Waist Circumference not a Better Predictor of Diabetes Risk Than Body Mass Index in U.S. Adolescents

Until more studies are available, physicians should continue to use BMI to identify high risk children, U-M researchers say

ANN ARBOR, Mich., Aug. 19, 2011 /PRNewswire-USNewswire/ -- 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."  

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.

Authors: In addition to Dr. Lee, authors include: Kateryna Kotlyarevska, M.D., Peter Wolfgram, M.D.  

Reference: DOI: 10.1016/j.jadohealth.2010.12.008

Conflict of Interest disclosures: None

Funding: Dr. Lee was supported by NIDDK K08DK082386 and the Clinical Sciences Scholars Program at the University of Michigan.

About U-M's CHEAR Unit: Founded in 1998, U-M's CHEAR Unit is a national leader in the analysis of the American health care system and the organization and financing of care for children. Since its inception, the CHEAR Unit has been awarded over $40 million in research grants from federal, state, and foundation sources. The CHEAR Unit comprises core faculty from the Schools of Medicine, Social Work, Dentistry, Pharmacy, Nursing, Public Health, Business and Law. Multidisciplinary teams provide the structure for research of community, state and national child health policies, practices, and programs. There are more than 30 faculty affiliated with CHEAR.

About C.S. Mott Children's Hospital:

The University of Michigan C.S. Mott Children's Hospital is consistently ranked as one of the best hospitals in the country. It was nationally ranked in all ten pediatric specialties in the U.S. News Media Group's 2011 edition of "America's Best Children's Hospitals" including third in the country for heart and heart surgery. In November, the hospital moves to a new 1.1 million square feet, $754 million state-of-the-art facility that will be home to cutting-edge specialty services for newborns, children and women.

SOURCE University of Michigan C.S. Mott Children's Hospital