Timing of HRT Key to Heart Benefit
Estrogen May Protect From Heart Disease, Stroke If Taken at Onset of Menopause
March 3, 2003 -- It turns out timing may be everything when it comes to hormone replacement therapy (HRT) and heart disease. A new review of the major research shows that taking estrogen around the time of menopause may protect against heart disease, but starting it later in life increases the risk.
The findings should reassure women who are worried that taking HRT for menopausal symptoms will increase their risk of heart disease. But the evidence is not strong enough to suggest that women take estrogen solely to protect their hearts.
"Recent clinical studies in older women have not refuted earlier studies suggesting a heart benefit for younger women," says researcher Richard H. Karas, MD. "The vast majority of women who are starting hormone replacement in this country are doing it around the time of menopause, and they have been unnecessarily scared to death about HRT."
Karas tells WebMD that news accounts of the widely reported Women's Health Initiative (WHI) gave the public the false impression that hormone replacement therapy increases the risk of heart disease and stroke in all women who take it. Findings from the study, released in July of 2001, led the American Heart Association (AHA) to advise doctors to stop prescribing the treatment for the prevention of heart disease.
Although the WHI findings showed an association between long-term hormone therapy and heart disease, stroke, and pulmonary embolism, most of the women in the study were well past the age of menopause. In their review, published in the winter issue of the journal Menopausal Medicine, Karas and colleague Thomas Clarkson, DVM, reviewed WHI and other major studies assessing heart disease risk in women taking hormone therapy.
"The literature demonstrates that HRT has beneficial effects in inhibiting the early stages of heart vessel disease but can have deleterious effects if initiated at older ages when some women have already developed disease," Clarkson says in a news release.
Clarkson's own studies in monkeys showed that animals treated with HRT at the onset of estrogen deficiency had a 70% inhibition in the arterial plaque buildup that leads to heart disease. No such benefit was seen when estrogen replacement was delayed following surgical menopause for a period equaling six years in women.