TUESDAY, Feb. 22, 2005 (HealthDay News) -- Hormone therapy, which doctors have often prescribed to postmenopausal women to prevent urinary incontinence, may actually increase its incidence and severity, a new study finds.
Data from the Women's Health Initiative (WHI) -- the major study of hormonal therapy -- found that risks for developing one kind or another of urinary incontinence were significantly greater for women who got the therapy than for those who didn't.
Many experts are now reluctant to recommend hormone replacement therapy (HRT) to incontinent patients, and these findings may support that trend.
"Would I prescribe hormonal treatment for urinary incontinence? No, never," said Dr. Jean Fourcroy, a trustee of the National Association for Continence.
The findings appear in the Feb. 23 issue of the Journal of the American Medical Association.
Researchers led by Dr. Susan Hendrix of Wayne State University School of Medicine, in Detroit, looked over data on nearly 23,300 women aged 50 to 79. They focused on symptoms of urinary incontinence occurring within one year of initiating HRT.
The team reported that the incidence of developing stress incontinence (urinary incontinence triggered by stressors such as heavy lifting or even coughing) more than doubled for women prescribed estrogen alone as a hormone therapy, compared to women given a placebo.
Urge incontinence, caused by an involuntary contraction of bladder muscles, was 32 percent more likely in women taking estrogen-only HRT, while the incidence of mixed incontinence, which has a multitude of causes, was increased by 79 percent.
Hormone-related increases in risk for stress or mixed incontinence were somewhat lower in women getting a combination of hormones, such as estrogen plus progestin, the researchers note. And in the case of urge incontinence, mixed hormonal therapy appeared to confer no increase in risk over a placebo.
Women already diagnosed with urinary incontinence at the start of the study reported an increase in the frequency and degree of the problem after being prescribed hormonal therapy, the researchers add.
The report on urinary incontinence and hormonal therapy couldn't have been made earlier because the complete Women's Health Initiative trial didn't end until February 2004 and "it takes a long time to be sure the records are complete and to get the information together," explained Hendrix, a professor of obstetrics and gynecology.
The finding that hormonal therapy worsened the outlook was "quite surprising," Hendrix said, and the treatment probably is still being prescribed for incontinence by many physicians.
"We have to educate patients and physicians about the effects of the medication so we can treat patients better," she said.
The report is yet another blow for HRT from data arising from the Women's Health Initiative. In July 2002, one arm of the study was unexpectedly halted after results found combined therapy increased women's risks for heart attack, stroke, blood clots and breast cancer. Sales of HRT have fallen sharply since that time.
This finding of an increased risk of urinary incontinence "is something of a surprise, because smaller trials have shown a benefit," said Dr. Catherine E. DuBeau, an associate professor of medicine at the University of Chicago, who wrote an accompanying editorial in the journal.
Her editorial advises that "clinicians should no longer prescribe long-term oral conjugated estrogens for treatment of urge, stress or mixed urinary incontinence in postmenopausal women aged 50 years or older."
However, the finding "is not the final word on using estrogens to treat urinary incontinence," DuBeau said. "There is still a lot we don't know about [the effectiveness of] topical estrogens," such as lotions or creams.
The most important result of the study "will be to get the word out to woman that they don't have to suffer from urinary incontinence," DuBeau said. Many women find the issue so embarrassing that they never tell their doctors about it, she said, even though a variety of helpful treatments are available, starting with behavioral therapy and moving on to drug treatment, if necessary. An implantable device has also been approved for use in extreme cases, she said.
Fourcroy said the study does have some weaknesses that could benefit from further analysis.
"One of the biggest things is that relief of urinary incontinence is associated with weight loss," Fourcroy said, and the new report has no information on participants' body-mass index, a measure of obesity. "We might see some subset differences if we looked at body-mass index information," she said.
But the bottom line, she said, is that hormonal therapy "is not the way to go."
The various forms of urinary incontinence, their causes and treatment, are outlined by the National Association for Continence.