Smoking and the risk of diverticular disease in women

Background: The relationship between smoking and the risk of diverticular disease is unclear. An observational cohort study was undertaken to investigate the association between smoking and diverticular disease. Methods: Women in the Swedish Mammography Cohort born between 1914 and 1948 were followed from 1997 to 2008. Information on smoking and other lifestyle factors was collected through questionnaires. Patients with symptomatic diverticular disease were identified from Swedish national registers. Relative risks (RRs) of symptomatic diverticular disease (resulting in hospital admission or death) according to smoking status were estimated using Cox proportional hazards models. Results: Of 35 809 women included in the study, 561 (1.6 per cent) had symptomatic diverticular disease. In multivariable analysis, current smokers had an increased risk of symptomatic diverticular disease compared with non-smokers after adjustment for age, intake of dietary fibre, diabetes, hypertension, use of acetylsalicylic acid, non-steroidal anti-inflammatory drugs or steroid medication, alcohol consumption, body mass index, physical activity and level of education (RR 1.23, 95 per cent confidence interval 0.99 to 1.52). Past smokers also had an increased risk (RR 1.26, 1.02 to 1.56). Smokers had a higher risk of developing a diverticular perforation/abscess than non-smokers (RR 1.89, 1.15 to 3.10). Conclusion: Smoking is associated with symptomatic diverticular disease.