Physical Activity, Diet, and Incident Urinary Incontinence in Postmenopausal Women: Women’s Health Initiative Observational Study

Background: Physical activity and macronutrient intake, important contributors to energy balance, may be independently associated with female urinary incontinence (UI). Methods: We evaluated the association of baseline self-reported physical activity and macronutrient intake, via food frequency questionnaire, with incident UI subtypes after 3 years among 19 741 postmenopausal women in the Women's Health Initiative Observational Study. Odds ratios (ORs) for incident urgency, stress, and mixed UI were calculated using multivariable logistic regression. Results: Women who reported total physical activity (metabolic equivalent task [MET]-hours/week) >= 30 versus <0.1 were 16% less likely to develop urgency UI (OR = 0.84; 95% CI 0.70, 1.00) and 34% less likely for mixed UI (OR = 0.66; 95% CI 0.46, 0.95), although linear trends were no longer statistically significant after adjusting for baseline weight and weight change (p trend = .15 and .16, respectively). The association between physical activity and incident stress UI was less consistent. Higher uncalibrated protein intake was associated with increased odds of incident urgency UI (>= 19.4% vs <14.1% of energy intake OR = 1.14; 95% CI 0.99, 1.30; p trend = .02), while CIs were wide and included 1.0 for calibrated protein intake. Other macronutrients were not associated with urgency UI and macronutrient intake was not associated with incident stress or mixed UI (p trend > .05 for all). Conclusions: Among postmenopausal women, higher physical activity was associated with lower risk of incident urgency and mixed UI, but not stress UI, independent of baseline weight and weight change. Higher protein intake was associated with increased risk of urgency UI, but no associations were observed between other macronutrient and UI subtypes.