Association between Triglyceride-Glucose index and onset of type 2 diabetes in metabolic Dysfunction-Associated steatotic liver disease population

Previous studies have demonstrated a strong correlation between the Triglyceride-Glucose Index(TyG) index and diabetes mellitus; however, limited research has focused on the relationship between the TyG index and the incidence of diabetes mellitus in the Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) population. This study aims to investigate the association between the TyG index and the occurrence of diabetes mellitus in the MASLD population in Japan. This retrospective cohort study included 2,741 patients with MASLD from Murakami Memorial Hospital in Japan, spanning the years 2004 to 2015. The primary method employed to investigate the relationship between the TyG index and the occurrence of diabetes was Cox proportional hazards regression. Additionally, a Generalized Additive Model and a two-piecewise linear regression model were utilized to assess whether a linear relationship exists between the TyG index and the development of diabetes, as well as to calculate threshold effects. After adjusting for variables that may potentially influence the occurrence of diabetes, we found that the TyG index was positively correlated with diabetes incidence (HR = 1.43, 95% CI: 1.03, 1.98) in MASLD population overall. Further in-depth analysis revealed a nonlinear relationship between the TyG index and the occurrence of diabetes. When the TyG index was less than 7.95, it exhibited a negative correlation (HR = 0.22, 95% CI: 0.07, 0.66); however, when the TyG index exceeded 7.95, it showed a positive correlation (HR = 1.68, 95% CI: 1.20, 2.36). Additionally, we conducted a subject working curve analysis on the TyG index and the two components used to calculate it, fasting blood glucose and triglycerides, and found that the TyG index demonstrated higher sensitivity and specificity in predicting the occurrence of diabetes in the MASLD population. TyG index exhibits a nonlinear relationship with the incidence of diabetes in the MASLD population, and its sensitivity and specificity are superior to those of fasting blood glucose and triglycerides.