GPT and diabetes mellitus: Some studies (Bazick et al., Leite et al., Sima et al., Leite et al., Williamson et al., Sima et al., Loomba et al.)reported that elevated ALT levels were found in patients with diabetes and NASH; however, two studies (Portillo-Sanchez et al., Prashanth et al.,) normal ALT levels in patients with diabetes and NASH.