MONDAY, Aug. 27, 2001 (HealthDayNews) -- A new twist on using estrogen to treat Alzheimer's disease in women has once again added torque to the ongoing debate over how useful the female hormone is in treating the incurable brain ailment.
That twist is the use of a single type of estrogen in high doses via a skin patch. Researchers say that three-way combination has never been tested on Alzheimer's patients before, and the results surprised them.
"All of the women experienced a significant increase in a variety of cognitive functions, such as memory and attention span," says lead investigator Dr. Sanjay Asthana, associate professor of medicine at the University of Wisconsin School of Medicine.
While the results of his 20-woman, short-term study are similar to other small-scale studies, more recent, large-scale studies have found that estrogen hormone therapy had no effect. However, Asthana says the factors that set his study apart from others may be what accounts for the big difference in results.
"What made our study different was that, first, we used very high doses of estrogen, and we used only a particular type of estrogen -- estradiol," says Asthana.
"We also believe that the delivery system, which was a patch, was also important because it offered the women a slow but steady flow of estrogen, which is much different from the effects you get when you have peaks and valleys associated with oral dosing," he says.
The study was partly funded by Novartis Pharmaceuticals, the makers of Estrace, the estrogen patch used in the study.
While another Alzheimer's research expert says she's intrigued by Asthana's findings, she says larger studies are needed to verify the new findings.
"It is important to realize that even within the context of this study, there are multiple comparisons and only a few of the tests show efficacy, so this does suggest that doing a larger, multi-center study looking at estradiol and patch formulations is warranted," says Mary Sano, associate professor of clinical neuropsychology at Columbia University.
In addition, Sano cautions that "higher doses of estrogen have other problems associated with them, and I'm not sure that long-term use is realistic." Those problems include increased risk of breast cancer and cancer of the uterine lining, she says.
The new, eight-week study focused on 20 women diagnosed with Alzheimer's disease at the Geriatric Research, Education and Clinical Center, at the Veteran Affairs Hospital in Seattle, Wash.
At the start of the study, a variety of tests documented attention skills, as well as verbal and visual memory and the women's ability to recognize common items featured in pictures. Asthana says the tests were somewhat different and more complex than those used in other studies, and that also may have played a role in the positive results.
Half the women then received a patch containing high concentrations of estradiol, while the other half received a placebo. Eight weeks later, the cognitive tests were given again.
The results, published in tomorrow's issue of the journal Neurology, found attention span improved 20 percent or more in women using the estrogen patch, while some verbal and visual memory increased up to 35 percent. Memory linked to pictures improved about 10 percent.
However, the length of the research -- just two months -- may be the study's Achilles' heel.
"In previous research, gains were often seen in the first eight weeks, but then those gains were lost as time went on, even when the estrogen therapy was continued," says Sano.
The idea that estrogen could help Alzheimer's patients was born from the fact that women patients outnumber men three-to-one. Estrogen levels drop drastically after menopause, and since Alzheimer's is a disease generally of old age, researchers assumed a connection.
How or why estrogen may help is a mystery, though researchers have some theories.
"One idea is that it affects the brain chemistry involved in helping cells communicate," says Asthana.
Sano says another theory is that estrogen may affect levels of amyloids, protein deposits associated with tissue degeneration in the brain of Alzheimer's patients.
What To Do
Sano and her colleagues are looking for healthy women over age 65 with a family history of Alzheimer's to take part in a nationwide study to measure the protective effects of more moderate levels of estrogen therapy on the incidence of Alzheimer's.
To learn more about the study, or find to a participating medical center near you, call (877)-DELAYAD or visit its Web site.
For more information on Alzheimer's disease, including the latest research on a variety of treatment options, visit the Alzheimer's Association.
