News release on the Federally Funded HERS study
Study Questions Estrogen-Heart Link
By DANIEL Q. HANEY, AP Medical Editor
ANAHEIM, Calif. (AP) -
Challenging a medical doctrine that has stood for two decades, a study
found no evidence that estrogen
supplements protect older women from heart disease.
The findings are
likely to confuse doctors and patients alike about the already complicated
decision of whether to take estrogen
for many years after menopause. Estrogen has both benefits and risks, including an increased chance of breast cancer.
The latest
research, released Monday, is the second major study to question the
doctrine that hormone replacement is a powerful
way to ward off heart disease, the leading killer of older women.
That belief has been a centerpiece of women's health
care since the 1980s and has helped make the estrogen pill Premarin the
most widely prescribed medicine in the United States.
Many doctors think estrogen
helps the heart largely because it seems to improve cholesterol levels
after women go through menopause. The pills lower total cholesterol and
``bad'' cholesterol, while raising ``good'' cholesterol. Doctors assume
these
changes translate into less heart disease, even though no experiments definitively prove this.
The first to put the idea to the test was the
landmark Heart and Estrogen-progestin Replacement Study - HERS - finished
two years ago. Its conclusion shocked doctors: Four years of treatment
with combination estrogen and progestin pills failed to lower
the risk of new heart attacks in women who already had heart disease.
While some physicians
immediately stopped putting their elderly heart patients on long-term
hormone replacement, many others
have simply refused to believe the results.
The
latest report backs up HERS' disturbing conclusion. It studied
post-menopausal women with heart disease to see if hormone replacement
slows the buildup of fatty deposits in their heart arteries, the major
underlying cause of heart attacks. It, too, found no
benefit from hormones.
``These results
are indeed somewhat surprising in view of the large body of evidence
indicating that estrogen does have a favorable effect on cholesterol and
heart disease,'' said the study's director, Dr. David Herrington of Wake
Forest University
Baptist Medical Center in Winston-Salem, N.C.
``We can't say for certain
there is no benefit, but we can rule out a large effect,'' he said.
Herrington presented the results in
Anaheim at the annual scientific meeting of the American College of Cardiology.
The results are unlikely to settle the question.
Dr. Sidney Smith of the
University of North Carolina, a spokesman for the American Heart
Association, noted that neither HERS nor the latest study shows whether
hormone replacement helps if begun early in menopause or before women
develop heart
disease.
The answer to those questions should come from the
federally sponsored Women's Health Initiative, which is examining the
effects
of hormone replacement on more than 27,000 women ages 50 to 79. The first results are expected in about five years.
Weighing the risks and
benefits of estrogen is already complex. Many women use it for a few years
to relieve hot flashes and other ill effects of menopause. Others stay on
the hormone for many years to improve cholesterol levels and to prevent
brittle bones and
vaginal changes, even though the treatment can also increase the risk of breast cancer.
Now doctors are clearly confused and divided over
what to expect from estrogen on the heart. However, many agree that even
if the hormone proves to be good, its benefit is unlikely to be as large
as that of statin drugs, which clearly lower cholesterol and
save lives.
In Herrington's
study, sponsored by the National Institutes of Health, 309 older women
with heart disease were randomly assigned to Premarin, the
estrogen-progestin combination Prempro or dummy pills. After four years,
doctors measured their heart
arteries and found no difference in the progression of their disease.
Dr. Marion Limacher of the University of Florida said
that until recently, she routinely recommended estrogen supplements for
older women with heart disease. Now she takes them off hormone replacement, largely as a result of HERS.
Nevertheless, she said, ``some doctors discount HERS as flawed or not to be believed.''
However, Dr. Michael H. Davidson of the Chicago
Center for Clinical Research said estrogen may still turn out to be good
for
many women's hearts. He presented evidence that estrogen plus a statin lower cholesterol more than does a statin
alone.
``We have several years to
go before we know which women will benefit from hormone replacement
therapy and which ones
should avoid it,'' Davidson said.