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Special report on Hormone Replacement Therapy
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A matter of choice
By Pauline Jestadt
As more and more baby boomer women approach menopause, they’re faced with what is arguably one of the most important health-related decisions of their lives: To take hormone replacement therapy (HRT) or not. The challenge for millions of Canadian women who will experience menopausal symptoms over the next decade will be to sift through the massive amounts of often conflicting scientific information and come to an informed decision to meet their own individual needs. Their decision must take into consideration their lifestyle, general health and physical activity status and their diet, as well as their personal risks for heart disease and cancer. The decision is not an easy or straightforward one and should always be made with the assistance of a primary care provider.
Many older women have never entertained the idea of hormone replacements or if they have, they’ve abandoned it. Research shows that only about 15-20 per cent of older Canadian women actually use HRT. And while in 1996, 2.86 million prescriptions for HRT were written, less than two million were actually filled. Some of these women fear that HRT will increase their breast cancer risk or they prefer to weather the menopause symptoms (hot flushes, sleep disturbances, mood swings, lack of energy, vaginal dryness) naturally. Others merely get fed up with the side effects of HRT, which can include unpredictable bleeding and headaches, as well as skin irritations if they use a patch. But there are those in the medical community who maintain that for most women, HRT is the best protection a woman can have against heart disease and osteoporosis, and does not significantly elevate cancer risks.
The Health Journal has prepared a special report to help sort out the facts from anecdotes and to assess the best available evidence behind HRT.
What is Menopause?
Menopause is the absence of menstruation for 12 consecutive months. Before this time, women experience a gradual waxing and waning of ovarian function and erratic production of the female hormones estrogen and progestin. The average age of menopause is 51, although one per cent of women become postmenopausal before the age of 40 and about five per cent don’t reach menopause until after age 55. The reduced production of female hormones results in increased total cholesterol, LDL (the so-called “bad” cholesterol) and triglycerides (another bad cholesterol), and a simultaneous decrease in HDL (“good” cholesterol). This can lead to blood pressure changes, obesity and diabetes, all risk factors for heart disease. Menopause can also be artificially induced through surgery or cancer treatments.
What is Hormone Replacement Therapy?
This prescription therapy consists of estrogen alone or estrogen combined with progestin. These hormones replace those once produced by the ovaries. Women who have had a hysterectomy need only estrogen replacements while women with an intact uterus (i.e. those who had not undergone a hysterectomy) need the progestin to protect against uterine cancer. HRT is available in pills, patches, gels, creams and even a vaginal ring to women once menopause is reached. The traditional approach to hormone replacements was to prescribe estrogen for 25 days and to add the progestin for 10-14 days each month. Today, more and more women are opting for hormones throughout the cycle. Some women prefer therapies which combine estrogen and progestin on a continuous daily schedule, since breakthrough bleeding is more predictable. This regimen helps ensure that enough progestin is taken every month, and it also may improve compliance since it simplifies the dosage. It’s important to understand that much of the currently available research is on estrogen alone. Information on the use of the newer combined products is just emerging now and should provide much more information in the future.
Benefits of HRT
Hot flushes
One of the most uncomfortable symptoms caused by estrogen deficiency is the often-intense perspiration, sometimes occurring several times a night. Research shows that HRT is by far the best current treatment for these hot flushes. Standard therapies can relieve symptoms by up to 90 per cent. HRT is also a preferred therapy for vaginal dryness and mood disturbances, which are also common complaints of women going through the menopause.
Osteoporosis
Thinning of the bones is one of the biggest health problems during menopause, with about one quarter of women facing this risk. Hip fractures in older women are one of the most important causes of death. A significant one fifth of women who suffer such fractures will die within a year. HRT helps prevent osteoporosis by preserving bone mineral density. However, this benefit disappears if the therapy is suspended, so women taking HRT to prevent osteoporosis should take it for life. In addition to HRT, women prone to osteoporosis can decrease their risk by daily intake of vitamin D and calcium from food or supplements and by starting an exercise program.
Heart disease
Another major health concern of older women is heart disease.
In 1997, almost 40,000 Canadian women lost their lives due to heart disease or stroke, making it the number one killer of women in this country. The risks of heart disease increase significantly after menopause, coinciding with the dwindling production of female hormones. HRT may decrease risks for heart disease because it lowers LDL and raises HDL. Estrogen also relaxes the blood vessels to improve blood flow to the heart. More than 30 observational studies conducted over the last two decades have reported up to a 50 per cent reduction in heart disease among women taking HRT. In these studies, researchers analyzed a group of women who chose to take HRT and documented the benefit.
