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| Drugs->Hormones: Menopausal Hormones |
Unlike other hormones described in this series of fact sheets, many large, reliable, long-term studies of estrogen and its effects on the body have been conducted. These studies suggested that estrogen could provide many important benefits.
Based on this early research many women were advised to take supplements of estrogen to relieve the symptoms of menopause and to reduce their risk of osteoporosis and heart disease.
But estrogen also is a good example of why it is important to wait until researchers have discovered both the benefits and risks of a hormone supplement before it becomes widely used. While some women are helped by estrogen during and after menopause, others are placed at higher risk for certain diseases if they take it.
As research yields new information about this hormone, women and their doctors continue to reevaluate their thinking about who should take estrogen supplements and who should not.
For many women, the helpful effects of estrogen might outweigh the possible harmful effects when taken relatively briefly around the time of menopause. Estrogen supplements decrease hot flashes and vaginal dryness, and lower the risk for osteoporosis, a bone-thinning disease that often disables older people. Estrogen therapy also may improve mood and psychological well-being.
Yet for all of its promise, estrogen supplementation also has raised a number of serious concerns because some harmful effects are more likely to occur in certain women. For example, estrogen is associated with an increased risk of cancer of the uterus among women who have not had a hysterectomy. To counteract this risk, a woman with a uterus is advised to take progestin, a synthetic form of the hormone progesterone, with their estrogen.
Using estrogen alone or with progestin is called menopausal hormone therapy (MHT). Early studies suggested menopausal hormone therapy could lower the risk for heart disease (the number-one killer of women in the U.S.) in postmenopausal women. But subsequent research now suggests that such therapy might actually elevate some women’s chances of developing this disease.
Menopausal hormone therapy also increases a woman’s risk of getting blood clots, which can block circulation in arteries and could lead to heart attack or stroke.
In 2002, an important study of menopausal hormone therapy by the Women’s Health Initiative, which is funded by the National Institutes of Health, was stopped after 5.2 years because serious health concerns arose. The investigators found that among every 10,000 women taking a combination of progestin and estrogen, there would be:
- 8 more cases of breast cancer than in women not using any hormones, which translates into a 26 percent increased risk,
- 7 more cases of heart disease (a 29 percent increased risk),
- 8 more cases of stroke (a 41 percent increased risk), and
- 8 more women who developed blood clots in their lungs, which is twice the rate occurring among women not taking any hormones.
But there also would be health benefits:
- 5 fewer cases of hip fracture (a 34 percent reduced risk), and
- 6 fewer cases of colorectal cancer (a 37 percent reduced risk).
The study was stopped early because the experts believed that by that time the health risks were greater than the health benefits. These risks are still small ones for an individual woman, but it is an important public health issue.
The portion of the study looking at hysterectomized women using only estrogen without progestin did not find similar risks, so it will continue.
Some studies suggest that estrogen may protect against Alzheimer's disease, but this has not yet been proven. In fact, in 2003 a related study, the Women’s Health Initiative Memory Study, reported that women age 65 and older taking a combination of estrogen plus progestin were at twice the risk of developing dementia as women not taking any hormones.
This means that every year there would be 23 additional cases of dementia in 10,000 women 65 and older taking these hormones compared to 10,000 women the same age not taking any hormones (a 105% increased risk).
As with the larger Women’s Health Initiative trial, the estrogen alone portion of this study is continuing.
So the decision whether to take estrogen is now far more complex and difficult. Although researchers have studied estrogen for many years, numerous questions about this hormone—once thought answered—are reemerging.
Before choosing this treatment, each woman, with the guidance and advice of her doctor, should weigh the pros and cons of menopausal hormone therapy and make an informed choice based on a realistic assessment of her personal risks and benefits.
Keep in mind that even after years of intense study, researchers continue to discover information about the benefits and risks of these menopausal hormones. As these new findings emerge, women and their doctors may have to frequently reassess their decisions about these supplements.
Many Questions, Few Answers
The NIA sponsors many research projects that will reveal more about the risks and benefits of hormone supplements. One goal is to determine whether DHEA, melatonin, and other hormonal supplements improve the health of older people, have no effect, or are actually harmful.
It is important to remember that these studies may not give immediate or final answers, especially in the cases of DHEA, melatonin, and hGH, since research on these supplements is fairly new. For example, some of the studies may simply give researchers more information about what kinds of questions they should ask in their next studies.
Research is a step-by-step process, and larger studies may be needed to give more definitive answers.
Until more is known about DHEA, melatonin, and hGH, consumers should view them with a good deal of caution - and doubt. Despite what advertisements or stories in the media may claim, hormone supplements have not been proven to prevent aging. Some harmful side effects already have been discovered, and further research may uncover others.
More is known about estrogen and testosterone, and people who are concerned about genuine deficiencies of these hormones should consult with their doctors about supplements. Meanwhile, people who choose to take any hormone supplement without a doctor's supervision should be aware that these supplements appear to have few clear-cut benefits for healthy individuals, and no proven influence on the aging process.
<==Can Hormones Prevent Aging? | What is a Hormone? | Heed The Warnings | How Hormones Work | DHEA | Growth Hormones | Melatonin | Testosterone | Menopausal Hormones==>
SOURCE:
For more information, contact the:
National Institute on Aging
U. S. Department of Health and Human Services
Public Health Service
National Institutes of Health
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