Timing Key in Hormone Heart Risk

Study: Hormone Therapy May Help Younger Women, Harm Older Ones

Medically Reviewed by Louise Chang, MD on April 03, 2007
From the WebMD Archives

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 mammograms.

Estrogen plus progestin, but not estrogen alone, was linked to an increased risk for breast cancer in previous WHI trials.

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SOURCES: Rossouw, J. TheJournal of the American Medical Association, April 4, 2007; vol 297: pp 1465-1477. Jacques E. Rossouw, MD, Women’s Health Initiative Branch, National Heart, Lung, and Blood Institute, Bethesda, Md. Ann L. Taylor, MD, professor of medicine and cardiology, University of Minnesota Medical School. Lila Nachtigall, MD, New York University School of Medicine, New York City.

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