Risk Factors for Cognitive Decline in African Americans

描述(由申请人提供)：有充分的证据表明，与年龄匹配的白人相比，年长的非裔美国人在认知表现测试中的表现往往更差。到目前为止，大多数研究都是横断面研究，重点是找出可以解释他们表现较差的因素。由于很难解释与单一时间点的测试测量相关的文化和教育偏差，这些研究需要通过检查认知功能的变化来补充。然而，很少有研究使用纵向设计来检查非裔美国人认知功能随时间变化的风险因素。引起越来越多关注的一个重要风险因素是心理社会压力及其与认知和认知衰退的关系。越来越多的研究表明，心理困扰程度、社会孤立和感知到的压力与认知衰退和痴呆症的发生率增加有关，但大多数研究只对年长的白人进行。由于年长的非裔美国人在美国社会中处于不利地位，他们往往高度暴露于慢性压力来源，并报告某些类型的心理社会压力水平较高，如感知到的歧视和社会孤立。拟议项目的目标是进行一项流行病学纵向研究，以检查可能解释心理社会风险因素与认知能力下降关系的生物学机制，这些因素在老年白人的研究中已被证明是重要的，但尚未在老年非裔美国人中进行研究。这项拟议的研究将利用风险因素数据、纵向统一结构的临床数据，以及对350多名老年非裔美国人随时间推移的认知能力的详细测量，这些人在基线水平上没有痴呆，并同意进行年度临床评估。此外，我们将检测血清中的炎症标志物，以检验心理社会应激与老年非裔美国人认知能力下降有关的假设，这种关系是由炎症标志物介导的。确定心理社会压力可能与认知功能变化有关的机制对公共卫生的重要性至关重要，并可能增加早期干预战略以防止或减缓快速增长的少数群体认知能力下降的可能性。了解慢性应激对老年人认知的影响方式以及潜在的生物机制对公共卫生的重要性至关重要，特别是在越来越重视早期发现和干预策略以改变并最终防止认知能力下降的时期。

DESCRIPTION (provided by applicant): It is well documented that older African Americans, on average, tend to perform more poorly on cognitive performance tests compared to age-matched Whites. Most research to date has been cross-sectional studies that focus on identifying factors that can account for their poorer performance. Because of the difficulty in accounting for cultural and educational biases associated with test measurement at a single point in time, these studies need to be complemented by examination of change in cognitive function. However, few studies have used a longitudinal design to examine risk factors for change in cognitive function over time in African Americans. One important risk factor that has gained increased attention is psychosocial stress and its relation to cognition and cognitive decline. A growing number of studies suggest that level of psychological distress, social isolation, and perceived stress are related to an increased rate of cognitive decline and dementia but the majority of the studies have only been conducted with older Whites. Older African Americans tend to be highly exposed to sources of chronic stress due to their disadvantaged position in US society, and report higher levels of some types of psychosocial stress, such as perceived discrimination and social isolation. The goal of the proposed project is to conduct an epidemiologic longitudinal study to examine the biological mechanisms that may account for the relation of psychosocial risk factors to cognitive decline that have been shown to be important in studies of older Whites, but have yet to be examined in older African Americans. The proposed study will capitalize on the risk factor data, longitudinal uniform structured clinical data, and detailed measures of cognitive abilities over time available on more than 350 older African Americans who are free of dementia at baseline and have agreed to annual clinical evaluations. In addition we will measure inflammatory markers in serum to test the hypothesis that psychosocial stress is related to cognitive decline in older African Americans, and this relation is mediated by inflammatory markers. The public health importance of identifying the mechanisms whereby psychosocial stress may be related to change in cognitive function is of critical importance and may increase the likelihood of early intervention strategies to prevent or slow cognitive decline in a rapidly growing minority population. The public health importance of understanding the ways in which chronic stress affects cognition in old age, as well as the underlying biologic mechanisms, is critical, particularly during a time of increased emphasis on early detection and intervention strategies to modify and ultimately prevent cognitive decline.