Triglyceride-glucose index and risks of suicide mortality in young adults: a nationwide population-based study

Background Suicide is a leading cause of death among young adults in South Korea. We investigated the association between triglyceride-glucose (TyG) index and suicide mortality in young adults. Methods This nationwide study analysed data from 6 667 138 individuals aged 20–39 using the National Health Insurance Database. Participants were grouped into TyG index quartiles. The primary outcome was suicide mortality. Results During a median follow-up duration of 10.7 years, 41 004 (0.6%) suicidal deaths occurred. The cumulative event rates for suicide mortality were highest among participants in TyG index quartile 4. Multivariable Cox analysis showed significant increases in the risks of suicide mortality in participants with TyG index quartile 4 compared with those in the low quartiles (adjusted HR 1.17, 95% CI 1.11 to 1.23, vs quartile 1; adjusted HR 1.15, 95% CI 1.10 to 1.20, vs quartile 1–3). The association between the TyG index and the risks of suicide mortality was positive and quasi-linear. Subgroup analysis showed a consistent trend of increasing HRs for suicide mortality with higher TyG index quartiles, with significant interactions between TyG index, sex and depression. Conclusion TyG index can be useful in identifying young individuals at an increased risk of suicide mortality.