Sleep Slow-Wave Activity as a Potential Vulnerability and Modifiable Risk Factor: Examining the Relationship from Chronic Stress to Accelerated Aging and Alzheimer's Disease

Black older adults in the United States demonstrate generally more adverse health outcomes than non- Hispanic white adults including disproportionately high rates of Alzheimer’s disease. These health disparities may reflect changes in biological processes that occur due to chronic stress. One candidate biological process is sleep slow-wave activity (SWA), which has been shown to be significantly altered by stress and lower in Black adults than in white adults. Because SWA dysfunction has been implicated in Alzheimer’s disease, it is essential to determine if reductions in SWA are associated with observed patterns of chronic stress and maladaptive aging in Black older adults. In this R01 project, we will characterize the EEG power dynamics of SWA in 200 Black older adults, between the ages of 55-80. Each participant will undergo ambulatory overnight sleep monitoring with polysomnography and a blood assessment panel for biomarkers of chronic stress, accelerated aging, and Alzheimer’s-related pathology (tau and amyloid β). Cognitive functioning will also be assessed. A subsample of 50 participants will be followed-up to two years post-assessment to examine the effects of aging and further determine the directionality of the relationship between SWA and Alzheimer’s biomarkers. It is predicted that chronic stress will be associated with impairments in SWA, and that these impairments, in turn, will be associated with biomarkers of accelerated aging and Alzheimer’s disease. In the context of a multidisciplinary team of experts, this Stephen I. Katz Award will also provide Dr. Jennifer Goldschmied, an early-stage investigator, the opportunity to change research direction by applying her established methodological expertise in the analysis of sleep SWA to the domain of aging. This new direction is poised to launch a novel program of research that could further elucidate the functional significance of SWA in the context of aging and potentially contribute to the development of novel treatment targets older adults.