INS and non-alcoholic fatty liver: NAFL: nonalcoholic fatty liver; NAFLD: nonalcoholic fatty liver disease; ALT: alanine aminotransferase; GGT: gamma-glutamyl transpeptidase; TGs: triglycerides; AST: aspartate aminotransferase; DM: diabetes mellitus; NASH: nonalcoholic steatohepatitis; HAIR: hypertension, ALT, insulin resistance.