High density lipoprotein cholesterol mediates the association between triglyceride-glucose index and coronary artery disease in non-diabetes patients

Abstract The triglyceride and glucose (TyG) index is considered a biochemical marker of insulin resistance (IR) and exhibits a significant correlation with cardiovascular disease occurrence. This study aims to explore the association between TyG index and coronary artery disease (CAD) in non-diabetes patients, and further evaluate the mediating role of high density lipoprotein cholesterol (HDL-C) in this relationship. Totally 1192 subjects firstly underwent selective coronary angiography (CAG) were enrolled in the present study, including 709 first diagnosed individuals with CAD and 402 non-CAD individuals. All participants were categorized into four groups according to quartile of the TyG index. The relationships of the TyG index with CAD were validated by logistic regression analysis and restricted cubic spline analysis (RCS). Mediation analysis was conducted to determine the indirect effects through HDL-C. Multiple linear regression analysis revealed the TyG index were significantly increased with LDL-C, apolipoprotein A-1(apoA-1), apolipoprotein B (apoB), and inversely associated with HDL-C. Multivariable logistic regression analysis revealed a significant positive association between the TyG index and CAD. Logistic regression and RCS analyses showed that the association between TyG index and CAD risk was statistically significant only in the middle HDL-C tertile [OR = 2.766 for TyG Q2, OR = 3.100 for TyG Q3, OR = 2.701 for TyG Q4), all p < 0.05]. A significant nonlinear relationship was also observed in this tertile ( p nonlinear < 0.05), after adjusting for covariates. The indirect effect of TyG index on CAD by HDL-C was 0.1372 (95% bootstrap CI: 0.0702 to 0.2156), while LDL-C and aopB showed no mediation effect on this association ( p > 0.05). The TyG index was independently associated with CAD risk. Mediation analysis confirmed that HDL-C exerted a significant mediating effect on the association. Comprehensive management of HDL-C for people with high TyG index facilitates primary prevention of cardiovascular diseases.