Association of cardiometabolic index and depressive symptoms with cardiovascular and cerebrovascular diseases in middle-aged and older adults: A national prospective cohort study.

BACKGROUND

Cardiovascular diseases (CVDs) are the leading cause of mortality globally, with ischemic heart disease and stroke being the primary contributors. Despite the widespread use of traditional risk assessment models, new biomarkers are needed to enhance predictive accuracy. Depression and cardiometabolic index (CMI) are strongly associated with CVD risk, but their combined effect remains understudied. This study aimed to examine the association between depression and CMI, individually or in combination, and the incidence of CVD in middle-aged and older adults.

METHODS

Using data from the China Health and Retirement Longitudinal Study (CHARLS), 5808 adults aged 45 years and older were included in this analysis. Cox proportional hazard models assessed both the individual and combined effects of depression and CMI on CVD risk. Causal mediation analysis further explored the potential mediating effects of depression and CMI on CVD.

RESULTS

During 9 years of follow-up, CVD occurred in 1140 participants, including 843 cases of coronary heart disease and 408 strokes. Following the adjustment for sociodemographic factors and health-related variables, a higher CMI was found to be significantly associated with an increased risk of stroke (HR: 2.015, 95 % CI: 1.458-2.786) and CVD (HR: 1.284, 95 % CI: 1.072-1.537). Additionally, depressive symptoms were significantly linked to an elevated risk of CVD (HR: 1.472, 95 % CI: 1.296-1.671). The highest incidence of CVD was found in those with a combination of depression and high CMI (HR: 1.647, 95 % CI: 1.319-2.056). Subgroup analyses revealed significant heterogeneity in the association of age, gender, education level, and chronic disease status in the risk of CVD. Mediation analyses showed a small indirect effect of CMI on CVD through depressive symptoms (ACME: -0.00186, 95 % CI: -0.00410-0.00), whereas the indirect effect of depressive symptoms on CVD through CMI was significant (ACME: -0.00108, 95 % CI: -0.00243 -0.00).

CONCLUSIONS

Both depression and CMI demonstrated significant associations with the risk of CVD. Furthermore, the likelihood of CVD occurrence was notably higher when both factors coexisted. The mediation analysis suggests that depression modulates CVD risk through metabolic abnormalities, providing an important basis for further pathological mechanism studies and comprehensive intervention strategies.