Posttransplant Outcome of Lean Compared With Obese Nonalcoholic Steatohepatitis in the United States: The Obesity Paradox

Morbid obesity is considered a relative contraindication for liver transplantation (LT). We investigated if body mass index (BMI; lean versus obese) is a risk factor for post-LT graft and overall survival in nonalcoholic steatohepatitis (NASH) and non-NASH patients. Using the United Network for Organ Sharing (UNOS) database, LT recipients from January 2002 to June 2013 (age ≥18 years) with follow-up until 2017 were included. The association of BMI categories calculated at LT with graft and overall survival after LT were examined. After adjusting for confounders, all obesity cohorts (overweight and class 1, class 2, and class 3 obesity) among LT recipients for NASH had significantly reduced risk of graft and patient loss at 10 years of follow-up compared with the lean BMI cohort. In contrast, the non-NASH group of LT recipients had no increased risk for graft and patient loss for overweight, class 1, and class 2 obesity groups but had significantly increased risk for graft (P < 0.001) and patient loss (P = 0.005) in the class 3 obesity group. In this retrospective analysis of the UNOS database, adult recipients selected for first LT and NASH patients with the lowest BMI have the worse longterm graft and patient survival as opposed to non-NASH patients where the survival was worse with higher BMI.