Abstract

Causal Association Between Atopic Dermatitis and Inflammatory Bowel Disease: A 2-Sample Bidirectional Mendelian Randomization Study

Inflamm Bowel Dis. 2022 Oct 3;28(10):1543-1548. doi: 10.1093/ibd/izab329.

 

Christa Meisinger 1Dennis Freuer 1

 
     

Author information

1Chair of Epidemiology, University of Augsburg, University Hospital Augsburg, Augsburg, Germany.

Abstract

Background: Observational studies postulated an association between atopic dermatitis (AD) and inflammatory bowel disease (IBD). However, it remains unclear whether this relationship is causal.

Methods: To determine whether AD is causally related to IBD and vice versa, a 2-sample Mendelian randomization study was conducted. Independent genetic instruments from the largest available genome-wide association study for AD (EAGLE eczema consortium without the 23andMe study including 10,788 cases and 30,047 controls) were used to investigate the association with IBD in the UK Biobank study (7045 cases, 456,327 controls) and a second European IBD sample (12,882 cases, 21,770 controls).

Results: Atopic dermatitis was strongly associated with higher risk of IBD as a whole (odds ratio [OR], 1.107; 95% confidence interval [CI], 1.035; 1.183; P = .003) in the UK Biobank study. The positive association was not significant in the other IBD study (OR, 1.114; 95% CI, 0.956; 1.298), but in meta-analyses of results from the 2 studies, the strong association could be confirmed (OR, 1.11; 95% CI, 1.04; 1.18). When evaluating the causal relationship in the other direction, IBD as a whole did not show an association with AD. Subtype analyses revealed that AD was suggestively associated with ulcerative colitis (UC; OR, 1.149; 95% CI, 1.018; 1.297) but not Crohn's disease (CD). However, there was a suggestive association between CD and AD (OR, 1.034; 95% CI, 1.004; 1.064) but not UC and AD.

Conclusions: This study supports a causal effect between AD and IBD-but not between IBD and AD. There seems to be considerable differences between UC and CD regarding their specific associations with AD. These findings have implications for the management of IBD and AD in clinical practice.

 

© Copyright 2013-2024 GI Health Foundation. All rights reserved.
This site is maintained as an educational resource for US healthcare providers only. Use of this website is governed by the GIHF terms of use and privacy statement.