The Associations between Inflammatory Bowel Disease and a Range of Other Diseases：Umbrella Review of Systematic Reviews and Meta-analyses

Abstract Background Multiple meta-analyses have reported inflammatory bowel diseases (IBD) are associated with an increased risk of diverse diseases, but the evidence quality remains unclear. Objectives We aimed to summarize and evaluate this existing evidence on the associations between IBD and a range of diseases a-crossed from meta-analyses. Methods PubMed, the Cochrane Library Database, Embase, Web of Science, CNKI Databases, Wanfang Databases and VIP Database were searched to obtain eligible literatures from inception to November 1, 2019. We appraised the methodological quality of the included meta-analyses using AMSTAR 2 tool, and evaluated the quality of evidence for each outcome using the GRADE approach. Results Nineteen articles covering associations between IBD and 28 types of health outcomes were included. The methodological quality of meta-analyses was rated moderate for 5.26%, low for 21.05%, and critically low for 73.68%. Overall, summary effect estimates were significant in 26 meta-analyses. The evidence quality was rated high for 3.57%, moderate for 21.43%, low for 28.57%, and very low for 46.43%. Evidence quality was high for association between IBD and an increased periodontitis risk (OR = 4.55; 95% CI, 3.00-6.19). Evidence quality was moderate for associations between IBD and an increased thyroid cancer risk (OR = 1.75; 95% CI, 1.48–2.07), myocardial infarction incidence (RR = 1.12; 95% CI, 1.05–1.21), preterm birth incidence (OR = 1.85; 95% CI, 1.67–2.05), stillbirth incidence (OR = 1.57; 95% CI, 1.03–2.38), gallstone disease prevalence (OR = 1.72; 95% CI, 1.40–2.12), and vitamin D deficiency prevalence (OR = 1.64; 95% CI, 1.30–2.08). Conclusions Though, associations between IBD and diverse diseases have been extensively studied, few of the reported associations have robust support. Further well-designed studies are essential to determine whether IBD increases the risk of other diseases.