Metabolic 'Footprint' May Be New Measure Of Obesity Risk In Kids

Adiponectin was an important discriminator between obese and normal-weight children, said Sandra G. Hassink, M.D., assistant professor of pediatrics at Thomas Jefferson University in Philadelphia, who presented the study.

"Factors such as cholesterol, blood pressure, triglyceride levels and measures of insulin sensitivity were not meaningful in differentiating between these two groups," she said.

But the study showed that adiponectin may be part of a "footprint" for heart disease risk in children.

"While obesity is a known risk factor for heart disease and diabetes, we don't know what factors determine which obese people are at greatest risk," said Hassink, who is also director of the Pediatric Weight Management Program at A.I. Dupont Hospital in Wilmington, Del. "The evidence is beginning to point to adiponectin as a key player in determining true risk," she said.

Adiponectin adheres to blood vessel walls, possibly protecting them by fighting inflammation at a cellular level. "Lower levels of adiponectin mean less protection for blood vessels, which may lead to adult heart disease," Hassink said.

The study included 23 normal-weight children (body mass indices, or BMI, below the 85th percentile) and 48 obese children (BMI above the 95th percentile). Five of the children were Hispanic, 15 African American and 51 Caucasian.

Besides lower adiponectin levels, the overweight children had significantly higher erythrocyte sedimentation rates or (ESR a marker for inflammation), higher total cholesterol and higher levels of leptin, a protein involved in regulating weight.

The adiponectin level in normal-weight children averaged 30.4 micrograms per milliliter of blood (ìg/ml) and 21.6 ìg/ml in obese children. Leptin levels averaged 37.6 nanograms per milliliter (ng/ml) in obese children and 8.5 ng/ml in normal-weight children. ESR in normal-weight children was 9.5 millimeters per hour (mm/hr) and 21.7 mm/hr in obese children. Total cholesterol averaged almost 17 milligrams per deciliter (mg/dL) higher in obese children compared to normal-weight children.

Hassink said the research on 71 children is "just a pilot study." But if larger studies confirm the findings, she said doctors may initiate lifestyle and medical interventions in this "at-risk group" long before early signs of heart disease.

Researchers have not yet identified drugs that affect adiponectin, she said. Weight loss may increase adiponectin levels. Co-authors are Darlise O'Conor, Susan Kirwin, Joe Glutting and Vicky Funanage.