P266 Atopic diseases are associated with the development of inflammatory bowel diseases: A nationwide population-based study

Abstract Background The association between atopic diseases and inflammatory bowel diseases (IBD) still remains unclear. We conducted a nationwide population-based study to investigate the effect of atopic diseases on the development of IBD. Methods A total of 9,950,548 subjects who received medical check-up between 2009 and 2012 were included and followed up until 2017. The presence of any atopic disease including atopic dermatitis (AD), allergic rhinitis (AR), and asthma were evaluated. Patients who developed IBD including Crohn’s disease (CD) and ulcerative colitis (UC) were identified using the claims data from National Health Insurance. Results During a mean follow up of 7.3 years, 1,426 (0.014%) subjects developed CD and 5,916 (0.059%) subjects developed UC. The incidences of CD (per 100,000 person-years) were 4.088, 2.255, and 2.344 in patients with AD, AR, and asthma,, respectively. The incidences of UC were 11.926, 9.857, and 9.377 in patients with AD, AR, and asthma, respectively. Multivariable analysis revealed that the adjusted hazard ratios (aHR) for incident CD in patients with AD, AR, and asthma were 2.21, 1.33, and 1.59 (95% confidence interval (CI) 1.251–3.896, 1.152–1.532, and 1.186–2.123, respectively) compared with controls. The risk for incident UC in patients in AD, AR, and asthma were 1.51, 1.32, and 1.28 (95% CI 1.081–2.101, 1.235–1.416, and 1.110–1.484, respectively) compared with controls. Moreover, increase in the number of atopic diseases gradually increased the risk for CD and UC; CD showed aHR of 1.36 and 1.65 (95% CI 1.180–1.571 and 1.143–2.370), and UC showed aHR of 1.30 and 1.49 (95% CI 1.216–1.398 and 1.247-1.170) in one, and two or more atopic diseases, respectively. Conclusion Patients with any atopic diseases showed an increased risk for IBD, while an increase in the number of atopic diseases gradually increased the risk for IBD.