Objective: Smoking has been reported as influencing disease activity in inflammatory bowel disease. The aim of our study was to elucidate the relationship between smoking and aspects of disease-specific quality of life in inflammatory bowel disease.
Design: Cross-sectional study.
Methods: In 1105 prevalent patients with inflammatory bowel disease, diagnosed according to the criteria of Lennard-Jones and Truelove and Witts, disease-specific quality of life was investigated using the Inflammatory Bowel Disease Questionnaire (IBDQ).
Results: In Crohn's disease, smoking females reported a lower quality of life than non-smoking females (all four dimensions of the IBDQ). Using an explanatory model of relationships between the four dimensions for the analysis, it became evident that smoking is associated with more bowel symptoms in young Crohn's disease females, with more emotional dysfunction in all Crohn's disease females, and with more systemic symptoms in all three diagnostic groups with marked bowel symptoms. Moderately smoking male ulcerative colitis patients reported fewer bowel complaints compared with non-smoking male ulcerative colitis patients.
Conclusion: There is a relationship between smoking and disease-specific quality of life in both ulcerative colitis and Crohn's disease. The hypothesis is presented that a part of the observed differences in the studied quality of life dimensions with respect to age, sex and disease group are related to concomitant oral contraceptive use.