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症(ADRD)对社会弱势群体的个人影响不成比例，但寿命心理社会应激源在这些差异中的作用尚不确定。社交网络被认为是抵御心理社会压力的关键来源，但尚不清楚它们是否缓和了应激源对ADRD风险的不利影响，或者社交网络提供的缓冲在不同的种族/民族群体中是否一致。睡眠障碍是一种潜在的生物行为机制，应激源可能通过这种机制增加ADRD的风险，但睡眠的中介作用尚未得到正式评估。了解心理社会应激源和可改变的复原力来源以及生物行为机制对ADRD风险的影响将指导潜在的干预措施，以减少ADRD差异。这项建议包括一项培训和研究计划，以发展候选人在ADRD研究方面的专业知识，为她开始专注于减少ADRD中的社会不平等的职业生涯做好准备。该研究建议应用因果推理方法来阐明早期社会劣势、心理社会和生物行为因素以及老年认知结果之间的复杂关系。具体目标是1)量化累积应激源与认知功能之间的联系，并确定应激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应激源对四个种族/民族的ADRD风险的不利影响中的作用(K00博士后研究)。这项研究将使用两个由NIA资助的大型纵向队列：1)美国中年发展研究(MIDUS)(F99)；以及2)Kaiser健康老龄化和多样化生活体验研究(KHANDLE)，这是一项将中年(40-50年前)收集的风险因素数据与加州老年非拉丁裔白人、黑人、亚洲人和拉丁裔美国人样本(K00)的风险因素当代评估联系起来的研究。这一奖学金申请符合2012年国家阿尔茨海默氏症项目法的优先事项，以解决ADRD的社会差距。拟议的项目将产生新的知识，并为候选人成为一名专注于ADRD差异的独立流行病学家提供关键的培训，通过发展以下方面的专业知识：1)心理社会压力的测量和机制(F99)；2)因果推断方法，包括中介建模(F99/K00)；3)ADRD的流行病学和定量ADRD研究方法，包括纵向分析和心理计量学(K00)；4)睡眠障碍的生理学和心理学(K00)；和5)学术研究职业的专业技能(K00)。该奖项提供的高级培训、指导和受保护的时间将为候选人提供必要的技能和经验，以领导最高质量的衰老研究并作为一名独立研究者取得成功。

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.