Effect of smoking on the long-term course of ulcerative colitis

OBJECTIVE: To evaluate the effects of smoking on the long term clinical course in patients with ulcerative colitis. METHODS: The medical charts of 556 patients with ulcerative colitis were reviewed retrospectively. Patients were classified as smokers (n = 85) or nonsmokers (n = 471) according to their smoking status during the course of the disease. Extent of colonic lesions, complications, medical requirements, and actuarial rate of colectomy were compared in smokers and nonsmokers. RESULTS: Mean follow-up (+/- SD) was longer in smokers than in nonsmokers (116 +/- 107 mo, vs 87 +/- 94 mo.). Less smokers than nonsmokers required oral steroids (52 vs 63%, P = 0.05). No difference between the groups was observed regarding the use of salicylates, the need for intravenous steroids, for immunosuppressive drugs, for colectomy, and the occurrence of complications. The actuarial rate of colectomy was less in smokers than in nonsmokers (32 +/- 12% and 42 +/- 6% at 10 years respectively. P = 0.04). Initial and cumulative extent of the disease process did not differ between the groups. However, in the subgroup of patients with limited disease at onset, development of pancolitis was less frequent in smokers than in nonsmokers (14 and 26%, respectively, P = 0.04). CONCLUSION: The lesser need for oral steroids and the lower actuarial rate of colectomy in smokers suggest that ulcerative colitis in smokers is characterized by a less severe clinical presentation and a better long term prognosis than in nonsmokers.