Pros and Cons of Hormone Therapy:
Making an Informed Decision
KNOW THE RISKS FOR HEART DISEASE, OSTEOPOROSIS AND BREAST CANCER
Since hormone therapy has been prescribed to reduce the risk of heart disease and osteoporosis, but may possibly increase a woman's risk of breast cancer, it is useful to look at what things increase a woman's risks for heart disease, osteoporosis and breast cancer. The following pages can help you understand what increases your risks, what we know about hormones and what you may be able to do to reduce some of the risks for these diseases whether you take hormones or not.
HEART DISEASE
Heart disease affects women particularly after menopause, in part because declining estrogen levels exert less protective effect on the heart. A disease of advancing age, older women have a greater risk of heart disease and stroke. About 1/3 of Canadian women over 50 will eventually die of heart disease, about half of them before age 74. Until recently, research and treatments have tended to focus more on men, whose symptoms appear about a decade earlier. There is greater awareness now about what increases women's risk for developing heart disease, the symptoms women experience and the concerns they face.
What Increases a Woman's Risk for Heart Disease?
Risk factors you can't change
- Advancing age
- Early family history: a father or brother with heart disease before the age of 55; a mother or sister with heart disease before the age of 65
- Early menopause (before 40-45)
- South Asian and Black women are more at risk of heart disease than Caucasian women
Risk factors you may be able to change
- High blood pressure
- High cholesterol: A low level of HDL (good cholesterol) combined with a high level of triglycerides puts a woman at an especially high risk of death from heart disease.
- Diabetes — a more important risk factor for women than for men
- Smoking: the risk of heart disease is even greater in smokers who also use oral contraceptives.
- Inactive lifestyle
- Significantly overweight — although this may be very difficult to change especially at this time of your life
There are social and economic conditions that are risks for heart disease: women with low levels of education, low income and those employed in jobs over which they have little control are at greater risk. There is some data to link severe and prolonged stress with heart disease. Some of these risk factors can be changed by what we do or eat, or by certain medications. Others can't - such as age!
Hormone Therapy and Heart Disease
The Debate: Is HT Good for Heart Health?
For many years researchers believed that hormone therapy was beneficial for coronary health. Medical practitioners routinely prescribed hormone therapy to women as a preventative measure for heart disease.
However, several new studies have cast significant doubt on this practice. Recent research has found that there is no coronary health benefit for women with a history of heart disease who take estrogen alone, or estrogen plus a progestin. The studies suggest that there is even the possibility of an increased risk for heart disease.
Research in-progress has also found that women without a history of heart disease may also face an increased risk when taking hormone therapy.
What Available Research Tells Us…
- Nurses Health Study (NHS): Observational data from this study suggests that postmenopausal women who take estrogen or estrogen plus a progestin have a significantly reduced risk of heart disease.
Critics note:
- The participants (all nurses) are not representative of the general population and are more likely to have had a decreased risk for heart disease before taking hormone therapy.
- Women who take HT have been found to be more attentive to improving their diet and exercise and, thus, reducing their risk of heart disease through natural methods.
- The study is based on observation and self-reporting techniques and not the more reliable practice of a randomized, double-blind trial.
- Postmenopausal Estrogen/Progestin Intervention (PEPI): A randomized trial involving postmenopausal women with no history of heart disease. Researchers found that estrogen-alone therapy had a positive effect on cholesterol levels.
Critics note:
- The study size was small and the duration was too short to determine the effects of hormone therapy on heart disease.
- The Heart and Estrogen/Progestin Replacement Study (HERS):): A randomized trial that found
that HT did not decrease the overall risk of heart attack and coronary death among post-menopausal women who already had heart disease. Women on HT had more coronary events (including heart attacks and death) in year one of the study, and fewer events in years four and five of the study, than women taking the placebo. The effects balanced out so that the HT did not affect the overall rate of heart disease. Women on HT were three times more likely to have blood clots in the legs or lungs than women taking the placebo, and to have an increased rate of gallbladder disease.
Critics note:
- The results are relevant only to those women with a previous heart condition and not for healthy women on hormone therapy.
- Estrogen Replacement and Atherosclerosis (ERA): A randomized trial that involved participants with a history of heart disease. Researchers found that both estrogen-alone and combined therapy (estrogen and progesterone) improved cholesterol levels. However, the study found no improvement in risks for heart disease.
Critics note:
- The results are relevant only to those women with a history of heart disease.
- The Women's Health Initiative Study (WHI):The WHI study was forced to stop the part of the study that was looking at the effects of using estrogen and progestin together, due to serious side effects. The data showed that women on estrogen and progestin had an increase in heart disease of 29%, an increase in strokes of 41% and a large increase in pulmonary emboli (blood clots in the lungs).
Critics note:
- We do not know whether these same results would apply to different types of hormones or hormones that are taken through different routes (for example, patches, creams or gels)
What We Still Need to Know...
