Background
Obesity is an established risk factor for urinary incontinence (UI).
We recently reported that participants randomized to lifestyle intervention had greater improvements in UI at 6 months compared to women in the control arm. We now report the effect of weight loss on UI at 18 months.
Methods
A total of 338 women (mean age=53; BMI= 36 +6; 22% from ethnic minorities) who were overweight or obese and reported >10 UI episodes per week, were randomized in a 2:1 ratio to either a lifestyle intervention or a control group. The lifestyle group attended 6 months each of weekly, biweekly and monthly group meetings and was taught behavioral strategies to change diet and physical activity. Number and type of incontinence episodes was determined by self monitoring diary.
Results
Overall, 86% of the women completed the 18 month trial. The mean weight loss at 18 months in the intervention and control groups was 5.9 kg and 1.3 kg, respectively (p<0.001). Despite large differences in weight loss, there were no significant differences between groups in decreased total, stress or urge incontinent episode frequency (p>0.40 for all), with both groups experiencing improvement. However, when the treatment groups were combined, there was a strong dose-response relationship between magnitude of weight loss and UI improvement; comparisons of women who gained weight from baseline to 18 months, lost 0-5% , 5-10% or >10% of initial body weight, showed a significant association between weight loss category and decreased total, stress and urge incontinent episodes (all p's <0.002). This effect was independent of treatment group or initial BMI. Compared to women who gained weight (reference group), the odds of having at least 70% improvement in overall urinary incontinence was 1.8 (1.1, 3.1) in women who lost 0 to 5%; 2.0 (1.0, 4.0) in women who lost 5-10% and 2.6 (1.5, 4.6) in women who lost >10% (p<.05).
Conclusions
Even modest weight loss appears to have significant benefits for UI through 18 months of follow-up. Weight loss should thus be considered as a first-line treatment for overweight/obese women with UI.
For the Program to Reduce Incontinence by Diet and Exercise (PRIDE)
PRIDE was supported by Grants U01 DK067860, U01 DK067861 and U01 DK067862