[Smoking, smoking cessation and Crohn's disease]

Area of Science:

• Gastroenterology and Internal Medicine
• Public Health and Epidemiology

Background:

• Smoking is more prevalent in Crohn's disease (CD) patients and exacerbates the condition.
• Conversely, ulcerative colitis predominantly affects non-smokers, with smoking potentially improving disease course.

Purpose of the Study:

• To systematically review the relationship between smoking, smoking cessation, and Crohn's disease.
• To synthesize current data on the impact of smoking on CD progression and management.

Main Methods:

• A systematic literature review was conducted using Medline (1980-2015).
• Keywords included 'Crohn's disease' or 'inflammatory bowel disease' and 'smoking' or 'smoking cessation'.
• 168 abstracts were dual-read, selecting 69 studies (case-control, retrospective, reviews, meta-analysis).

Main Results:

• Smoking increases the risk of CD complications, disease recurrence, and the need for surgery, corticosteroids, or immunosuppressants.
• These negative effects of smoking are more pronounced in women.
• Smoking cessation demonstrably improves disease course and is a vital management strategy.

Conclusions:

• Smokers with CD require consistent counseling on the detrimental effects of smoking and the benefits of cessation.
• Assistance in quitting smoking should be an integral part of Crohn's disease management.
• Study heterogeneity was noted regarding study types, population characteristics, smoking status definitions, and cessation validation.