Depression and risk of incident heart diseases among older adults at CKM stages 0–3: evidence from the China Health and Retirement Longitudinal Study

BACKGROUND: Evidence on the association between depression and incident ischemic heart disease (IHD) in individuals with cardiovascular kidney metabolic (CKM) syndrome is limited. This study investigated this association in older adults at CKM stages 0-3. METHODS: Data was extracted from the China Health and Retirement Longitudinal Study (CHARLS). Participants meeting the criteria were included. Depression was defined as Center for Epidemiologic Studies Depression (CESD) scale ≥10. IHD mainly contained heart attack, coronary heart disease, angina, congestive heart failure. Association between depression and IHD was estimated in participants at CKM stage 0-3 using logistic regression models. The directed acyclic graph (DAG) was also used for variable selection. Association between depression and CKM stage 4 was also evaluated. Subgroup analyses (strata including sex, marital status, etc.), interaction p‑values and restricted cubic splines (RCS) were also conducted. Six sensitivity analyses were conducted, comprising using original data, inverse probability of treatment weighting (IPTW), treating the CESD score as both a categorical and continuous variable, etc. Simple mediation analyses were conducted to examine whether changes in BMI, CRP, and WBC mediated the depression‑IHD association. RESULTS: 4,738 participants were included. After multivariable adjustment, depression was significantly associated with an increased risk of IHD (OR 1.62, 95%CI:1.34-2.03) and CKM stage 4 (OR 2.43, 95%CI:1.62-3.66). Similarly, when variables were selected by DAG, the OR was 1.67 (1.34,2.07) for IHD and 2.45 (1.66,3.64) for progression to CKM stage 4. The trend persisted across the 6 sensitivity analyses. RCS revealed a linear relationship between CESD score and IHD risk, with consistent associations across subgroups and no significant mediation effects. CONCLUSION: Depression was prospectively associated with a higher risk of IHD among participants at CKM stages 0-3. This finding offers a new perspective for the management of IHD in the context of CKM syndrome.