GPT and steatosis: Plasma DPP4 activity was significantly higher in NAFLD than in no-NAFLD patients (209,481.8 ± 62,658.3 nmol/min/ml vs. 167,287 ± 61,513.2 nmol/min/ml, p = 0.02) and directly correlated with the severity of hepatic impairment, as expressed by greater steatosis grade (r = 0.33, p = 0.04) and lobular inflammation (r = 0.31, p = 0.03) at the biopsy and higher AST (r = 0.41, p = 0.027), ALT (r = 0.30 p = 0.03), GGT (r = 0.41, p = 0.017), LDL cholesterol (r = 0.31, p = 0.048) and FIB-4 (r = 0.52, p = 0.004).