Patients with atopic diseases prone to inflammatory bowel disease

The presence of any atopic disease increases the risk of developing inflammatory bowel disease (IBD), which rises progressively as the number of atopic disease increases, a study has found.

Researchers looked at a cohort of 9,923,521 individuals. Those with atopic diseases—such as atopic dermatitis (AD), allergic rhinitis (AR), and asthma—were more likely to be older, female, be residing in urban areas, have never smoked, and have abstained from alcohol. They also tended to have a higher body mass index and more comorbidities, including diabetes, hypertension, dyslipidaemia, stroke, and ischaemic heart disease.

Over a mean follow-up period of 7.3 years, 1,419 patients (0.014 percent) developed Crohn’s disease (CD) and 5,897 (0.059 percent) developed ulcerative colitis (UC). The incidence rates of CD were 3.756, 2.248, and 2.346 per 100,000 person-years in the AD, AR, and asthma groups, respectively. The corresponding incidence rates of UC were 11.952, 9.818, and 9.358 per 100,000 person-years.

Multivariable Cox analysis revealed a significant association between atopic diseases and IBD. Adjusted hazard ratios [aHRs] for CD were 2.02 (95 percent confidence interval [CI], 1.118–3.663), 1.33 (95 percent CI, 1.149–1.529), and 1.60 (95 percent CI, 1.193–2.136) in the AD, AR, and asthma groups vs controls. The corresponding aHRs for UC were 1.51 (95 percent CI, 1.082–2.104), 1.32 (95 percent CI, 1.229–1.410), and 1.29 (95 percent CI, 1.115–1.491).

Notably, IBD risk increased progressively with the number of atopic diseases. The aHRs for CD associated with 1 and ≥2 atopic diseases were 1.35 and 1.65, respectively, while the aHRs for UC were 1.30 and 1.49, respectively.

Subgroup analyses revealed that the effect of AR on UC was stronger among elderly adults, men, those who were metabolically unhealthy, and current smokers. Meanwhile, the impact of AD on UC was greater among current smokers.

The present data suggest that patients with atopic diseases and abdominal symptoms should be closely monitored for the early detection of IBD, the researchers said.