In the fully-adjusted model (model III) adjusted for age, gender, BMI, SBP, TG, TC, HDL-C, LDL-C, BUN, Scr, smoking status, drinking status, family history of diabetes age, for every 1 unit increase in the AST/ALT ratio, the risk of incident of diabetes decreased by 60% (HR = 0.40, 95% CI: 0.33 to 0.48, P < 0.001). Here, GPT is linked to diabetes mellitus.