title: Utility of Ultrasound, Transaminases, and Visual Inspection to Assess Nonalcoholic Fatty Liver Disease in Bariatric Surgery Patients.
abstract: BACKGROUND
  Nonalcoholic fatty liver disease (NAFLD) is common in adults with extreme obesity and can impact long-term health and survival. Liver biopsy is the only accurate test for diagnosis and staging, but is invasive and costly. Non-invasive testing offers an attractive alternate, but the overall accuracy remains a significant issue. This study was conducted to determine the accuracy and clinical utility of pre-operative ultrasound and liver transaminase levels, as well as intra-operative hepatic visual inspection, for assessing presence of NAFLD as confirmed by hepatic histology.
  
  
  METHODS
  Data was collected prospectively from 580 morbidly obese adult patients who underwent Roux-en-Y gastric bypass surgery with intraoperative wedge biopsy between January 2004 and February 2009. Complete data for ultrasound, ALT and AST levels, and documented visual inspection was available for 513 patients.
  
  
  RESULTS
  The prevalence of NAFLD was 69 % and that of NASH was 32 %. The individual non-invasive clinical assessments demonstrated low sensitivity, specificity, and accuracy for detecting the presence of steatosis, steatohepatitis, or fibrosis. The combination of normal or abnormal results for all tests improved predictive utility. Abnormal tests with all three assessments had a sensitivity of 95-98 % and a specificity of 28-48 % for major histologic findings in NAFLD/NASH. Normal tests with all three assessments had a sensitivity of 12-22 % and a specificity of 89-97 % for major histologic findings in NAFLD/NASH.
  
  
  CONCLUSIONS
  Although individual clinical tests for NAFLD have limited accuracy, the use of combined clinical tests may prove useful.
authors.affiliation: Geisinger Obesity Research Institute, Danville, PA, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Petrick
authors.affiliation: Geisinger Obesity Research Institute, Danville, PA, USA. ptrben@aol.com.
authors.forename: Peter
authors.initials: P
authors.lastname: Benotti
authors.affiliation: Geisinger Obesity Research Institute, Danville, PA, USA.
authors.forename: G Craig
authors.initials: GC
authors.lastname: Wood
authors.affiliation: Geisinger Obesity Research Institute, Danville, PA, USA.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Still
authors.affiliation: Geisinger Obesity Research Institute, Danville, PA, USA.
authors.forename: William E
authors.initials: WE
authors.lastname: Strodel
authors.affiliation: Geisinger Obesity Research Institute, Danville, PA, USA.
authors.forename: John
authors.initials: J
authors.lastname: Gabrielsen
authors.affiliation: Geisinger Obesity Research Institute, Danville, PA, USA.
authors.forename: David
authors.initials: D
authors.lastname: Rolston
authors.affiliation: Geisinger Obesity Research Institute, Danville, PA, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Chu
authors.affiliation: Geisinger Obesity Research Institute, Danville, PA, USA.
authors.forename: George
authors.initials: G
authors.lastname: Argyropoulos
authors.affiliation: Geisinger Obesity Research Institute, Danville, PA, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Ibele
authors.affiliation: Temple University School of Medicine, Philadelphia, PA, USA.
authors.forename: Glenn S
authors.initials: GS
authors.lastname: Gerhard
mesh_terms: D000328:Adult; D050110:Bariatric Surgery; D001706:Biopsy; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008099:Liver / Q000473:pathology; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000000981:diagnostic imaging / Q000473:pathology*; D009767:Obesity, Morbid / Q000150:complications / Q000601:surgery*; D010808:Physical Examination; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D000637:Transaminases / Q000032:analysis* / Q000097:blood; D014463:Ultrasonography
chemical_list: D000637:Transaminases
keywords: Bariatric surgery; Nonalcoholic fatty liver disease; Nonalcoholic steatohepatitis; Ultrasound