(Ivanhoe Newswire) -- With an obesity epidemic brewing among U.S. children, there is concern that overweight and obese children need to be screened for chronic medical conditions including high cholesterol levels. University of Michigan researchers have determined, however, that body fat is not an effective indicator of high cholesterol in children.

Pediatricians Joyce Lee, M.D., MPH, and Matthew Davis, M.D., MAPP led the study. "We found, actually, that using body mass index to find kids with high cholesterol does not work well," Lee, assistant professor in the Department of Pediatrics and Communicable Diseases at the U-M Medical School is quoted as saying. "There were many overweight and obese kids who had normal cholesterol, and there were a fair number of healthy-weight kids who had high cholesterol."
 
The study was conducted in response to the American Academy of Pediatrics (AAP) revision of its cholesterol screening guidelines in July 2008, advocating a cholesterol check for kids who have increased risk of heart disease. Generally, that means all children who are overweight or obese, which is about 30 percent of kids in the U.S.

"Our results indicate that the AAP guidelines for cholesterol screening in kids may need to be revised," said Lee. "Otherwise, we may be missing high cholesterol in some kids and unnecessarily testing others."

The authors performed the study using national data from thousands of children to see whether 'body mass index' (BMI), a measure of body fat based on height and weight, is a reliable way to identify children with high cholesterol levels. They looked at the relationships of BMI to total cholesterol and to low density lipoprotein (LDL), or "bad," cholesterol.

Children were classified as overweight if their BMI was between the 85th and 95th percentiles, and defined as obese if their BMI was greater than the 95th percentile for weight based on age and height. Children had abnormal cholesterol levels if they had total cholesterol greater than 200 mg/dl or LDL cholesterol level of greater than 130 mg/dl.
 
This study found that screening all overweight or obese children would identify approximately 50 percent of children with abnormal cholesterol levels, but would also lead to unnecessary testing for up to 30 percent of children.