Issue 15

Clinical Question

What is the incidence rate of non-alcoholic fatty liver disease (NAFLD) in patients with IBD?

Editor’s Bottom Line

The Montreal group has demonstrated that NAFLD develops in IBD patients at a much higher rate (3 to 9-fold) than the general population and that a small proportion (2%) of these patients progress to advanced liver fibrosis.

Editorial Note

IBD patients with minor liver function test abnormalities should be investigated for NAFLD and fibrosis.

Reference

Bessissow T, Le NH, Rollet K, et al. Incidence and predictors of nonalcoholic fatty liver disease by serum biomarkers in patients with inflammatory bowel disease. Inflamm Bowel Dis. 2016 Aug;22(8):1937–44. https://www.ncbi.nlm.nih.gov/pubmed/27379445

Synopsis

At baseline, 321 patients (the cohort) with documented IBD were screened to ensure they had no liver disease, NAFLD, hepatitis viruses or significant alcohol consumption. The Hepatic Steatosis Index (HSI) and serum fibrosis biomarker, fibrosis-4 (FIB-4), were used to assess the presence of NAFLD during follow-up.

“HSI, defined as: 8 x AST/ALT + BMI (+2, if female; +2, if diabetes), was employed to diagnose NAFLD. FIB-4 was adopted to diagnose advanced liver fibrosis and was calculated as: age (year) x [AST/platelet count (10⁹/L)] x AST. As per standard cut-off values, the outcomes were defined as HSI ≥36 for NAFLD and as FIB-4 ≥2.67 for advanced liver fibrosis.”

The cohort, 321 consecutive patients with IBD, was followed for a median of 3.2 years (1118.2 patient years (PY)). They had a median BMI of 22.9 kg/m² and age of 33.7 years; 47% were males and ⅔ had Crohn’s disease. During follow-up, one third of patients (n=108) developed NAFLD and and 2% of these developed advanced liver fibrosis. This translated to a NAFLD incidence rate of 9.1/100 PY in comparison with 0.29 to 3.1/100 PY for the general population. Independent predictors of NAFLD were active IBD, duration of IBD, and prior IBD-related surgery.

Details

Study Design: Retrospective cohort study
Funding: Fonds de la Recherche en Santé
Allocation: n/a
Setting: Single centre, Canada
Level of Evidence: 2b (Oxford Levels of Evidence

The summary and conclusion in this issue of E-mentoring in IBD pertains to the manuscript(s) being reviewed, and should be considered in the context of what is already known surrounding the topic and incorporated into practice as deemed appropriate by the individual learner.