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

项目总结/摘要 老年人的步态障碍是常见的，昂贵的，并导致功能独立性的丧失， 非裔美国人（AA）比白人多。然而，人们对流动性下降的途径知之甚少，而且严重 在戒酒协会当替补先前的研究表明，高血压、脑小血管疾病（例如，梗死和白色 物质高信号）和认知能力差可能对步态有实质性影响，并且在AA中更普遍。 这些因素也与脑灌注有关。白人静态脑灌注较低， 与较慢的步态速度相关，这种关系被收缩压（SBP）和年龄所改变。 这些关系尚未在AA中进行研究，晚年血压、脑灌注和 流动性尚未确定。 因此，对这些因素如何影响流动性的理解有限。这项研究将收集的措施， 在密西西比的杰克逊，通过3 T动脉自旋标记灌注MRI测量的birthy样本中的脑灌注， 将把研究结果与明尼苏达州的一组白人进行比较。非裔美国人和白色人的结合 与会者将使我们能够进一步理清与流动性下降有关的种族和地域影响。 这项研究将经济有效地确定历史和晚年血压水平，晚年脑血管疾病， 灌注和晚年流动性AA和白人通过这三个目标节省大量成本： 目的1：确定晚年最佳SBP范围与更好的活动性和更少的活动性相关 随着年龄的增长和脑灌注水平的下降。H1：与更好的移动性相关的最佳BP范围 在脑灌注较高的老年人中，活动性下降较少， 脑灌注水平较低和年龄较大。 目的2：量化晚年血压、中年血压和累积血压与晚年脑灌注的关系。 H2：较高的中年BP和较大的累积BP暴露与较低的 脑灌注比晚年血压高。 目的3：量化晚年血压、脑灌注和活动性相互关系的种族差异。 流动性下降。H3.1：AA的脑灌注低于白人。H3.2：在所有参与者中， 更好的脑灌注，与更好的活动性和更少的活动性下降相关的最佳BP范围， AA比白人低。 研究结果将为测试和改进BP管理中的个性化药物提供第一个证据基础 并将阐明AA中流动性差异的原因。

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.