GPT and type 2 diabetes mellitus: After adjustment of both glycated hemoglobin and SBP, we observed positive direct causal effects of ALT (IVW OR = 1.956, 95% CI = 1.681–2.231, p < 0.001) and AST (IVW OR = 1.617, 95% CI = 1.264–1.970, p = 0.008) on T2DM with DR (Fig 3A and 3B).