Triglyceride–Glucose Index Predicts Cardiovascular Outcome in Metabolically Unhealthy Obese Population: A Nationwide Population-Based Cohort Study

Background This study assesses the prognostic value of the triglyceride–glucose (TyG) index for cardiovascular (CV) risk in subgroups based on metabolic health and obesity status. Methods Originally, 514,866 participants were enrolled from the Korean National Health Insurance Service-National Health Screening Cohort. The study participants were categorized into four groups: metabolically healthy non-obese (MHNO), metabolically unhealthy non-obese (MUNO), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO). The TyG index was calculated using the following formula: ln (fasting triglyceride [mg/dL]×fasting plasma glucose [mg/dL]/2). Participants were followed from 2009 to 2015 for CV events and CV mortality according to the TyG index. Results After exclusions, the final study cohort contained 292,206 people. During the follow-up, 9,138 CV events and 1,163 CV deaths were documented. When the high and low TyG groups were compared, the high TyG group had a substantially increased risk of CV events among the MUNO and MUO participants (multivariable-adjusted hazard ratio [HR], 1.18; 95% confidence interval [CI], 1.07–1.30 and 1.27 [1.14–1.42], respectively). In participants with MUO status, CV mortality was also significantly increased in the high TyG group compared with the corresponding low TyG group (multivariable-adjusted HR, 1.48; 95% CI, 1.13–1.93). In contrast, a high TyG index was not related to CV mortality in the MHNO, MHO, and MUNO groups. Conclusion The predictive value of the TyG index can vary across populations. Among MUO participants, the TyG index was significantly and positively correlated with unfavorable CV outcomes.