Triglyceride-Glucose and Body Shape Index (TyG-ABSI): A Novel Dual Biomarker for Predicting Stroke Risk in Middle-Aged and Older Chinese Adults—A Nationwide Cohort Study

Background Stroke is a leading global cause of morbidity and mortality, disproportionately affecting aging populations. Metabolic syndrome, obesity, and related dysfunctions are well-established risk factors. The triglyceride-glucose (TyG) index reflects insulin resistance, while the A Body Shape Index (ABSI) indicates abdominal adiposity. Their combination, TyG-ABSI, integrates metabolic and phenotypic risk for precision stratification, yet its prospective validation for stroke prediction in middle-aged and older adults remains underexplored. Objectives This study examined the association between TyG-ABSI and incident stroke risk in middle-aged and older Chinese adults, evaluating its utility as a novel predictive biomarker. Methods This study utilized data from the China Health and Retirement Longitudinal Study (CHARLS) conducted between 2011 and 2018. A cohort of 7,358 participants with no prior history of stroke was selected through a rigorous screening process that excluded individuals based on specific criteria such as age, incomplete TyG-ABSI data, and missing stroke information. The predictive capacity of TyG-ABSI for incident stroke was evaluated using multivariable Cox proportional hazards regression models. Three models were constructed: an unadjusted model, a model adjusted for age and sex, and a fully adjusted model that included potential confounders such as education level, place of residence, marital status, smoking status, alcohol consumption, hypertension, diabetes mellitus, heart disease, dyslipidemia, and BMI. Additionally, restricted cubic spline (RCS) analysis was performed to explore the potential non-linear relationship between TyG-ABSI and incident stroke. Receiver operating characteristic (ROC) curve analysis was conducted to assess the predictive performance of TyG-ABSI for incident stroke across different adjustment models. Results Elevated TyG-ABSI correlated with increased stroke risk in a dose-dependent manner (highest vs. lowest quartile: HR = 1.57, 95% CI = 1.18–2.08, P = 0.0019). Urban residents showed a stronger association (OR = 1.04, 95% CI = 1.03–1.05) than rural counterparts (OR = 1.01, 95% CI = 0.98–1.03; interaction P = 0.038). The AUC in the fully adjusted model was 0.701, indicating moderate predictive accuracy. Conclusion TyG-ABSI robustly predicts incident stroke in middle-aged and older Chinese adults, with a significant dose-dependent relationship. This dual marker enhances precision risk stratification by integrating metabolic and obesity-related factors, offering clinical value for tailored prevention. Urban-rural disparities highlight the need for targeted strategies.