The impact of bariatric surgery on in-patient clinical outcomes among patients with autoimmune hepatitis

Autoimmune hepatitis (AIH) is a form of liver inflammation in which immune cells target hepatocytes, inducing chronic inflammatory states. Bariatric surgery (BS) was shown to reduce inflammation in severely obese patients. We hypothesize that obese patients with AIH and BS have lower prevalence of liver-related complications and in-patient mortality compared to those without BS. The National Inpatient Sample from 2007 to 2013 was queried for hospitalizations of adults over 18 years of age with a diagnosis of AIH. Of those, hospitalizations with BS were selected as cases and those with morbid obesity as controls. Case-control 1:2 matching was done based on sex, age, race, and comorbidities. Primary outcomes were prevalence of liver-related complications and in-patient mortality. Independent risk factors of in-patient clinical outcomes were identified using multivariate regression analysis. From 137,834 hospitalizations with a diagnosis of AIH, 688 with BS were selected as cases, and 1295 were matched as controls. The prevalence of ascites was higher in the BS group compared to the control (odds ratio 1.73, 95% confidence interval (CI) 1.27–2.36). The prevalence of cirrhosis (36.8% vs 33.2%), portal hypertension (7.4% vs 10.0%), hepatic encephalopathy (10.6% vs 8.7%), and varices and variceal bleeding (3.9% vs 5.5%) was not statistically different from case controls, (P > .05). BS was an independent risk factor for ascites (adjusted odds ratio (aOR) 1.87; 95% CI 1.36–2.56) and hepatic encephalopathy (aOR 1.42; 95% CI 1.03–1.97) but was an independent protective factor against in-patient mortality (aOR 0.21, 95% CI 0.08–0.55) once adjusted for age, sex, race, and comorbidities.