GPT and diabetes mellitus: The subgroup comparison indicated no significant improvements in both AST and ALT in NAFLD patients without diabetes who received pioglitazone therapy compared with those who received placebo [AST: MD = −5.5, 95% CI: (−11.33) - 0.33, P = 0.06; ALT: MD = −17.79, 95% CI: (−38.14) - 2.57, P = 0.09; Supplementary Figure 1], while there was a significant reduction in AST in patients with diabetes [MD = −7.48, 95% CI: (−14.27) - (−0.7), P = 0.03; Supplementary Figure 1], but not in ALT [MD = −12.74, 95% CI: (−26.33) - 0.84), P = 0.07; Supplementary Figure 1].