Association between cardiometabolic index (CMI) and suicidal ideation: The mediating role of depression and cardiovascular disease

Background Although existing evidence has shown a significant relationship between lipids and suicidal ideation, the relationship between Cardiometabolic index (CMI) and suicidal ideation remains unclear. This study aimed to explore the association between CMI and suicidal ideation. Furthermore, we explored whether several common CMI-related diseases mediate this association. Methods This cross-sectional study analyzed data from 13,549 adults in the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018. Weighted multivariate regression models and restricted cubic spline (RCS) were used to examine the association between CMI and suicidal ideation. Subgroup and interaction analyses were conducted to assess the robustness of findings across different populations. Mediation analysis was performed to evaluate the potential mediating roles of depression, coronary artery disease (CVD), hypertension, and diabetes in this relationship. Results In the fully adjusted model, each unit increase in CMI was associated with a 17 % increase in the risk of suicidal ideation. Compared to the lowest tertile, participants in the highest tertile had a 41 % increased likelihood of suicidal ideation (95 % CI: 1.05-1.91). The association between CMI and suicidal ideation was consistent across different populations (all P for interaction >0.05). Depression and CVD partially mediated this relationship, accounting for 20.4 % and 4.5 % of the total effect, respectively. Conclusions CMI is associated with an increased risk of suicidal ideation, with depression and CVD acting as partial mediators in this relationship. Reducing CMI with the goal of improving obesity and glucose and lipid disorders may be a key strategy to reduce suicidal ideation.