Non-insulin-based insulin resistance indexes in predicting severity for coronary artery disease

Triglyceride and glucose (TyG) index, triglyceride glucose-body mass (TyG-BMI) index, triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio, and metabolic score for insulin resistance (METS-IR) are considered simple and reliable indicators of insulin resistance (IR). Although they have been associated with coronary artery disease (CAD), evidence supporting this is limited. Here, this is the first study to demonstrate the relationship between TyG-BMI index and CAD severity. The performance of the four non-insulin-based IR indexes in predicting CAD severity was explored.

We retrospectively analyzed 485 CAD patients between August 2020 and August 2021 in China, who were assigned into single- and multi-vessel CAD groups according to the coronary angiography (CAG) results. All patients were stratified into groups based on the tertiles of the TyG index, TyG-BMI index, TG/HDL-C ratio, and METS-IR.

Patients in the multi-vessel CAD group had significantly higher TyG index, TyG-BMI index, TG/HDL-C ratio and METS-IR than those in the single-vessel CAD group. After adjusting for confounding factors, these four indicators were significantly associated with the risk of multi-vessel CAD. Notably, the highest tertile of TyG index, TyG-BMI index, TG/HDL-C ratio and METS-IR were significantly associated with the risk of multi-vessel CAD compared to participants in the lowest tertile. We also constructed receiver operating characteristic (ROC) curve, to assess CAD severity. The area under the curve (AUC) of the ROC plots was 0.673 (95% CI 0.620-0.726; P < 0.001) for TyG index, while those for the TyG-BMI index, TG/HDL-C ratio, and METS-IR were 0.704 (95% CI 0.652-0.755; P < 0.001), 0.652 (95% CI 0.597-0.708; P < 0.001), and 0.726 (95% CI 0.677-0.775; P < 0.001), respectively.

TyG-BMI index is not only significantly associated with CAD severity, but is also an independent risk factor for multi-vessel CAD. The TyG index, TyG-BMI index, TG/HDL-C ratio, and METS-IR could be valuable predictors of CAD severity. Among the four non-insulin-based IR indexes, METS-IR had the highest predictive value, followed by TyG-BMI index.