The relationship of triglyceride-glucose index with epicardial adipose tissue thickness in prediabetic obese patients

Objectives: Obesity is a heterogeneous disease that increases the risk of a number of metabolic and cardiovascular diseases (CVDs). Prediabetes is an intermediate hyperglycemic state in which glycemic parameters are above normal but below the diabetes threshold. Epicardial adipose tissue (EAT) is one of the organ-specific visceral, ectopic fat deposits. As with obesity and prediabetes, EAT is also associated with increased insulin resistance (IR). In recent years, the triglyceride glucose index (TyG) has been recommended as an alternative test to determine IR. The TyG index has been studied in a number of metabolic and cardiovascular disorders associated with IR, but its relationship with EAT thickness has not yet been evaluated. Methods: The study included 176 prediabetic and obese patients. EAT thicknesses were assessed with echocardiography by the same cardiologist. The EAT thickness, TyG index, anthropometric obesity indices (body mass index (BMI), waist circumference (WC), and waist-hip ratio (WHR)), homeostatic model assessment (HOMA-IR), and biochemical parameters were compared. Results: The EAT thickness of males (6.19±1.46) was significantly higher than that of females (5.33±1.49) (p<.001). The following correlations between EAT thickness and related parameters were observed: WC (r=.529), BMI (r=.514), ALT (r=.358), TyG index (r=.338), HOMA-IR (r=.322), and WHR (r=.262) (p<.001 for all). Multiple regression analysis showed that WC (Beta=.428; p=.004), age (Beta=.223; p<.001), BMI (Beta=.196; p=.029), ALT (Beta=.168; p=.012) and TyG index (Beta=.128; p=.049) were the strongest independent variables correlated with EAT thickness. A model based on WC, BMI, age, TyG index, and ALT provided the best R2 (.387) for estimating EAT thickness (p<.001). Conclusions: The TyG index showed a significant and independent relationship with EAT and may be helpful as an indicator of EAT thickness. Keywords: Epicardial adipose tissue, triglyceride-glucose index, obesity, prediabetes