Association between cardiometabolic index and mortality risk in patients with depression: A comprehensive analysis based on two national cohorts

Depression is associated with increased cardiometabolic morbidity and mortality. However, the prognostic value of integrated biomarkers for mortality risk in this population is underexplored, particularly across different ethnicities. The cardiometabolic index (CMI), a composite measure of central obesity and dyslipidemia, has demonstrated predictive utility in general populations, but its role in depression is unknown. To investigate and validate the association between CMI and mortality risk in adults with depression using 2 large, nationally representative cohorts from the United States and China. This study utilized data from the National Health and Nutrition Examination Survey and the China Health and Retirement Longitudinal Study. CMI was calculated as the waist-to-height ratio multiplied by the triglyceride/high-density lipoprotein–cholesterol ratio. Cox proportional hazards models will be employed to examine the association between CMI and all-cause and cardiovascular mortality in participants with depression, after adjusting for potential confounders. This bi-national study evaluates CMI as a prognostic tool for mortality in the depression population. If its utility is confirmed, CMI could serve as a simple, cost-effective biomarker to identify high-risk individuals, facilitating targeted preventive strategies and improving clinical outcomes.