title: Predictors of nonalcoholic steatohepatitis (NASH) in obese patients undergoing gastric bypass.
abstract: BACKGROUND
  Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are conditions gaining increasing recognition in hepatology as a potential cause of cirrhosis and end-stage liver disease. Obesity is one of the main risk factors. The aims of this study were to determine the frequency of NAFLD in obese patients and to identify variables that predict NASH.
  
  
  METHODS
  A prospective study was conducted of obese patients undergoing gastric bypass over a 20-month period. Assessment included liver function tests and evaluation of insulin resistance with the homeostatic model assessment (HOMA-IR). Liver biopsy was performed in all patients at the time of surgery. Clinical and biochemical variables were analyzed using a multivariate analysis to identify independent predictors of NASH.
  
  
  RESULTS
  127 consecutive patients were included (62% female, 38% male, mean age 40+/-11 years, mean body mass index 42+/-6 kg/m(2)). Arterial hypertension was present in 52 patients (41%) and type 2 diabetes in 18 (14%). NAFLD was confirmed in 80 patients (63%), 47 (37%) had simple steatosis, and 33 (26%) had NASH. Cirrhosis was found in 2 patients corresponding to 1.6% of the total population. On multivariate analysis, AST >31 (IU/L) (OR 3.38, CI 1.17-9.8) and HOMA-IR >5.8 (OR 4.18, CI 1.39-12.49) independently predicted NASH.
  
  
  CONCLUSIONS
  NAFLD is highly prevalent in morbidly obese patients. A high proportion of these patients exhibit NASH on histological examination. Insulin resistance represents the main predictor of NASH.
authors.affiliation: Facultad de Medicina, Universidad Católica de Chile, Santiago, Chile.
authors.forename: Camilo
authors.initials: C
authors.lastname: Boza
authors.forename: Arnoldo
authors.initials: A
authors.lastname: Riquelme
authors.forename: Luis
authors.initials: L
authors.lastname: Ibañez
authors.forename: Ignacio
authors.initials: I
authors.lastname: Duarte
authors.forename: Enrique
authors.initials: E
authors.lastname: Norero
authors.forename: Paola
authors.initials: P
authors.lastname: Viviani
authors.forename: Alejandro
authors.initials: A
authors.lastname: Soza
authors.forename: Jose Ignacio
authors.initials: JI
authors.lastname: Fernandez
authors.forename: Alejandro
authors.initials: A
authors.lastname: Raddatz
authors.forename: Sergio
authors.initials: S
authors.lastname: Guzman
authors.forename: Marco
authors.initials: M
authors.lastname: Arrese
mesh_terms: D000328:Adult; D001706:Biopsy; D005234:Fatty Liver / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D015390:Gastric Bypass; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D008099:Liver / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000150:complications* / Q000601:surgery; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors