Systematic Review With Meta-analysis: Epidemiology of Nonalcoholic Fatty Liver Disease in Patients With Inflammatory Bowel Disease

Background: Nonalcoholic fatty liver disease (NAFLD) is increasingly identified in patients with inflammatory bowel disease (IBD), but there are few systematic reviews and meta-analyses of the studies of NAFLD in IBD patients.

Methods: MEDLINE, Web of Science, Cochrane Library, and Scopus were searched (until August 2018) to identify observational studies that reported the prevalence and risk factors for NAFLD in IBD patients. Pooled prevalence, odds ratios (OR), mean difference (MD), and 95% confidence intervals (95% CI) were calculated. Study quality was assessed using the modified Newcastle-Ottawa scale.

Results: Of the 662 citations evaluated, 19 studies (including 5620 subjects) reported the prevalence of NAFLD in IBD population and were included for the analysis. The overall pooled prevalence was 27.5% (95% CI, 20.7%-34.2%). The prevalence was higher in older patients (MD = 8.22; 95% CI, 6.22-10.22), type 2 diabetes (OR = 3.85; 95% CI, 2.49-5.95), hypertension (OR = 3.18; 95% CI, 2.36-4.28), obesity (OR = 2.79; 95% CI, 1.73-4.50), insulin resistance (OR = 6.66; 95% CI, 1.28-34.77), metabolic syndrome (OR = 4.96; 95% CI, 3.05-8.05), chronic kidney disease (OR = 4.83; 95% CI, 1.79-13.04), methotrexate use (OR = 1.76; 95% CI, 1.02-3.06), surgery for IBD (OR = 1.28; 95% CI, 1.02-1.62), and longer duration of IBD (MD = 5.60; 95% CI, 2.24-8.97).

Conclusions: We found that NAFLD was not uncommon in the IBD population. Older age, metabolic risk factors, methotrexate use, prior surgery, and longer duration of IBD are predictors for the presence of NAFLD in IBD. Screening of NAFLD might be recommended among IBD patients with the aforementioned factors.