STUDY 1: TO COMPARE THE RELIABILITY OF MMT AND IV GLUCAGON STIMULATION TEST

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。细胞功能的测量可以作为试图减缓或阻止细胞破坏的临床试验的主要终点。有许多方法可以评估这一点，因为细胞对各种口服和静脉注射分泌剂有反应。临床上最常用的试验是C-肽对口服混合餐(混合餐耐量试验)和静脉注射胰高血糖素的反应(高血糖素刺激试验，GST)。这些测试在持续时间、刺激类型和途径、诱发的高血糖程度以及受试者和研究人员的负担方面有所不同。此外，目前还不知道这两种测试之间的可靠性是否存在差异。因此，在这些测试条件下确定C肽测量的可靠性将是本研究的主要结果。其他分析将使用适当的线性或非线性回归模型来描述两个测试之间关系的性质。模型还将根据数据来源、年龄、性别、糖尿病病程和血糖值等变量进行调整。多个中心的大约120名参与者将被要求接受四项测试：两项MMT和两项GST，相隔3-10天。受试者将在糖尿病试验网的支持下进行研究。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Measurement of ¿-cell function can serve as the primary end point of clinical trials attempting to slow or stop ¿-cell destruction. There are numerous ways to assess this as the ¿-cell responds to various oral and IV secretagogues. The most commonly used tests in clinical practice are the C-peptide response to either an oral mixed meal (Mixed Meal Tolerance Test, MMTT) and to administration of IV glucagon (Glucagon Stimulation Test, GST). These tests differ in duration, type and route of stimulus, degree of hyperglycemia induced and subject and investigator burden. Further, it is not known whether there are differences in reliability between these two tests. Thus, determination of reliability of C-peptide measures under these test conditions will be the primary outcome of this study. Additional analyses will describe the nature of the relationship between the two tests using a linear or non-linear regression model as appropriate. Models will also adjust for variables such as the source of the data, age, sex and duration of diabetes and glucose value. Approximately 120 participants at multiple centers will be asked to undergo four tests: two MMTT and two GST, 3-10 days apart. Subjects will be studied under the auspices of Diabetes TrialNet.