Prevalence and Predictors of Nonalcoholic Steatohepatitis in Obese Patients Undergoing Bariatric Surgery: A Department of Defense Experience

Nonalcoholic steatohepatitis (NASH) is a silent liver disease that can lead to inflammation and subsequent scaring. If left untreated, cirrhosis may ensue. Morbidly obese patients are at an increased risk of NASH. We report the prevalence and predictors of NASH in patients undergoing morbid obesity surgery. A retrospective review was conducted on morbidly obese patients undergoing weight reduction surgery from September 2005 through December 2008. A liver biopsy was performed at the time of surgery. Patients who had a history of hepatitis infection or previous alcohol dependency were excluded. Prevalence of NASH was studied. Predictors of NASH among clinical and biochemical variables were analyzed using multivariate regression analysis. One hundred thirteen patients were analyzed (84% female; mean age, 42.6 +/- 11.4 years; mean body mass index, 45.1 +/- 5.7 kg/m(2)). Sixty-one patients had systemic hypertension (54%) and 35 patients had diabetes (31%). The prevalence of NASH in this study population was 35 per cent (40 of 113). An additional 59 patients (52%) had simple steatosis without NASH. Only 14 patients had normal liver histology. On multivariate analysis, only elevated aspartate aminotransferase (AST) (greater than 41 IU/L) was the independent predictor for NASH (odds ratio, 5.85; confidence interval, 1.06 to 32.41). Patient age, body mass index, hypertension, diabetes, hypercholesterolemia, and abnormal alanine aminotransferase did not predict NASH. NASH is a common finding in obese population. Abnormal AST was the only predictive factor for NASH.