcopenia was associated with an increased hazard of depressive symptoms based on cross-sectional and cohort study. Three distinct depressive trajectories were identified: persistently low-level normal trajectory (Cluster 1), slowly elevating depressive trajectory (Cluster 2), rapidly elevating depressive trajectory (Cluster 3). After adjusting for covariates (age, gender, education, marital status, smoking, chronic diseases, etc.), ASD combined with sarcopenia group had a significantly higher odds of belonging to cluster 3 (OR=4.130, 95%CI: 2.455–6.948) and cluster 2 (OR=2.436, 95%CI: 1.700–3.941) compared to the reference trajectory. ASD and sarcopenia are jointly associated with first-onset depressive symptoms and adverse depressive trajectories in adults aged ≥45, with a stronger link to rapidly elevating trajectories, which emphasizes the value of integrated psychosomatic screening and intervention targeting ASD and sarcopenia for the management of depressive symptom progression.