GPT and diabetes mellitus: As shown in Fig. 2, after adjusting for sex, age, BMI, LDL-C, TC, ALT, AST, Scr, SBP, DBP, smoking, drinking, and family history of diabetes, a significant nonlinear relationship was found between TyG index and risk of future diabetes (P < 0.001), and the slope of the curve showed an upward tendency with the increase of TyG index.