Smoking and risk of colonic diverticulosis: A meta-analysis

BACKGROUND/OBJECTIVES: The possible relationship between smoking and risk of colonic diverticulosis has been suggested by recent epidemiological studies, although the results were inconsistent. This meta-analysis was conducted to summarize all available data. METHODS: A comprehensive literature review was conducted using the MEDLINE and EMBASE databases through May 2017 to identify all studies that compared the risk of colonic diverticulosis among current and former smokers versus nonsmokers. Effect estimates from each study were extracted and combined together using the random-effect, generic inverse variance method of DerSimonian and Laird. RESULTS: Of 465 potentially eligible articles, three prospective cohort studies with 130,520 participants met the eligibility criteria and were included in the meta-analysis. The risk of colonic diverticulosis in current smokers was significantly higher than nonsmokers with the pooled risks ratio of 1.46 (95% confidence interval [CI], 1.13–1.89). However, the risk of colonic diverticulosis in former smokers was not significantly higher than nonsmokers with the pooled risk ratio of 1.13 (95% CI, 0.88–1.44). CONCLUSIONS: A significantly increased risk of colonic diverticulosis among current smokers is demonstrated in this study.