Background: Non-alcoholic fatty liver disease (NAFLD) is a common concomitant condition in patients with inflammatory bowel disease (IBD). We aim to assess the magnitude of this association.
Methods: We searched MEDLINE, EMBASE and Scopus libraries for the period up to February 2023 to identify studies reporting cohorts of IBD patients in which NALFLD was evaluated.
Results: Eighty-nine studies were analyzed. The overall prevalence of NAFLD was 24.4% (95%CI, 19.3-29.8) in IBD, 20.2% (18.3-22.3) in Crohn's disease and 18.5% (16.4-20.8) for ulcerative colitis. Higher prevalence was found in male compared to female patients, in full papers compared to abstracts, and in cross-sectional studies compared to prospective and retrospective ones. The prevalence of NAFLD in IBD has increased in studies published from 2015 onwards: 23.2% (21.5-24.9) vs. 17.8% (13.2-22.9). Diagnostic methods for NAFLD determined prevalence figures, being highest in patients assessed by controlled attenuation parameter (38.8%; 33.1-44.7) compared to ultrasonography (28.5%; 23.1-34.2) or other methods. The overall prevalence of fibrosis was 16.7% (12.2-21.7) but varied greatly according to the measurement method.
Conclusion: One-quarter of patients with IBD might present with NAFLD worldwide. This proportion was higher in recent studies and in those that used current diagnostic methods.
Keywords: Crohn´s disease; cohort studies; epidemiology; inflammatory bowel disease; metabolic liver disease; risk factors; ulcerative colitis.