More than half the participants -- 58.3 percent -- had at least one of the six risk factors, 27.4 percent had two or more and 13.5 percent had three or more, Harrell said.
Some children ages 8 and 9 -- 8.3 percent -- already showed three or more risk factors. Among teenagers 14-17, 11 percent had three or more. The highest rates of multiple risk factors -- 16.2 percent -- were in those entering or about to enter puberty.
The most common risk factor, found in 42.2 percent, was a low HDL level. HDL levels were rated low if they were less than 40 milligrams per deciliter in boys or 50 mg/dL in girls. Researchers also found high triglycerides in 8.6 percent of children.
Triglycerides were deemed high if they were at least 100 mg/dL in children aged 10 or younger or 130 mg/dL in those older than 10.
More than one in four subjects were overweight with a body mass index at or above the 95th percentile for their age, gender and height.
Previously, scientists documented a high level of obesity in teens. The UNC study is looking at the development of six metabolic syndrome risk factors beginning prior to puberty and continuing through the teen years.
"Some insulin resistance is normal with puberty," Harrell said. "In addition, obesity increases with puberty, earlier in girls than in boys. As we follow the children, we'll see whether these factors persist in adolescence."
Significantly more girls -- 16.3 percent -- than boys -- 10.7 percent -- had three or more risk factors, which the researchers attribute to more overweight among girls.
High insulin in the blood -- more than 25 microunits per liter -- was found in 16.1 percent of the children. High blood pressure was detected in 7.7 percent. Children were considered to have high blood pressure if their average systolic or diastolic pressure was at or above the 95t
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Contact: David Williamson
919-962-8596
University of North Carolina at Chapel Hill
10-Nov-2003