UT Southwestern Medical Center scientists say that people with a larger waist-to-hip ratio may be at increased risk for heart disease. The research evaluates the association between different measures of obesity and the prevalence of arterial disease. "Our study shows that people who develop fat around the middle have more atherosclerotic plaque than those who have smaller waist-to-hip ratios," said Dr. James de Lemos, associate professor of internal medicine and senior author of the study.
"The risk was the same for both men and women who develop abdominal fat," he added.
Prior studies examining the association between obesity and cardiovascular risk reported varied results for overweight subjects who eventually had clinical cardiovascular events. The patients often were evaluated for obesity on the sole measurement of body mass index (BMI), a weight-to-height ratio commonly used in doctors' offices to gauge obesity.
The UT Southwestern findings, however, suggest that BMI alone might not give a clear enough picture of heart disease risk
"BMI was used as the primary measure of obesity rather than alternative measures such as waist circumference or waist-to-hip ratio. The latter measures have demonstrated stronger correlations for cardiovascular risk than BMI," said Dr. de Lemos.
In the UT Southwestern study, researchers looked at men and women between the ages of 18 and 65. Nearly 3,000 individuals participated in a total of three medical visits each, which included an in-home health survey, blood and urine collection, and a detailed clinical exam complete with abdominal magnetic resonance imaging and coronary artery calcium scans.
The prevalence of coronary artery calcium was strongly associated with waist circumference and waist-to-hip ratio in addition to high BMI. Hip circumference alone, however, was not a strong indicator for coronary calcium deposits.
"We think the key message for people is to prevent accumulation of central fat early on in their lives. To do so, they will need to develop lifelong dietary and exercise habits that prevent the development of the 'pot belly,'" he added.
The research will be published in the Aug. 21 issue of the Journal of the American College of Cardiology.