Active and passive smoking behaviour and cessation plans of patients with Crohn's disease and ulcerative colitis.

BACKGROUND: Smoking is a remarkable risk factor in inflammatory bowel disease (IBD), with negative effects on Crohn's disease (CD) and positive effects on ulcerative colitis (UC). This makes different changes in smoking behaviour after diagnosis between CD and UC likely. Changes in active smoking, cessation plans and passive smoking were studied in IBD patients. METHODS: 820 IBD patients were sent a questionnaire on active and passive smoking, and cessation plans. A total of 675 (82%) patients (380 CD and 295 UC) responded. RESULTS: More ever smoking UC patients stopped smoking before diagnosis than CD patients (63% vs 22%; p<0.001), resulting in 30% former smokers at diagnosis in UC and 13% in CD (p<0.001). The smoking cessation rates at and after diagnosis are equal between CD and UC. Half of the CD patients stopped smoking after diagnosis leading to less present smokers in CD than in a control population (26% (95% confidence interval: 21.1%-29.9%) vs 33%). For both CD (22% vs 35%; p=0.044) and UC (24% vs 53%; p=0.024) continuing smokers after diagnosis were less often higher educated than quitters. Cessation plans (89%), passive smoking in childhood and present passive smoking were not different between CD and UC patients. CONCLUSION: There are no differences in changes in smoking behaviour at and after diagnosis between CD and UC patients, suggesting a lack of knowledge in these patients about the link between their disease and smoking behaviour. However, CD patients seem less refractory to smoking cessation than the general population. Therefore it is worthwhile putting energy in helping CD patients stop smoking.

Effects of active and passive smoking on disease course of Crohn's disease and ulcerative colitis.

BACKGROUND: Smoking is a remarkable risk factor for inflammatory bowel disease (IBD), aggravating Crohn's disease (CD) while having beneficial effects on ulcerative colitis (UC). We studied the effects of active and passive smoking in Dutch IBD patients. METHODS: A questionnaire focusing on cigarette smoke exposure was sent to 820 IBD patients. Returned questionnaires were incorporated into a retrospective chart review, containing details about disease behavior and received therapy. RESULTS: In all, 675 IBD patients (380 [56%] CD and 295 [44%] UC) responded. At diagnosis there were 52% smokers in CD, 41% in the general population, and 28% in UC. The number of present smokers in CD is lower than in the general population (26% versus 35%). No detrimental effects of active smoking on CD were observed, but passive smokers needed immunosuppressants and infliximab more frequently than nonpassive smokers. Active smoking had beneficial effects on UC, indicated by reduced rates of colectomy, primary sclerosing cholangitis, and backwash-ileitis in active smokers compared to never smokers, and higher daily cigarette dose correlated with less extensive colitis and a lower need for therapy. Furthermore, smoking cessation after diagnosis was detrimental for UC patients, indicated by increased needs for steroids and hospitalizations for patients that stopped smoking after compared to before the diagnosis. CONCLUSIONS: Active smoking is a risk factor for CD, but does not affect the outcome; passive smoking is detrimental for the outcome of CD patients. In UC, active smoking shows dose-dependent beneficial effects. Our data suggest that passive smoking is a novel risk factor for CD.