Insulin resistance surpasses remnant cholesterol: the triglyceride–glucose index as a stronger predictor of coronary artery disease

Introduction Remnant cholesterol (RC), a lipid index representing the cholesterol amount in triglyceride-rich lipoproteins (such as VLDL and chylomicron remnants), is associated with coronary artery disease (CAD). The triglyceride/glucose index (TyG) is a marker of cardiometabolic disease. However, the usefulness of RC and the TyG index in predicting CAD remains unclear. Aim Evaluate the correlations of two biomarkers (RC and TyG index) with CAD, and compare their predictive performance for established CAD. Methods We conducted a case–control study including 1,722 patients with angiographically confirmed CAD and 1,435 individuals without CAD. RC was calculated as: total cholesterol – (LDL-C + HDL-C), all in mmol/L. The TyG index was determined as ln [fasting triglyceride level (mg/dL) × fasting plasma glucose level (mg/dL)]/2. Spearman correlation assessed associations with CAD. Receiver operating characteristic (ROC) curves evaluated discriminatory ability. RC and TyG were stratified into quartiles, and multivariate logistic regression was used to estimate the probability of CAD in each quartile, adjusting for conventional risk factors. Results Both RC and TyG correlated weakly but significantly with CAD, with a stronger monotonic relationship for TyG (r=0.194 vs r=0.126; p<0.0001). In ROC analysis, TyG showed better discriminatory performance than RC (AUC=0.612 vs AUC=0.573; respectively). After a multivariate analysis (logistic regression), for RC, a significant association with CAD emerged from the 3rd quartile (OR=1.318; 95% CI: 1.055–1.647; p=0.015), while the 4th quartile showed a non-significant trend (OR=1.244; 95% CI: 0.998–1.552; p=0.052). Diabetes (p<0.0001), smoking (p<0.0001) and hypertension (p<0.0001) were also significantly associated with CAD. In the logistic regression for the TyG index, the association with CAD increased progressively across quartiles, reaching statistical significance in the 4th quartile (OR=1.447; 95% CI: 1.152–1.819; p=0.002). Hypertension (p<0.0001), type 2 diabetes (p<0.0001), and smoking (p<0.0001) were independently associated with CAD. Conclusions RC and TyG index are independently associated with CAD. Incorporating these markers into clinical assessment protocols may enhance early risk stratification and help prevent premature atherosclerosis. However, the TyG index shows a stronger correlation and better predictive capacity, underscoring its role in detecting cardiometabolic diseases such as CAD.Insulin resistance