EFFECT OF GLYCEMIC INDEX AND CEREAL FIBER ON VASCULAR ENDOTHELIAL FUNCTION

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。 采用高分辨率超声对肱动脉进行血流介导的扩张术(FMD)是一种公认的无创生物测定方法，可用于检测人体内皮细胞产生的一氧化氮(NO)。NO被认为是一种有效的血管扩张剂，但在维持健康的内皮细胞和抑制动脉粥样硬化的发生、发展和临床表现的关键步骤方面，NO也具有相当大的作用。餐后状态可能在动脉粥样硬化的发展中起关键作用。富含谷物纤维的饮食与降低心血管疾病的风险有关。相反，高血糖指数(GI)饮食与心血管死亡率的增加有关。我们推测，谷物纤维对FMD的有益影响强于GI的潜在不良影响。因此，我们假设，无论GI如何，富含谷类纤维的早餐会显著改善FMD。相比之下，我们假设一顿低谷类纤维的高GI早餐会损害FMD。我们还假设，一顿低胃肠指数和谷类纤维的早餐对餐后FMD没有影响。采用高分辨率超声和边缘检测软件对18岁-健康成人进行四餐[(1)高纤维，低GI；(2)高纤维，高GI；(3)低纤维，低GI；(4)低纤维，高GI]每餐前、后2小时和4小时的肱动脉血流介导性扩张(FMD)检测。将使用重复测量的方差分析来评估应对膳食挑战的口蹄疫密度的差异。

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. Flow-mediated dilation (FMD) of the brachial artery using high-resolution ultrasound is a well accepted non-invasive bioassay for in vivo endothelium-generated nitric oxide (NO) in humans. NO has been characterized as a potent vasodilator, but NO also has a considerable role in maintaining healthy endothelium and inhibiting key steps in the development, progression, and clinical manifestations of atherosclerosis. The postprandial state may be critical in the development of atherosclerosis. Diets high in cereal fiber have been linked to reduced risk of cardiovascular disease. Conversely, high-glycemic index (GI) diets have been linked to increased cardiovascular mortality. We postulate that the beneficial effect of cereal fiber on FMD is stronger than the potentially adverse effect of GI. Therefore, we hypothesize that breakfast meals high in cereal fiber will acutely improve FMD, regardless of GI. By contrast, we hypothesize that a high-GI breakfast meal that is low in cereal fiber will impair FMD. We also hypothesize that a breakfast meal that is low in both GI and cereal fiber will have no effect on postprandial FMD. Brachial artery flow-mediated dilation (FMD) will be assessed before and at 2 h and 4 h after each of four breakfast meals [(1) High-fiber, Low GI; (2) High-fiber, High-GI; (3) Low-fiber, Low-GI; (4) Low-fiber, High-GI] using high-resolution ultrasound and edge-detection software in healthy adults ages 18-64. Analysis of variance with repeated measures will be used to assess differences in FMD in response to the meal challenges.