title: Elevated concentrations of liver enzymes and ferritin identify a new phenotype of insulin resistance: effect of weight loss after gastric banding.
abstract: BACKGROUND
  Several studies have associated elevated liver enzymes (LFTs), obesity, and type 2 diabetes (T2DM), and a link has been established between insulin resistance (IR) and elevated ferritin concentrations. We examined the relationship between LFTs, ferritin, and IR in morbid obese subjects and the effect of weight loss after bariatric surgery.
  
  
  METHODS
  We measured liver enzymes, ferritin, insulin resistance, and glucose tolerance (by OGTT) in 159 morbid obese subjects (BMI = 44.4 +/- 0.4 kg/m(2)) at baseline, 6 months and 1 year after laparoscopic-adjustable-gastric banding (LAGB). Subjects were divided in two groups: increased LFTs (ALT > 30; AST/ALT < 1) vs. normal LFTs.
  
  
  RESULTS
  A large proportion of morbid obese subjects had increased LFTs (44%) which were associated with increased IR and ferritin, suggesting potential liver disease. A majority of the morbidly obese with increased LFTs, IGT, and T2DM, were male and had almost double ferritin concentrations, strongly correlated with ALT (r = 0.43, p < 0.0001). Both ferritin and ALT correlated with waist circumference and IR. One year after, LAGB glucose tolerance improved, LFTs and IR were reduced; ferritin did not change significantly, but was still correlated with IR.
  
  
  CONCLUSIONS
  Ferritin may be an additional useful marker for more severe hepatic IR.
authors.affiliation: Institute of Clinical Physiology, National Research Council Pisa, Pisa, Italy.
authors.forename: Amalia
authors.initials: A
authors.lastname: Gastaldelli
authors.forename: Lucia
authors.initials: L
authors.lastname: Perego
authors.forename: Michele
authors.initials: M
authors.lastname: Paganelli
authors.forename: Giorgio
authors.initials: G
authors.lastname: Sesti
authors.forename: Marta
authors.initials: M
authors.lastname: Hribal
authors.forename: Alberto O
authors.initials: AO
authors.lastname: Chavez
authors.forename: Ralph A
authors.initials: RA
authors.lastname: Defronzo
authors.forename: Antonio
authors.initials: A
authors.lastname: Pontiroli
authors.forename: Franco
authors.initials: F
authors.lastname: Folli
mesh_terms: D000328:Adult; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D005293:Ferritins / Q000097:blood*; D015391:Gastroplasty; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D010535:Laparoscopy; D008111:Liver Function Tests; D008297:Male; D009767:Obesity, Morbid / Q000378:metabolism* / Q000601:surgery; D012189:Retrospective Studies; D000637:Transaminases / Q000097:blood*; D015431:Weight Loss / Q000502:physiology*
chemical_list: D005293:Ferritins; D000637:Transaminases