A Case-Control study on the risk factors of IBD in 258 Iranian patients

Abstract

Introduction: Ulcerative colitis (UC) and Crohn's disease (CD) are chronic inflammatory bowel diseases (IBD) with uncertain etiology thought to be triggered by interactions between various environmental, genetic and immunologic factors. Role of different factors in IBD are controversial.

Materials and Methods: The aim of this study is to determine the possible risk factors in a group of Iranian patients with IBD. Ninety five consecutive cases of CD and 163 cases of UC were included. Age matched controls were randomly selected. A total of 489 controls for UC and 285 controls for CD were enrolled. A standard record concerning many variables was completed. Logistic regression analysis was used to evaluate potential confounding variables.

Results: A statistically significant protective effect for smoking in UC was found (OR=0.18 95% CI=0.064- 0.504, p ‹ 0.05). The risk of UC increases with prolonged exposure to OCP (OR=0.99, 95% CI=0.98-0.99, p ‹ 0.05). In patients with CD, 15 cases (15.8%) reported a previous history of appendectomy compared with 19 controls (6.7%) (OR=2.6, 95% CI= 1.2-5.4, p < 0.05). Tonsillectomy was reported by 16 patients (16.8%) with CD compared with 25 controls (8.8%) (OR= 2.1, 95% CI= 1.07-4.1, p ‹ 0.05). The logistic regression analysis showed that both appendectomy and tonsillectomy are risk factors in CD. No association with other variables was found for either disease.

Conclusion: Current smoking was a significant protective factor in UC. We observed a relationship between duration of OCP use and UC. Duration of using OCP in UC cases was significantly more than controls. Both appendectomy and tonsillectomy were risk factors in CD in this study