Saturday, May 23, 2015
New study suggests that metabolic syndrome may increase cardiovascular risk more in black women than in white women
"It appeared that the cardiovascular disease risk was elevated in black women by the presence of only two or three metabolic abnormalities to a degree that would require four or more metabolic abnormalities among white women," says Dr. Michelle Schmiegelow, author of the study and research fellow at University Hospital Gentofte, Denmark. Metabolic syndrome is a cluster of risk factors that occur together and increase the risk of stroke and diabetes. The risk factors are increased blood pressure, high triglyceride levels, low levels of "good" cholesterol, impaired glucose metabolism and abdominal obesity. Previous studies have indicated that obesity without metabolic syndrome (defined here as having at least three of the risk factors) is not associated with an increase in cardiovascular disease risk. However, these studies focused predominantly on white participants. Researchers analyzed a multi-ethnic group of postmenopausal women aged 50-79 recruited by the Women's Health Initiative, assessing cardiovascular disease risk according to weight and metabolic health status. Of the 14,364 participants, around 47% were white, 36% were black and 18% were Hispanic. Participants were classified as "overweight" if approximately 10% over their ideal body weight for size and "obese" if around 30 pounds over their ideal weight. Participants were followed up for 13 years. During this time, 1,101 women had either developed coronary heart disease or had an ischemic stroke for the first time. The researchers found that, among black women with 2-3 metabolic risk factors, the relative risk of cardiovascular disease increased by 117% in those that were obese and increased by 77% in women who were overweight. In comparison, white women with 2-3 metabolic risk factors who were obese or overweight experienced cardiovascular events as often as white women with normal weight and without any metabolic disorders. In the absence of metabolic syndrome, black women who were obese or overweight had a higher risk of cardiovascular disease compared with normal weight black women. In contrast, white women without metabolic syndrome had a similar risk of cardiovascular disease regardless of weight classification. Dr. Schmiegelow suggests the findings imply that metabolic syndrome may underestimate cardiovascular disease risk in black women and overestimate it in white women, at least in postmenopausal women.