Flaws Seen in Major U.S. Study on HRT
New study finds therapy may still benefit younger women
MONDAY, June 28, 2004 (HealthDayNews) -- A major U.S. government trial whose findings prompted many women to drop hormone replacement therapy (HRT) was fundamentally flawed, claims a critical new study.
Because most of the participants in the trial were older women, HRT may still prevent heart disease and ease menopausal symptoms in younger women, says new research from Yale University that appears in the June issue of Fertility and Sterility.
The combination estrogen-progestin part of the Women's Health Initiative (WHI), a 15-year research program on postmenopausal women, was abruptly halted in July 2002 after participants in that trial showed an increased risk of heart disease, breast cancer and stroke. Last year, the memory portion of the WHI was stopped because there was an increased risk of dementia in women over 65. This spring, the estrogen-only arm of the trial was also cut short after research showed the hormone appeared to increase stroke risk and did not help lower heart attack risk. All the risks, and the publicity on them, have led millions of women to question using HRT.
A lot of criticism of the WHI trials, both past and present, has revolved around the age of the participants. The age range of the women was from 50 to 79, with the average age being 63.
As a result, most of these women may have had the beginnings of heart disease when the trial started, which made the trial fundamentally unable to test the hormones for primary prevention, said study author Dr. Frederick Naftolin, director of the Center for Research in Reproductive Biology at Yale University School of Medicine.
The Yale findings were backed by other experts who repeated earlier criticism that the WHI study simply didn't have enough of a younger age group to make it relevant to menopausal women.
"It did not have sufficient power to say anything," said Dr. Richard Grazi, director of reproductive endocrinology at Maimonides Medical Center in New York City.
"The WHI was not a study about menopause," noted Dr. Wulf H. Utian, executive director of the North American Menopause Society. "It was designed to try and confirm what the observational data suggested, that heart attacks could be prevented by using these hormones. Because they had to have enough heart attacks to get statistical significance, they had to go with the group that had the highest prevalence of heart attacks -- and that was older women."
"Clearly, some of the conclusions of the WHI do stand -- that combined continuous hormones do slightly increase the risk of breast cancer when used for more than five years, they do not reduce the incidence of heart attacks, they do increase the risk of strokes," he said.
But Utian stressed these findings cannot be extrapolated to all groups of women.
At the National Heart, Lung, and Blood Institute, which ran the WHI trials, a spokesperson would only say, "The key issue here appears to be the ages of the subjects, and we've always tried to stress that the results of the WHI were regarding women aged 50 to 79. We don't have anything more to say in that regard."
Given all the back-and-forth on the therapy's safety and effectiveness, what should a younger woman experiencing menopausal symptoms think of when considering HRT?
"They should consider small, increased levels of risk or increased levels of benefit along with potentially death-causing disease, but it's the day-to-day quality of life that is really the most important issue -- and quality of life is not well evaluated in any of the most recent studies," Utian said.
Naftolin, meanwhile, is part of a new research group that hopes to answer the question of whether hormones reduce the risk of heart disease when given to menopausal women.
The researchers plan to randomize women aged 50 to 54 to receive hormones or a placebo and then measure, over a period of five years, the thickness of the blood vessels, an indication of heart disease.
"Hormone therapy isn't for everybody. It's not necessary for everybody, and in some cases it might be harmful," Naftolin said. "But like every other therapy, people who have certain categories of disease should be entitled to have consideration of every possible therapy."
For more on the Women's Health Initiative, visit the National Heart, Lung, and Blood Institute.