HIGH-COMPLEX-HIGH-REFINED-CHO MEALS, AND LOW-CHO MEALS ON ENDOTHELIAL FUNCTION

这个子项目是许多利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 使用高分辨率超声对肱动脉进行血流介导的扩张（FMD）是一种公认的用于人体内内皮产生的一氧化氮（NO）的无创生物测定法。 NO已被表征为有效的血管扩张剂，但NO在维持健康内皮和抑制动脉粥样硬化的发展、进展和临床表现的关键步骤中也具有相当大的作用。 由于餐后状态可能在动脉粥样硬化的发展中至关重要，并且由于谷物纤维含量高的饮食与心血管疾病风险降低有关，因此我们假设高碳水化合物，高纤维膳食将急剧改善FMD。 相比之下，我们假设低碳水化合物的膳食会损害FMD，而高碳水化合物、低纤维的膳食对FMD没有影响。 我们还假设，在低碳水化合物餐中添加高纤维早餐谷物将减弱低碳水化合物餐后观察到的FMD损伤。将在四次早餐前、早餐后2 h和4 h评估肱动脉血流介导的扩张（FMD）（高碳水化合物，高纤维;高碳水化合物，低纤维;低碳水化合物，低纤维;低碳水化合物，高纤维），使用高分辨率超声和边缘检测软件在12名8-17岁的超重或有超重风险的参与者中进行，12名参与者年龄在18-64岁之间，12名参与者年龄在65岁及以上。 重复测量的方差分析将用于评估FMD对膳食挑战的反应差异。

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. Because the postprandial state may be critical in the development of atherosclerosis, and because diets high in cereal fiber have been linked to reduced risk of cardiovascular disease, we hypothesize that a high-carbohydrate, high-fiber meal would acutely improve FMD. By contrast, we hypothesize that a low-carbohydrate meal will impair FMD, and that a high-carbohydrate, low-fiber meal will have no effect on FMD. We also hypothesize that the addition of a high-fiber breakfast cereal to the low-carbohydrate meal will attenuate the impairment of FMD observed after the low-carbohydrate meal. Brachial artery flow-mediated dilation (FMD) will be assessed before and at 2 h and 4 h after each of four breakfast meals (high-carbohydrate, high-fiber; high-carbohydrate, low-fiber; low-carbohydrate, low-fiber; low-carbohydrate, high-fiber) using high-resolution ultrasound and edge-detection software in 12 participants ages 8-17 who are overweight or at-risk for overweight, 12 participants ages 18-64, and 12 participants ages 65 and older. Analysis of variance with repeated measures will be used to assess differences in FMD in response to the meal challenges.