Waist Size Helps Predict Heart Risk in Teenagers

A new study uses waist measurements and body mass index to help predict health risks in teenagers.

Using waist measurements together with body mass index may better predict a teenager’s cardiovascular risk than using B.M.I. alone, a new study finds.

Pediatricians and medical groups routinely use B.M.I. as a measure of unhealthy weight in children. But the index, calculated by dividing one’s weight in kilograms by the square of one’s height in meters, cannot differentiate between fatty and lean tissue. So an athletic, muscular teen could be classified as overweight or obese using B.M.I. alone.

Some researchers have proposed using waist circumference percentile — or a similar measure, waist-to-height ratio — as a better gauge of health. But the new study, published in Archives of Pediatrics & Adolescent Medicine, found that neither measurement alone was sufficient.

In the study, Dr. Brian W. McCrindle and colleagues at the Hospital for Sick Children in Toronto gathered detailed data on more than 4,000 14- and 15-year-olds. Those with a B.M.I. in the 85th to 95th percentile for their age were classified as overweight, while those in the 95th percentile or above were described as obese.

Among those groups, the higher the waist-to-height ratio, the higher their total cholesterol and the lower their good, or HDL, cholesterol. Teenagers whose B.M.I. put them in the obese category also showed a trend toward higher blood pressure with higher waist-to-height ratios.

Waist size should be half of height or less, the researchers found. Above that ratio, they began seeing associations with cardiovascular risk factors.

“While B.M.I. is a useful number,” Dr. McCrindle said, “using it together with waist circumference might give you a better indicator of what someone’s risk is for complications associated with obesity.”

Article written by ANAHAD O’CONNOR, Reporter