CLINICAL TRIAL: A NOVEL DIAGNOSTIC TEST TO DETECT VITAMIN B12 DEFICIENCY

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 维生素B-12缺乏是一个常见的问题，影响到普通美国人，特别是老年人。老年人面临临床前维生素B-12缺乏症的风险，因为随着年龄的增长，维生素B-12吸收不良和萎缩性胃炎的发生率增加。老年人缺乏维生素B-12可能会引发严重的并发症，包括痴呆症、阿尔茨海默病、S病和癌症。目前诊断B-12缺乏症的方法是不够的，因为它们缺乏特异性，没有明确的参考范围，或者价格昂贵。 我们建议的测试，被称为B-12呼气测试-BBT，将具有非侵入性、易于管理和保质期长的优势。BBT将使医生能够准确地检测B-12缺乏症。我们的目标是在治疗可以避免并发症的临床前阶段确定维生素B-12缺乏症。诊断这种缺乏症是有意义的，因为它可以用适当的维生素B-12补充剂有效而廉价地治疗。 这项测试的基本科学原理是，丙酸的代谢受到维生素B-12可获得性的限制。口服示踪剂量的13C-非放射性标记丙酸后，维生素B-12缺乏者呼吸中的13CO2量减少。第一阶段的赠款证明了这一概念的可行性。在第二阶段，我们将完善测试程序，简化测试。我们将检查较小剂量的丙酸，一次20分钟的呼吸收集，并消除禁食状态超过1小时的需要。

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. Vitamin B-12 deficiency is a common problem that affects the general US population and the elderly in particular. The elderly are at risk for preclinical vitamin B-12 deficiency due to the increased presence of B-12 malabsorption and atrophic gastritis as a consequence of aging. The deficiency of vitamin B-12 in the elderly has potentially serious complications including dementia, Alzheimer?s disease, and cancer. Current approaches to diagnosing B-12 deficiency are inadequate because they lack specificity, have poorly defined reference ranges or are expensive. Our proposed test, known as the B-12 Breath Test-BBT, will have the advantage of being non-invasive, be easy to administer and have a long shelf life. The BBT will allow physicians to accurately test for B-12 deficiency. Our goal is to identify vitamin B-12 deficiency in a preclinical stage when treatment can avert complications. Diagnosing this deficiency is meaningful because it can be effectively and inexpensively treated with appropriate vitamin B-12 supplementation. The underlying scientific principle of the test is that the metabolism of propionate is limited by the availability of vitamin B-12. After orally administering a tracer dose of 13C-non-radioactive, labeled propionate, the amount of 13CO2 is reduced in the breath of vitamin B-12 deficient individuals. The phase I grant demonstrated the feasibility of this concept. In Phase II we will refine the testing procedure and simplify the test. We will examine a smaller dose of propionate, a single 20-minute breath collection and eliminate the need to be in a fasted state for greater than 1 hour.