Abstract
INTRODUCTION AND HYPOTHESIS: The goal of this study was to characterize associations between caffeine consumption and severity of urinary incontinence (UI) in US women. We hypothesized that moderate and high caffeine intake would be associated with UI in US women when controlling for other factors associated with UI. METHODS: US women participated in the 2005-2006 and 2007-2008 National Health and Nutrition Examination Survey (NHANES), a cross-sectional, nationally representative survey. Using the Incontinence Severity Index, UI was categorized as "any" and "moderate/severe". Types of UI included stress, urge, mixed, and other. Food diaries were completed, and average water (grams/day), total dietary moisture (grams/day), and caffeine (milligrams/day) intake were calculated into quartiles. Stepwise logistic regression models were constructed adjusting for sociodemographics, chronic diseases, body mass index, self-rated health, depression, physical activity, alcohol use, dietary water and moisture intake, and reproductive factors. RESULTS: From the 4,309 nonpregnant women (aged ≥20 years) who had complete UI and dietary data, UI prevalence for any UI was 41.0 % and 16.5 % for moderate/severe UI, with stress UI the most common type (36.6 %). Women consumed a mean caffeine intake of 126.7 mg/day. After adjusting for multiple factors, caffeine intake in the highest quartile (≥204 mg/day) was associated with any UI [prevalence odds ratio (POR) 1.47, 95 % confidence interval (CI) 1.07-2.01], but not moderate/severe UI (POR 1.42, 95 % CI 0.98-2.07). Type of UI (stress, urgency, mixed) was not associated with caffeine intake. CONCLUSIONS: Caffeine intake ≥204 mg/day was associated with any UI but not with moderate/severe UI in US women.