title: Isotretinoin and risk of inflammatory bowel disease: a French nationwide study.
abstract: OBJECTIVE
  Isotretinoin, a drug widely prescribed for severe acne, has been suspected to increase the risk of ulcerative colitis (UC), but data are conflicting. To further examine the association between isotretinoin use and risk for UC and Crohn's disease (CD), we conducted a large nationwide case-control study in France.
  
  
  METHODS
  We used information from the National Health Insurance system for all French people covered by the general scheme between 1 January 2008 and 31 December 2010, totaling over 50 million individuals (i.e., 76% of the whole French population). All incident claims for UC and CD and all medical drug reimbursements were automatically recorded in the database. For each case, four controls were matched on age, gender, year of enrollment, and follow-up duration. The association between isotretinoin use and UC or CD claim was estimated by conditional logistic regression.
  
  
  RESULTS
  We included 7,593 cases of inflammatory bowel disease (IBD; 3,187 UC, 4,397 CD, and 9 indeterminate colitis) and 30,372 controls; among them, 26 cases (0.3%) (15 UC (0.5%) and 11 CD (0.3%)) and 140 controls (0.4%) were exposed to isotretinoin. Isotretinoin exposure was not associated with an increased risk for UC (odds ratio (OR)=1.36 (95% confidence intervals (CI): 0.76, 2.45)) but was associated with a decreased risk for CD (OR=0.45 (95% CI: 0.24, 0.85)), P value for homogeneity between UC and CD=0.001. Results were similar in analyses restricted to individuals below the age of 40 years, to cases with colonoscopy or intestinal surgery, or when adjusting for other acne treatments.
  
  
  CONCLUSIONS
  In this population-based case-control study, isotretinoin use was not associated with increased UC risk but was associated with a decreased CD risk. This study provides reassuring data for people using isotretinoin.
authors.affiliation: 1] Department of Gastroenterology, University Hospital of Bicêtre, Assistance Publique Hôpitaux de Paris, Université Paris-Sud, Le Kremlin Bicêtre, France [2] INSERM, UMRS 1018, Team 9, Centre for Research in Epidemiology and Population Health, Institut Gustave Roussy, Université Paris-Sud, Villejuif, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Racine
authors.affiliation: Caisse Nationale de l'Assurance Maladie des Travailleurs Salariés, Paris, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Cuerq
authors.affiliation: INSERM, UMRS 1018, Team 9, Centre for Research in Epidemiology and Population Health, Institut Gustave Roussy, Université Paris-Sud, Villejuif, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Bijon
authors.affiliation: Caisse Nationale de l'Assurance Maladie des Travailleurs Salariés, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Ricordeau
authors.affiliation: Caisse Nationale de l'Assurance Maladie des Travailleurs Salariés, Paris, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Weill
authors.affiliation: Caisse Nationale de l'Assurance Maladie des Travailleurs Salariés, Paris, France.
authors.forename: Hubert
authors.initials: H
authors.lastname: Allemand
authors.affiliation: Department of Dermatology, Hôpital Henri-Mondor, Assistance Publique Hôpitaux de Paris, Université Paris Est Créteil Val de Marne, Créteil, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Chosidow
authors.affiliation: INSERM, UMRS 1018, Team 9, Centre for Research in Epidemiology and Population Health, Institut Gustave Roussy, Université Paris-Sud, Villejuif, France.
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Boutron-Ruault
authors.affiliation: 1] Department of Gastroenterology, University Hospital of Bicêtre, Assistance Publique Hôpitaux de Paris, Université Paris-Sud, Le Kremlin Bicêtre, France [2] INSERM, UMRS 1018, Team 9, Centre for Research in Epidemiology and Population Health, Institut Gustave Roussy, Université Paris-Sud, Villejuif, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Carbonnel
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000139:chemically induced*; D003424:Crohn Disease / Q000139:chemically induced*; D016208:Databases, Factual; D003879:Dermatologic Agents / Q000009:adverse effects*; D005260:Female; D005602:France; D006801:Humans; D015474:Isotretinoin / Q000009:adverse effects*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors
chemical_list: D003879:Dermatologic Agents; D015474:Isotretinoin