VALIDATION OF AN OXALATE ABSORPTION 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来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心机构，不一定为研究者机构。尿中草酸的排泄量是草酸钙肾结石形成的重要决定因素。饮食中的草酸盐约占排泄量的一半，另一半在体内产生。目前没有有效的治疗方法来减少尿液中草酸盐的排泄量，尽管这种方法可以减少草酸钙结石的形成。目前还没有已知的减少内源性草酸盐合成的方法，但有证据表明，膳食草酸盐的吸收可以改变。与膳食共同摄入钙以结合饮食中的草酸盐似乎是最有效的调节剂。此外，一些研究表明，一些结石形成者过度吸收草酸盐。这些人，特别是，可以受益于有针对性的营养方法。在本方案中，将检查在标准条件下测定草酸盐吸收的试验的重现性。目前使用的测试来测量草酸盐的吸收是由个人的再现性差。据推测，这种变异性是由于摄入固体食物前的草酸负荷。第二个假设是在测试之前或之后不需要饮食控制。

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. The amount of oxalate excreted in urine is an important determinant in the formation of calcium oxalate kidney stones. Dietary oxalate comprises approximately half of the amount excreted and the other half is made within the body. There is no proven treatment currently available for decreasing the amount of oxalate excreted in urine, although such a strategy should decrease calcium oxalate stone formation. There are no known means of decreasing endogenous oxalate synthesis, but there is evidence that the absorption of dietary oxalate can be modified. The co-ingestion of calcium with meals to bind oxalate in the diet appears to be the most effective modifier. Furthermore, several studies have indicated that some stone formers hyperabsorb oxalate. Such individuals, in particular, may benefit from a targeted nutritional approach. In this protocol, the reproducibility of a test to determine the absorption of oxalate under standard conditions will be examined. Currently used tests to measure oxalate absorption are marred by a poor reproducibility in individuals. It is hypothesized that this variability is due to the ingestion of the oxalate load before solid food. A second hypothesis is that dietary control is not required before or after the test.