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.研究背景：本综述旨在通过整合纵向研究数据，探讨特应性皮炎（atopic dermatitis, AD）是否会增加炎症性肠病（inflammatory bowel disease, IBD）的发病风险。 综述概况：本综述纳入了探讨因暴露于特应性皮炎而发生炎症性肠病、克罗恩病（Crohn’s disease, CD）或溃疡性结肠炎（ulcerative colitis, UC）风险的队列研究与病例对照研究。检索了PubMed、CENTRAL、Embase、Scopus及Web of Science电子数据库，检索时限截至2024年10月2日。最终纳入8项回顾性队列研究，共涉及61,190,816名研究对象。荟萃分析结果显示，特应性皮炎是炎症性肠病的显著危险因素（比值比（odds ratio, OR）=1.37，95%置信区间（95% confidence interval, CI）：1.31~1.43），未观察到统计学异质性。合并分析结果表明，暴露于特应性皮炎是克罗恩病（OR=1.51，95%CI：1.31~1.76）与溃疡性结肠炎（OR=1.33，95%CI：1.13~1.56）的显著危险因素。两项荟萃分析均存在较高的研究间异质性，I²值分别为83%与89%。敏感性分析结果仍具有统计学意义。 核心要点：本研究证实特应性皮炎与炎症性肠病之间存在关联，该关联在克罗恩病与溃疡性结肠炎中均稳定存在。鉴于特应性皮炎患者的炎症性肠病发病风险仅小幅升高，其临床相关性或有待商榷。