Smoking habits and recurrence in Crohn's disease

Smoking may be a risk factor for surgical recurrence of Crohn's disease. However, other variables associated with recurrence could be confounding factors for smoking. The aim of this study was to evaluate the role of smoking as an independent predictor of clinical, surgical, and endoscopic recurrence.

In a series of 182 patients who underwent surgery for Crohn's disease, a multivariate analysis was performed that included all of the significant variables associated with recurrence: sex, age at diagnosis, time between onset of symptoms and surgery, site of disease, indication for surgery, extent of disease, extraintestinal manifestation, and smoking habit.

Independent predictors of clinical recurrence by the Cox proportional hazard model were smoking (hazard ratio, 1.46; 95% confidence interval [CI], 1.1-1.8), extraintestinal manifestations (hazard ratio, 1.61; 95% CI, 1.0-2.5), and extent of disease (hazard ratio, 1.57; 95% CI, 1.0-2.4). Smoking was the only significant predictor of surgical recurrence (hazard ratio, 2.0; 95% CI, 1.2-2.3). For endoscopic recurrence, logistic regression showed that smoking (odds ratio, 2.2; 95% CI, 1.2-3.8) and extent of disease (odds ratio, 2.6; 95% CI, 1.0-6.7) were predictive factors of recurrence.

Smoking is an independent risk factor for clinical, surgical, and endoscopic recurrence in Crohn's disease.