Comparative mortality associations of the triglyceride glucose index (TyG) and TyG-related anthropometric indices in older adults with type 2 diabetes

The triglyceride-glucose (TyG) index and TyG-related anthropometric indices are accessible markers integrating metabolic and anthropometric information. However, few large community-based studies have directly compared multiple TyG-related indices in relation to both all-cause and cardiovascular mortality among older adults with type 2 diabetes mellitus (T2DM). We therefore evaluated their association patterns, non-linear dose-response relationships, and incremental prognostic value in this population. This community-based cohort study included 56,182 older adults with T2DM who participated in the Wuhan Elderly Health Management Program in 2018. Baseline TyG, TyG-ABSI, TyG-BMI, TyG-WC, and TyG-WHtR were calculated, and mortality outcomes were ascertained through linkage with the Wuhan Mortality Surveillance System through January 26, 2024. Multivariable Cox regression models were used to estimate associations with all-cause and cardiovascular mortality. Restricted cubic spline and threshold analyses characterized non-linear dose-response relationships, and time-stratified analyses assessed temporal variation in associations. Incremental prognostic performance was evaluated using C-index, time-dependent area under the curve (AUC), net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision-curve analysis. During a median follow-up of 5.56 years, 9,236 all-cause deaths, including 4,126 cardiovascular deaths, occurred. TyG-ABSI showed the most consistent positive association with mortality among the evaluated indices, with fully adjusted hazard ratios per 1-SD increase of 1.104 (95% CI 1.082–1.127) for all-cause mortality and 1.096 (1.064–1.130) for cardiovascular mortality. TyG was also positively associated with both outcomes, whereas TyG-BMI showed inverse associations in conventional Cox models and TyG-WC and TyG-WHtR showed weaker or less consistent associations. Non-linear relationships were observed across all five indices, with mortality risk generally decreasing toward an intermediate minimum and increasing beyond data-derived turning points. Associations also varied over follow-up, with the positive associations of TyG and TyG-ABSI becoming more evident after 2 years and the inverse associations of several anthropometric derivatives attenuating. At 5 years, TyG-ABSI yielded the largest improvements in AUC and NRI, whereas TyG-BMI yielded the largest IDI; however, absolute gains in overall discrimination were small, and decision curves showed limited separation between models. In this large community-based cohort of older adults with T2DM, TyG and TyG-related anthropometric indices showed distinct, non-linear, and time-varying associations with all-cause and cardiovascular mortality. TyG-ABSI showed the most consistent positive associations, but no single index consistently dominated across prognostic metrics and incremental discrimination was modest. These findings argue against treating TyG-related indices as interchangeable or ranking them solely by association strength, and their potential roles in community-based risk stratification require external validation. Not applicable.