Triglyceride glucose index for the detection of the severity of coronary artery disease in different glucose metabolic states in patients with coronary heart disease: a RCSCD-TCM study in China

BACKGROUND: Triglyceride glucose (TyG) index is a new marker associated with atherosclerosis. This study aimed to assess the association between TyG index and the severity of coronary artery disease (CAD) in patients with coronary heart disease (CHD) and further explore the association between TyG index and CAD severity in different glucose metabolic states. METHODS: This multi-centre retrospective study included 731 patients with CHD between January 1, 2014 and September 30, 2020 in China. All patients were stratified into groups based on the tertiles of TyG index (T1: 5.48 ≤ TyG index ≤ 7.17; T2: 7.18 ≤ TyG index ≤ 7.76; T3: 7.77 ≤ TyG index ≤ 10.82). The number of diseased vessels [single-vessel and multi-vessel CAD (≥ 50% stenosis in ≥ 2 large vessels)] represented the severity of CAD, which was measured using coronary angiography (CAG). Glucose metabolic states were defined by the American Diabetes Association as normal glucose regulation (NGR), prediabetes mellitus (Pre-DM), and diabetes mellitus (DM). RESULTS: The baseline analysis results showed significant differences in the clinical and biological characteristics of CHD patients according to TyG index tertiles (P < 0.05 to < 0.001). Logistic regression analysis showed that the TyG index was significantly related to the risk of multi-vessel CAD (odds ratio [OR]: 1.715; 95% confidence interval [CI] 1.339-2.197; P < 0.001). The OR for multi-vessel CAD in TyG index T3 compared to that of T1 was 2.280 (95% CI 1.530-3.398; P < 0.001). Receiver operating characteristic (ROC) curve was generated to evaluate the accuracy of the TyG index in detecting the CAD severity, and the area under the curve (AUC) of the ROC plots was 0.601 (95% CI 0.559-0.643). The association between TyG index and multi-vessel CAD was significant in patients with DM, achieving the highest OR among the different glucose metabolic states (OR: 1.717; 95% CI 1.161-2.539; P < 0.05). CONCLUSION: TyG index was associated with CAD severity in patients with CHD, and an increased TyG index could identify patients with a high risk of multi-vessel CAD. There was an association between TyG index and CAD severity for the condition of DM.