Association between triglyceride-glucose index and in-hospital all-cause mortality under different glucose metabolism status among patients with coronary artery disease

Abstract Background: The triglyceride-glucose (TyG) index, as a reliable surrogate marker of insulin resistance, is independently associated with the prognosis of cardiovascular diseases. This current study aimed to investigate the relationship between the TyG index and in-hospital all-cause mortality of coronary artery disease (CAD) in patients with different glucose metabolic statuses. Methods: This study enrolled 10 964 patients with CAD in China between January 1, 2016 to December 30, 2021. All the patients were divided into groups according to tertiles of the TyG index as T1 group (TyG index < 6.84), T2 group (6.84 ≤ TyG index < 7.38), and T3 group (TyG index ≥ 7.38). Glucose metabolic status was classified as normal glucose regulation, pre-diabetes mellitus, and diabetes mellitus (DM), according to the American Diabetes Association’s standard. The primary outcome was in hospital all-cause mortality. Results: We observed a significant relationship between the TyG index and in-hospital all-cause mortality of patients with CAD in this study. After adjusting for sex, age, body mass index, smoking, drinking, hypertension, estimated glomerular filtration rate, antiplatelet drug use, antilipidemic drug use, and antihypertensive drug use in the logistic regression model, the TyG index was still an independent risk factor for in-hospital death in patients with CAD, and the T3 group [odds ratio (OR), 2.311; 95% confidence interval (CI) = 1.237–4.317; P = 0.009) was correlated with a 2.311-fold risk of in-hospital all-cause mortality compared with the T1 group. In the subgroup analysis of different glucose metabolic status, the T3 group (OR, 1.541; 95% CI: 1.013–2.344; P = 0.043) were associated with a significantly higher risk of in-hospital all-cause mortality in CAD patients with DM. Conclusions: An increased TyG index was correlated with a higher risk of in-hospital all-cause mortality. Our study indicated that TyG as an estimation index for evaluating IR could be a valuable predictor of in-hospital death of CAD patients, especially for individuals with DM.