The causal association between inflammatory bowel disease and pancreatitis: A 2-sample Mendelian randomization study

Clinical studies showed a relationship between inflammatory bowel disease (IBD) and pancreatitis. Nonetheless, the causal relationship between IBD and pancreatitis has yet to be established. We employed Mendelian randomization (MR) to determine potential causal associations between IBD and pancreatitis. Genome-wide association study data on IBD were acquired from the International Inflammatory Bowel Disease Genetics Consortium. Summary statistics for pancreatitis were from the FinnGen database and BioBank Japan. Inverse-variance weighting (IVW) was used to perform a 2-sample MR analysis. Heterogeneity tests, horizontal pleiotropy tests, and sensitivity analyses were used to ensure the consistency and accuracy of our results. In the European population, the incidence of acute pancreatitis (AP) in IBD populations was a 6.3% higher risk than in the control population (odd ratio [OR]: 1.063, 95% confidence interval [CI]: 1.008–1.121, IVW P  = .023), while chronic pancreatitis (CP) was elevated by 7.5% (OR: 1.075, 95% CI: 1.004–1.153, IVW P  = .039). The incidence of AP (OR: 1.056, 95% CI: 1.010–1.105, IVW P  = .017) and CP (OR: 1.070, 95% CI: 1.009–1.135, IVW P  = .024) in Crohn disease (CD) populations were higher than in the control population. AP incidence in ulcerative colitis (UC) populations was a 7.0% higher risk than in the control population (OR: 1.070, 95% CI: 1.007–1.137, IVW P  = .030), and AAP incidence was elevated by 18.9% (OR: 1.189, 95% CI: 1.009–1.135, IVW P  = .024). In the East Asian population, UC has a causality relationship with CP (OR: 1.290, 95% CI: 1.119–1.487, IVW P  = .0004). In the European population, IBD and its 2 types have potential causality with AP; IBD and CD have potential causality with CP. In the East Asian population, UC has a causal association with CP.