Cardiovascular-Kidney-Metabolic syndrome and suicidal death in a nationwide cohort study

Background Individual cardiometabolic diseases are associated with psychiatric conditions and suicide. However, the association between the recently proposed Cardiovascular-Kidney-Metabolic (CKM) syndrome framework and suicide-related mortality remains unevaluated.Methods We analyzed data from 4,601,001 participants in the Korean National Health Insurance Service database, categorizing CKM health into Stages 0-4. The association between CKM stages and suicide-related mortality was evaluated using multivariable Cox regression with sequential adjustment for clinicodemographic variables, comorbidity, and claims-based psychiatric diagnoses, and using Fine-Gray subdistribution hazard models treating non-suicide death as a competing event.Results During a median follow-up of 10.11 years, 12,034 suicidal death events occurred. After adjustment, advanced CKM stages were associated with an increased risk of suicidal death (stage 3: adjusted HR 1.328, 95% CI 1.217-1.449; stage 4: adjusted HR 1.319, 95% CI 1.220-1.426), and the association persisted after further adjustment for other psychiatric disorders. Estimates were attenuated but remained significant in Fine-Gray models accounting for the competing risk of non-suicide death (stage 3: subdistribution HR 1.199, 95% CI 1.098-1.310; stage 4: 1.246, 95% CI 1.150-1.349). Exploratory subgroup analyses indicated that the association was most pronounced in younger adults aged 20-39 and in individuals without a claims-based diagnosis of depression.Conclusions Advanced CKM syndrome is associated with increased suicide-related mortality. Mental health surveillance within the clinical management of CKM dysfunction may serve as a potential preventive strategy. Future studies are needed to evaluate the utility of CKM-based risk stratification in suicidal death prevention.