Reduce Obesity and Diabetes

Overview

This study examines risk factors for type 2 diabetes in children representing multiple discrete ethnic groups. It also examines the short term effects of school-based health education supervised exercise on metabolic risk factors for type 2 diabetes mellitus in children. The investigators hypothesize that exercise and health education will significantly improve insulin sensitivity in all children, especially in children who are already insulin resistant, thereby lowering the risk that they will go on to develop type 2 diabetes mellitus. The specific hypotheses being tested are: 1. Insulin resistance will be most evident in overweight children while an impaired ability of the pancreas to release insulin will be most evident in children with a family history of type 2 diabetes mellitus. 2. Exercise will significantly improve insulin resistance (as measured by the fasting glucose/insulin ratio) with little effect on insulin secretory capacity in children. 3. Participation in a school-based health, nutrition, and exercise education program will have long term beneficial effects on health related behaviors and on insulin resistance in all children, regardless of their level of diabetes risk.

The prevalence of type 2 diabetes mellitus (type 2 DM) among adolescents has increased \> 10 fold over the past decade. Type 2 DM reflects the interactions of genes/traits conveying an increased risk of impaired function of the pancreatic cells that secrete insulin (islet cells)and muscle/liver insulin sensitivity with environmental factors such as reduced levels of activity and increasing adiposity. Both impaired islet cell function and insulin resistance are independently associated with increased risk of subsequent diabetes mellitus and may be considered as 'prediabetic' phenotypes. This study examines the prevalence of prediabetic phenotypes and the effects of supervised exercise/nutrition education on risk factors for type 2 DM in 6th-8th grade students who will undergo a 5 minute intravenous glucose tolerance test, as well as measurements of other diabetes risk factors including family history, body composition, circulating concentrations of molecules (cytokines) that are markers of inflammation , and lipid profiles, before and after participating in the intervention. These studies will also be used to calculate both the ability of the pancreas to secrete insulin and the sensitivity of the students to insulin. No previous studies have isolated the effects of exercise and nutrition education on different diabetes subphenotypes in children. To insure the necessary ethnic diversity necessary to these studies, data will be pooled in a multisite study with Mt. Sinai, North Shore/LIJ, Maimonides, and Winthrop Hospitals. We will remain in contact with students to track subsequent development of diabetes intervention effects on lifestyle. We hypothesize that diabetes risk in most students will be reduced by exercise and education in a healthy lifestyle but that the type of health benefit (i.e., improved body fatness, improved insulin sensitivity, improved insulin secretion, improved cholesterol, or decreased inflammation) will be different between ethnic groups. The results of these studies will, we believe, demonstrate the benefits of health and physical education programs to all students, regardless of diabetes risk, and will also enable us to better understand how diabetes develops in children and what expectations we can have for health improvement in different ethnic groups from such an intervention.