GPT and metabolic dysfunction-associated steatotic liver disease: ALT levels were higher in GDM, but not above the upper limit of the reference range; however, alterations in ALT are associated with non-alcoholic fatty liver disease which features an increase in insulin resistance, and an elevated ALT is associated with increased risk for GDM (36) though, notably, gamma-glutamyl transferase is a superior predictor of GDM (37).