Consistent with the MANOVA test, the results of the propensity score matching analysis indicated that patients in the NASH group displayed a significant reduction of ALT levels in the blood compared to patients with simple steatosis with a median change from baseline of − 25iU/l (− 38 to − 16) in the NASH group vs. − 5 iU/l (− 21 to 4) in the NAFL group, p = 0.003. This evidence concerns the gene GPT and non-alcoholic fatty liver.