Pear-shaped people are those who put on weight around their hips and thighs.

Apple-shaped people tend to put on weight around their midsection.

Earlier studies indicated that pear-shaped adults have higher blood pressure and lower levels of the "good cholesterol" known as high-density lipoprotein (HDL) than those with the apple shape.

But a study in Circulation, the journal of the American Heart Association, found that with 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 those who were apple-shaped.

The mass of the left side of the heart, which does most of the pumping, was larger for children with podgy midsections.

Fat distribution

Professor Stephen Daniels, of the University of Cincinnati College of Medicine and Children's Hospital Medical Center in Cincinnati, said: "Where fat is distributed appears to be a more important influence on cardiovascular risk factors in young people than total fatness.

"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 Prof Daniels said overall fitness definitely helps reduce cardiovascular risks.

He said doctors should consider a person's fat distribution to determine how vigorously to treat risk factors.

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.

Recruited from local schools

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.

In addition to DEXA, the tests were carried out for blood pressure and levels of blood fats.

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.

In part, that is because this region tends to thicken when high blood pressure makes the heart work harder to pump blood.