- Many studies have focused on the effects of estrogen alone and not on the combination of estrogen and progesterone. Adding progesterone for women with a uterus counters the greatly increased risk of endometrial cancer produced by estrogen alone. There is some indication that progestins may decrease estrogen's positive effects, but this remains to be seen.
Despite the complexity of contradictory studies, a few things have become clear to medical experts.
The Heart and Stroke Foundation of Canada has issued the following new recommendations for hormone therapy and heart health:
- Hormone therapy should not be prescribed to women who already have a history of heart disease.
- Hormone therapy should not be prescribed solely in order to reduce the risk of developing heart disease.
- Other non-medicinal measures can be undertaken to reduce the risk of heart disease, such as stopping smoking, becoming more active and reducing blood pressure and cholesterol levels.
To Help Reduce Your Risk of Heart Disease...
- Stop smoking: Cigarette smoking is the main preventable heart disease risk factor for women. It is a stronger risk factor for heart attack in middle-aged women than in men and the risk is 20 times greater in women who use oral contraceptives.
- Eat a healthy diet, low in fat and cholesterol. There is strong evidence showing that people who eat 5 or more servings of fruit and vegetables a day will likely have a lower incidence of heart disease.
- Consider vitamin E supplements (in the range of 200-800 i.u. daily), which may reduce the risk of heart disease. Check with your doctor before taking Vitamin E if you have high blood pressure or rheumatic heart disease or if you are taking blood thinners or blood pressure medications.
- Exercise regularly: aerobic exercise is particularly beneficial to the heart.
OSTEOPOROSIS
Osteoporosis, a condition of brittle bones resulting from gradual loss of normal bone structure and density, mainly affects post-menopausal women. Lower estrogen levels after menopause speed up bone loss, with the greatest loss happening in the first 5-6 years after the last period, and then declining more slowly. About 25% of North American women over 65 have osteoporosis, which can result in easily broken bones in the wrist, spine or hip. 1 in 6 women will break their hips, half by age 79; of those who do, 1 in 5 die from complications and about 5% become dependent on others for care.
What Increases a Woman's Risk for Osteoporosis?
Risk factors you can't change
- Advanced age
- A family history of osteoporosis (parent, sibling)
- Caucasian - Asian - fair skinned - small-boned
- Early menopause (before 40-45)
- Extended time without periods
- Certain diseases (hypothyroidism, chronic kidney disease, rheumatoid arthritis)
- Use of certain drugs (e.g. high doses of thyroid drugs, long-term use of steroids, anticonvulsants and others)
Risk factors you may be able to change
- Low bone density (determined by testing)
- Lack of exercise
- Diet low in calcium and Vitamin D
- Smoking
- High caffeine intake (more than 3-4 cups/day)
- Excessive use of alcohol
Unfortunately, evaluating risk factors detects only about 30% of women with osteoporosis. Even bone densitometry tests may not predict which women are at risk of having a bone fracture because of osteoporosis.
Hormone Therapy and Osteoporosis
What Available Research Tells Us...
- Research shows hormone therapy has a positive effect on bone mineral density and risk of spinal and hip fracture.
- Estrogen and progesterone have positive effects on bone formation and bone loss.
- In order to have a beneficial effect, long-term hormone therapy over 10 years is required.
- Estrogen's ability to preserve bone density appears to last only as long as women take the drug.
| Research shows... |
| Of 100 women (age 50) at average risk of osteoporosis and who do not take hormones, about 15 may suffer a hip fracture in their lifetime. If all 100 take long-term hormone therapy, 5 fewer may have a hip fracture. |
| Of 100 women (age 50) at high risk of osteoporosis who do not take hormones, 36 out of 100 women may break a hip in their lifetime. If the 100 women at high risk took hormones, 9 to 11 fewer women may break a hip.
|
What We Still Need to Know...
- It is not clear whether women benefit by starting HT immediately after menopause or later. A recent study indicates that women who did not start taking hormones until they were in their late 60s had about the same level of bone density by their 70s as those who started at menopause and never stopped.
- We don't know the effects of HT compared to a high calcium diet and regular weight-bearing exercise on bone density.
| You May Have Heard About Bisphosphonates... |
| New non-hormonal drugs, alendronate (Fosamax) and etidronate with calcium (Didrocal) have been approved in Canada specifically for osteoporosis. A category of drugs called bisphosphonates, they help reduce the *breakdown of bone and increase bone density. Further research is needed on long term use and effects. Ask your doctor if you need more information. |
To Help Reduce Your Risk of Osteoporosis...
- Maintain adequate levels of calcium (1500 mg/day for a woman not taking hormone therapy; or 1000 mg./day if on HT) and of vitamin D (200 i.u per day if under age 50; 400-600 i.u. per day if over 50).
