Insulin Resistance and Cognitive Dysfunction in Obese Adolescents: Pilot Study

The short-term goal of this project is to conduct a feasibility study at Winthrop University Hospital to determine how well extremely obese (BMI > 99%tile corrected for age) children and adolescents can be recruited into an exercise program and evaluated in an efficient fashion, and to identify particular strategies (e.g., medical examination feedback) that can serve as potential benefits to research subjects and their families. In addition investigators will evaluate the effect of the exercise program on physical fitness, insulin resistance, and neurocognitive functioning as well as the relationship between insulin sensitivity and neurocognitive function among adolescents who participate in the exercise program.

The long-term goal of this project is to evaluate a large, multi-ethnic sample of adolescents, 14 to 19 years of age, to systematically assess cognitive function and school performance, fitness and examine the relationship between performance on those outcome variables and a variety of biomedical and psychosocial factors that may directly or indirectly influence brain function and test-taking performance.

High body mass index (BMI) among children and adolescents continues to be a public health concern in the United States. The most recent figures from the National Health and Nutrition Examination Survey (NHANES) for 2007-2008 report that 18.1% (95% CI, 14.5%-21.7%) of 12- through 19-year-old adolescents were at or above the 95th percentile of BMI for age. Children with high BMI often become obese adults, and obese adults are at risk for many chronic conditions. High BMI in children may also have immediate consequences, such as elevated lipid concentrations and blood pressure.

It now appears that neurocognitive dysfunction is also more common in obese children and adolescents. In a large population study of 2,519 children, 8 to 16 years of age, a brief neuropsychological assessment showed a statistically significant, albeit modest relationship between cognitive test scores and BMI that persisted after adjusting for confounding variables. Obesity is also associated with several conditions which known to affect brain function, including sleep apnea, insulin resistance, hypertension, and chronic inflammatory factors (e.g., by these variables cannot be determined, unfortunately, because those variables were not measured.

It is important to note, however, that there is not complete agreement on linkages between obesity and cognition.