Triglyceride–glucose index and its derived anthropometric indices: a comparative analysis for mortality prediction in the population cohort of the URRAH study

Background and aims: The triglyceride–glucose (TyG) index is an established surrogate marker of insulin resistance and has been consistently associated with adverse cardiovascular outcomes. Composite indices combining TyG with anthropometric measures, such as body mass index (BMI) and waist circumference (WC), have been proposed to enhance risk prediction. However, their incremental prognostic value remains uncertain. This study aimed to compare the predictive performance of TyG, BMI, and WC with that of their derived multiplicative indices (TyG-BMI and TyG-WC) for all-cause and cardiovascular mortality. Methods and results: Data were analysed from the multicentre URRAH cohort, including 17,742 participants for the evaluation of TyG-BMI and a sub-analysis of 7052 individuals for TyG-WC. Over a median follow-up of 11.7 years, 2650 all-cause deaths occurred, including 1158 cardiovascular deaths. The TyG index showed a strong and independent association with both outcomes. Although TyG-BMI and TyG-WC were significantly associated with mortality, their risk patterns largely reflected those of their individual components. In multivariable models, inclusion of the derived indices did not meaningfully improve model fit, discrimination, individual risk prediction, or clinical usefulness. Conclusion: In this large general cohort, the TyG index was confirmed as a robust predictor of all-cause and cardiovascular mortality. In contrast, derived indices combining TyG with BMI or WC did not confer meaningful incremental prognostic value beyond modelling TyG and anthropometric measures separately, supporting the use of TyG as a simple and clinically informative marker for mortality risk stratification.