Blood vessels show effects of body fat in teens

Wednesday, September 21st 2005, 1:08 pm

By: News On 6

DALLAS (AP) _ Excess body fat in teens _ even those who are not overweight _ seems to be linked to less elastic blood vessels, a condition that can mean future cardiovascular disease, researchers say in a new study.

The findings underscore the dangers of the obesity epidemic, even in youngsters. An estimated 30 percent of schoolchildren are believed to be overweight.

``The message about this is that it's yet another reason to be concerned about the rise in overweight and obesity among young people,'' said Peter Whincup, lead author of the study and professor of cardiovascular epidemiology at St. George's Hospital Medical School in London. ``One does need to avoid becoming overweight.''

The relationship of fat to blood vessel elasticity is continuous, ``so a few pounds will make a difference,'' said Whincup.

``It is surprising that in early adolescence there is already evidence of this change,'' said Dr. JoAnn Manson, chief of preventive medicine at Harvard's Brigham and Women's Hospital. ``The fact that that is apparent even in young adolescents is of great concern.''

If one's blood vessels are elastic, it's easier for them to pump more blood. The heart has to work harder to pump blood through stiff blood vessels, leaving a person more likely to develop high blood pressure.

``What you want is a very pliable blood vessel that has a lot of give and take,'' said Dr. Sarah Blumenschein, director of preventive cardiology at Children's Medical Center-University of Texas Southwestern. ``Obesity itself appears to be an independent factor for decreased flexibility.''

For the study published this week in the American Heart Association journal Circulation, researchers used ultrasound to measure the elasticity of blood vessels in 471 children ages 13-15. There were 152 children in the study who had undergone similar evaluations when they were 9-11.

The study found that excess fat was even more strongly linked to stiffer blood vessels than cholesterol levels.

``It's interesting that someone has finally documented some real measures,'' said Dr. Stuart Berger, a pediatric cardiologist and medical director of the Herma Heart Center at Children's Hospital of Wisconsin.

The study also found an association between less elastic vessels and the number of characteristics of metabolic syndrome, a cluster of conditions that increases the risk for heart disease.

Metabolic syndrome is defined as three or more of the following: a big waist, high blood pressure, high levels of blood fats called triglycerides, low levels of good cholesterol and evidence of insulin resistance.

Whincup said that while the study found that excess fat was an independent factor for decreased blood vessel flexibility, it's known that obesity is also related to certain metabolic factors. ``These things do all seem to tie together,'' he said.

Researchers say that studies have shown that vascular problems due to obesity can be reversed by losing weight and increasing exercise.

``There's so much data to suggest that early intervention can reverse this,'' Berger said.

Blumenschein said that the message to parents is to not become complacent about their child's weight.

``There's a component of denial here in our society,'' she said. ``It's very important for the community to start early with these kids.''