The majority of past clinical studies have shown that women who use estrogen substantially reduce their risk of developing and dying from heart disease. One or two studies demonstrate conflicting evidence, but they are far outnumbered by the positive reports. Results from a 1991 study showed that after 15 years of estrogen replacement, risk of death by CVD was reduced by almost 50 percent and overall deaths were reduced by 40 percent. Some researchers credit this reduction to oral estrogen's ability to maintain HDL and LDL at their healthier, premenopausal levels, through its interaction with proteins in the liver. Others believe it is estrogen's direct effect on the blood vessels themselves (through receptors on the vessel walls) which creates this benefit. In the latter case, both oral estrogen and the skin patch would be effective. Studies are underway to determine which mechanism contributes most to a healthy heart.
Many doctors now believe that estrogen replacement benefits women at risk for heart disease (but not those with blood clots--see "Cautions to Estrogen Use"). Risk factors for heart disease include a strong family history of CVD, high blood pressure, obesity, and smoking.
At any time of life, women who smoke are much more likely to develop heart disease or have a stroke than women who do not smoke. But after menopause, a smoker's risk climbs dramatically. Low estrogen levels and smoking are separate risk factors for CVD. When the two are combined, the risk is much higher than either one alone. Smoking also raises your risks for some types of cancer and for chronic lung disease, such as emphysema. Fortunately, quitting smoking--at any age--can cut the risk of disease almost immediately. Studies have shown that when older people quit, they increase their life expectancy. Their risk of heart disease goes down, their lungs function better, and blood circulation improves. So quitting smoking, whether before, during or after menopause, can have a definite impact on both the length and quality of your life.
Should women be treated with a drug to prevent a disease they might never get (osteoporosis, heart disease)? Some people will be placed at higher risk, while others will benefit. Each woman should make a decision about HRT based on her own family history and life experiences.
Many women who have quit smoking say they found support in group counseling sessions. Local chapters of the American Cancer Society and the American Heart Association are good places to start looking for a smoking cessation group. Nicotine gum and nicotine patches available over-the-counter may also help.
While we know that estrogen users have a decreased risk of CVD, women with certain preexisting heart conditions are usually advised not to take HRT or ERT. These conditions include blood clots and recent heart attacks. Researchers hope to further investigate nonhormonal methods of preventing heart disease such as weight reduction or control, exercise, smoking cessation, and dietary modification. According to a 5-year study reported in 1988, weight gain (a common occurrence among many menopausal women) significantly raises blood pressure, total and LDL cholesterol, and fat levels. Together, these make up a dangerous recipe for heart disease. Several other studies also noted that having about one drink per day had a protective effect on the heart. Physicians advise caution in this area, however, as excess alcohol can increase risks for other serious problems.
While cardiovascular benefits associated with oral estrogen are fairly well-known, there is surprisingly little information on the cardiovascular effects of progestin combined with estrogen. Some studies suggest that progestins counteract the favorable effects of estrogen alone, while other studies show no such effect. This remains just one more gray area where questions outnumber reliable answers.