Changing shape of disease: nonalcoholic fatty liver disease in Crohn's disease-a case series and review of the literature.

BACKGROUND: With improvements in therapy for inflammatory bowel disease (IBD) and changes in the prevalence of obesity, the phenotype of Crohn's disease (CD) is changing. These changes may herald an increase in the incidence of nonalcoholic fatty liver disease (NAFLD) in this population.
METHODS: Over a 10-month period we identified seven patients with CD who required liver biopsy for elevated liver function tests (LFTs), with an ultimate diagnosis of NAFLD. We performed a retrospective chart review and literature search to identify relevant data on NAFLD and CD. Specifically, we abstracted prior and current IBD-related medication exposures, disease severity, and the presence of typical comorbidities associated with NAFLD.
RESULTS: We describe seven patients with CD and biopsy-proven NAFLD. The majority of these patients were overweight or obese, had quiescent CD, and were more likely to be receiving a tumor necrosis factor-alpha inhibitor. Review of the literature produced a total of 29 articles describing NAFLD in IBD patients, primarily restricted to historical autopsy and surgical series. Limited contemporary studies highlight the rising prevalence of NAFLD in treated IBD populations.
CONCLUSIONS: NAFLD is increasing in incidence and prevalence among the general population. With improvements in therapy, NAFLD is likely increasing among the CD population as well. When evaluating an IBD patient with abnormal LFTs, clinicians need to consider NAFLD. NAFLD may impact IBD management in the future if therapeutic modalities are limited due to elevated LFTs. Further, patients should be monitored for excessive weight gain and counseled regarding healthy dietary and exercise habits.