Inflammatory bowel disease is likely to be associated with other chronic inflammatory disorders, results from two recent population-based studies have found.
Investigators observed an increased prevalence of asthma, arthritis, chronic renal disease, multiple sclerosis, and psoriasis, among other conditions, in patients with IBD, compared with population controls.
The findings “remind us that the effects of IBD extend to every corner of the body, including the lung and the central nervous system,” Edward V. Loftus Jr., M.D., of the division of gastroenterology and hepatology at Mayo Clinic College of Medicine, Rochester, Minn., wrote in an editorial about the studies (Gastroenterology 2005;129:1117–20). They “lend credence to the emerging concept that patients with one immune-mediated condition are more likely than the general population to have another autoimmune disease.”
In the larger of the two studies, Gauree Gupta, M.D., and associates at the University of Pennsylvania, Philadelphia, identified 20,173 patients from the United Kingdom's General Practice Research Database diagnosed with Crohn's disease and ulcerative colitis between January 1988 and October 1997.
Each patient was randomly matched for age, gender, and primary care practice to 4 controls, which amounted to 80,666 controls (Gastroenterology 2005;129:819–26.)
On cross-sectional analysis, the investigators found that the relative odds of a diagnosis of multiple sclerosis, demyelination, and/or optic neuritis in patients with Crohn's disease and ulcerative colitis as compared with their matched controls was 1.54 and 1.75, respectively.
“These observations are important to confirm the previously hypothesized association of IBD and demyelinating disorders,” the investigators wrote. They are also “essential to help place into context reports of the onset or exacerbation of demyelinating disorders in patients taking anti-TNF? therapies for conditions such as rheumatoid arthritis, psoriasis, and IBD.”
In a similar study led by Charles N. Bernstein, M.D., of the University of Manitoba, Winnipeg, investigators set out to determine the relationship between IBD and common respiratory and neurologic diseases. They analyzed data from the University of Manitoba IBD database, which included 8,072 patients diagnosed with IBD between 1984 and 2003 (Gastroenterology 2005;129:827–36). Each patient was randomly matched for age, gender, and geographic location to 10 people in the general population.
Compared with controls, Crohn's disease and ulcerative colitis patients were significantly more likely to have arthritis, asthma, bronchitis, psoriasis, and pericarditis. The investigators also observed an increased risk for chronic renal disease and multiple sclerosis among ulcer patients but not Crohn's disease patients, while arthritis and asthma ranked as the most common nonintestinal comorbidities.
Dr. Bernstein and his associates wrote that the “link between these diseases and IBD may stimulate research pursuing the link of these organ systems on an immune basis. More practically, these data reinforce that respiratory complaints in patients with IBD should be taken seriously and, at the least, standard pulmonary function tests should be performed. However, routine pulmonary function testing cannot be recommended at this time.”
The study was partially supported by the Crohn's and Colitis Foundation of Canada and the Canadian Institutes of Health Research.