What are the effects of menopausal hormones on heart disease?

WHI researchers have found that estrogen plus progestin does not protect but may increase the risk of heart disease among generally healthy postmenopausal women. The greatest increased risk occurred in the first year (2). The most recent analysis of WHI results showed that estrogen plus progestin use was associated with a 24-percent overall increase in the risk of heart disease, with an 81-percent increased risk in the first year of use (19). 

Another randomized trial, the Heart and Estrogen/Progestin Replacement Study (HERS), concluded that estrogen combined with progestin has no beneficial effects on the heart in women with a history of heart disease. After 6.8 years of followup, there was no reduction in the risk of heart attacks or deaths from heart disease (20). 

The Women's Estrogen-Progestin Lipid-Lowering Hormone Atherosclerosis Regression Trial (WELL-HART), a randomized study looking at the effects of estrogen alone and estrogen plus progestin on women with coronary artery disease found that neither hormone treatment had any significant effect on the progression of the disease (21). 

Some observational studies in which women reported whether they were using menopausal hormones have found evidence that estrogen alone may protect a woman against coronary heart disease (22). Most of the participants in these studies were healthy women at low risk for developing heart disease. The WHI is continuing to investigate the effects of estrogen alone on the heart in a randomized clinical trial that is expected to conclude in 2005.

Questions and Answers About Menopausal Hormone Use

• What is menopause?

• What are menopausal hormones and why are they used?

• How do scientists determine the health outcomes associated with hormone use?

• Do the benefits of hormone use after menopause outweigh the risks?

• What are the effects of hormone use on the uterus?

• How does menopausal hormone use affect breast cancer risk and survival?

• How does menopausal hormone use affect the risk of ovarian cancer?

• What are the effects of menopausal hormones on heart disease?

• What are the effects of menopausal hormones on bone health?

• What are the effects of postmenopausal hormone use on quality of life and cognitive functions, specifically memory and learning?

• Are there other benefits or risks associated with menopausal hormone use?

• What are the risks of menopausal hormones for women who have a history of cancer?

• Does the route of administration of hormones make a difference?

• Are there any alternatives for women who choose not to take menopausal hormones?

• What research still needs to be done?