Cardiovascular and Cerebrovascular Risk Factors for Mobility Limitation in the Jackson Heart Study

摘要 行走是人类生活的一项核心活动。活动受限，或行走困难或不能，会限制一个人的 能够独立工作、独立生活、参与社区生活。心脏和大脑健康是 通向移动性限制的最强可修改路径。非裔美国人背负着不成比例的 心血管疾病、脑血管疾病、认知障碍和行动受限， 但大多数关于这些条件之间的关系的研究主要是在 白人人口。活动受限的生物学和最佳预防策略可能有所不同 种族/族裔，突出了在代表性不足的人群中进行研究的迫切需要。拟议的研究 将在杰克逊心脏研究(JHS)中增加经过验证的行动能力、残疾和身体表现的衡量标准， 一项针对非裔美国人的队列研究，旨在调查高危人群中心血管疾病的原因。JHS 参与者参加了三次考试(考试1,2000-2004年，考试2,2005-2008年，考试3,2009-2013年)； 第四次考试计划从2020年开始，对剩余的3500名参与者(平均年龄=65岁)进行测试。考试 将包括广泛的心血管疾病测量、社会经济状况、心理社会健康、认知测试和大脑 核磁共振检查。我们建议进行一项辅助研究，以增加既定的活动限制措施：步态速度和步态速度0.6m/S， 以及自我报告的行走四分之一英里或爬10级楼梯的困难/无力。我们将利用近20年的 CVD/CBVD危险因素的多年数据和新收集的亚临床血管疾病和脑疾病的数据 健康，以更好地了解暴露于危险因素的时间和活动受限的中介途径 在非裔美国人身上。我们假设暴露在高血压、高空腹血糖和 中年肥胖与老年人活动受限的关系比暴露在这些环境中更强 晚年的危险因素。我们将使用新的统计中介方法来量化潜在的 调解员解释CVD/CBVD风险因素与行动限制之间的关系，同时允许我们 测试这些调解人的潜在交互作用。这项研究将支持我们的长期目标， 非裔美国人的功能性健康，以维护独立和参与 社区。了解心脏和大脑健康与活动受限之间的联系对于减少 健康方面的种族差异。此外，功能措施的增加将有助于将JHS扩展为 当代研究非裔美国人的心血管健康和老龄化。

ABSTRACT Walking is a core activity of human life. Mobility limitation, or difficulty or inability to walk, can limit a person's ability to work, live independently, and participate in the community. Heart and brain health are two of the strongest modifiable pathways to mobility limitation. African Americans have a disproportionate burden of cardiovascular disease (CVD), cerebrovascular disease (CBVD), cognitive impairment, and mobility limitation, but the majority of research on the relationship between these conditions has been conducted in predominantly white populations. The biology and optimal prevention strategies for mobility limitation may differ by race/ethnicity, highlighting a critical need for research in underrepresented populations. The proposed research will add validated measures of mobility, disability, and physical performance to the Jackson Heart Study (JHS), a cohort study of African Americans, designed to investigate causes of CVD in a high-risk population. JHS participants have undergone three exams (Exam 1, 2000-2004, Exam 2, 2005-2008, Exam 3, 2009-2013); Exam 4 is scheduled on the 3,500 remaining participants (mean age = 65 years) beginning in 2020. The exam will include extensive CVD measures, socioeconomic status, psychosocial health, cognitive testing, and brain MRI. We propose an ancillary study to add established measures of mobility limitation: gait speed <0.6 m/s, and self-reported difficulty/inability to walk a quarter of a mile or climb 10 stairs. We will leverage the nearly 20 years of data on CVD/CBVD risk factors and newly collected data on subclinical vascular disease and brain health to better understand the timing of exposure to risk factors and mediating pathways to mobility limitation in African Americans. We hypothesize that exposure to high blood pressure, high fasting glucose, and adiposity in midlife will have stronger associations with mobility limitation in older adults than exposure to these risk factors in late life. We will use novel statistical mediation methods to quantify the extent to which potential mediators explain the relationship between CVD/CBVD risk factors and mobility limitation, while allowing us to test for potential interactions by these mediators. This research will support our long-term goal to enhance functional health among African Americans, in order to preserve independence and participation in the community. Understanding the link between heart and brain health and mobility limitation is critical to reduce racial disparities in health. Moreover, the addition of the functional measures will help expand JHS into a contemporary study cardiovascular health and aging in African Americans.