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

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。测量细胞功能可以作为临床试验的主要终点，试图减缓或阻止细胞破坏。有许多方法可以评估这一点，因为细胞对各种口服和IV促分泌素有反应。临床实践中最常用的试验是C肽对口服混合餐（混合餐耐受性试验，MMTT）和IV胰高血糖素给药（胰高血糖素刺激试验，GST）的反应。这些试验的持续时间、刺激类型和途径、诱导的高血糖程度以及受试者和研究者负担不同。此外，尚不清楚这两种测试之间是否存在可靠性差异。因此，确定这些试验条件下C肽测量的可靠性将是本研究的主要结局。额外的分析将使用线性或非线性回归模型（如适用）描述两种检测之间关系的性质。模型还将调整数据来源、年龄、性别、糖尿病持续时间和血糖值等变量。多个中心的大约120名参与者将被要求接受四项测试：两项MMTT和两项GST，间隔3-10天。受试者将在Diabetes TrialNet的主持下进行研究。

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.