It has long been known that a woman's risk for heart disease rises after the onset of menopause. But is that the result of falling levels of the hormone estrogen that accompany menopause or actually a consequence of aging?
The answer to the question has long eluded researchers. Conflicting evidence has caused some to suggest that heart risk has an effect on menopause instead of the other way around, pushing women into an early end to their menstrual periods. A decade of controversy surrounding the risks and benefits of hormone replacement therapy—including whether it protects women against heart attacks—has fueled the confusion.
Now a provocative study led by researchers at the University of Pittsburgh sheds new light on the issue, demonstrating that a woman's LDL or bad cholesterol rises markedly during the year before and after menopause begins—the time period that coincides with a significant drop in levels of estrogen.
In the study involving 1,054 women, average LDL levels ranged between 113 and 116 during three to five years before the last menstrual period, and then rose to above 125 by the year after menopause before leveling off in the subsequent three to five years at just below 130.
Current government cholesterol guidelines regard 130 as borderline optimal for most people, with levels below 100 viewed as optimal. For patients with other risk factors such as high blood pressure or being overweight or having a family history of heart disease, the predominant advice is to get LDL levels below 100.
"The data underscore the need to monitor LDL cholesterol levels as women approach the menopause transition," says Kim Sutton-Tyrrell, an epidemiologist at the University of Pittsburgh and senior author of the study. The findings were published this month in the Journal of the American College of Cardiology.
The study "helps to understand the role of a woman's natural estrogen in protecting the heart and affecting risk factors for coronary disease," says JoAnn Manson, chief of preventive medicine at Harvard-affiliated Brigham and Women's Hospital, Boston, who wasn't involved with the study.
Dr. Manson said the findings point out the importance of "knowing your numbers" when it comes to cholesterol and other heart-related risk factors as women enter menopause. Many women and their doctors don't think to get a cholesterol check at that time of their lives, she added. She also says that exercise is a fundamental strategy to respond to the impact of menopause on heart risk.
"Physical activity is so key," she says. "It will do a lot to avoid weight gain and build muscle mass, which helps boost the metabolic rate." Reducing the amount of visceral fat—that which accumulates around the waistline—can help improve cholesterol levels.
For patients unable to keep cholesterol levels in check with exercise and healthy diets, widely used cholesterol-lowering drugs called statins are an option, researchers say, but they caution that the study's findings aren't a call for women at menopause to seek out a prescription medication before trying other prevention strategies.
The new study is from a broader inquiry called the Study of Women's Health Across the Nation, or SWAN, which began in 1995 and is sponsored by the National Institute on Aging. Researchers are following more than 3,300 women though their transition to menopause.
Participants were considered to have entered menopause when they had gone 12 months without a menstrual period, irrespective of their age. The average age of menopause is 51: It typically occurs between ages 45 and 55.
Estrogen's association with heart protection is well-established. For instance, in a separate 29,000-patient study published in the journal Obstetrics & Gynecology last May, a team led by Dr. Manson found that women who had their ovaries removed during a hysterectomy, and thus had dramatically lower levels of natural estrogen, had a higher risk of death from any cause as well as from fatal and non-fatal heart attacks compared to women who had a hysterectomy that spared their ovaries.
But researchers cautioned that the new data don't affect recommendations from a variety of health-care groups, including the American Heart Association and the American College of Obstetricians and Gynecologists, against using hormone replacement therapy as a strategy to prevent heart disease.
Hormone replacement therapy may have heart benefits if initiated in early menopause, but concerns about breast cancer and other risks weigh against its use except for short-term treatment of hot flashes and other menopause symptoms.
source: online.wsj
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