Coffee and caffeine intake and risk of urinary incontinence: a meta-analysis of observational studies

BACKGROUND Previous results from studies on the relationship between coffee/caffeine consumption and risk of urinary incontinence (UI) are inconclusive. We aim to assess this association using a meta-analysis of observational studies. METHODS Pertinent studies were identified by searching electronic database (Embase, PubMed and Web of Science) and carefully reviewing the reference lists of pertinent articles until July 2015. Random-effects models were used to derive the summary ORs and corresponding 95 % CIs. RESULTS Seven studies (one case-control, two cohort and four cross-sectional) were included in our meta-analysis. The summary ORs for any versus non-consumption were 0.75 (95 % CI 0.54-1.04) for coffee and 1.29 (95 % CI 0.94-1.76) for caffeine consumption. Compared with individuals who never drink coffee, the pooled OR of UI was 0.99 (95 % CI 0.83-1.18) for regular coffee/caffeine drinkers. Coffee/caffeine consumption was not associated with moderate to severe UI (OR 1.18, 95 % CI 0.88-1.58). In stratified analyses by gender, no significant association was found between UI risk and coffee/caffeine consumption in both men (OR 0.99, 95 % CI 0.42-2.32) and women (OR 0.92, 95 % CI 0.80-1.06). By subtype, the pooled ORs were 1.01 (95 % CI 0.86-1.19) for stress UI, 0.99 (95 % CI 0.84-1.16) for urge UI and 0.93 (95 % CI 0.79-1.10) for mixed UI. CONCLUSIONS This meta-analysis found no evidence for an association between coffee/caffeine consumption and the risk of UI.