Triglyceride-glucose index and mortality risk in individuals with or without chronic kidney disease: Insights from a national survey of United States adults, 1999-2018

Background and aims: The Triglyceride-Glucose Index (TyG) has been proposed as a predictor to mortality, yet its association remains incompletely understood for individuals with or without chronic kidney disease (CKD). Methods and results: We analyzed data from the National Health and Nutrition Examination Survey spanning the years 1999-2018. CKD was defined as eGFR level <60 ml/min/1.73 m(2) or urinary albumin creatinine ratio >= 30 mg/g. We employed the Cox proportional-hazards model to evaluate the incident risk of mortality associated with TyG among both non-CKD and CKD individuals. In the current analysis, 19,426 individuals were without CKD, while 2975 individuals had CKD. The overall mean TyG was 8.65, with significant difference between non-CKD and CKD individuals (8.60 vs 8.95, P < 0.001). The TyG index exhibited linear associations with incident cardiovascular disease (CVD) mortality and all-cause mortality among non-CKD and CKD individuals, respectively. A per-unit increase in the TyG index was significantly associated with CVD mortality for both non-CKD (HR = 1.24, 95%CI = 1.09-1.41) and CKD participants (HR = 1.19, 95%CI = 1.04-1.36), with no significant difference in the associations between the two groups (P = 0.091). For both non-CKD and CKD participants, TyG index was significantly associated with CVD mortality and all-cause mortality among those with age <65, but not for those with age >= 65. Conclusions: Our findings underscore the TyG index's as a valuable predictive tool for assessing the risk of all-cause and CVD mortality in both individuals with and without CKD.