- Exercise. Weight-bearing exercise is potentially the most effective strategy for preventing and treating bone mineral density loss and preventing fracture. Studies show the effect of regular exercise reduced the risk of hip fracture by about half. Exercise programs for elderly women can reduce falls and related injuries.
- Stop smoking, or try to cut down.
- Limit alcohol and caffeine.
- Prevent falls and fractures: not all fractures are associated with osteoporosis. Muscle strength and flexibility, a tendency to fall, hazards in the home, icy streets, all influence the chance of fracture. Falls are more common among elderly people using drugs such as antidepressants and sedatives and can be reduced by fewer medications. Proper lighting, railings, correct eyeglasses, can all help to prevent falls and fractures.
BREAST CANCER
Breast cancer, a disease of uncontrolled growth of abnormal cells in the breast, is more common among women as they age. 1 out of 10 North American women after age 50 will develop breast cancer, half by age 69. Of those who develop breast cancer, 3 out of 10 die within 10 years.
Some Concerns...
Breast cancer is of concern to women considering hormone therapy because:
- Some studies suggest that hormones used after menopause do increase the risk of breast cancer; others suggest they do not. When the studies were pooled together the data indicated no extra risk with short-term use (less than 3-5 years); and a 35% increased risk when hormones are used longer than 5 years or more.
- Data from 2 large studies in 2000 indicates that long-term use of progestins may contribute a higher risk for breast cancer than estrogen-alone therapy.
- Ø The Women's Health Initiative Study results showed a 29% greater risk of developing invasive breast cancer in healthy women on estrogen and progesterone.
| Research shows... |
| Of 100 women (age 50) at average risk of breast cancer who do not take hormones, about 10 may get breast cancer in their lifetime. If all 100 take long-term hormone therapy, 3 more may get breast cancer.
|
| Of 100 high risk women (age 50) who do not take hormones, 19 may get breast cancer in their lifetime. If all 100 take hormones, 6 more women may get breast cancer.
|
- There is growing concern among scientists and consumers that exposure to chemicals that act as "environmental estrogens," (called xenoestrogens - substances that mimic estrogens), including organochlorines used in pesticides, may contribute to increasing rates of breast cancer. Research remains inconsistent. The lower incidence of breast cancer in other parts of the world suggests that diet and environmental pollutants may play a role.
What Increases a Woman's Risk of Breast Cancer?
- Family history (mother or sister who develop breast cancer before menopause)
- Never bearing children
- Having first child after 30
- Previous breast biopsy showing abnormal cells
- Early 1st period (menarche) / late last period (menopause)
The majority of women diagnosed with breast cancer do not have these risk factors nor do they have genes for breast cancer.
To Help Reduce Your Risk of Breast Cancer...
- Ensure you have breast exams: Regular breast self-examination, professional breast exams yearly and mammograms every 2 years for women over 50 are recommended.
- Maintain a healthy diet: diets low in fat and high in fruits and vegetables, high in soy and other phytoestrogens are thought to have some protective effects against breast cancer. (See Handout on Phytoestrogens)
- Exercise: Recent studies suggest benefits of exercise for reducing the risk of breast cancer.
- Stop smoking, or try to cut down.
- Reduce exposure to environmental estrogens where possible.
| In Case You've Heard About SERMs... |
| Selective estrogen-receptor modulators (SERM), often referred to as "designer estrogens," are now coming onto the market. They are promoted to have the heart and bone protective benefits of estrogen without the risks of uterine and breast cancer. Studies have only been short term and measured bone density, not fracture, and improvements in blood lipids, not reductions in rate of heart attack and stroke. These drugs do not improve hot flashes. These new developments may be promising, but need to be carefully watched. |
What Available Research Tells Us So Far...
- A 1998 study found that tamoxifen, an anti-estrogen used to treat breast cancer or for breast cancer prevention, reduced breast cancer risk by 49%. However, the study also noted serious side effects for this medication, including a large increased risk for endometrial cancer, pulmonary emboli, stroke and deep venous thromboses.
- A 2 year study found that raloxifene (Evista), a medication prescribed for the prevention of osteoporosis, contributed to an increase in bone mineral density and a reduction of LDL ("bad") cholesterol levels without an increase in breast cancer risk. However, there was found to be an increased risk for blood clots.
- The Study of Tamoxifen and Raloxifene (STAR) is a large, randomized trial that will be examining healthy postmenopausal women with a higher than average risk for breast cancer for a duration of five years. Begun in 1999, 2 groups of women will each take either tamoxifen (Nolvadex) or raloxifene (Evista) to examine which drug provides the most benefit for breast cancer prevention.
Critics note that the lack of a placebo group makes this study of little use to determine the possible risks of each medication. Data from this study will not be available for a few more years.
What We Still Need to Know...
So far most of the studies for SERMS have been short-term trials. Longer randomized trials are required to determine the full range of benefits and risks for SERMs.
