Waist circumference, a measure of belly fat, is not a better predictor than body mass index for identifying children with an increased risk of developing type 2 diabetes, according to a study by University of Michigan researchers.
Results of the study, led by U-M C.S. Mott Children's Hospital pediatric endocrinologist Joyce M. Lee, M.D., M.P.H., appear online today ahead of print in the Journal of Adolescent Health.
Increases in obesity and type 2 diabetes in children and adolescents in the United States have led to increased interest in early identification of high-risk children, including those with high insulin levels, as they have an increased risk for developing type 2 diabetes.
The predictor used most widely in the primary care setting and which has been recommended by the American Academy of Pediatrics is body mass index, also known as BMI.
"There is increasing interest in measuring waist circumference in children to assess for chronic disease risk," says Lee, a member of the Child Health Evaluation and Research (CHEAR) Unit. "Providers may be unsure of whether they should be measuring body mass index, weight circumference or both to determine those risks."
"Waist circumference measures excess fat around the belly, which is an important risk factor for type 2 diabetes," Lee adds. "It has been suggested that waist circumference should be used instead of BMI for prediction of diabetes risk than obesity."
Using data from the National Health and Nutrition Examination Survey from 1999-2002, U-M researchers evaluated BMI, waist circumference, fasting glucose and insulin levels in an ethnically diverse sample of 1,571 adolescents.
Researchers found that close to 12% of the study population had insulin resistance and that BMI and waist circumference were equivalent in their ability to identify children with insulin resistance, a risk factor for diabetes.
"Waist circumference does not seem to provide a distinct advantage over BMI for identifying high-risk adolescents. Our findings suggest that further studies are needed before waist circumference is included as part of routine pediatric primary care screening," Lee says.
Currently, the AAP recommends that primary care providers use BMI as a screening tool for identifying overweight and obese children. Based on their findings, Lee and colleagues suggest that national organizations that issue screening guidelines should continue to encourage providers to focus on solely on BMI measurement for now.
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