Background
The triglyceride-glucose index (TyG index) has been suggested as a credible surrogate marker of insulin resistance (IR) for many years. Its value in predicting and diagnosing cardiovascular disease has been reported recently. However, few studies have reported that it can be used as a marker for atherosclerosis and coronary artery disease (CAD), which is one of the main causes of cardiovascular-related death. This study will attempt to prove that the TyG index can be a useful marker for predicting atherosclerosis and has diagnostic significance for symptomatic CAD.
Methods
The baseline data of 3059 cardiology patients, as well as their clinical data, biochemical parameters and medical histories, were collected from our clinical cases over the last three years. Further screening resulted in 1581 data points of symptomatic CAD. The TyG index was calculated by the formula Ln (fasting triglycerides (mg/dl) × fasting blood glucose (mg/dl)/2). CAD was defined as a nonzero Gensini score on coronary angiography. Participants were divided into four groups according to TyG index tertiles.
Results
We evaluated 1581 patients, and the majority were male (41.9%) and elderly (59.5%). Cardiometabolic risk factors were positively associated with the TyG index. Arterial damage, including carotid and coronary damage, was highly associated with the TyG index. After adjustment for sex, age and multiple risk factors, Poisson regression analysis indicated that the prevalence ratios for carotid plaque and coronary stenosis were 1.11 (95% Cl 0.55–2.11; P = 0.01) and 2.94 (95% Cl 0.58–1.50; P = 0.01), respectively. Moreover, the TyG index has better diagnostic efficacy for symptomatic CAD than do fasting glucose and triglycerides (AUC TyG = 0.734; AUC fasting glucose = 0.611; AUC triglyceride = 0.717).
Conclusion
The TyG index is a useful marker for predicting atherosclerosis and may be a diagnostic indicator for symptomatic CAD.