The new findings suggest a possible estrogen benefit for women in their 50s, but experts say it's too early to recommend hormones to help the heart.
The study also confirmed previous findings that estrogen treatment does not protect older, postmenopausal women against heart disease.
In March 2004 researchers stopped an estrogen study due to concerns about an increased risk of stroke among older women taking the hormone. Researchers later reported that long-term treatment may be associated with an increased risk of blood clots and dementia.
In July 2002 researchers stopped a study of women taking both estrogen and progestin after long-term use of the combination hormone treatment was linked to an increased risk of heart disease, stroke, and breast cancer among older women.
'Suggestion' Of Protection
The new study looked at nearly 11,000 women aged 50 to 79 years taking only estrogen. Women who have not had a hysterectomy must take progestin along with estrogen. Taking estrogen alone increases the risk of uterine cancer.
Researchers reported no overall difference in heart attack risk among women who took the hormone and those who did not.
But there was a suggestion of less heart disease with estrogen use among women who began taking the hormone between the ages of 50 and 59.
The findings are reported in the latest issue of the Archives of Internal Medicine.
Pluses And Minuses
Researcher Judith Hsia, MD, says there were far too few women in their 50s in the study to confirm that early estrogen use protects the heart. Most women were in their 60s and 70s when they entered the study.
"This should not be taken as a recommendation that any woman should take hormones to protect against heart disease," she tells WebMD. "The only reason to take estrogen at this point is for menopausal symptoms, and women considering the therapy need to weigh the risks and benefits carefully."
On the plus side, hormone therapy is the most effective treatment for hot flashes and other menopausal symptoms, and it has been shown to help prevent osteoporosis, she says.
On the minus side, findings suggest an increase in risk for strokes, blood clots, and dementia among long-term estrogen users.
But ob-gyn Isaac Schiff, MD, tells WebMD that there is intriguing evidence that the risks associated with estrogen and estrogen-plus-progestin may be limited to women who start taking the hormones later in life.
Schiff is chief of obstetrics and gynecology at Massachusetts General Hospital in Boston. He also chaired the American College of Obstetricians and Gynecologists (ACOG) task force on hormone therapy.
In a 2004 report, the task force concluded that hormone estrogen, or estrogen-plus-progestin, should be used for the treatment of menopause-symptoms only in the "smallest effective dose for the shortest possible time."
Schiff says many of his patients have told him that they feel better taking hormones and want to continue taking them.
"There was a lot of anxiety three or four years ago that taking hormones early in menopause would increase a woman's risk of developing heart disease," he says. "But this risk does not appear to be borne out. Some studies even suggest that the longer women are on hormones the better off they are if they start early enough."
He says the estrogen findings should be seen as reassuring to women considering hormone therapy to relieve hot flashes and other symptoms of menopause.
"We can now tell a woman in her early 50s who may have had her last period three months ago and has menopause symptoms that her risk of developing heart disease will not increase if she takes estrogen," he says. "That is the good news from this study."
Sources: Hsia, J. Archives of Internal Medicine, Feb. 13, 2006; Judith Hsia, MD, professor of medicine, George Washington University, Washington, D.C. Isaac Schiff, chief of obstetrics and gynecology, Massachusetts General Hospital, Boston; chairman, American College of Obstetricians and Gynecologists (ACOG) Task Force on Hormone Therapy.
By Salynn Boyles
Reviewed by Michael W. Smith, MD
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