GPT and diabetes mellitus: When comparing with the lowest quartile of AST/ALT ratio, the multivariate HRs for the incident of diabetes were 0.71 (0.62–0.82) for Q2, 0.50 (0.42–0.59) for Q3, 0.35 (0.29–0.43) for Q4, The P for trend of AST/ALT ratio with categorical variables in the fully-adjusted model was consistent with the result when AST/ALT ratio was a continuous variable.