Central Adiposity Is More Strongly Associated With Stress Urinary Incontinence Than Body Mass Index: A Comparative National Health and Nutrition Examination Survey Analysis.

INTRODUCTION: Obesity is a well-established risk factor for stress urinary incontinence (SUI); however, the relative contribution of central vs overall adiposity remains unclear. We hypothesized that central adiposity, measured by waist-to-height ratio (WHtR), would demonstrate a stronger association with SUI than BMI.

METHODS: This cross-sectional study analyzed adult women participating in the National Health and Nutrition Examination Survey 2011 to 2018 cycles. SUI was defined as self-reported urine leakage during physical exertion, coughing, or sneezing. Anthropometric indices (BMI, waist circumference, and WHtR) were evaluated as continuous variables and quartiles. Survey-weighted multivariable logistic regression models were constructed adjusting for age, diabetes, smoking status, parity, menopausal status, and physical activity.

RESULTS: A total of 5445 women were included, representing approximately 57.9 million US women. The weighted prevalence of SUI was 26.4%. All adiposity indices were independently associated with SUI; however, WHtR demonstrated the strongest association. Each 0.1-unit increase in WHtR was associated with a 30% higher odds of SUI (adjusted odds ratio 1.30, 95% CI 1.21-1.39), compared with a 4% increase per 1 kg/m2 increment in BMI. Women in the highest WHtR quartile had nearly a threefold higher odds of SUI compared with the lowest quartile. Associations were consistent across menopausal strata without significant interaction.

CONCLUSIONS: Central adiposity, quantified by WHtR, appears to be more strongly associated with SUI than overall adiposity. Incorporating WHtR into routine clinical assessment may enhance risk stratification and help identify women who could benefit from targeted interventions aimed at reducing abdominal adiposity.