Benefits of Hormone Replacement Therapy Questioned
by JoAnne Lagendyk
Recent studies on the risks and benefits of HRT (hormone replacement therapy) may cause women to think twice before they opt for hormones to deal with menopausal complaints.
While women have turned to HRT for relief of menopausal hot flashes and sexual dysfunction, their doctors have been more interested in HRT’s reputed ability to prevent heart disease and osteoporosis. Until now, medical practitioners justified the increased risk of breast cancer posed by HRT by citing increased protection against both osteoporosis and heart disease.
However, several recent studies have cast doubt on the protective qualities of HRT. A U.S. study of 25,000 women taking HRT has found that, far from protecting the heart as many researchers had assumed, the therapy may have put the women at a slightly higher risk of heart attacks and strokes.
The study, known as the “Hormone Replacement Therapy Trial” of the Women’s Health Initiative, is the first large-scale controlled clinical trial to question whether HRT prevents heart disease in healthy post-menopausal women. (Other studies have looked at women already suffering from heart disease.) Researchers found that the women taking HRT were having slightly more heart attacks, strokes and blood clots in the lungs than those who had been assigned to the control group.
These results mirror those of the HERS (Heart and Estrogen-progestin Replacement Study) which were released 2 years ago. In this study, four years of HRT failed to lower the risk of new heart attacks in women who already had heart disease.
In March 2000, yet another study confirmed these findings. Dr. David Herrington of Wake Forest University Baptist Medical Center in Winston-Salem, N.C. studied 309 older women with heart disease who were randomly assigned to Premarin (an equine based oral estrogen), Prempro (an estrogen-progestin combination) or a placebo. After four years, doctors measured their heart arteries and found no difference in the progression of their disease.
How did HRT get the reputation of preventing heart disease?
Dr. Kerstin Rödström from Gothenburg University and colleagues report that women who used HRT were at a lower risk of cardiovascular problems before they started their treatment than women who did not use HRT.
The study looked at 1201 women over a 24-year period and found that 14.9% of them used HRT at some point during that period. Before the start of their treatment, these women, say the authors, had significantly lower blood pressure, were less obese and belonged to a higher social group than the women who did not use HRT.
Previous Studies Flawed
The researchers noted that over the last thirty years, many studies have reported how postmenopausal HRT reduced death from cardiovascular disease - some indicating an almost 50% reduction in risk. Based on their findings, the authors think that prior studies that showed beneficial effects of HRT during menopause were flawed by the pre-existing differences in the health of users as opposed to non-users.
The team found the women most likely to use HRT were less obese, had lower blood pressure, better access to health care and were in a higher socio-economic group than women who did not use HRT. In other words, rather than HRT making women healthy, healthier (and wealthier) women tend to take HRT.
Cancer Risk Increases with Length of Use
It has been acknowledged for some years that, for women with an intact uterus, using estrogen alone enormously increases the risk of developing endometrial cancer. Now, a new four-year, case-controlled study¹ of 1,025 women, 48 years of age and older, directed by Dr. Meera G. Jain of the University of Toronto has reported that extended use of combined estrogen/progestin also increases the risk of endometrial cancer. Until Dr. Jain’s results are confirmed in additional studies, it would be prudent for any woman on HRT to be monitored annually using vaginal ultrasound.
Researchers at the National Cancer Institute in Rockville, Md., followed more than 46,000 postmenopausal women and found that those who had taken HRT in the previous 4 years had a risk of developing breast cancer 40% higher than that of women who did not use HRT².
Dr. Meir Stampfer, a professor of epidemiology and nutrition at Harvard University’s School of Public Health in Boston, said that the study’s important message is that the risk of breast cancer increases with each year of HRT use. A decade of estrogen-progestin therapy use can increase a postmenopausal woman’s risk of breast cancer by 80 per cent, he said.
“For short-term use [two to three years], there is not a great risk,” said Dr. Stampfer, who co-wrote an editorial about the research in Journal of the Amercian Medical Association.
HRT was also thought to prevent the gradual loss of bone density (osteoporosis) that occurs beginning at menopause. Women with osteoporosis stand a greater chance of fracturing their hips, which can have devastating consequences.
However, an on-going study³ of women in Framingham, Mass. reported back in 1993 that HRT preserves bone density only while it is being taken. Once the therapy is stopped, bone loss begins. The study showed that, 10 years after stopping HRT, the bone density of women who took hormones and those who did not was virtually identical. Most women begin HRT around age 50, but since most hip fractures occur around the age of 80, the protection against hip fracture can only be maintained by 30 or more years of continuous HRT. Taking HRT for this period of time is now considered risky in terms of breast cancer.
So what is a woman to do?
The vast majority of women in our society experience menopause as a nuisance but are rarely incapacitated. They should think twice before accepting HRT to protect their hearts and bones. A safer way to prevent heart disease and osteoporosis is to eat a healthy diet, quit smoking and perform weight-bearing exercise every other day.
For those women who find that menopause negatively affects their quality of life, a short-term course of HRT might be considered. Once the HRT has taken effect, other possibilities can be explored: there are non-hormonal remedies for almost every menopausal complaint. Generally speaking, attention to diet, including increased consumption of fruits and vegetables, a reduction in alcohol intake, and perhaps the addition of soy-based foods (phytoestrogens) and natural remedies are all worthy of consideration.
- “Hormone replacement therapy and endometrial cancer in Ontario, Canada”, Journal Of Clinical Epidemiology, Vol: 53, Issue 4, April 2000
- “Menopausal Estrogen and Estrogen-Progestin Replacement Therapy and Breast Cancer Risk”, Journal of the American Medical Association, Vol. 283 No. 4, January 26, 2000
- New England Journal of Medicine, Vol. 329, No. 16, October 14, 1993