title: Insulin resistance is independently associated with liver aminotransferases in diabetic patients without ultrasound signs of nonalcoholic fatty liver disease.
abstract: BACKGROUND
  It has been shown that elevated levels of alanine and aspartate aminotransferases (ALT and AST) are associated with insulin resistance and type 2 diabetes mellitus; however, the pattern of this association in diabetic patients with negative or mild steatosis is not well understood. The aim of this study was to assess the association between elevated liver enzymes and insulin resistance in diabetic subjects without ultrasound signs of nonalcoholic fatty liver disease (NAFLD) (i.e., with less than 30% steatosis).
  
  
  METHODS
  In a cross-sectional study, a total of 670 diabetic subjects without established causes of liver injury were included. Patients with evidence of NAFLD in ultrasonography were not included. Fasting blood samples were obtained and plasma glucose, insulin, glycosylated hemoglobin (HbA1c), C-peptide, alkaline phosphatase, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lipid profile were measured. Three indices of insulin sensitivity/insensitivity: Homeostasis model assessment of insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), and McAuley were also calculated.
  
  
  RESULTS
  Elevated ALT was significantly (p < 0.001) correlated with fasting insulin, C-peptide, HOMA-IR, QUICKI, McAuley, and waist circumference. The same correlations were also observed for AST, which in all cases were weaker than ALT. Multivariate regression analysis showed that, among the above-mentioned variables, only HOMA-IR and fasting insulin were independently correlated with both ALT and AST. This correlation was independent of body mass index (BMI) or waist circumference.
  
  
  CONCLUSIONS
  In type 2 diabetes, in the absence of a detectable steatosis by ultrasonography, ALT and AST are associated with hyperinsulinemia and insulin resistance, independent of obesity. This finding possibly indicates that in diabetes a mild stage of steatosis is sufficient to mediate the association between insulin resistance and aminotransferases.
authors.affiliation: Endocrinology and Metabolism Research Center, Vali-Asr Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. esteghamati@tums.ac.ir
authors.forename: Alireza
authors.initials: A
authors.lastname: Esteghamati
authors.forename: Sina
authors.initials: S
authors.lastname: Noshad
authors.forename: Omid
authors.initials: O
authors.lastname: Khalilzadeh
authors.forename: Mohammad
authors.initials: M
authors.lastname: Khalili
authors.forename: Ali
authors.initials: A
authors.lastname: Zandieh
authors.forename: Manouchehr
authors.initials: M
authors.lastname: Nakhjavani
mesh_terms: D000410:Alanine Transaminase / Q000096:biosynthesis*; D000886:Anthropometry / Q000379:methods; D001219:Aspartate Aminotransferases / Q000096:biosynthesis*; D003430:Cross-Sectional Studies; D048909:Diabetes Complications / Q000175:diagnosis; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D005234:Fatty Liver / Q000000981:diagnostic imaging / Q000201:enzymology; D005260:Female; D006706:Homeostasis; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D008055:Lipids / Q000737:chemistry; D008099:Liver / Q000201:enzymology* / Q000293:injuries; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease; D012044:Regression Analysis; D014463:Ultrasonography
chemical_list: D007328:Insulin; D008055:Lipids; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase