Effects of active and passive smoking on disease course of Crohnʼs disease and ulcerative colitis

Abstract

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.

Review article: ulcerative colitis, smoking and nicotine therapy

“…1,4,5,10,16,24 That is to say, heavier smokers are less likely to develop UC than lighter smokers 4 and current smokers who have a diagnosis of UC are more likely to have milder disease than ex-smokers and nonsmokers with UC. 1,4,5,24 Indeed, relatively heavy smokers have been observed to have less macroscopic and histological evidence of disease on colonoscopic examination, as compared with lighter smokers, ex-smokers and nonsmokers with UC. 4 Intermittent smokers have often been reported to experience symptomatic exacerbation during periods of nonsmoking and alleviation of symptoms on recommencement of smoking.…”

“…2,5,6,15,20 The observation that heavier smokers who quit smoking are more susceptible to the rebound effect of developing UC, compared to lighter smokers, also corroborates the notion of a dose-dependent relationship. 6,9,10,16 Current smokers with UC have been found to have less relapses, 33 require fewer hospitalisations 1,6,24,34,35 and demonstrate a reduced need for oral corticosteroid and immunosuppressant therapy for their disease, compared to ex-smokers and nonsmokers with UC. 1,5,24 However, not all studies have observed a significant difference in this regard between these patient groups.…”

“…6,9,10,16 Current smokers with UC have been found to have less relapses, 33 require fewer hospitalisations 1,6,24,34,35 and demonstrate a reduced need for oral corticosteroid and immunosuppressant therapy for their disease, compared to ex-smokers and nonsmokers with UC. 1,5,24 However, not all studies have observed a significant difference in this regard between these patient groups. 6,35 Those patients who quit smoking after diagnosis of UC often experience an exacerbation in their disease course, and have been uniformly shown to have increased hospitalisation rates and need for oral corticosteroids and immunosuppressants.…”

“…6,35 Those patients who quit smoking after diagnosis of UC often experience an exacerbation in their disease course, and have been uniformly shown to have increased hospitalisation rates and need for oral corticosteroids and immunosuppressants. 1,2,6,24,34,36 It remains divided as to whether smoking reduces the rate of surgery required in UC, particularly colectomy. Fraga et al 11 found that nonsmokers and especially exsmokers underwent surgery for their UC more frequently than current smokers.…”

“…Since then, numerous studies of the relationship between smoking and UC have confirmed this observation and demonstrated that smoking not only appears to protect against the development of UC, but in fact ameliorates the clinical course of the disease. [1][2][3][4][5][6]24 Subjectively, in a cohort of smokers with UC, over half-indicated smoking improved their disease and none felt smoking had a detrimental effect on their UC. 27 Similarly, in a group of ex-smokers with refractory UC, 14 out of 15 achieved prolonged clinical remission without steroids, following resumption of low-dose smoking.…”