Some experts believe that the heart-protection reported in these studies was due to a healthier lifestyle, and therefore better health, of women who chose to take HRT. However, a major Canadian survey of women in 1994 found that HRT users were not healthier than non-users. It is possible that women taking HRT become more health conscious since they visit their doctor regularly for prescriptions and while there, they probably get their blood pressure checked, counseling on lifestyle choices and maybe even a mammogram. While one recent study found that older women with confirmed heart disease do not benefit from HRT, these results don’t necessarily apply to all women. We should be cautious about using the results of this study, which for the most part involved women who had suffered a heart attack or had undergone cardiac surgery, to make treatment decisions about younger, healthier women. Another larger study of HRT in healthy women should provide more reliable information on the impact of HRT in the general population, but it won’t be available for at least another five years. In the meantime, for most women, the benefits of HRT far outweigh the risks, and when you consider just the non-heart related benefits, these are even greater.
Alzheimer’s disease
This degenerative brain disorder is more common among women than men and is related to the aging process. There is some emerging evidence showing that HRT improves cognitive function by up to 25-30 per cent. This could be because of a direct effect of estrogen on the brain or because of relief of insomnia and other menopausal symptoms.
Other benefits
There are reports that HRT prevents stroke, improves incontinence and helps remove wrinkles by slowing the breakdown of collagen. But these have not been supported by extensive research.
RISKS OF HRT
Breast cancer
It is the second leading cause of death among women, so it’s understandably a huge concern for those entering menopause.
Study after study has shown that breast cancer risk is not elevated with short-term use of HRT. Hot flushes normally subside within five years anyway, so many women will not need to use this therapy for longer. While the breast cancer risk is elevated somewhat, probably about three percent overall, in long-term users of HRT, the type of cancer these women typically acquire is a less serious form of the disease. Newer research suggests even less of a risk.
One study found that estrogen replacement does not elevate the breast cancer risk of women with a history of benign breast disease any more than having had the cancer does. Women who are concerned about breast cancer should remember that in general, their risk for heart disease is far greater than their risk for breast cancer. Nevertheless, guidelines developed by health professionals still recommend that HRT not be used in women with a history of breast cancer and used only cautiously in women with a family history of breast cancer.
Other cancers
In years past, when HRT consisted only of estrogen, there was a significant risk of cancer of the endometrium (the lining of the uterus) in patients with an intact uterus. However, the newer therapies that combine estrogen with progestin dramatically reduce the risk of uterine cancer. The down side is that adding progestin may decrease some of the estrogen’s beneficial effects on cholesterol levels. Other evidence appears to support the belief that HRT decreases the risk of colon cancer, the second most common type of cancer among non-smoking Canadian women.
Blood clots and gallbladder disease
Hormone therapies increase the risk for blood clots in the veins, but the increased risk is extremely small in healthy women. Gallbladder disease is also increased, but again, the research shows it’s a small risk and the cases are rarely fatal. It’s important to remember that both of these complications are uncommon in women in their 50’s, the typical age of menopause.
Other risks
Side effects of estrogen include nausea, headaches, breast tenderness and heavy bleeding. Some women should not take HRT including those who are pregnant and those with unexplained vaginal bleeding or liver disease. HRT should be used cautiously in women who have seizures or migraines.
What are SERMS?
SERMS are selective estrogen-receptor modulators. They’re also called “designer estrogens”. These compounds act like estrogen in some tissues but not others. Theoretically, a SERM would reduce the risk of heart disease and osteoporosis while protecting against breast, endometrial and colorectal cancers. The two SERMS currently available in Canada (tamoxifen and raloxifene) fill some, but not all, of this bill. Tamoxifen is a treatment for breast cancer, but this agent can significantly increase risks of blood clots and uterine cancer and the jury is still out on whether it has any positive effects on heart disease or osteoporosis. As for raloxifene, a treatment for osteoporosis, studies show it decreases the incidence of breast cancer by 50 per cent and it also has been shown to have positive effects on blood cholesterol levels, although there’s still no hard evidence of its benefits on heart disease.
How should I take HRT?
Estrogens are prescribed orally, transdermally (patch) or vaginally. The pill and patch are equally effective in treating menopausal symptoms such as hot flushes and sleep disturbances, and they should provide the same protection to the bones. The liver metabolizes the pill, the “grand-daddy” of HRT treatments, in a process that stimulates the positive effects on blood cholesterol. Patches avoid the liver, so the cholesterol changes are lesser, but they generally deliver estrogen (few patches contain progestin) in a consistent and predictable manner.
Women with gallbladder disease or uncontrolled hypertension, or who are taking drugs that affect the liver, may want to consider this option. Those with digestion problems, difficulty swallowing or who simply have an aversion to taking pills, may also want to opt for the patch. The patch’s superior absorption could also make it a good choice for women with a history of hormonal difficulties such as headaches. However, skin irritations are a side effect in 10-20 per cent of patch users. Vaginal estrogen in the form of creams or a vaginal ring also avoids the liver, but release less of the hormone into the body. These may be the preferred mode of delivery for women experiencing severe vaginal dryness. A new hormonal gel applied directly to the inner arms or thighs is effective in alleviating menopausal symptoms, too. It does not affect the liver and causes relatively few skin irritations.
Pauline Jestdat is a medical writer in Toronto.
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