| Additional Analyses from the
Women’s Health Initiative
Effect of Hormone Therapy on Risk of Heart Disease May Vary by
Age and Years Since Menopause
Secondary analyses of findings from the Women’s Health Initiative
(WHI) suggest that women who begin hormone therapy within 10 years
of menopause may have less risk of coronary heart disease (CHD)
due to hormone therapy than women farther from menopause. Overall,
hormone therapy did not reduce the risk of CHD. However, the farther
a woman was from the onset of menopause when she began hormone
therapy, the greater her risk of CHD due to hormone therapy appeared
to be. Although these findings did not meet statistical significance,
they suggest that the health consequences of hormone therapy may
vary by time from menopause.
These findings are consistent with the primary publications from
the WHI trials of estrogen plus progestin and estrogen-alone (total
of 27,347 participants) in showing no overall benefit for CHD,
and in suggesting that risk due to hormones may differ depending
on age or years since menopause.
“Postmenopausal Hormone Therapy and Risk of Cardiovascular Disease
by Age and Years Since Menopause,” will be published in the April
4 issue of the Journal of the American Medical Association.
In a secondary analysis, scientists reanalyze previously collected
data and findings in an effort to clarify or ask new questions.
In the case of this latest WHI analysis, the authors combined the
data from the two trials to explore in more detail the previously
observed trends in hormone effects by distance from the menopause.
Differences in hormone therapy effects were examined in three age
categories (50 to 59, 60 to 69, and 70 to 79) or in years since
the onset of menopause (less than 10, 10 to 19, and 20 or more).
The Women’s Health Initiative and the newly published analyses
are funded by the National Heart, Lung, and Blood Institute of
the National Institutes of Health.
The analyses also suggest that the increased risk in heart disease
due to hormone therapy in older women is primarily in those who
also have hot flashes and night sweats. Study participants who
had these symptoms were more likely to have risk factors for CHD
such as high blood pressure or high blood cholesterol, but it was
not clear whether this explained their higher risk on hormone therapy.
Other results from the analyses of the combined trials include:
- Confirmation that hormone therapy increases the risk of stroke
and this risk does not appear to be influenced by age or time
- Even in women within 10 years of menopause, there appears to
be an increased risk of breast cancer in women taking estrogen
with a progestin
- There was a trend (not statistically significant) towards reduced
risk for death associated with hormone use in younger compared
to older women.
WHI is a major 15-year research program designed to address the
most frequent causes of death, disability and poor quality of life
in postmenopausal women -- cardiovascular disease, cancer, and
osteoporosis. Both the estrogen plus progestin and estrogen-alone
trials of the WHI were stopped early because of increased health
risks and the failure to prevent heart disease. Specifically, the
estrogen plus progestin trial was stopped after 5.6 years because
of an increased risk of breast cancer and because overall risks,
including increased risks for heart attack, stroke, and blood clots,
outnumbered benefits. The estrogen-alone study was stopped after
6.8 years because of an increased risk of stroke and no reduction
in risk of CHD. The estrogen-alone study also found an increased
risk of blood clots.
Jacques Rossouw, M.D. chief of the Women’s Health Initiative Branch
at NHLBI, and lead author of the study, is available to comment
on the implications of the new study for women considering hormone
therapy at different ages. He will note that the findings may be
somewhat reassuring to younger women considering hormone therapy
for short term relief of symptoms, but do not change the current
recommendation that hormone therapy should not be used at any age
for prevention of CHD. Women considering hormone therapy should
have risk factors such as blood pressure and blood cholesterol
measured and managed, and have regular mammograms. Dr. Rossouw
can comment on the need for additional research to explore the
overall findings and the finding regarding night sweats and hot
To schedule interviews with Dr. Rossouw, contact the NHLBI Communications
Office at 301-496-4236 or e-mail email@example.com.
Part of the National Institutes of Health, the National Heart,
Lung, and Blood Institute (NHLBI) plans, conducts, and supports
research related to the causes, prevention, diagnosis, and treatment
of heart, blood vessel, lung, and blood diseases; and sleep disorders.
The Institute also administers national health education campaigns
on women and heart disease, healthy weight for children, and other
topics. NHLBI press releases and other materials are available
online at: www.nhlbi.nih.gov.
The National Institutes of Health (NIH) — The Nation's
Medical Research Agency — includes 27 Institutes and
Centers and is a component of the U.S. Department of Health and
Human Services. It is the primary federal agency for conducting
and supporting basic, clinical and translational medical research,
and it investigates the causes, treatments, and cures for both
common and rare diseases. For more information about NIH and
its programs, visit www.nih.gov.