Association Between Triglyceride Glucose Index and Triglyceride Glucose-Obesity Composite Indices and the Risk of Ischemic Heart Disease

Objective To explore the association between the triglyceride-glucose index (TyG) and TyG-obesity composite indices, including TyG-waist circumference (TyG-WC), TyG-body mass index (TyG-BMI), and TyG-waist-to-height ratio (TyG-WHtR), and the risk of ischemic heart disease (IHD), and to provide reference for the prevention of IHD.

Methods The sample of this study was derived from the West China Elderly Preventive and Treatment Merging Cohort, from which 9628 elderly individuals from the retrospective cohort were selected. Cox regression models were used to analyze the association between TyG-related indices and the risk of IHD. Receiver operating characteristic (ROC) curves were plotted to assess and compare the performance of TyG-related indices in predicting the occurrence of IHD.

Results The participants were followed up for a median of 2.82 years, with 7.2% (694/9628) of the participants experiencing IHD events. Multivariate Cox regression showed that after controlling for the covariates, including sex, age, educational attainment, smoking, drinking, exercise, dietary habits, medication history, and whether the participant had hypertension, every time TyG, TyG-WC, TyG-BMI and TyG-WHtR increased by one standard deviation (SD), the risk of IHD increased by 12% (hazard ratio HR=1.12, 95% confidence interval CI: 1.04-1.20), 21% (HR=1.21, 95% CI: 1.12-1.31), 20% (HR=1.20, 95% CI: 1.12-1.29), and 19% (HR=1.19, 95% CI: 1.10-1.28), respectively. Both the TyG index and TyG-obesity composite indices were positively correlated with IHD risk, showing a linear relationship (P<0.05). TyG-WC (area under the curveAUC=0.680, 95% CI: 0.660-0.700, P<0.001), TyG-BMI (AUC=0.674, 95% CI: 0.654-0.695, P<0.001), and TyG-WHtR (AUC=0.678, 95% CI: 0.658-0.698, P<0.001) demonstrated better predictive performance than TyG did (AUC=0.669, 95% CI: 0.648-0.689, P<0.001).

Conclusion Elevated levels of TyG and TyG-obesity composite indices were associated with a higher risk for IHD, and combining TyG with BMI, WC, and WHtR may lead to better performance in risk assessment for IHD than using TyG alone.