Study Finds Association Between Asthma and Inflammatory Bowel Disease

There is an association between asthma and the development of Crohn’s disease and with early and late-onset ulcerative colitis, according to a recent research.

A study published in Clinical Gastroenterology and Hepatology investigated the link between asthma and inflammatory bowel diseases (IBD) through a population-based case-control study that included health administrative data from Alberta, Canada. The cases considered in the study incorporated individuals enrolled in the Alberta Health Care Insurance Plan (AHCIP) and had at least 1 diagnostic code for either Crohn’s disease or ulcerative colitis.

“Studies have also shown that IBD is associated with respiratory disorders, including asthma and chronic obstructive pulmonary disease,” wrote the researchers. “Because asthma is more commonly diagnosed in early childhood than IBD, we hypothesized that individuals diagnosed with asthma were more likely to be subsequently diagnosed with IBD compared with those without asthma.”

The association between IBDs and asthma was calculated through comparing the odds of an asthma diagnosis preceding a diagnosis of Crohn’s disease or ulcerative colitis with the odds of an asthma diagnosis among those without IBD.

Of the total participants with a previous asthma diagnosis, 14.5% of patients had incident Crohn’s disease while 12.8% had ulcerative colitis. While odds of Crohn’s disease were significantly increased in those with pre-existing asthma, there was no age group that modified the association. For ulcerative colitis, the age of IBD diagnosis there was an association for those diagnosed with ulcerative colitis at 16 years old or younger, and for those older than 40.

“These findings are consistent with previous studies examining the association between asthma and IBD. Thus, the totality of evidence suggests that patients with asthma are at higher risk of developing IBD,” the authors explained. “This may serve as a red flag to help identify patients presenting with chronic gastrointestinal symptoms that may benefit from priority referrals to gastroenterologists.”

The researchers suggested future studies to determine the distinct mechanisms that link asthma and IBD. These areas of research should include shared genetic susceptibility, environmental exposures, and microbial influences, according to the study.