Depressive symptom trajectories and risk of CVD among rural older adults in China: a CHARLS-based cohort study

The association between trajectories of depressive symptoms and the risk of cardiovascular disease (CVD) in rural older adults remains insufficiently understood. This study aimed to investigate the impact of depressive symptom trajectories on the incidence of CVD among rural older adults in China. Data were obtained from the China Health and Retirement Longitudinal Study (CHARLS), including 2,482 rural participants aged 60 years and above without baseline CVD. Depressive symptoms were assessed across five survey waves (2011, 2013, 2015, 2018, 2020) using the 10-item Center for Epidemiologic Studies Depression Scale (CESD-10). Shape-based time-series clustering (K-Shape) identified five distinct depressive symptom trajectories: Stable-Low, Stable-Moderate, Increasing, Decreasing, and Stable-High. Multivariate logistic regression and sex-stratified analyses were conducted to examine the associations between trajectory groups and incident CVD (heart disease or stroke). Compared to the Stable-Low group, the Stable-High trajectory was significantly associated with an increased risk of CVD (OR = 3.16, 95% CI: 1.98–4.96). Other high-risk trajectories included the Stable-Moderate (OR = 2.29, 95% CI: 1.87–2.82) and Increasing (OR = 1.76, 95% CI: 1.41–2.19) groups. In sex-stratified models, patterns were broadly similar with larger point estimates in females; the Decreasing trajectory was not associated with CVD events within either sex. The model demonstrated moderate discrimination (AUC = 0.692). Persistent and worsening depressive symptoms are associated with higher CVD risk among rural older adults, with larger effect estimates in females, suggesting greater vulnerability to sustained depressive-symptom burden in relation to later CVD occurrence. In the overall sample, the Decreasing trajectory was associated with higher odds of CVD, but this association was not significant within sex strata and should be interpreted cautiously. These findings highlight the importance of longitudinal psychological assessment and sex-specific risk appraisal in CVD prevention among rural older adults.