The relationship between BMI and urinary incontinence subgroups: results from EpiLUTS.

Aims: To evaluate the relationship between body mass index (BMI) and urinary incontinence (UI) in adults ≥40 from the United States, United Kingdom, and Sweden.
Methods: This was a secondary analysis of EpiLUTS-a population-representative, cross-sectional, Internet-based survey conducted to assess the prevalence and HRQL impact of urinary symptoms. UI was evaluated by the LUTS Tool and categorized by subgroups: no UI, urgency urinary incontinence (UUI), stress urinary incontinence (SUI), mixed urinary incontinence (MUI) (UUI + SUI), UUI + other UI (OI), SUI + OI, and OI. Descriptive statistics were used. Logistic regressions examined the relationship of BMI to UI controlling for demographics and comorbid conditions.
Results: Response rate was 59%; 10,070 men and 13,178 women were included. Significant differences in BMI were found across UI subgroups. Obesity rates were highest among those with MUI (men and women), SUI + OI (women), UUI and UUI + OI (men). Logistic regressions of each UI subgroup showed that BMI ≥ 30 (obese) was associated with UI in general and MUI (women) and UUI + OI (men). Among women, being obese increased the odds of having SUI and SUI + OI. Women with BMI 25-29.9 (overweight) were more likely to have UI in general and SUI with and without other incontinence (SUI, MUI, and SUI + OI). Being overweight was unrelated to any form of UI in men.
Conclusions: Results were consistent with prior research showing BMI is associated with higher risk of UI. These findings indicate substantial differences in obesity by gender and UI subtype, suggesting different mechanisms for UI other than purely mechanical stress on the bladder.
(© 2013 Wiley Periodicals, Inc.)