Prevalence of Non-alcoholic Steatohepatitis in Morbidly Obese Subjects Undergoing Gastric Bypass

Background: Obesity is the most common cause of non-alcoholic steatohepatitis (NASH). This is a prospective study to determine the incidence and severity of NASH in patients undergoing Roux-en-Y gastric bypass (RYGBP) for morbid obesity. We also examined the relationship between NASH and potential risk factors. Methods: In 48 consecutive patients at RYGBP, a core liver biopsy was obtained from the left lateral segment. A single liver pathologist reviewed the histology for steatosis, ballooning/disarray, necroinflammation, and fibrosis. Results: 84% of patients were female, and average BMI was 51. 18% had WHR >1. The following risk factors were present: DM 16%; hyperlipidemia 61%; HTN 47%; and abnormal LFTs 18%. 90% had abnormal liver histology, and 56% qualified for the diagnosis of NASH. Only DM and abnormal LFTs were found to be significantly related to NASH. Conclusions: NASH is a common co-morbidity of obesity and requires systemized grading and staging to develop accurate knowledge of the incidence, severity, natural history and impact of weight loss.