> Health and Disease > Aging

Heart disease among women is on the increase. This may be because its incidence rises after menopause, and women in the baby-boom generation are nearing the age of menopause. But something else is happening here.

Between 1979 and 1994, the rate of heart attacks among women increased by 36 percent; while for men it decreased by eight percent. Hormone replacement therapy (HRT) has been prescribed for women during the same period of time.

For about 25 years now, women have been advised to take premarin, the most commonly prescribed estrogen, which is derived from pregnant mare’s urine. Provera or synthetic progesterone was also prescribed to reduce their risk of heart disease. We know that estrogens decrease total cholesterol by increasing good cholesterol (HDL) and decreasing bad cholesterol (LDL). However, they also increase levels of harmful fats known as triglycerides.

Recommendations to take hormones for heart disease were based on observational studies, the largest of which was the Harvard Nurses’ Health Study. Begun in 1976, researchers conducting the nurses’ study sent out thousands of questionnaires to nurses every two years. They were asked whether they were taking estrogen. Results showed that women taking estrogen had 50-per-cent fewer heart attacks.

Critics pointed out that well-designed studies were required before HRT could be recommended for prevention.

Researchers set up further studies that sought to answer two questions: did hormone replacement therapy (HRT) prevent further heart attacks in women who already had heart disease (secondary prevention)? Did HRT prevent heart attacks in healthy women (primary prevention)?

The largest study on secondary prevention known as the Heart and Estrogen-Progestin Replacement Study was published in 1998. In this study, half of 2,763 women with known heart disease - the average age of whom was 66.7 years - got HRT and half got placebo. Over four years, both groups had the same number of heart attacks. However, the hormone group had more gallbladder disease and a higher incidence of blood clots in the lungs and legs.

A smaller study known as the Estrogen Replacement and Athersocerosis Study looked at 309 women who already had proven heart disease. A study of baseline and follow-up angiograms on each woman compared HRT to placebo, provera to placebo, yet found no effect on slowing heart disease.

Neither did the Women’s Health Initiative (WHI), the largest-ever randomized, controlled trial of HRT for primary prevention. The estrogen plus progestin trial of the WHI involved 16,608 women ages 50 to 79 years, who got either premarin .625 mg and provera 2.5 mg per day or placebo.

This eight-year study was stopped at the five-year mark when researchers concluded that the risks of taking HRT outweighed the benefits. Breast-cancer risk rose by 26 percent, heart-disease risk by 29 percent, and stroke-risk by 41 percent. For every group of 10,000 women who took HRT for one year, an additional seven heart attacks, eight more breast cancers, eight additional strokes, and eight more blood clots in the lungs occurred.

A further section of the WHI trial continues to look at the role of estrogen alone in preventing heart disease and will be completed in 2005.

Two studies show a possible beneficial effects of natural estrogen derived from plant sources (estriol). We also know that natural progesterone increases HDL cholesterol and reduces spasm of the heart arteries. But no clear evidence supports HRT as useful for either primary or secondary prevention of heart disease.

The prevention and treatment of heart disease is at the top of women’s health priorities. For these purposes, alternative medicine holds much promise compared to conventional medicine.

Are You at Risk?

Which of these risk factors applies to you?

Decrease in estrogen and progesterone at menopause or after hysterectomy. Natural hormone supplements, especially natural progesterone, have beneficial effects.

Carolyn DeMarco, MD, is a general practitioner with a special interest in women’s health and alternative medicine. She is also the author of two books, both available to view at demarcomd.com.

Source: alive #256, February 2004