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. AIMS: 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 91months. 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.