Prevalence of nonalcoholic fatty liver disease (NAFLD) and utility of FIBROspect II to detect liver fibrosis in morbidly obese Hispano-American patients undergoing gastric bypass.

BACKGROUND: Our study describes the prevalence of nonalcoholic steatohepatitis (NASH) and liver fibrosis in Hispano-American morbidly obese patients and the utility of different serum markers to predict significant liver fibrosis in this population.
METHODS: We perform a retrospective chart review of all patients undergoing Roux-en-Y gastric bypass with routine liver biopsy performed at Valley Baptist medical center during a 24-month period (2005-2006).
RESULTS: Of 129 liver biopsies, only 25.7% had some degree of steatosis, but about 55% had NASH, and 30.9% had liver fibrosis. Of those patients with liver fibrosis, only 6.9% had moderate to severe fibrosis (stages 2-4), and only one patient had cirrhosis (0.7%). Of the 129 patients, only 92 had a FIBROspect score II in their chart, and they ranged from 9 to 95, with a mean of 28.3. Of these patients, 36 had a score less than 20, and none had significant fibrosis in their biopsy. FIBROspect II® score (cutoff <20) had a negative predictive value (NPV) of 100% (confidence interval (CI) 95%, 0.9035-1) positive predictive value (PPV) of 15% (CI 95%, 0.0838-0.2693), sensitivity of 100%, and specificity of 42% to predict stage 2 fibrosis or higher.
CONCLUSIONS: NASH and liver fibrosis are present in a high percentage of morbidly obese patients. Liver function tests and ultrasound are not reliable tests to diagnose or rule out advance liver fibrosis. The use of FIBROspect II® score in the preoperative evaluation of morbidly obese patients can rule out significant liver fibrosis (stages 2-4) and avoid the morbidities related to liver biopsy.