Study to Investigate the Pathophysiology of Type 2 Diabetes in Youth

Conditions

Beta-cell Function | Childhood Obesity | Impaired Glucose Tolerance | Insulin Resistance | Metabolic Syndrome | Pre-Diabetes

Trial Phase

Trial Purpose and Description

Trial Purpose

The purpose of the study is to determine the role of beta-cell function and insulin resistance in the development of impaired glucose tolerance (IGT) and type 2 diabetes in children and adolescents who have an increased risk of developing type 2 diabetes due to overweight/obesity or a family history of overweight/obesity, diabetes and/or impaired fasting glucose. It is hypothesized that: 1)Obese adolescents with IGT will be more insulin resistant than obese adolescents with NGT. Insulin resistance will be the best predictor of changes in glucose tolerance status., 2)Beta cell function will be impaired in obese adolescents with IGT compared to obese adolescents with NGT., 3)Obese adolescents with IGT will present with greater intramyocellular, intrahepatic and visceral fat than obese adolescents with NGT. Furthermore, obese adolescents with IGT will have larger adipocytes, while having significantly fewer adipocytes compared to obese adolescents with NGT. Obese adolescents with IGT will also have altered expression of key genes related to insulin resistance., and 4)Abnormalities in endothelial function as manifested by low FMD and PAT are already present in obese adolescents with IGT and are linked to insulin resistance.


Participation Guidelines

Age:
8 Years - 22 Years
Gender:
Both

Eligibility Criteria

Inclusion Criteria:

  • Lean (not overweight or obese) will be defined as a body mass index (BMI) (kg/m2) less than the 85th percentile specific for age and gender, overweight will be defined as a BMI between the 85th and 95th percentiles, and obesity will be defined as a BMI greater than the 95th percentile1. Following the oral glucose tolerance test (OGTT, 75 gm) (HIC #11190), children will be classified as normal glucose tolerant if plasma glucose at two hours is is =140 mg/dl. To enter the study all children and adults must be in good general health, have a normal medical history and physical exam, and have no endocrinopathies (normal thyroid function test) or other diseases that might affect glucose metabolism.
  • Eligibility will be determined by a comprehensive family and medical history and physical examination prior to enrollment in the study. Tanner stage of pubic breast and gonadal development will be determined by physical examination and by measurements of estradiol, testosterone and IGF1 as biochemical markers of pubertal development.

Exclusion Criteria:

  • Medications that are known to alter glucose or insulin metabolism, such as oral steroids, or certain psychiatric medications, such as Celexa, Lithium and Paxil. Children and adults will be excluded from participating in the PAT test if they have a latex allergy. Lean subjects must have at least one parent, grandparent or sibling with overweight/obesity (BMI >25), type 2 diabetes, and/or impaired fasting glucose (IFG) (fasting glucose >100 mg/dl). A fasting plasma glucose level will be obtained via finger stick in parents of potential volunteers in whom status of diabetes or IFG is unknown. Exclusion criteria also include known diabetes or taking any medication that alters liver function and blood pressure. Youth on chronic anti-inflammatory medications or who consume alcohol are also excluded.
Sponsor:
National Institute of Child Health and Human Development
Yale University
Dates:
04/20/2001
Last Updated:
Study HIC#:
0102012241