Is there a role for estrogen in the prevention and treatment of urinary incontinence? ===================================================================================== * Jayna M. Holroyd-Leduc * Sharon E. Straus Hendrix SL, Cochrane BC, Nygaard IE, Handa VL, Barnabei VM, Igesia C, et al. Effects of estrogen with and without progestin on urinary incontinence. *JAMA* 2005;293:935-48. ***Background:*** The role of estrogen in the treatment of urinary incontinence is unclear. Given that the lower urinary tract shares a common embryologic origin with the genital tract, it has been theorized that urinary incontinence may be related to atrophy associated with estrogen loss. However, epidemiologic and trial evidence has shown both beneficial and harmful effects of estrogen on urinary incontinence.1,2 ***Design:*** This study included 23 296 healthy, postmenopausal women aged 50–79 years enrolled in the Women's Health Initiative hormone replacement therapy (HRT) trial and for whom baseline and 1-year data on urinary incontinence (defined as self-reported involuntary urine leakage of any amount in the past year) were available. Women were randomly assigned to receive either placebo or HRT in the form of conjugated equine estrogen (0.625 mg/d) with or without medroxyprogesterone (2.5 mg/d) based on their hysterectomy status. Participants, clinic staff and outcome assessors were blinded to group allocation. Primary outcomes were incident urinary incontinence at 1 year among women without baseline incontinence (*N* = 8255) and severity of incontinence among those with urinary incontinence at baseline (*N* = 15 041). Urinary incontinence was further subdivided by type (stress, urge or mixed). Measurements of severity included self-reported frequency, amount, associated limitations in daily activities and “degree of bother.” View this table: [Table1](http://www.cmaj.ca/content/172/8/1003/T1) Table 1. ***Result:*** HRT was associated with an increased 1-year incidence of all types of urinary incontinence among women who were continent at baseline (Table 1). It was also associated with an increase in the severity of urinary incontinence among women who were incontinent at baseline (Table 2). View this table: [Table2](http://www.cmaj.ca/content/172/8/1003/T2) Table 2. ***Commentary:*** This large, well-designed, multicentre, randomized trial appears to resolve the controversy around estrogen and urinary incontinence. The results consistently demonstrate that there is no role for estrogen in the prevention or treatment of urinary incontinence, even when the definition of urinary incontinence was altered in a sensitivity analysis. These findings require us to re-examine the biological effect of estrogen on the lower urinary tract. A recent study3 suggested that estrogen may actually alter collagen metabolism, which would result in damage to the periurethral connective tissues essential for effective urethral closure. This would help explain why estrogen had its strongest effect on the development of stress incontinence, which is related to increased urethral mobility, poor intrinsic sphincter function and weakness in the muscles of the pelvic floor. The Women's Health Initiative trial showed that the risk of developing comorbidities was increased among women taking estrogen with or without progestin. Several of these comorbid conditions could have increased the risk of urinary incontinence, which would explain in part the differences in incident urinary incontinence between the placebo and HRT groups. ***Practice implications:*** Although estrogen is no longer a treatment option for urinary incontinence, there are effective alternative treatments. These include pelvic floor muscle exercises, bladder training, prompted voiding, anticholinergic medications and surgery.1 Unfortunately, the main barrier to effective management of urinary incontinence is not a lack of treatment options but rather a lack of communication between patients and their health care providers about this problem.4 ## References 1. 1. Holroyd-Leduc JM, Straus SE. Management of urinary incontinence in women: scientific review. JAMA 2004;291(8):986-95. [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.1001/jama.291.8.986&link_type=DOI) [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=14982915&link_type=MED&atom=%2Fcmaj%2F172%2F8%2F1003.atom) [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=000189182000027&link_type=ISI) 2. 2. Moehrer B, Hextall A, Jackson S. Oestrogens for urinary incontinence in women [review]. *Cochrane Database Syst Rev* 2003(2):CD001405. 3. 3. Jackson S, James M, Abrams P. The effect of oestradiol on vaginal collagen metabolism in postmenopausal women with genuine stress incontinence. Br J Obstet Gynaecol 2002;109:339-44. [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.1111/j.1471-0528.2002.01052.x&link_type=DOI) 4. 4. Ricci JA, Baggish JS, Hunt TL, Stewart WF, Wein A, Herzog AR, et al. Coping strategies and health care-seeking behavior in a US national sample of adults with symptoms suggestive of overactive bladder. Clin Ther 2001;23:1245-59. [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.1016/S0149-2918(01)80104-1&link_type=DOI) [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=11558861&link_type=MED&atom=%2Fcmaj%2F172%2F8%2F1003.atom) [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=000170733600009&link_type=ISI)