Project Summary: Sleep, particularly obstructive sleep apnea (OSA), is identified as a modifiable risk factor for Alzheimer's disease (AD), with evidence linking sleep disruptions to dementia and AD. Therapeutic trials for OSA show potential cognitive benefits and alterations in brain regions. OSA is associated with inflammation, potentially contributing to neurodegeneration. Socioenvironmental factors, such as neighborhood disadvantage, influence cognitive decline and AD pathology. In OSA, neighborhood characteristics also impact severity. Disparities exist in AD and OSA research, notably affecting Black women who are underrepresented and at heightened risk of AD. Considering the increased susceptibility to AD observed among both Black individuals and women, and recognizing their inadequate representation in AD research, it becomes crucial to investigate modifiable risk factors for AD in Black women. The present study proposes to 1) Test the moderating influence of sleep apnea on the relationship between inflammation and cognitive performance and p-Tau levels among Black women, and 2) Determine if sleep apnea mediates the relationship between neighborhood socioeconomic disadvantage/neighborhood perceptions and cognition and p-Tau among Black women. Study visits will take place at community sites in predominanUy Black neighborhoods in both LA and SD. There will be a baseline visit and a follow-up visit 24 months after baseline (+/- 60 days). Baseline visits will include consent, blood draw, cognitive testing, explanation and completion of questionnaires, and consent and instruction on both an actigraphy device and home sleep test. Follow-up visits will involve re-consenting, blood draw, cognitive testing, mood-related questionnaires, and home sleep tests. This project aims to extend the parent grant by investigating the impact of obstructive sleep apnea (OSA) on inflammation, tau, and cognitive function in Black women. It will identify key OSA metrics influencing these relationships. Additionally, subjective measures of neighborhood social cohesion and disorder will be integrated to complement objective assessments of neighborhood disadvantage and explore their associations with OSA, tau, and cognitive function. The project aligns with my learning and research goals, enhancing my expertise in sleep as an Alzheimer's disease risk factor, collection, analysis, and interpretation of AD biomarkers, design and management of clinical research using a community-based approach, and advanced training in longitudinal research design and related data analytic methods. The obtained preliminary data will support future NIH 1<23 application, facilitating my growth into an independent researcher.