Women should make lifestyle changes and lower their cholesterol before menopause, when their risk for heart disease begins to increase, according to a study reported today at the American Heart Association's 43rd Annual Conference on Cardiovascular Disease Epidemiology and Prevention.
"The main message from this study is that the perimenopausal period is a key time for addressing primary prevention of heart disease in women, in terms of lifestyle changes and other interventions," says Carol Derby, Ph.D., assistant professor of neurology and of epidemiology and social medicine at Albert Einstein College of Medicine in Bronx, N.Y. "Even if everything else were constant and there were no age-related changes in heart disease risk factors, just crossing the age threshold will make a lot more people eligible for treatment, according to the latest guidelines."
Researchers applied the 2001 update of the National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP III) guidelines for diagnosing and treating cholesterol disorders to a large group of perimenopausal women. "Perimenopausal" women are those who are approaching menopause, which may occur around age 55.
The ATP III guidelines recognize that women older than age 55 may have an increased risk for heart disease.
Derby and her co-workers wanted to evaluate the number of perimenopausal women who would qualify for treatment of cholesterol disorders now, before menopause, and later, as they age. They analyzed data from the ongoing Study of Women's Health Across the Nation (SWAN), a long-term investigation of women's health during the middle years of life.
"The idea was to look at where the women are now, in terms of risk factors, and then try to predict where they will be when they reach age 55," says Derby. "Just by virtue of aging - if no other risk factors change - these women will be bumped into a different risk category according to the NCEP III guidelines once they reach age 55."
For their analysis, researchers applied the NCEP "greater than age 55" criterion to 1,349 women ages 42 to 52. There were 653 whites, 424 African Americans, 98 Japanese, 90 Hispanics and 84 Chinese women. The evaluation considered the women's cholesterol values, blood pressure, body mass index (BMI, a measure of body size and obesity), and other factors affecting heart disease risk.
Most had normal blood pressure, and 80 percent were nonsmokers. BMI averaged 28.7, which made the women overweight as a group. In general, the women included in the analysis were "pretty healthy," Derby says. Overall, their cholesterol levels were within normal ranges.
The researchers estimated that according to the women's current risk factors, 19 percent of the Hispanics, 18 percent of the African Americans, 15 percent of the whites, 8 percent of the Japanese, and 5 percent of the Chinese women studied were eligible for lifestyle modification alone or combined with drug therapy to reduce cholesterol levels.
The estimated overall effect of adding the ATP III age criterion increased the proportion of women requiring lifestyle modification by 5 percent and the proportion requiring cholesterol-lowering drugs by 2 percent. The researchers projected that their risk for heart disease would shift so that almost 20 percent of them would become eligible for some form of cholesterol-lowering therapy after age 55. The magnitude of the shift was greatest among Hispanics (27 percent), African Americans (23 percent) and whites (19 percent), and lowest among Japanese (11 percent) and Chinese (8 percent) women. "If efforts to modify risk factors are not successful during the pre- and perimenopausal years, large numbers of women, particularly Black and Hispanic women, will rather abruptly require more aggressive treatment during their postmenopausal years," the researchers conclude. Cholesterol is not the only risk factor that women need to think about before reaching menopause, Derby says. Several heart disease risk factors begin to change near menopause, including blood pressure, BMI, and increased fat accumulation in the abdomen.
According to the American Heart Association, women can lower their risk of heart disease by making lifestyle changes such as improving their diet, increasing physical activity and not smoking.
"We don't know whether these changes are age related or hormonal," she says. "It's hard to separate those two issues. That's why the SWAN study is important. In the SWAN study, we're looking at hormonal changes and controlling for the effects of aging as we follow a cohort of women through the menopause transition in an effort to tease out these effects."