Long-term effect of bariatric surgery on resolution of nonalcoholic steatohepatitis (NASH): An external validation and application of a clinical NASH score

Abstract Background Nonalcoholic steatohepatitis (NASH) is an important etiology of end stage liver disease. Long-term effect of bariatric surgery in improvement of NASH is not clear. Objectives To validate a scoring system for predicting NASH in morbidly obese patients and using it to evaluate the long term effect of bariatric surgery on NASH. Setting Tertiary Referral Hospital, Taiwan. Methods A new 5-point clinical NASH (C-NASH) score incorporating BMI, ALT and triglyceride was validated in a group of 307 bariatric patients (mean age 30.2 years old, BMI 45.0 kg/m 2 ) with concurrent liver biopsy form 2003 to 2008. Remission of NASH in 5741 obese subjects undergoing bariatric/metabolic surgery with long-term follow-up was then evaluated using the C-NASH score. Results Among 307 patients with liver biopsy, the prevalence of NASH was 44.0%. At baseline, the NASH group had significantly worse fasting glucose levels, triglycerides, uric acid, AST, ALT, GGT and HbA1c. The diagnostic sensitivity of C-NASH score was 84.4% and the accuracy was 68.4%. Among 5741 bariatric patients, the prevalence of high risk for NASH evaluated by C-NASH score was 40.9%. Post-operative follow up showed good weight loss and almost complete remission of high risk for NASH up to 10 years. Patients with gastric banding had less weight loss, higher mean level of C-NASH score and incidence of persistent high risk for NASH compared to other procedures at follow-up. Conclusion This study demonstrated that improvement in C-NASH score suggesting remission of NASH is durable up to 10-y in all kind of bariatric procedures.