Triglyceride-glucose index variability and risk of all-cause and cardiovascular mortality

Triglyceride-glucose (TyG) index is a reliable marker of insulin resistance with predictive value for cardiovascular risk. While metabolic variability independently impacts cardiovascular outcomes and mortality, the clinical significance of TyG index variability remains unclear. We investigated whether higher TyG index variability increases the risk of mortality. This retrospective cohort study analyzed data from 3,094,062 individuals who participated in the National Health Screening Program from 2009 to 2014. TyG index variability independent of the mean (VIM) was calculated and participants were categorized into quartiles. Cox proportional hazards regression analysis was used to estimate hazard ratio (HR) with 95% confidence interval (CI) for all-cause and cardiovascular mortality. Over a median follow-up of 9.1 years, a total of 137,339 (4.44%) deaths were recorded, including 15,261 (0.56%) from cardiovascular causes. Mortality rose stepwise across TyG index VIM quartiles. Compared to Quartile 1, Quartile 4 had the highest risk of all-cause mortality (HR 1.18, 95% CI 1.16-1.21, P < 0.001) and cardiovascular mortality (HR 1.13, 95% CI 1.06-1.21, P < 0.001). Higher TyG index variability is associated with increased all-cause and cardiovascular mortality. Serial monitoring of changes in TyG index may contribute to reducing mortality risk through early detection and intervention.