Association of the triglyceride-glucose index with cardiovascular mortality risk and competing risks in arthritis patients.

This study aims to investigate the relationship between the triglyceride-glucose index (TyG) and all-cause mortality as well as cardiovascular mortality in arthritis patients. Additionally, it seeks to analyze the nonlinear characteristics and threshold effects of TyG index. We included 5,559 adult participants with arthritis from the 1999-2018 National Health and Nutrition Examination Survey (NHANES). The TyG index was calculated using fasting triglycerides and glucose levels. We employed Cox proportional hazards models and restricted cubic spline analyses to examine the relationship between TyG index and all-cause mortality in arthritis patients. Competing risks models were used to analyze the association between TyG index and cardiovascular mortality as well as mortality from other causes. Over a median follow-up period of 7.8 years, 1,388 cases of all-cause mortality were recorded among arthritis patients, including 369 cases of cardiovascular mortality. After adjusting for confounding factors, TyG index was found to be nonlinearly positively associated with all-cause mortality (P = 0.0019), with a significant increase in mortality risk when TyG index ≥ 8.43. Compared to the quartile 2 of TyG index, the highest quartile was associated with a 36% increased risk of all-cause mortality (HR 1.36, 95% CI 1.12-1.65). Additionally, competing risks models indicated that high TyG index levels were significantly associated with increased risks of cardiovascular mortality and mortality from other causes. Subgroup analyses confirmed the robustness of the association between TyG index and cardiovascular mortality in arthritis patients. The TyG index is nonlinearly associated with all-cause mortality and represents a potential prognostic indicator for mortality risk in arthritis patients.