title: Prospective study of the long-term effects of bariatric surgery on liver injury in patients without advanced disease.
abstract: OBJECTIVE
  Severe obesity is implicated in development of nonalcoholic fatty liver disease (NAFLD). Bariatric surgery induces weight loss and increases survival time of obese patients, but little is known about its effects on liver damage. We performed a 5-year prospective study to evaluate fibrosis and nonalcoholic steatosis (NASH) in severely obese patients after bariatric surgery.
  
  
  METHODS
  Bariatric surgery was performed on 381 patients. Clinical and biological data, along with liver biopsies, were collected before and at 1 and 5 years after surgery.
  
  
  RESULTS
  Five years after surgery, levels of fibrosis increased significantly, but 95.7% of patients maintained a fibrosis score <or= F1. The percentage of patients with steatosis decreased from 37.4% before surgery to 16%, the NAFLD score from 1.97 to 1, ballooning from 0.2 to 0.1. Inflammation remained unchanged. The percentage of patients with probable or definite NASH decreased significantly over 5 years, from 27.4% to 14.2%. The kinetics of insulin resistance (IR) paralleled that of steatosis and ballooning; the greatest improvements occurred within the first year and were sustained 5 years later. Steatosis and ballooning occurred more frequently in patients with a refractory IR profile. In multivariate analysis, the refractory IR profile independently predicted the persistence of steatosis and ballooning 5 years later.
  
  
  CONCLUSIONS
  Five years after bariatric surgery for severe obesity, almost all patients had low levels of NAFLD, whereas fibrosis slightly increased. Steatosis and ballooning were closely linked to IR; long-term effects could be predicted by early improvement in IR.
authors.affiliation: Service d'Hépato-Gastroentérologie, CHRU de Lille, Université Lille 2, France. p-mathurin@chru-lille.fr
authors.forename: Philippe
authors.initials: P
authors.lastname: Mathurin
authors.forename: Antoine
authors.initials: A
authors.lastname: Hollebecque
authors.forename: Laurent
authors.initials: L
authors.lastname: Arnalsteen
authors.forename: David
authors.initials: D
authors.lastname: Buob
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Leteurtre
authors.forename: Robert
authors.initials: R
authors.lastname: Caiazzo
authors.forename: Marie
authors.initials: M
authors.lastname: Pigeyre
authors.forename: Hélène
authors.initials: H
authors.lastname: Verkindt
authors.forename: Sébastien
authors.initials: S
authors.lastname: Dharancy
authors.forename: Alexandre
authors.initials: A
authors.lastname: Louvet
authors.forename: Monique
authors.initials: M
authors.lastname: Romon
authors.forename: François
authors.initials: F
authors.lastname: Pattou
mesh_terms: D000328:Adult; D017677:Age Distribution; D000704:Analysis of Variance; D050110:Bariatric Surgery / Q000379:methods*; D001707:Biopsy, Needle; D015992:Body Mass Index; D015331:Cohort Studies; D005234:Fatty Liver / Q000453:epidemiology / Q000209:etiology / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015994:Incidence; D008103:Liver Cirrhosis / Q000453:epidemiology / Q000209:etiology / Q000473:pathology*; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D011300:Preoperative Care; D011336:Probability; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D017678:Sex Distribution; D018709:Statistics, Nonparametric; D013995:Time; D016896:Treatment Outcome