title: Does smoking influence Crohn's disease in the biologic era? The TABACROHN study.
abstract: BACKGROUND
  While most studies have found a negative effect of smoking on Crohn's disease (CD) phenotype, more recent data have failed to reproduce this association, which might be due to a current wider use of thiopurines and biologic therapy. The TABACROHN study aimed at defining the impact of smoking on CD in the largest published series.
  
  
  METHODS
  This multicenter cross-sectional study included 1170 CD patients. Patients were classified as nonsmokers, current smokers, or former smokers according to their present smoking status. Clinical data regarding disease characteristics, treatment, and complications were collected.
  
  
  RESULTS
  Smokers were more frequently under maintenance treatment when compared to nonsmokers. In addition, current smokers presented higher use of biologic drugs compared to nonsmokers. Tobacco exposure and a higher tobacco load were independent predictors of need for maintenance treatment and stenosing phenotype, respectively.
  
  
  CONCLUSIONS
  In the era of early and widespread use of immunosuppressants and biologics, tobacco exposure is an independent predictor of need for maintenance treatment, specifically biologic therapy. The wider use of biologics and immunosuppressants could account for the existence of no major differences in disease behavior and complications between nonsmokers and current smokers.
authors.affiliation: Hospital Clinic/IDIBAPS, Barcelona, Spain.
authors.forename: Tiago
authors.initials: T
authors.lastname: Nunes
authors.forename: Maria Josefina
authors.initials: MJ
authors.lastname: Etchevers
authors.forename: Olga
authors.initials: O
authors.lastname: Merino
authors.forename: Sonia
authors.initials: S
authors.lastname: Gallego
authors.forename: Valle
authors.initials: V
authors.lastname: García-Sánchez
authors.forename: Ignacio
authors.initials: I
authors.lastname: Marín-Jiménez
authors.forename: Luis
authors.initials: L
authors.lastname: Menchén
authors.forename: Manuel
authors.initials: M
authors.lastname: Barreiro-de Acosta
authors.forename: Guillermo
authors.initials: G
authors.lastname: Bastida
authors.forename: Sara
authors.initials: S
authors.lastname: García
authors.forename: Elena
authors.initials: E
authors.lastname: Gento
authors.forename: Daniel
authors.initials: D
authors.lastname: Ginard
authors.forename: Fernando
authors.initials: F
authors.lastname: Gomollón
authors.forename: Maite
authors.initials: M
authors.lastname: Arroyo
authors.forename: David
authors.initials: D
authors.lastname: Monfort
authors.forename: Esther
authors.initials: E
authors.lastname: García-Planella
authors.forename: Benito
authors.initials: B
authors.lastname: Gonzalez
authors.forename: Carme
authors.initials: C
authors.lastname: Loras
authors.forename: Carles
authors.initials: C
authors.lastname: Agustí
authors.forename: Carolina
authors.initials: C
authors.lastname: Figueroa
authors.forename: Miquel
authors.initials: M
authors.lastname: Sans
mesh_terms: D000328:Adult; D001691:Biological Therapy; D003424:Crohn Disease / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D003430:Cross-Sectional Studies; D005060:Europe / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D055815:Young Adult