Association between Triglyceride-Glucose Index and risk of all-cause and cardiovascular mortality in adults with prior cardiovascular disease: a cohort study using data from the US National Health and Nutrition Examination Survey, 2007–2018

Objective The association between the Triglyceride-Glucose (TyG) Index and mortality rates in patients with cardiovascular disease (CVD) remains unclear. This study investigates the association between the TyG index and the incidence of all-cause and CVD-specific mortality among individuals with a history of CVD. Design Population-based cohort study. Setting Data were sourced from the US National Health and Nutrition Examination Survey (2007–2018) and linked mortality data, with follow-up continuing until 31 December 2019. Participants The study population comprised 3422 individuals aged 20 years or older with a documented history of CVD. Outcome measures We examined the association between the TyG index and the risk of all-cause and cardiovascular mortality. Results Over a median follow-up of 5.79 years, 1030 deaths occurred, including 339 due to CVD. Cox regression analysis, adjusted for multiple confounders, showed that individuals in the highest TyG index quartile, compared with those in the lowest, had HRs of 0.76 (95% CI: 0.60 to 0.96) for all-cause mortality and 0.58 (95% CI: 0.39 to 0.89) for CVD mortality. There was a significant inverse relationship between higher TyG index levels and lower mortality risks. For each unit increase in the TyG index, the adjusted HRs for all-cause and CVD mortality decreased by 18% (HR 0.82; 95% CI: 0.71 to 0.94) and 27% (HR 0.73; 95% CI: 0.57 to 0.92), respectively. Conclusions TyG index values are negatively associated with all-cause and CVD mortality risks among individuals with previous CVD. Further interventional studies are needed to clarify the impact of TyG levels on cardiovascular health.