WEDNESDAY, Dec. 19, 2001 (HealthDayNews) -- Women seeking to reduce their risk of urinary tract infections (UTIs) shouldn't look to hormone replacement therapy (HRT). A new study says it's not going to help you -- and it could even increase your risk.
The idea that HRT might make a difference grew out of the theory that as a woman ages, the corresponding drop in hormone production changes conditions in the vagina. Those changes include a rise in pathogens and a decrease in protective flora -- the so-called "good" bacteria that keep the vaginal tract healthy, says study author Dr. Jeanette Brown.
The result is an increase in the number of bacteria that eventually cause UTIs.
"These observations have led investigators to propose hormonal treatment, which re-established the premenopausal flora, as a therapy to prevent recurring UTIs," says Brown, director of the Women's Continence Center at the University of California at San Francisco.
And two previous studies showed that estrogen applied directly into the vagina appeared to help decrease the risk of UTIs -- adding more fuel to the speculation that HRT may do the same, Brown says.
But while the theory sounded plausible, her study results didn't bear out those findings. Indeed, Brown and her group discovered that women who took HRT had higher rates of UTIs.
"Oral [HRT] appears to increase the risk," says Brown.
The finding doesn't surprise Dr. Charles Ascher-Walsh, a uro-gynecologist at Columbia Presbyterian Medical Center, in New York City.
"The idea here is that adding estrogen might somehow decrease the risk of UTI. But in reality, younger women have a much higher rate of UTIs than post menopausal women, and younger women certainly have enough estrogen. So, the theory really falls short," says Ascher-Walsh.
In addition, he says it has never been proven that "a drop in estrogen increases the risk of UTIs in older women. I don't know if this has ever been proven."
In the new study, Brown and colleagues analyzed data on UTIs in 2,763 women, aged 44 to 79. All were participating in the Heart and Estrogen/Progestin Replacement Study, a four-year trial that compared the effects of HRT to a placebo for a variety of symptoms.
At the start of the study and at regular examinations during the four years, the women were asked questions related to UTIs, Brown says. They were also asked to describe any vaginal symptoms
in the week before their examinations, including itching, dryness or discharge. They were also queried on the frequency of sexual activity as well as on cigarette and alcohol use.
At the end of the study all the data was analyzed.
The result: Very little difference in the number of UTIs between women who took hormones and those who did not. When a difference was recorded, Brown says the women who took HRT were slightly more likely to experience infections.
While the previous studies showed topically applied estrogen did appear to decrease the risk of UTIs, Ascher-Walsh says doses used in Brown's study may not have been high enough to produce the same results.
The women in Brown's study took 0.625 milligrams of conjugated estrogen, plus 2.5 milligrams of medroxyprogesterone acetate.
The study appears in the current issue of the journal Obstetrics and Gynecology.
What To Do
To learn more about treatments for chronic UTIs, visit The Urology Channel. Or check the National Kidney and Urologic Diseases National Clearinghouse.
For more information on HRT, visit the National Institute on Aging.
