title: Does active smoking really influence the course of Crohn's disease? A retrospective observational study.
abstract: BACKGROUND
  Active smoking has been associated with a higher risk of developing Crohn's disease (CD). However, its impact on clinical outcomes has been controversial among studies.
  
  
  OBJECTIVE
  To evaluate the influence of active smoking on initial manifestations of CD, the development of disease-related complications, and therapeutic requirements.
  
  
  METHODS
  Patients diagnosed with CD within a ten-year period (1994-2003) were identified. Clinical and therapeutic features until October 2008 or loss of follow-up were recorded. Smoking status was assessed at each major disease-related event (e.g. penetrating and stricturing complications, perianal disease, intestinal resection, introduction of immunomodulators or biological agents).
  
  
  RESULTS
  A total of 259 patients were included in the study with a median follow-up period of 91 months. At diagnosis, 50.5% were active smokers and only 12% of them quit smoking during follow-up, mostly after a major disease-related event occurred. Smoking at diagnosis was not associated with a particular CD presentation. Active smoking did not influence the development of strictures, intraabdominal and perianal penetrating complications, or increased resectional surgery, biological therapy or immunomodulators requirements.
  
  
  CONCLUSIONS
  Patients who develop CD while smoking seem to have a similar disease course to those who never smoked.
authors.affiliation: Hospital Universitari Germans Trias i Pujol, Badalona (Catalonia), Spain.
authors.forename: Yamile
authors.initials: Y
authors.lastname: Zabana
authors.forename: Esther
authors.initials: E
authors.lastname: Garcia-Planella
authors.forename: Manuel
authors.initials: M
authors.lastname: Van Domselaar
authors.forename: Míriam
authors.initials: M
authors.lastname: Mañosa
authors.forename: Jordi
authors.initials: J
authors.lastname: Gordillo
authors.forename: Antonio
authors.initials: A
authors.lastname: López San Román
authors.forename: Eduard
authors.initials: E
authors.lastname: Cabré
authors.forename: Eugeni
authors.initials: E
authors.lastname: Domènech
mesh_terms: D000328:Adult; D003424:Crohn Disease / Q000150:complications / Q000473:pathology* / Q000628:therapy; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012907:Smoking / Q000009:adverse effects*; D016540:Smoking Cessation / Q000706:statistics & numerical data; D016896:Treatment Outcome