Serum estradiol levels are not associated with urinary incontinence in midlife women transitioning through menopause

Objective: We evaluated the relationship between annually measured serum endogenous estradiol and the development or worsening of stress and urge incontinence symptoms during a period of 8 years in women transitioning through menopause. Methods: This is a longitudinal analysis of women with incontinence in the Study of Women's Health Across the Nation, a multicenter, multiracial/ethnic prospective cohort study of community-dwelling women transitioning through menopause. At baseline and at each of the eight annual visits, the Study of Women's Health Across the Nation elicited the frequency and type of incontinence using a self-administered questionnaire and drew a blood sample on days 2 to 5 of the menstrual cycle. All endocrine assays were performed using a double-antibody chemiluminescent immunoassay. We analyzed the data using discrete Cox survival models and generalized estimating equations with time-dependent covariates. Results: Estradiol levels drawn at either the annual visit concurrent with or previous to the first report of incontinence were not associated with the development of any (hazard ratio, 0.99; 95% CI, 0.99-1.01), stress, or urge incontinence in previously continent women. Similarly, estradiol levels were not associated with the worsening of any (odds ratio, 1.00; 95% CI, 0.99-1.01), stress, or urge incontinence in incontinent women. The change in estradiol levels from one year to the next was also not associated with the development (hazard ratio, 0.98; 95% CI, 0.97-1.00) or worsening (odds ratio, 1.03; 95% CI, 0.99-1.05) of incontinence. Conclusions: We found that annually measured values and year-to-year changes in endogenous estradiol levels had no effect on the development or worsening of incontinence in women transitioning through menopause.