Being Overweight Hurts Kids' Arteries

Even a little bit of extra fat in the adolescent years weakens the body's ability to fight heart disease in adult life, a British study suggests.

Usng ultrasound to peer at the arteries of 471 youngsters between the ages of 13 and 15, researchers at St. George's Hospital Medical Center in London found that extra fat lessened "distensibility," a measure of arteries' ability to expand.

"This is more evidence that being overweight as an adolescent does have long-term implications," says study author Peter H.

Whincup, a professor of cardiovascular epidemiology at St.

George's, whose work is reported in the Sept. 20 online issue of the journal Circulation.

It's been known that severe obesity in teenagers damages the endothelium, the delicate lining of the arteries, reducing their ability to expand. This study, the researchers report, suggests that the damage can occur at "body-mass index levels well below those considered to represent obesity."

Traditionally, Whincup says, the major concerns about heart disease have been blood pressure, cholesterol and "above all, smoking."

"What we are looking at here is an early model of risk, the balance of determinants in the early years of life," he says.

"Obesity, or degrees of it, are the dominant factors at this stage."

Until recently heart-disease risk factors such as high cholesterol and high blood pressure were uncommon in childhood, the researchers note. One reason for the study was that such risk factors have become increasingly common as the rate of childhood obesity has soared.

Some of the children in the study had been studied earlier, when they were 9 to 11 years old, so the researchers could look at the effects of various heart-disease risk factors over time.

They found that insulin resistance, diastolic blood pressure -- the second number in a blood-pressure reading -- and levels of C-reactive protein, a marker of inflammation, were also associated with reduced distensibility. The association with blood pressure showed up as early as age 9, the researchers report.

"The message is not for individuals at this stage," Whincup says.

Instead, he says, society at large needs to take more steps to keep children and adolescents slimmer.

"There is no magic formula," he says. "It is simply that calorie intake is too high in relation to expenditures of energy."

A combination of better diet and more exercise -- standard recommendations for adults -- apply to adolescents as well, Whincup says.

Dr. Stephen Daniels, a professor of pediatrics at the Cincinnati Children's Hospital Center who is a spokesman for the American Heart Association, agrees that the study is significant.

"This whole concept of distensibility is potentially an important one," he says, "because one of the difficulties in understanding the early process of atherosclerosis is how to look at it. This is one way to do it."

The real-life lesson of the study is that overweight "is having an adverse effect at many levels," Daniels says. "In a world where more and more children are getting into obesity, this says that we have to be more aggressive in trying to prevent it."