GPT and type 2 diabetes mellitus: After adjustment of both glycated hemoglobin and DBP, we also observed positive direct causal effects of ALT (IVW OR = 1.974, 95% CI = 1.704–2.243, p < 0.001) and AST (IVW OR = 1.631, 95% CI = 1.294–1.969, p = 0.004) on T2DM with DR (Fig 3A and 3B).