Women who go into early menopause are twice as likely to suffer from coronary heart disease and stroke, new Johns Hopkins-led research suggests.
The association holds true in patients from a variety of different ethnic backgrounds, the study found, and is independent of traditional cardiovascular disease risk factors, the scientists say.
"If physicians know a patient has entered menopause before her 46th birthday, they can be extra vigilant in making recommendations and providing treatments to help prevent heart attacks and stroke," says Dhananjay Vaidya, Ph.D., an assistant professor in the Division of General Internal Medicine at the Johns Hopkins University School of Medicine, and leader of the study published in the October issue of the journal Menopause. "Our results suggest it is also important to avoid early menopause if at all possible."
For example, he says, research has shown that smokers reach menopause, on average, two years earlier than non-smokers do, so quitting smoking may delay it.
Notably, the researchers said, their findings about the negative impact of early menopause were similar whether the women reached it naturally or surgically, via removal of reproductive organs, he says, though more research is needed. Often, Vaidya says, women who undergo hysterectomies have their ovaries removed, which precipitates rapid menopause. "Perhaps ovary removal can be avoided in more instances," he says, which might protect patients from heart disease and stroke by delaying the onset of menopause.
Cardiovascular disease is the number one killer of women in the United States, according to the Centers for Disease Control and Prevention.
Previous studies, Vaidya says, have shown a link between early menopause and heart disease and stroke among white women, but similar associations had not been demonstrated in more diverse populations. Hispanic and African-American women, he says, tend, on average, to go through menopause somewhat earlier than women of European descent.
Vaidya and his colleagues examined data from 2,509 women involved in the Multi-Ethnic Study of Atherosclerosis, a longitudinal, ethnically diverse cohort study of men and women aged 45 to 84 years, all enrolled between 2000 and 2002 and followed until 2008. Of the women, 28 percent reported early menopause, or menopause that occurs before the age of 46. Vaidya emphasizes that although the risk of heart attack and stroke was doubled in these groups, the actual number of cardiac and stroke events recorded among study participants was small. Only 50 women in the study suffered heart events, while 37 had strokes.
Menopause is a process during which a woman's reproductive and hormonal cycles slow, her periods (menstruation) eventually stop, ovaries stop releasing eggs for fertilization and produce less estrogen and progesterone, and the possibility of pregnancy ends. A natural event that takes place in most women between the ages of 45 and 55, menopausal onsets and rates are influenced by a combination of factors including heredity, smoking, diet and exercise.
Vaidya says some women are treated with hormone replacement therapy (HRT) to control menopause symptoms such as profuse sweating and hot flashes, but its widespread long-term use has been limited after large clinical trials showed that it increased the risk of heart attacks in some women. In Vaidya's study, no role was detected for HRT in potentially modifying the impact of early menopause.
"Cardiovascular disease processes and risks start very early in life, even though the heart attacks and strokes happen later in life," he says. "Unfortunately, young women are often not targeted for prevention, because cardiovascular disease is thought to be only attacking women in old age. What our study reaffirms is that managing risk factors when women are young will likely prevent or postpone heart attacks and strokes when they age."
This research was supported by contracts N01-HC-95159 through N01-HC-96169 from the National Institutes of Health's National Heart, Lung, and Blood Institute.
Melissa Wellons, M.D., M.H.S., of the University of Alabama at Birmingham and Pamela Ouyang, M.B.B.S., a professor of cardiology at Johns Hopkins, were also involved in the study.