Psychosocial and Neighborhood Mechanisms and Consequences of Black-White Sleep Disparities on Cognition

FUNDED PARENT UF1 SUMMARY African American/Black adults are at an elevated risk for mild cognitive impairment (MCI) and Alzheimer's disease and related dementias (ADRD)1–3.Thus, the identification of modifiable factors underlying this heightened risk is urgently needed. One such modifiable factor essential to cognitive health is sleep. Specifically, sleep is associated with impaired cognitive functioning and risk for mild cognitive impairment, particularly within Black adults4–6. Additionally, life stressors and protective/resilient factors are associated with cognitive and sleep health7–12, but limited research has revealed how all these factors interconnect to explain observable differences in cognitive functioning within Black adults. Understanding these associations is even more pressing in midlife – a period of life (a) where the sleep-cognition relationship has not been extensively investigated, (b) for which Black people are at a high risk of cognitive dysfunction, and (c) represents an ideal period to target for intervention13. The overall objective of this study, branded Healthy Aging in Neighborhoods of Diversity Across the Life Span (HANDLS) Sleep, is to identify mechanisms of Black-White sleep disparities and the mechanisms that account for Black-White differences in ADRD risk. The study includes annual assessments across 3 years to assess sleep duration and quality, cognitive functioning, inflammatory biomarkers (e.g., CRP, IL-6), life stressors (e.g., perceived neighborhood disorder), and resilience factors (e.g., spirituality, coping) in a sample of middle-aged (30-64 years) Black and White participants from the HANDLS Study. The HANDLS Sleep Study includes three specific aims: Aim 1: determine if there are racial differences in the daily coupling of sleep and mobile cognitive functioning and whether differences in this coupling are moderated by life stressors (e.g., financial strain and neighborhood disorder); Aim 2: test longitudinal associations among sleep and performance on mobile cognitive assessments and explore the role of life stressors, protective factors (e.g., spirituality and neighborhood cohesion) and inflammation; Aim 3: determine whether changes in the strength of the daily coupling of sleep and performance on mobile cognitive assessments relate to racial differences in traditional annual measures of cognitive decline over 3 years, and to elucidate the potential mediational role of inflammation. The HANDLS Sleep Study is innovative because it will examine the association between sleep and cognitive functioning over various time intervals (daily and annual), and it will also examine the relationship of life stressors, sleep, inflammatory biomarkers, and/or resilient factors on racial disparities in cognitive decline. Furthermore, this research is significant because of its potential to identify psychosocial and contextual factors related to impaired sleep and cognition that could serve as the basis for evidence-based interventions.