Neuroendocrine Factors in Adolescent Obesity

描述（由申请人提供）：肥胖是一种流行病，比以往任何时候都更年轻。肥胖与几种激素分泌模式的变化有关，包括生长素、生长激素（GH）和胰岛素，这些激素在青少年群体中尚未得到研究。胃促生长素是一种主要的胃激素，能增加食欲，是一种促生长激素。本研究将通过频繁采血和生长激素释放激素和精氨酸刺激生长激素试验，比较超重和正常体重少女ghrelin和GH分泌的变化。这些激素与胰岛素抵抗（通过1h核磁共振波谱测量）和身体成分（通过双能x线吸收仪和磁共振成像测量）之间的关系将被研究。这项研究还将确定餐后胃饥饿素对测试餐的反应，这些反应因主要宏量营养素的类型而异，这可能预测随后一餐的饥饿程度和摄入量。了解饥饿素和生长激素与肥胖相关的变化及其与身体成分、胰岛素抵抗和食欲的关系，将有助于制定减少肥胖并发症的策略。

DESCRIPTION (provided by applicant): Obesity is an epidemic that is striking people at younger ages than ever before. Obesity is associated with changes in the secretory patterns of several hormones including ghrelin, growth hormone (GH), and insulin, which have not been examined in the adolescent age group. Ghrelin, a primarily gastric hormone, increases appetite and is a GH secretagogue. This study will compare the alteration in secretion of ghrelin and GH in overweight and normal weight adolescent girls through frequent blood sampling and GH stimulation testing with growth hormone releasing hormone and arginine. The relationship between these hormones and insulin resistance, measured by 1H-nuclear magnetic resonance spectroscopy, and body composition, measured by dual energy x-ray absorptiometry and magnetic resonance imaging, will be investigated. This study will also determine the postprandial ghrelin response to test meals that vary by the type of predominant macronutrient, which may predict the degree of hunger and amount of intake at a subsequent meal. Understanding obesity-related changes in ghrelin and GH and their relationship to body composition, insulin resistance, and appetite will help in the development of strategies to reduce complications of obesity.