Smoking prevalence and its influence on disease course and surgery in Crohn's disease and ulcerative colitis

Abstract

Summary Background Smoking demonstrates divergent effects in Crohn's disease (CD) and ulcerative colitis (UC). Smoking frequency is greater in CD and deleterious to its disease course. Conversely, UC is primarily a disease of nonsmokers and ex‐smokers, with reports of disease amelioration in active smoking. Aim To determine the prevalence of smoking and its effects on disease progression and surgery in a well‐characterised cohort of inflammatory bowel diseases (IBD) patients. Methods Patients with smoking data of the Sydney IBD Cohort were included. Demographic, phenotypic, medical, surgical and hospitalisation data were analysed and reported on the basis of patient smoking status. Results 1203 IBD patients were identified comprising 626 CD and 557 UC with 6725 and 6672 patient‐years of follow‐up, respectively. CD patients were more likely to smoke than UC patients (19.2% vs. 10.2%, P < 0.001). A history of smoking in CD was associated with an increased proportional surgery rate (45.8% vs. 37.8%, P = 0.045), requirement for IBD‐related hospitalisation (P = 0.009) and incidence of peripheral arthritis (29.8% vs. 22.0%, P = 0.027). Current smokers with UC demonstrated reduced corticosteroid utilisation (24.1% vs. 37.5%, P = 0.045), yet no reduction in the rates of colectomy (3.4% vs. 6.6%, P = 0.34) or hospital admission (P = 0.25) relative to nonsmokers. Ex‐smokers with UC required proportionately greater immunosuppressive (36.2% vs. 26.3%, P = 0.041) and corticosteroid (43.7% vs. 34.5%, P = 0.078) therapies compared with current and never smokers. Conclusions This study confirms the detrimental effects of smoking in CD, yet failed to demonstrate substantial benefit from smoking in UC. These data should encourage all patients with IBD to quit smoking.

Smoking cessation improves Crohn's disease outcomes regardless of the use of anti-TNF or immunomodulator

“…Strengths of the study included the prospective design, use of time-dependent analysis and adjustment for confounding factors. The results generated, however, were similar to the Sydney IBD Cohort data,2 which comprised of analysis of prospectively collected data from a defined geographical population with a median of 9 years of follow-up (6275 patient-years) compared to 3 years (1557 patient-years) in this study. The limited power was demonstrated as wide CIs that could not demonstrate statistically significant reduction in need for surgery in quitters (IRR: 1.78, 95% CI 0.56 to 5.58)) or former smokers (IRR: 0.76: 95% CI 0.29 to 2.00), versus continuing smokers (IRR: 1.21, 95% CI 0.50 to 2.92).…”

Transient Receptor Potential Channels in Intestinal Inflammation: What Is the Impact of Cigarette Smoking?

“…First, it worsens CD, necessitating increased need for steroids and immunosuppressive drugs, more frequent relapses and surgery [126]. Moreover, current smokers have a two times higher risk and ex-smokers have a 1.8 times higher risk of developing CD in comparison to never-smokers.…”

Risk factors for recurrence of Crohn's disease requiring surgery in patients receiving post-operative anti-tumor necrosis factor maintenance therapy

“…Previous studies have shown that smoking is both a risk factor for relapse of CD in general and for surgical recurrence in particular [14][15][16][17] . A recent multicenter prospective cohort study showed that despite the widespread use of immunosuppressants and anti-TNF antibodies, smokers with CD have a more severe disease course, including greater requirements for treatment, than non-smokers 18) .…”