Lifecourse Stressors and Social Disparities in Cognitive Aging: The Roles of Social Networks and Sleep Disturbance

阿尔茨海默病和相关痴呆（ADRD）对社会弱势群体的影响不成比例，但终身社会心理压力源在这些差异中的作用尚不确定。社会网络被假设为抵御社会心理压力源的关键来源，但尚不清楚它们是否会缓和压力源对ADRD风险的不利影响，或者社会网络提供的缓冲是否在不同种族/民族群体中是一致的。睡眠障碍是应激源增加ADRD风险的潜在生物行为机制，但睡眠的中介作用尚未得到正式评估。了解心理社会压力源、可改变的恢复力来源和生物行为机制对ADRD风险的影响，将指导潜在的干预措施，以减少ADRD的差异。该提案包括一个培训和研究计划，以发展候选人在ADRD研究方面的专业知识，为她开始一个专注于减少ADRD社会不平等的职业生涯做好准备。本研究建议运用因果推理方法，阐明早期社会劣势、社会心理和生物行为因素与老年期认知结果之间的复杂关系。具体目标是：1)量化累积压力源与认知功能之间的关系，确定压力源如何解释认知功能的社会差异（F99论文研究）；2)确定社会网络和睡眠障碍在早期生活压力源对四个种族/民族的ADRD风险的不利影响中的作用（K00博士后研究）。本研究将使用nia资助的两个大型纵向队列：1)美国中年发展研究（MIDUS） （F99）；2)凯撒健康老龄化和多样化生活经验研究（KHANDLE），这是一项生命历程研究，将中年（40-50年前）收集的风险因素数据与加利福尼亚老年非拉丁裔白人、黑人、亚洲人和拉丁裔人的风险因素、认知能力下降和痴呆的当代评估联系起来（K00）。该奖学金申请与2012年国家阿尔茨海默病项目法案的优先事项一致，以解决ADRD的社会差异。拟议的项目将产生新的知识，并为候选人提供重要的培训，使其成为一名独立的流行病学家，通过发展以下方面的专业知识：1)社会心理压力的测量和机制（F99）；2)因果推理方法，包括中介建模（F99/K00）；3) ADRD的流行病学和定量研究方法，包括纵向分析和心理测量学（K00）；4)睡眠障碍的生理和心理（K00）；5)从事学术研究所需的专业技能（K00）。该奖项提供的高级培训、指导和保护时间将为候选人提供领导高质量老龄化研究所需的技能和经验，并使其成为一名成功的独立研究者。

Alzheimer’s disease and related dementias (ADRD) disproportionately affect individuals from socially disadvantaged groups, but the role of lifespan psychosocial stressors in these disparities is uncertain. Social networks are hypothesized to be key sources of resilience against psychosocial stressors, but it is unknown if they moderate the adverse effects of stressors on ADRD risk or whether the buffering provided by social networks is consistent across diverse racial/ethnic groups. Sleep disturbance is a potential biobehavioral mechanism via which stressors may increase ADRD risk, but the mediating role of sleep has not been formally evaluated. Understanding the effects of psychosocial stressors and modifiable sources of resilience and biobehavioral mechanisms on ADRD risk will guide potential interventions to reduce ADRD disparities. This proposal encompasses a training and research plan to develop the candidate’s expertise in ADRD research, preparing her to launch a career focused on reducing social inequalities in ADRD. The research proposal applies causal inference methods to elucidate the complex relationships between early social disadvantages, psychosocial and biobehavioral factors, and cognitive outcomes in older adulthood. The Specific Aims are to 1) quantify the association between cumulative stressors and cognitive function and determine how stressors explain social disparities in cognitive function (F99 dissertation research); and 2) determine the roles of social networks and sleep disturbances in the adverse effects of early-life stressors on ADRD risk across four racial/ethnic groups (K00 postdoctoral research). This research will use two large NIA-funded longitudinal cohorts:1) the Midlife Development in the United States Study (MIDUS) (F99); and 2) the Kaiser Healthy Aging and Diverse Life Experience Study (KHANDLE), a life-course study linking risk factor data collected in mid-life (40-50 years ago) with contemporary assessments of risk factors, cognitive decline, and dementia in a sample of older non-Latino Whites, Blacks, Asians, and Latinos in California (K00). This fellowship application aligns with the 2012 National Alzheimer’s Project Act priority to address social disparities in ADRD. The proposed project will generate new knowledge and provide crucial training for the candidate’s advancement to become an independent epidemiologist focused on ADRD disparities by developing expertise in 1) measurements and mechanisms of psychosocial stress (F99); 2) causal inference methods, including mediation modeling (F99/K00); 3) the epidemiology of ADRD and quantitative ADRD research methods, including longitudinal analyses and psychometrics (K00); 4) the physiology and psychology of sleep disturbances (K00); and 5) professional skills for an academic research career (K00). The advanced training, mentorship, and protected time provided by this award will provide the candidate with the skills and experience necessary to lead the highest quality aging research and succeed as an independent investigator.