DALLAS, Feb. 2 -- Children with chubby tummies have more heart disease risk factors than their pear-shaped peers, according to a new study published in today's Circulation: Journal of the American Heart Association.
Earlier studies had indicated that compared to individuals who tend to put on weight in their hips and thighs, adults who gain weight around the mid-section -- known as the apple silhouette -- have higher blood pressure and lower levels of the "good" cholesterol known as high-density lipoprotein (HDL).
In this study of children and adolescents, greater upper body fat was associated with higher levels of the blood fat, triglycerides, and lower HDL cholesterol. In addition, systolic blood pressure -- the upper number of a blood pressure reading -- was highest in children with the most fat overall and in the apple-shaped kids. The mass of the left side of the heart, which does most of the pumping, was larger for children with pudgy midsections.
"Where fat is distributed appears to be a more important influence on cardiovascular risk factors in young people than total fatness," says Stephen R. Daniels, M.D., Ph.D., professor of pediatrics and environmental health at the University of Cincinnati College of Medicine and Children's Hospital Medical Center in Cincinnati, and lead author of the study. "You can already see this relationship in children as young as nine and even in kids who are not necessarily overweight at this stage."
Whether an individual's fat distribution can be changed from the apple pattern to the pear pattern is not known, but overall fitness definitely helps reduce cardiovascular risks, he says. Physicians should consider a person's fat distribution to determine how vigorously to treat risk factors, Daniels adds. The relationship between body shape and cardiovascular risk factors has not been extensively studied in young people, but a new way of measuring fat distribution made such a study feasible.
The technique, called dual-energy X-ray absorptiometry (DEXA), has been used extensively to check bone mineral density for osteoporosis. It can also determine body fat distribution more accurately than many of the indirect measuring methods previously used. DEXA uses low-level X-rays to penetrate the body. The degree of that penetration is used to measure tissue density -- whether of bones, as in osteoporosis, or fat, he explains. The technique uses less radiation than a dental X-ray, "roughly equivalent to the background amount a person would be exposed to by flying from Cincinnati to the West Coast." The researchers studied 127 boys and girls between nine and 17 years of age. They were recruited from local schools and included 68 males and 59 females; 72 were white and 55 were black.
In addition to DEXA, the tests for blood pressure and levels of blood fats, which included total cholesterol, HDL cholesterol and triglycerides were administered. Each person underwent an ultrasound procedure called an echocardiogram to determine the size and thickness of the left ventricular region of his or her heart.
The greater the left ventricular mass, the greater the risk of heart disease, Daniels says. In part, that is because this region tends to thicken when high blood pressure makes the heart work harder to pump blood. But there are also risks associated with increased left ventricular mass that are independent of blood pressure for reasons that are not entirely clear," he adds.
The above story is based on materials provided by American Heart Association. Note: Materials may be edited for content and length.
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