Abstract
BACKGROUND: Dietary nutrient intake contributes to urination; however, the association between dietary nutrient intake, especially that of fat, and urinary incontinence (UI) is not well understood. The most common types of UI include stress UI (SUI) and urgency UI (UUI). OBJECTIVE: To investigate the potential effect(s) of dietary fat intake on UI and explore its mechanism of action in relation to body mass index (BMI). METHODS: A cross-sectional survey of data from 15,121 individuals (20-85 years of age) from the National Health and Nutrition Examination Survey (2001-2008), a random population-based sample, was performed. Data regarding dietary nutrient intake were collected through 24 h dietary recall interviews. UI and covariate data were collected through in-person interviews. UI was assessed according to the American Urological Association Symptom Index. The odds ratio (OR) for SUI and UUI were calculated using multivariate logistic regression analysis. The mediation effect was estimated using observational mediation analysis. RESULTS: Higher total fat intake was positively associated with increased odds for developing UI (OR 1.44 [95% confidence interval (CI) 1.08-1.93]). Females who consumed more saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA) were more likely to develop SUI. BMI partially explained the association between total fat, SFA, MUFA, and PUFA and SUI; the proportions of the mediation effect of BMI were 14.7%, 13.0%, 18.7%, and 16.3%, respectively. CONCLUSIONS: Results of this study emphasize the key role of dietary fat intake in the prevalence of UI. Higher fat intake was positively associated with UI and BMI partially mediated the effect of fat intake on SUI.