Apple Shapes Aren't at Higher Heart Risk

In the past, studies have shown that obese people with a so-called “apple shape” have three times the heart attack and stroke risk than obese people with different fat distribution.

But now a large international study challenges that finding, saying waist circumference, body-mass index (BMI), and waist-to-hip ratio each has a similar impact on heart attack and stroke risk.

The study, published Friday in the Lancet, followed 220,000 adults for nearly a decade. Of that number, 14,000 suffered a heart attack or stroke. The research confirmed that obesity is an important predictor of cardiovascular disease, but that BMI (a measure of body fat based on height and weight), waist circumference, and waist-to-hip ratio all affected risk the same.

What’s more, information on blood lipids, systolic blood pressure, and diabetes history is still a better predictor of risk, the study suggests. The work was done by the Emerging Risk Factors Collaboration, a consortium of 200 scientists from 17 countries led from the University of Cambridge.

“Whether assessed singly or in combination, body-mass index, waist circumference, and waist-to-hip ratio do not improve prediction of first-onset cardiovascular disease when additional information exists on blood pressure, history of diabetes, and cholesterol measures,” the researchers wrote.

The take-away for general practitioners is that they should continue using blood cholesterol profiles and blood pressure measurements in determining patient cardiovascular risk, researchers said.

However, “The main finding of this study does not, of course, diminish the importance of adiposity (obesity) as a major modifiable determinant of cardiovascular disease,” researchers also wrote.

Such a study was important, researchers noted, because previous studies had major design limitations and resulted in differing recommendations.

In an accompanying editorial published with the study, Dr. Rachel R. Huxley and Dr. David R. Jacobs Jr., of the University of Minnesota School of Public Health, wrote: “the study dispelled previous hope that assessment of body size could replace the cost, time, and inconvenience of blood lipids assay. It had been suggested that knowledge attained from an individual’s age, sex, blood pressure, history of diabetes, smoking status, and a measure of body size would be equivalent to the information obtained from a blood test. Such an option could be important, particularly in resource-poor settings. However, findings of the Emerging Risk Factors Collaboration’s study showed that inclusion of BMI and waist circumference could only marginally compensate for the lack of information about total and HDL cholesterol in a risk-prediction model.”