title: Aspirin in the aetiology of Crohn's disease and ulcerative colitis: a European prospective cohort study.
abstract: BACKGROUND
  Aspirin has detrimental effects on the gastrointestinal tract mucosa and may play a role in the aetiology of inflammatory bowel disease.
  
  
  OBJECTIVE
  To investigate if the regular use of aspirin is associated with the development of Crohn's disease (CD) and ulcerative colitis (UC) using, for the first time, a prospective cohort study design.
  
  
  METHODS
  A total of 135,780 men and women in Europe, aged 30-74years, were recruited into the European Prospective Investigation into Cancer and Nutrition study. Participants completed questionnaires at baseline detailing their regular aspirin use and were then followed up to identify those who developed either incident CD or UC. Each case was matched with four controls and odds ratios (OR) were calculated, adjusting for cigarette smoking. Potential interactions between aspirin and smoking were assessed.
  
  
  RESULTS
  A total of 35 participants developed CD and a further 84 were diagnosed with UC. Regular aspirin intake was positively associated with the risk of developing CD (OR=6.14, 95% CI=1.76-21.35). In those who took aspirin and smoked there was no detectable increased risk of CD (OR=0.30, 95% CI=0.03-3.08). No association was found between regular aspirin use and UC (OR=1.29, 95% CI=0.67-2.46).
  
  
  CONCLUSIONS
  A strong positive association between regular aspirin use and CD, but not UC, was observed. The data suggest that regular aspirin use should be measured in epidemiological work on CD. If such findings are consistent in other work then aspirin may affect the development of CD in a middle-aged to elderly population.
authors.affiliation: Norfolk and Norwich University Hospital NHS Trust, Norwich, UK. simon.chan@doctors.org.uk
authors.forename: S S M
authors.initials: SS
authors.lastname: Chan
authors.forename: R
authors.initials: R
authors.lastname: Luben
authors.forename: M M
authors.initials: MM
authors.lastname: Bergmann
authors.forename: H
authors.initials: H
authors.lastname: Boeing
authors.forename: A
authors.initials: A
authors.lastname: Olsen
authors.forename: A
authors.initials: A
authors.lastname: Tjonneland
authors.forename: K
authors.initials: K
authors.lastname: Overvad
authors.forename: R
authors.initials: R
authors.lastname: Kaaks
authors.forename: H
authors.initials: H
authors.lastname: Kennedy
authors.forename: K-T
authors.initials: KT
authors.lastname: Khaw
authors.forename: E
authors.initials: E
authors.lastname: Riboli
authors.forename: A R
authors.initials: AR
authors.lastname: Hart
mesh_terms: D000328:Adult; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects*; D001241:Aspirin / Q000009:adverse effects*; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000139:chemically induced*; D003424:Crohn Disease / Q000139:chemically induced*; D005060:Europe; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D044465:White People
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001241:Aspirin