Feb. 16, 2010 -- Women who take combined hormone therapy for just a few years around the time of menopause appear to have no decrease in heart disease risk, new research suggests. If anything, their risk may go up slightly.
The analysis of data from the study that first linked hormone therapy to heart disease found that even in the first two years of use, treatment with estrogen plus progestin was associated with a small, but not statistically significant increase in heart risk when started within 10 years of menopause.
The number of menopausal women in the study who had heart attacks and strokes was quite small, however, and experts say the advice to those contemplating hormone therapy for the relief of hot flashes and other menopausal symptoms remains unchanged.
“Our findings are consistent with the current guidelines to use hormone therapy in the smallest doses for the shortest possible time for symptoms only,” lead researcher Sengwee Toh, ScD, of Harvard Medical School tells WebMD. “We found no evidence of a protective benefit in the early years of use.”
Hormone Therapy and the Heart
It is now well known that taking combined hormone therapy for many years is associated with an increased risk for heart attacks and strokes in older women who are well past menopause.
But it has not been clear if this risk extends to women who take hormones for just a few years around the time of menopause.
Some studies even suggest that short-term hormone therapy may actually be protective against heart disease in younger women.
In an effort to better understand the impact of combined hormone treatment on heart disease risk around the time of menopause, Toh and colleagues examined data from the widely publicized hormone therapy intervention trial known as the Women’s Health Initiative (WHI).
The WHI included more than 16,000 women, half of whom were randomized to receive combined estrogen plus progestin hormone therapy between 1993 and 1998. The other half of the group received placebos. In 2002, the hormone therapy arm of the trial was suspended because of increased rates of heart disease, breast cancer, and blood clots. Toh and colleagues looked more closely at the data to see if outcomes were influenced by the time span between menopause onset and start of hormone therapy.
Compared to women randomized to the placebo arm of the trial, women who commenced combined hormone therapy within 10 years of menopause had a slight increase in heart disease risk during the first two years of use, but this increase in risk did not reach statistical significance and was considered small.
Perhaps the more important finding was that there was clearly no evidence of a protective effect.
“The available evidence suggests that estrogen plus progestin therapy does not reduce the risk for coronary heart disease during the first 3 to 6 years of use in women who initiated therapy close to menopause,” Toh and colleagues write. “Because the typical duration of use of hormone therapy is short, most women contemplating estrogen plus progestin therapy for the relief of menopausal symptoms should not expect protection against heart disease.”
Is Today’s Hormone Therapy Safer?
Hormone therapy researcher JoAnn Manson, MD, who was a principal investigator for the WHI trial, tells WebMD that women taking hormone treatments today for menopausal symptoms may have a lower risk for treatment-related side effects than the women in the original trial.
That’s because the women who participated in the WHI intervention trial were taking much higher doses of estrogen than women typically take today and they took them for longer periods.
It is generally believed, but has not been proven in clinical studies, that the lower-dose hormone formulations widely used today are safer than the higher-dose formulations used a decade ago.
Many women now use a low-dose hormone patch, which has been shown to have a lower risk for blood clots.
“There is always a trade-off when you take any drug,” says Manson, who is chief of the division of preventive medicine at Boston’s Brigham and Women’s Hospital. “But it is important to point out that heart disease is not common in women around the time of menopause. Their risk is very low.”
Manson agrees with the current recommendation that women experiencing troubling menopausal symptoms take hormones in the lowest effective doses for the shortest duration possible.
She says most women should be able to discontinue treatment within two to four years.
North American Menopause Society Director Margery Gass, MD, says women with mild to moderate symptoms may find the relief they need with lifestyle modification and natural remedies.
“These things do work for many women,” she says.