INDICES FOR DETERMINING SOMATOTROPIN DEFICIENCY IN ADULTS

本研究的主要目的是比较一组通常用于识别生长激素缺乏症患者的诊断测试，并确定每种测试在生长激素缺乏症成人人群中诊断使用的相对效用。使用零假设，我们期望在年龄、性别、种族血统和体重指数相匹配的情况下，发现在区分临床诊断的生长激素缺乏个体与健康对照受试者的能力方面，两种测试之间没有差异。本研究的第二个目的是评估这些刺激试验以及血浆IGF-I水平在生长激素缺乏症高潜力患者亚群中的价值。本研究的第三个目标是通过确定和记录与每项试验相关的不良事件的频率和严重程度来评估每项试验的安全性。这将是一个多中心的横断面设计研究，涉及100名患者。大约20至25名患者将在我们的机构进行研究。本研究将代表三个患者群体。生长激素缺乏（患病）人群将由大约40名被诊断患有多种激素缺乏（两种或两种以上先前确定的激素缺乏）的成人起病垂体功能减退症患者代表。对照人群将由大约40名年龄在18至70岁之间的健康志愿者代表。志愿者的选择将进行匹配，使小组组成在以下变量方面与多种激素缺乏的实验组相似：年龄，性别，种族血统和体重指数（BMI）。第三组将包括大约20名临床诊断为有器质性垂体疾病的患者，他们要么有一种已知的激素缺陷，要么没有。五种生长激素刺激试验和一种生长激素依赖性生化标志物（IGF-1）的诊断效用将被评估。每个测试将根据其与患者的临床诊断（生长激素缺乏或正常）的一致性来判断。刺激试验包括：精氨酸；左旋多巴;精氨酸/左旋多巴;精氨酸/生长激素释放激素（GHRH）和胰岛素耐量试验（ITT）。刺激试验的顺序将由预先编写的随机表确定，表中列出了每个患者编号的特定试验顺序。

The primary objective of this study is to compare a set of diagnostic tests commonly used to identify patients with somatotropin deficiency and determine the relative utility of each test for diagnostic use in somatotropin-deficient adult populations. Using the null hypothesis, we expect to find no difference between the tests in ability to discriminate clinically diagnosed somatotropin-deficient individuals from healthy control subjects when matched for age, gender, ethnic origin, and body mass index. The secondary objective of this study is to evaluate the value of these stimulation tests as well as that of plasma IGF-I levels in a sub-population of patients who have a high potential for somatotropin deficiency. A third objective of the study is to evaluate the safety of each test by determining and recording the frequency and severity of adverse events associated with each test. This will be a multi-center study of cross-sectional design, involving 100 patients. Approximately 20 to 25 patients will be studied at our institution. Three patients' populations will be represented in this study. The somatotropin-deficient (diseased) population will be represented by approximately 40 patients who have been diagnosed to have adult-onset hypopituitarism with multiple hormone deficiencies (two or more previously identified hormone deficiencies). The control population will be represented by approximately 40 healthy volunteers between 18 and 70 years of age. Volunteer selection will be matched so that the group composition resembles that of the multiple hormone- deficient experimental group for the following variables: age, gender, ethnic origin, and body mass index (BMI). A third group will include approximately 20 patients who have been clinically diagnosed as having organic pituitary disease and either one or no known hormonal deficiencies. The diagnostic utility of five somatotropin stimulation tests and one somatotropin-dependent biochemicla marker, (IGF-1) will be evaluated. Each test will be judged according to its agreement with the clinical diagnosis of the patient (either somatotropin deficient or normal). Stimulation tests include the following: Arginine; l-dopa; arginine/ l-dopa; arginine/growth hormone-releasing hormone (GHRH) and insulin tolerance test (ITT). The order of stimulation test administration will be determined by a pre-written randomized table listing a specific test sequence for each patient number.