Do you know how old your kids' arteries are?

It's a potentially important question as scientists increasinglyuncover links between healthy habits in childhood and risk for heart disease later in life. And there are growing concerns about the cardiovascular health of millions of children in the U.S. who are considered obese or overweight.

A new study suggests there is a simple way to assess a child's arterial health with a calculation based on an often-overlooked component of cholesterol: triglycerides.

The calculation is the ratio of triglycerides to HDL, or good cholesterol. It can be easily determined from a standard cholesterol blood test. In the study, based on nearly 900 children and young adults, researchers at Cincinnati Children's Hospital Medical Center found that the higher the ratio, the greater the likelihood a child would have stiff and damaged arteries.

'We are demonstrating vascular changes in supposedly healthy adolescents,' said Elaine Urbina, head of preventive cardiology at Cincinnati Children's and lead author of the study. 'Stiff vessels make your heart work harder. It isn't good for you.' The study was published in the journal Pediatrics in April.

The problem is also called hardening of the arteries. In adults it typically arises from a combination of aging and the cumulative impact of blood pressure, cholesterol and other assaults on the walls of blood vessels over decades of life. It carries heightened risk for heart attacks, strokes and sudden death.

When it shows up in children, it's a sign of 'accelerated aging,' Dr. Urbina said, and likely raises the risk of dangerous outcomes relatively early in adult life. The good news is that doctors believe health can be restored to young people's arteries with regular physical activity and a healthy diet. This includes cutting back on sugary beverages and foods high in carbohydrates such as potatoes, white rice and pasta.

In late 2011, concern that a generation of children is growing up with already established heart risks prompted federal health officials with the support of the American Academy of Pediatrics to recommenduniversal cholesterol screening for kids, preferably between ages 9 and 11.

Generally, the focus of attention in such tests is LDL, or bad cholesterol, which at high levels has long been associated with increased chances of heart attacks and strokes. A large body of evidence shows that heart risk can be reduced by lowering LDL with one of a class of drugs called statins.

But high triglycerides and low HDL