Higher suicide risk in type 1 diabetes compared to cancer and the general population in Korea

Background: People with diabetes have increased suicide risk. However, it is unclear whether those with type 1 diabetes (T1D) have a higher risk than those with cancer, a disease associated with significant psychological stress and suicide risk. Objectives: To evaluate suicide risk among adults with T1D compared to matched cohorts of patients with cancer and the general population. Methods: This population-based matched-cohort study examined adults aged ≥19 years (45,944 with T1D and 45,944 with cancer matched for age, sex, and index year) using data from the Korean National Health Insurance Database for January 2009–December 2015 and including 229,720 matched controls without diabetes or cancer (1:5). Composite suicide outcomes were death by suicide or hospitalization for a suicide attempt (intentional self-harm, fatal toxic substance, toxic effect of carbon monoxide, psychotropic medication, wrist laceration, fall, and asphyxia). Results: Participants had a median age of 62 years and a median follow-up duration of 10.3 years. T1D was significantly associated with an increased risk of composite suicide outcomes (adjusted hazard ratio [aHR] = 2.02; 95% confidence interval [CI] = 1.87–2.19) compared to controls. Individuals with T1D had significantly higher composite suicide outcome risk than patients with cancer (1:1) (aHR = 1.75; 95% CI = 1.55–1.97). Younger (Age < 50) and lower-income patients with T1D had a higher suicide risk than those without diabetes or cancer. Conclusion: This nationwide study demonstrated a significant association between T1D and increased suicide risk compared to the general population and patients with cancer. This underscores the importance of mental health screening and targeted interventions for this population.