The association between triglyceride-glucose index and its combination with obesity indicators and stroke: CHARLS 2011-2020

Abstract

Background In the Chinese population, limited research has been conducted on the association between the triglyceride-glucose (TyG) index and its combination with obesity indicators in relation to stroke and its mortality. Methods This study enrolled a total of 8,207 participants from the China Health and Retirement Longitudinal Study (CHARLS) 2011–2020. Cox proportional hazards model, restricted cubic spline (RCS) and receiver operating characteristic (ROC) analysis were employed to examine the association between the triglyceride-glucose (TyG) index and its combined obesity-related indicators with stroke and its mortality. Mediation analysis was conducted to explore the mutual potential mediating role of TyG and obesity indicators in the above relationships. Results In this study, TyG, TyG-BMI, TyG-WHtR, and TyG-WC were significantly and positively associated with stroke and its mortality. Restricted cubic spline models revealed nonlinear associations between TyG and TyG-BMI with stroke risk, while TyG-WC and TyG-WHtR demonstrated linear associations with stroke mortality after adjusting for relevant covariates. TyG-WHtR, TyG-BMI and TyG-WC had more robust diagnostic efficacy than TyG for risk of stroke. TyG-WHtR or TyG-WC had the highest diagnostic efficacy for stroke and its mortality (AUC:0. 696, 95% CI 0.677–0.715), slightly higher than the other indicators. Associations between TyG, TyG-WC, TyG-WHtR, and TyG-BMI with stroke were found to be stronger among individuals who were ≥ 55 years of age, male. The relationship between TyG and stroke is partially mediated by obesity measures, while the relationship between obesity measures and stroke is partially mediated by TyG. Conclusion Compared with the traditional single TyG, the combination of TyG and obesity indicators could improve the prognostic accuracy of stroke mortality, enhance diagnostic efficacy for stroke and its mortality, and uncover additional associations with stroke. These findings carry noteworthy implications for the timely identification of individuals at risk of stroke, and refining risk stratification.