OUTLINE: Patients undergo a comprehensive medical examination including current and past medical history, family history, review of prescription medications, a physical examination including a body and visceral-fat assessment, and anthropometric (DEXA and bone-age x-ray) and blood pressure measurement. Blood samples are collected to measure growth hormone, adipokines (adiponectin, leptin), cytokines (IL-6 and CRP), fasting insulin, fasting glucose, lipids, oxidized LDL, hypothalami-pituitary-gonadal function (estrogen, FSH, LH, testosterone), and thyroid function (free T4 and TSH). Patients also complete questionnaires on dietary intake and physical activity.