Incidence and Risks for Nonalcoholic Fatty Liver Disease and Steatohepatitis Post-liver Transplant: Systematic Review and Meta-analysis

Background. The true incidence and unique risk factors for recurrent and de novo nonalcoholic fatty liver (NAFLD) and nonalcoholic steatohepatitis (NASH) post-liver transplant (LT) remain poorly characterized. We aimed to identify the incidence and risk factors for recurrent and de novo NAFLD/NASH post-LT. Methods. MEDLINE via PubMed, Embase, Scopus, and CINAHL were searched for studies from 2000 to 2018. Risk of bias was adjudicated using the Newcastle-Ottawa Scale. Results. Seventeen studies representing 2378 patients were included. All were retrospective analyses of patients with post-LT liver biopsies, with the exception of 2 studies that used imaging for outcome assessment. Seven studies evaluated occurrence of recurrent NAFLD/NASH, 3 evaluated de novo occurrence, and 7 evaluated both recurrent and de novo. In studies at generally high or moderate risk of bias, mean 1-, 3-, and >= 5-year incidence rates may be 59%, 57%, and 82% for recurrent NAFLD; 67%, 40%, and 78% for de novo NAFLD; 53%, 57.4%, and 38% for recurrent NASH; and 13%, 16%, and 17% for de novo NASH. Multivariate analysis demonstrated that post-LT body mass index (summarized odds ratio = 1.27) and hyperlipidemia were the most consistent predictors of outcomes. Conclusions. There is low confidence in the incidence of recurrent and de novo NAFLD and NASH after LT due to study heterogeneity. Recurrent and de novo NAFLD may occur in over half of recipients as soon as 1 year after LT. NASH recurs in most patients after LT, whereas de novo NASH occurs rarely. NAFLD/NASH after LT is associated with metabolic risk factors.