Timing Key in Hormone Heart Risk
Study: Hormone Therapy May Help Younger Women, Harm Older Ones
April 3, 2007 - Hormone therapy may not pose heart risks for all women, a
new report shows.
Starting hormone therapy within 10 years of menopause does not increase a
woman’s risk for heart disease, according to a new analysis from the trial that
first alerted women to the treatment’s potential health risks.
There was even a suggestion of a reduced risk of heart disease among women
under 60 who took estrogen or estrogen plus progestin, but the association
could have been due to chance.
Researchers from the National Heart, Lung, and Blood Institute (NHLBI)
revisited earlier data from the Women’s Health Initiative (WHI) in an effort to
determine if the cardiovascular impact of hormone therapy varied by age or
years since the beginning of menopause.
Benefit and Harm
Millions of women abandoned hormones following a WHI report five years ago
suggesting an increased risk of heart disease, stroke, breast cancer, and blood
clots among older study participants taking estrogen and progestin, compared
with women who didn’t take hormones.
The risks have been less clear for women in their late 40s and 50s, who take
hormones primarily for hot flashes and other menopause symptoms and are at low
risk for heart disease.
In their new report, published Wednesday in TheJournal of the
American Medical Association, NHLBI researchers for the first time combined
data from the Prempro (estrogen plus progestin) and the Premarin (estrogen
alone) arms of the WHI.
The combined analysis confirmed a very different heart disease risk profile
among women who take hormones around the time of menopause and those who take
them later in life, WHI project officer Jacques Rossouw, MD, tells WebMD.
“With regard to coronary heart risk we saw evidence, although it was not
conclusive, that hormone therapy may benefit younger women and harm older
women,” he says.
The researchers found no increased risk of heart disease among women who
begin hormone therapy within 10 years of the onset of menopause. Taking
hormones 20 or more years after menopause or taking them after age 69 was
associated with increased heart risk.
The findings should reassure younger women taking estrogen or estrogen plus
progestin to treat hot flashes, night sweats, and other menopausal symptoms,
American Heart Association spokeswoman Anne L. Taylor, MD, tells WebMD.
Taylor is professor of medicine and cardiology at the University of
Minnesota Medical School.
“The recommendation has been to take the lowest effective dosage of hormones
for the briefest duration possible, but that didn’t really tell women much,”
Taylor says. “This study adds a time element by telling us that [heart disease]
risk is not increased in the first 10 years of use for women who start
treatment before reaching menopause.”
Stroke Risk Higher
The new analysis showed an increase in stroke risk among women in the WHI
trials taking hormones, compared with those on placebo, regardless of age. The
increase was not seen in women under 60 taking estrogen alone, however.
The combined data showed a 32% overall increase in stroke risk that was not
influenced by years since menopause, Rossouw says.
He adds that women on hormone therapy should have their blood pressure
checked regularly, regardless of age, and they should have regular
Estrogen plus progestin, but not estrogen alone, was linked to an increased
risk for breast cancer in previous WHI trials.