Obese children grow up to have bigger left ventricles in their hearts, putting them at risk for heart disease, researchers said on Monday.

“Simply being obese means your heart has to work harder, even in childhood,” said Shengxu Li, a medical researcher at Tulane University and co-author of the study.

“The added burden of high blood pressure ... and other related health problems can actually contribute to a change in the structure of the heart,” Li said.

While the heart enlargement “can be stopped and even reversed with appropriate interventions,” Li said, the data show a need to prevent and curb weight problems sooner in children.

Researchers also found a link between larger left ventricles and high blood pressure.

Li and others at Tulane used an echocardiograph to monitor the hearts of 467 young adults ages 20 to 38. The patients have been participating in the study since the early 1970s and have been screened twice for height, weight and risk factors since childhood. About two-thirds of those studied were white and another third were black.

The National Institutes of Health and the American Heart Association funded the study, which appears in the November issue of association’s journal “Circulation.”

It is the latest in a series of studies on childhood obesity, which experts say is a growing problem.

About 9 million U.S. children over age 6 are considered obese, according to an Institute of Medicine report released in September. That report called for better food labeling, school-mandated exercise and other lifestyle changes.

In adults, obesity is defined as having a body mass index, a weight-to-height ratio, of more than 30. That usually means being 30 pounds overweight for an average woman and about 35 to 40 pounds overweight for an average man.

Definitions are less clear for children, who are typically defined as “overweight,” a larger category that includes obese children.

SOURCE: Circulation, November 30, 2004.