Supplementary Material for: Does atopic dermatitis increase the risk of inflammatory bowel disease? A meta-analysis of data from 61 million participants

Background: This review aimed to examine if atopic dermatitis (AD) led to an increased risk of inflammatory bowel disease (IBD) by collating data from longitudinal studies.
Summary: Cohort and case-control studies examining the risk of IBD, Crohn’s disease (CD), or ulcerative colitis (UC) due to exposure to AD were included in this review. Articles were searched on PubMed, CENTRAL, Embase, Scopus, and Web of Science electronic repositories up to 2nd October 2024. Eight retrospective cohort studies with 61,190,816 participants were included. The meta-analysis found that AD was a significant risk factor for IBD (OR: 1.37 95% CI: 1.31, 1.43). No statistical heterogeneity was noted. Pooled analysis showed that exposure to AD was a significant risk factor for both CD (OR: 1.51 95% CI: 1.31, 1.76) and UC (OR: 1.33 95% CI: 1.13, 1.56). Both meta-analyses had high inter-study heterogeneity with I2=83% and I2=89% respectively. Results remained significant on sensitivity analysis.
Key Messages: Our study shows an association between AD and IBD. The association was persistent for both CD and UC. Given the small increase in risk of IBD in AD, its clinical relevance may be questionable.

背景：本研究旨在通过汇总纵向研究的数据，探讨特应性皮炎（AD）是否会导致炎症性肠病（IBD）的风险增加。摘要：本综述纳入了探讨因暴露于AD而引发炎症性肠病（IBD）、克罗恩病（CD）或溃疡性结肠炎（UC）风险的队列研究和病例对照研究。检索了PubMed、CENTRAL、Embase、Scopus和Web of Science电子数据库，截止至2024年10月2日。纳入了8项回顾性队列研究，共涉及61,190,816名参与者。元分析结果显示，AD是IBD的一个显著风险因素（OR：1.37，95% CI：1.31，1.43），未发现统计学异质性。合并分析显示，AD的暴露对CD（OR：1.51，95% CI：1.31，1.76）和UC（OR：1.33，95% CI：1.13，1.56）的风险增加均有统计学意义。两次元分析均存在较高的研究间异质性，分别为I2=83%和I2=89%。敏感性分析结果显示，结果依然具有统计学意义。关键信息：本研究揭示了AD与IBD之间的关联，该关联对CD和UC均持续存在。鉴于AD中IBD风险的增加幅度较小，其临床相关性可能存在疑问。