Children who are overweight but otherwise "healthy" may have stiff arteries, putting them at increased risk for heart disease, a study shows.

As people age, the arteries normally lose some of their elasticity, making them less responsive to changes in blood flow. Stiff arteries put increased strain on the heart, often leading to high blood pressure.

The rising prevalence of childhood obesity is associated with the premature development of cardiovascular risk factors such as high cholesterol and high blood pressure, the study team notes. In addition, there is emerging evidence that such obesity-related conditions predict the development of heart disease in adulthood.

Dr. Walter P. Abhayaratna, of Canberra Hospital, Australian Capital Territory, and colleagues assessed the relationship among body fatness, physical activity, and "arterial stiffness" in 573 healthy children whose average age was 10 years.

They found a positive link between a higher body weight and the presence of stiff arteries.

Weight loss, the study team notes, has been shown to improve blood vessel dysfunction related to obesity. Further studies, they add, are needed to evaluate whether public health efforts to promote physical activity and weight loss in children will reduce arterial stiffness and attenuate the progression of cardiovascular disease.