NEW YORK (Reuters Health) – Obesity is a known risk factor for heart attacks and it’s usually determined by calculating a person’s body mass index (BMI), which is based on their height and weight. New research suggests, however, that another obesity measure, the waist-to-hip ratio, is a better predictor of heart attacks.
As the name implies, the waist-to-hip ratio is a calculation of a person’s waist circumference divided by their hip circumference. A high ratio results in the so-called "apple-shaped body," whereas a low ratio indicates a "pear-shaped body." Previous reports have linked a high ratio with a greater risk of heart disease.
"The main message from the new…report is that current practice with BMI as the measure of obesity is obsolete, and results in considerable underestimation of the grave consequences of the overweight epidemic," Dr. Charlotte Kragelund, from Akershus University, and Dr. Torbjorn Omland, from the University of Oslo, both in Norway, comment in a related editorial.
The findings, which appear in The Lancet, are based on a comparison of BMI and waist-to-hip ratio in predicting heart attacks in more than 26,000 subjects drawn from 52 countries and representing several major ethnic groups.
Consistent with previous reports, Dr. Salim Yusuf, from McMaster University in Hamilton, Ontario, and colleagues found that the risk of heart attack increased as BMI rose. However, after accounting for waist-to-hip ratio and other risk factors, the association was no longer statistically significant.
By contrast, waist-to-hip ratio predicted the heart attack risk, and the correlation remained significant even after accounting for other factors. The risk of heart attack increased progressively as waist-to-hip ratio climbed, with subjects in the highest ratio group being 75 percent more likely to experience an attack than those in the lowest ratio group.
"Our findings suggest that substantial reassessment is needed of the importance of obesity for cardiovascular disease in most regions of the world," the authors conclude.
