INDICES FOR DETERMINING SOMATOTROPIN DEFICIENCY IN ADULTS

本研究的主要目的是比较一组诊断测试通常用于识别生长激素缺乏症患者，并确定每个测试的相对效用，用于诊断生长激素缺乏症的成年人群。 使用零假设，我们期望发现当年龄、性别、种族和体重指数匹配时，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，测试之间没有差异。 本研究的次要目的是评价这些刺激试验的价值以及在具有高生长激素缺乏可能性的患者亚群中血浆IGF-I水平的价值。 本研究的第三个目的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价每项试验的安全性。这将是一项横断面设计的多中心研究，涉及100例患者。 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3个患者人群。 生长激素缺乏（患病）人群将由约40名被诊断为成人发作垂体功能减退伴多种激素缺乏（两种或多种先前确定的激素缺乏）的患者代表。 对照人群将由约40名18 - 70岁的健康志愿者代表。 志愿者选择将被匹配，使得组组成类似于多种激素缺乏实验组的以下变量：年龄、性别、种族和体重指数（BMI）。 第三组将包括大约20名临床诊断为器质性垂体疾病的患者，这些患者有一种或没有已知的激素缺乏症。将评估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。 将根据其与患者临床诊断（生长激素缺乏或正常）的一致性来判断每项测试。 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）和胰岛素耐受试验（ITT）。 将通过预先编写的随机表确定刺激试验给药顺序，该表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.