Asthma Is Associated With Subsequent Development of Inflammatory Bowel Disease: A Population-based Case-Control Study.
OBJECTIVE
Asthma and the inflammatory bowel diseases (IBD) each arise through complex interactions between genetic and environmental factors, and share many environmental risk factors. We examined the association between asthma and Crohn's disease or ulcerative colitis.


METHODS
We performed a population-based case-control study using health administrative data from the province of Alberta, Canada. The odds of a diagnosis of asthma preceding the diagnosis of either Crohn's disease (N = 3087) or ulcerative colitis (N = 2377) were compared with the odds of diagnosis of asthma among persons without IBD (N = 402,800) using logistic regression. Effect measure modification by age at diagnosis of IBD (16 years or less, 17-40 years, or older than 40 years) was tested using a likelihood ratio test.


RESULTS
A diagnosis of asthma was associated with increased odds of incident Crohn's disease (adjusted odds ratio [OR], 1.45; 95% confidence interval [CI], 1.31-1.60). No effect measure modification was observed for age at diagnosis for Crohn's disease (P = .42). However, we observed effect measure modification by age at diagnosis for ulcerative colitis (P = .0103), with an adjusted OR of 1.49 (95% CI, 1.08-2.07) among individuals diagnosed at an age of 16 years or less (OR) and an adjusted OR of 1.57 (95% CI, 1.31-1.89) among individuals diagnosed at an age older than 40 years. However, there was no association between asthma and ulcerative colitis among individuals diagnosed between ages 17 and 40 (adjusted OR, 1.05; 95% CI, 0.86-1.26).


CONCLUSIONS
In a population-based case-control study, we associated asthma with Crohn's disease, and with early and late-onset ulcerative colitis.
Department of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada; Synder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada; O'Brien Institute for Public Health, University of Calgary, Calgary, Alberta, Canada.
M Ellen
ME
Kuenzig
Department of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada; O'Brien Institute for Public Health, University of Calgary, Calgary, Alberta, Canada.
Cheryl
C
Barnabe
Department of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada.
Cynthia H
CH
Seow
Department of Medicine, University of Calgary, Calgary, Alberta, Canada; Synder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada.
Bertus
B
Eksteen
Department of Production Animal Health, University of Calgary Faculty of Veterinary Medicine, Calgary Alberta, Canada.
Maria E
ME
Negron
Division of Gastroenterology, Department of Medicine, Cedars-Sinai, Los Angeles, California.
Ali
A
Rezaie
Department of Medicine, University of Calgary, Calgary, Alberta, Canada.
Remo
R
Panaccione
CHEO Inflammatory Bowel Disease Centre, Division of Gastroenterology, Hepatology and Nutrition, The Children's Hospital of Eastern Ontario, Ottawa, Canada; Department of Pediatrics and School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, Canada.
Eric I
EI
Benchimol
Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada.
Mohsen
M
Sadatsafavi
Arthritis Research Canada, Division of Rheumatology, University of British Columbia, BC, Canada.
J Antonio
JA
Aviña-Zubieta
Department of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada; Synder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada; O'Brien Institute for Public Health, University of Calgary, Calgary, Alberta, Canada. Electronic address: ggkaplan@ucalgary.ca.
Gilaad G
GG
Kaplan
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000416:Alberta / Q000453:epidemiology; D001249:Asthma / Q000150:complications*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003093:Colitis, Ulcerative / Q000453:epidemiology*; D003424:Crohn Disease / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult
Age at Diagnosis; Asthma; Crohn's Disease; Effect Measure Modification; Ulcerative Colitis