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 (R) 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 (R) 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.