A Wayne State University School of Medicine study published in the Feb. 23, 2005, issue of the Journal of the American Medical Association has found that hormone replacement therapies once touted for beneficial effects on urinary incontinence may actually increase the incidence of incontinence in postmenopausal women.
Menopausal hormone therapy consisting of oral estrogen plus progestin or estrogen alone has long been used to treat postmenopausal women and, until recently, was credited with many benefits well beyond the indications for symptomatic relief of hot flashes, night sweats and vaginal dryness, according to background information in the article. One of the purported benefits of menopausal hormone therapy was to improve the symptoms of urinary incontinence; thus, it has often been prescribed to treat incontinence.
"We have to educate patients and physicians about the effects of the medication so we can treat patients better," said Susan L. Hendrix, D.O., WSU professor of obstetrics & gynecology, in an interview with HealthDay earlier this week.
Dr. Hendrix along with her colleagues conducted a study to determine the effects of estrogen and progestin or estrogen alone on the one-year incidence and severity of symptoms of three types of incontinence in healthy postmenopausal women: stress incontinence, which occurs when involuntary pressure is put on the bladder by coughing, laughing, sneezing, lifting or straining; urge incontinence, which is generally attributable to involuntary contracts of the bladder muscle; and mixed urinary incontinence, which involves involuntary leakage associated with urgency and also with exertion, effort, sneezing or coughing.
The researchers analyzed data from the Women's Health Initiative, a multicenter double-blind, placebo-controlled, randomized clinical trial of menopausal hormone therapy in 27,347 postmenopausal women aged 50 to 79 years enrolled between 1993 and 1998. Existence of any urinary incontinence symptoms was known for 23,296 participants at baseline and one year.
Women were randomized to receive estrogen alone, estrogen plus progestin or placebo. The WHI trials were designed to evaluate the effects of menopausal hormone therapy using estrogen and progestin or estrogen alone in preventing coronary heart disease and hip fractures in postmenopausal women. Both trials ended prematurely because more harm than benefit was observed.
However, the researchers found that menopausal hormone therapy increased the incidence of all types of urinary incontinence at one year among women who were continent at baseline.
The risk was highest for stress incontinence (1.87-fold increased risk with estrogen plus progestin; estrogen alone, 2.15-fold increased risk), followed by mixed incontinence (1.49-fold increased risk with estrogen plus progestin; estrogen alone, 1.79-fold increased risk). Combination therapy had no significant effect on developing urge incontinence, but estrogen alone increased the risk by 1.32 fold.
Among women who reported having urinary incontinence at baseline, both frequency and amount of incontinence worsened in both trials. Women receiving menopausal hormone therapy were more likely to report that urinary incontinence limited their daily activities and bothered or disturbed them at one year.