The association between triglyceride-glucose index and all-cause/cardiovascular mortality in patients with different glucose metabolism status

Objectives The triglyceride-glucose index (TyG) is a significant parameter for evaluating metabolic health, but its link to mortality across various glucose metabolism statuses is still uncertain. The purpose of this study was to investigate the relationship between TyG and the risk of all-cause and cardiovascular mortality in normoglycemia, dysglycemia, and diabetic populations. Methods Participants who took part in the NHANES for nine cycles were chosen and divided into three categories: normoglycemia, dysglycemia, and diabetes. Cox regression and restricted cubic spline (RCS) models were used to assess the linear and nonlinear relations between TyG and mortality, respectively. To evaluate the predictive power of TyG and the atherogenic index of plasma (AIP) for mortality, a time-dependent ROC curve was utilized. Subgroup analyses were carried out separately based on age, sex, and blood-pressure status. Results After a median observation period of 9.2 years, 2,199 deaths from all causes and 606 cardiovascular-related deaths were recorded. In the normoglycemic group, a single standard unit rise in TyG correlated with a 37% increase in all-cause mortality and a 42% increase in cardiovascular mortality. Among the diabetics, the RCS revealed a U-shaped relation of TyG with all-cause/cardiovascular mortality, with a threshold value of 9.1. No significant associations were identified in dysglycemia. TyG outperformed the AIP in predicting 3-year mortality in normoglycemic and diabetic groups. Subgroup analyses revealed a significant age-specific interaction in the TyG-mortality association, with significance in individuals <65 but not ≥65 years of age. Conclusion Our findings highlight TyG's predictive role in populations with different glucose metabolism, contributing new evidence for public fields and medical practice.