Mobility Decline: Relations to Cerebral Perfusion, Small Vessel Disease Progression, and Longitudinal Blood Pressure Exposures

项目摘要/摘要 老年人的步态障碍是常见的，代价高昂，并导致功能独立性的丧失，更多 因此，在非裔美国人(AA)中，他们的比例要高于白人。然而，人们对流动性下降的途径知之甚少，而且知之甚少 在戒酒协会留学。先前的研究表明高血压、脑小血管疾病(如脑梗塞和白色病变) 物质高强度)和认知不良可能对步态有实质性影响，在再障患者中更为普遍。 这些因素也与脑灌注量有关。白人患者的静态脑血流灌注较低 与较慢的步态速度有关，这种关系被收缩压(SBP)和年龄修正。 这些关系在再生障碍性贫血中尚未被研究，以及晚年血压、脑血流灌注和 流动性还没有被描述出来。 因此，人们对这些因素如何影响流动性的了解有限。这项研究将收集以下措施 在密西西比州杰克逊市通过3T动脉自旋标记的灌注MRI和 将把研究结果与明尼苏达州一群白人进行比较。非裔美国人和白人的结合 参与者将使我们能够进一步理清与流动性下降相关的种族和地理影响。 这项研究将经济有效地定义历史和晚年血压水平、晚年大脑 灌流和晚年移动性AA和白色，通过以下三个目标节省大量成本： 目标1：确定晚年最佳SBP范围与更好的机动性和更少的机动性相关 随着年龄和脑灌注量的增加而下降。H1：与更好的移动性相关的最佳BP范围 而活动性下降程度较低的老年人脑血流灌注较高，且随年龄增加而增加 较低的大脑灌注水平和较高的年龄。 目的2：量化晚期血压、中年血压和累积血压与晚期脑血流灌注的关系。 H2：较高的中年BP和较大的累积BP暴露将与较低的BP更密切相关 脑血流灌注率高于晚年血压。 目标3：量化晚年血压、脑血流灌注和流动性之间的种族差异 机动性下降。H3.1：再生障碍性贫血患者的脑血流灌注将低于白人。H3.2：在所有参与者中 更好的大脑灌注，与更好的移动性和更少的移动性下降相关的最佳血压范围 再生障碍性贫血低于白人。 研究结果将为BP管理中测试和改进个性化药物提供第一个证据基础 与流动性有关，并将阐明造成再生障碍性疾病流动性差异的因素。

PROJECT SUMMARY/ABSTRACT Gait disturbances in older adults are common, costly, and contribute to loss of functional independence, more so in African Americans (AA) than whites. Yet the pathway to mobility decline is poorly understood and grossly understudied in AA. Prior studies suggest hypertension, cerebral small vessel disease (e.g., infarcts and white matter hyperintensities) and poor cognition may have substantial effects on gait and are more prevalent in AA. These factors are also associated with cerebral perfusion. Lower static cerebral perfusion in whites is associated with slower gait speed, and this relationship is modified by systolic blood pressure (SBP) and age. These relationships have not been examined in AA, and interrelations of late-life BP, cerebral perfusion and mobility have not been characterized. Thus, there is limited understanding of how these factors affect mobility. This study will collect measures of cerebral perfusion in a biracial sample in Jackson, Mississippi via 3T arterial spin labeled perfusion MRI and will compare findings to whites in a cohort in Minnesota. The combination of African American and white participants will enable us to further disentangle race- and geographic influences related to mobility decline. This study will cost-effectively define interrelations of historical and late-life BP levels, late-life cerebral perfusion and late-life mobility AA and whites at substantial cost savings via these three aims: Aim 1: Determine optimal SBP ranges in late life associated with better mobility and less mobility decline across age and cerebral perfusion levels. H1: Optimal BP ranges associated with better mobility and less decline in mobility will be lower in older adults with higher cerebral perfusion and will increase with lower cerebral perfusion levels and older age. Aim 2: Quantify relations of late-life BP, mid-life BP, and cumulative BP to late-life cerebral perfusion. H2: Higher mid-life BP and greater cumulative BP exposures will be more strongly associated with lower cerebral perfusion than late-life BP. Aim 3: Quantify racial differences in interrelations of late-life BP, cerebral perfusion and mobility/ mobility decline. H3.1: Cerebral perfusion will be lower in AA than in whites. H3.2: Among all participants with better cerebral perfusion, optimal BP ranges associated with better mobility and less mobility decline will be lower in AA than in whites. Findings will provide the first evidence base for testing and refining personalized medicine in BP management in relation to mobility and will elucidate contributors to mobility disparities in AA.