Although a woman's short-term risk of coronary heart disease is generally lower than a man's before the age of 50 (unless she has diabetes, in which case her risk is similar to her male counterpart), her "lifetime risk" greatly increases with age. Menopause appears to be the tipping point at which women's risk of coronary heart disease catches up with men's risk.
Many doctors and scientists believe that much of this effect is due to estrogen, which is produced during a woman's fertile years. Estrogen lowers LDL cholesterol and raises HDL cholesterol.
After menopause, however, when the ovaries stop production, estrogen's protective effect is lost. The rate of coronary heart disease in women who have experienced menopause is actually two to three times that of women in the same age group who have not experienced menopause. And compared with women who experience menopause at age 50 or later, women who reach menopause before age 45 are at an increased risk.
One theory suggests that the protection of the pre-menopausal years is related to iron lost through menstrual blood. Iron contributes to the oxidation of cells, and research has shown that it is associated with increased atherosclerosis.
When women menstruate, they lose iron, but after menopause, iron can build up in the body. Excess iron can be found in the blood, but it's also stored in organs such as the heart and liver. It's important that once women reach menopause they no longer take multivitamins or supplements with iron in them.
In the past, hormone replacement therapy was thought to have a beneficial effect on coronary heart disease. Up until 1998, most studies suggested that estrogen/progestin (hormone) therapy reduced heart attack rates in women. In 1998, however, the Heart and Estrogen/Progestin Replacement Study (HERS) found that hormone therapy resulted in an increase in events related to coronary heart disease and had no benefits on cardiovascular health. Moreover, estrogen/progestin caused venous thromboembolism, a condition in which blood clots develop in the leg and can travel to the lungs.
Four years later, the Women's Health Initiative (WHI) Estrogen-Plus-Progestin Study was ended prematurely because the risks were found to outweigh the benefits of hormone therapy. In fact, estrogen/progestin caused an increased risk of events related to coronary heart disease, stroke, breast cancer, and pulmonary embolism.
Although the women taking estrogen/progestin did have a decreased risk of hip fracture and colon cancer, the harm from hormone therapy overshadowed the benefits. In addition, subsequent findings indicated a significant two-fold increase in mental decline or dementia among women older than age 65 who took hormone therapy.
The WHI Estrogen-Alone Study, which examined the effect of estrogen without progestin on women who had a hysterectomy, also found that there was no benefit in preventing coronary heart disease in women, although early events appeared less pronounced.
As a result of the findings from the HERS and WHI studies, hormone therapy is no longer recommended to prevent coronary heart disease in women, and doctors are directed to treat symptoms of menopause with the lowest dose of hormones for the shortest time possible.
Unfortunately, weight gain frequently accompanies menopause; this leads to an increase in risk factors associated with the metabolic syndrome, including increased abdominal obesity, decreased levels of HDL cholesterol, and elevated levels of blood pressure, blood glucose, and triglycerides. Overall, a menopausal woman with these untreated risk factors is more vulnerable to all the manifestations of coronary heart disease, including heart attack, heart failure, and sudden cardiac death.
But it's not just menopause that increases a woman's risk of coronary heart disease. Other risk factors play a significant role, too.
One factor in particular, cholesterol, is affected by menopause. The next page details the risk in women from cholesterol, and how it changes after menopause.
For more information on coronary heart disease, see:
- Symptoms of Coronary Heart Disease in Women: Women typically do not have obvious signs of heart disease, making it difficult to diagnose. Find out who should get tested.
- Diagnosing Coronary Heart Disease in Women: A range of tests are available if your risk is higher than 5 percent. Learn what these are, and why some aren't always accurate.
- Treatment of Coronary Heart Disease in Women: Traditional treatment isn't always effective in women. Learn about lifestyle changes to keep your heart healthy.
- Coronary Heart Disease: This condition is the culmination of years of plaque buildup in the arteries. Find out how to prevent it.
This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.