Sleep Duration and Cardiometabolic-Kidney-Metabolic Syndrome: The Role of Depressive Symptoms in a Longitudinal Study

Sleep disturbances are increasingly recognized as modifiable risk factors for metabolic and cardiovascular diseases. However, the relationship between sleep duration patterns and Cardiometabolic-Kidney-Metabolic (CKM) syndrome remains underexplored, particularly regarding the mediating role of mental health factors. This study investigates the longitudinal association between sleep duration and CKM risk, examining whether depressive symptoms mediate this relationship.

We analyzed data from 6462 participants (aged ≥45 years) from the China Health and Retirement Longitudinal Study. Sleep duration was self-reported and categorized as short (<7 hours), optimal (7-9 hours), or long (>9 hours), with 2-year sleep trajectories also defined. CKM syndrome was classified per American Heart Association guidelines, and depressive symptoms were assessed via the 10-item Center for Epidemiologic Studies Depression Scale. Associations were examined using multivariable logistic regression, restricted cubic splines, and causal mediation analysis.

Baseline short sleep duration was independently associated with increased CKM risk (adjusted OR = 1.148; 95% CI: 1.014-1.299). Persistently abnormal sleep over two years further elevated this risk (OR = 1.259; 95% CI: 1.077-1.471). We observed a significant non-linear dose-response relationship between sleep duration and CKM risk (P = 0.031). Causal mediation analysis showed that depressive symptoms partially mediated this association (ACME = -0.002; P < 0.001). Subgroup analyses revealed stronger associations among women, individuals with lower education, and urban residents.

Both short and persistently abnormal sleep independently increase CKM syndrome risk, with depressive symptoms acting as a key mediator. These findings highlight the importance of integrated interventions targeting sleep optimization and mental health management, particularly for high-risk demographic subgroups. Sleep assessment should be incorporated into CKM risk stratification and prevention strategies.