Years after a large study on hormone replacement therapy revealed health risks among older women using it to prevent chronic disease, the number of women who take hormones continues to decline, according to a new study.
The researchers found that in 2009 and 2010, less than 5% of postmenopausal women over age 40 were using either oestrogen alone or oestrogen and progestin, compared to about 22% in 1999 and 2000.
Decline is understandable
Dr JoAnn Manson at Harvard Medical School, a leader of the Women's Health Initiative (WHI) research, said the decline is appropriate.
The WHI reported in 2002 that taking oestrogen plus progestin appeared to increase the risks of stroke, heart disease and breast cancer.
"We now understand that women more distant from the onset (of) menopause and at increased risk of cardiovascular disease have adverse outcomes on hormone therapy and that hormone therapy should not be used for prevention of heart disease or prevention of chronic disease because it is associated with some risks," said Dr Manson, chief of preventive medicine at Brigham and Women's Hospital.
The latest report is published in Obstetrics & Gynecology. Based on survey responses from more than 10 000 women, the authors saw a steady drop, supporting the results from other studies that have assessed short-term impacts of the WHI.
Dr Brian Sprague, the lead author of the current study and a professor at the University of Vermont, and his colleagues found that as the years progressed, fewer and fewer women reported taking hormones.
"From this study we have no way of teasing out what's driving these changes," Dr Sprague said, adding that it's likely due to concerns from both women and their physicians about the health risks of taking hormones.
The increased breast cancer risk from hormone therapy was a major driver in turning people away from hormone therapy, said Dr Robert Langer, a WHI researcher who's currently the principal investigator at the Jackson Hole Center for Preventive Medicine in Jackson, Wyoming.
"I think it's a really substantial overreaction" to the harms that were found in the Women's Health Initiative (WHI) study, Dr Langer said.
The WHI found that eight additional women out of every 10000 would get breast cancer, an increased risk of 26%.
But he said those results applied to older women taking hormones to prevent chronic disease, not necessarily to younger women seeking relief from menopausal symptoms.
"The pendulum may have swung too far in the direction away from hormone therapy use," Dr Manson said.
She said it's possible that concerns over the health risks of hormone therapy may be preventing women from getting relief from symptoms.
"In a younger woman who has hot flashes, night sweats, and impaired quality of life, it is very likely that the benefits of short term hormone therapy will outweigh the risks," she said.
After the initial findings in 2002, subsequent studies - both from WHI data and other trials - have tried to clarify the health risks of hormone therapy for different age groups.
For younger women closer to menopause, for instance, some studies have found an increased risk of breast cancer while others have found a lower risk of heart disease and death compared to women not taking hormones.
Dr Manson is part of an ongoing trial looking at the effects of hormone therapy on heart disease risk for women ages 42 to 58 - a younger age group on average than the WHI.
Another ongoing study is comparing the heart disease risks among women who begin taking hormone therapy soon after menopause or more than a decade later.
(Reuters Health, August 2012)