Examining the Evidence
Q Does HRT diminish urinary incontinence?
<huc>A</huc> Not at all. On the contrary, it increases the risk among continent women and worsens symptoms in incontinent ones, according to a study of Women’s Health Initiative (WHI) participants.
Based on weak evidence, some experts have recommended hormone replacement therapy (HRT) as initial treatment of urinary incontinence in hypoestrogenic menopausal women. In fact, HRT has been used for this indication for several decades, mainly because there are estrogen receptors on urinary tract tissues.
This substudy of the WHI involving 27,347 women contradicts the longstanding practice of prescribing HRT for urinary incontinence: Both conjugated equine estrogen (CEE) and CEE with medroxyprogesterone acetate (MPA) stimulated new symptoms or aggravated existing ones.
How these data stack up
These findings are consistent with those of the Heart and Estrogen/Progestin Replacement Study (HERS),1 but contradict small observational studies. In addition, a large cross-sectional investigation of osteoporotic fractures had found estrogen use in post-menopausal women to be associated with almost double the risk of daily urinary incontinence—though these findings did little to change clinical practice.2
Major advantages of the WHI study are its large size and great statistical power. Since medications were not prescribed for therapy and since this was a blinded study, the placebo effect was also neutralized. Participants were followed over 3 years.
Unfortunately, the study provides no information for women below the age of 50.
What about other HRT formulations?
Only 1 dose of CEE with and without a single dose of MPA was utilized, although the authors cite an observational study3 of different formulations of estrogen-progestin and estrogen alone that “suggested an increased risk” of urinary incontinence with HRT. The authors also note that theirs is the first randomized trial to demonstrate that estrogen alone increases urinary incontinence.
The bottom line
Without any convincing evidence to the contrary, clinicians should avoid prescribing estrogen—with or without a progestin—to prevent or treat urinary incontinence in menopausal women.
1. Grady D, Brown JS, Vittinghoff E, et al. Postmenopausal hormones and incontinence: the Heart and Estrogen/Progestin Replacement Study. Obstet Gynecol. 2001;97:116-120.
2. Brown JS, Seeley DG, Fong J, Black DM, Ensrud KE, Grady D. Urinary incontinence in older women: who is at risk? Study of Osteoporotic Fractures Research Group. Obstet Gynecol. 1996;87:715-721.
3. Grodstein F, Fretts R, Lifford K, Resnick N, Curhan G. Association of age, race, and obstetric history with urinary symptoms among women in the Nurses’ Health Study. Am J Obstet Gynecol. 2003;189:428-434.