Sleep in Neurocognitive Aging and Alzheimer’s Research (SANAR)

Project Abstract

This Diversity Supplement to Sleep in Neurocognitive Aging and Alzheimer's Research (SANAR; R01 AG067568) expands the Parent Grant's examination of how obstructive sleep apnea (OSA) accelerates cognitive decline among US Hispanic/Latino adults, who have > 2-fold risk of dementia and early cognitive decline compared to non-Hispanic Whites. This Supplement examines gray matter (GM) microstructure integrity as an OSA-sleep-related marker of accelerated cognitive decline by testing the hypotheses that (1) OSA is associated with lower GM microstructure integrity, and (2) lower GM microstructure integrity is a marker of accelerated subclinical cognitive decline.

This Supplement aims to (1) determine if prior and persistent exposures to (a) OSA and (b) OSA-related hypoxemic burden are associated with lower hippocampal GM microstructure integrity; (2) determine if hippocampal GM microstructure integrity (a) is associated with average 12-year cognitive change among participants with and without OSA, and (b) mediates associations between OSA and 12-year average cognitive change; and (3) determine the independent and interactive association of NDBP and OSA with hippocampal GM microstructure integrity. This Supplement also provides the Diversity Supplement Candidate with mentored research training, structured coursework, and preliminary data vital for an NIH career-development award application, to propel the Diversity Supplement Candidate into a career as an independent physician scientist.

This Supplement will utilize the multi-center (Miami, Bronx, Chicago, San Diego), ethnically diverse, community-based Hispanic Community Health Study/Study of Latinos (HCHS/SOL), its ancillary studies (SOL-INCA [R01 AG048642], SOL-INCA-MRI [R01 AG054548]), SOL-INCA2 (R01 AGR56048642), and SANAR (Parent Grant). The Supplement utilizes data from participants enrolled in Miami (n >600), who at baseline were cognitively intact middle-aged and older adults (>/= 45-years) with and without OSA.

At Visit 1 (2008- 2011), studies acquired self-reported sleep data, portable sleep apnea studies, and cognitive evaluations. Cognitive evaluations were twice repeated, 7 and 12-years after Visit 1. GM microstructure integirty is quantified as the mean diffusivity of water measured using diffusion tractography imaging (DTI), a modality included in the MRI protocol.

MRI was obtained 2016-2022. SANAR enriches this data by obtaining 24-hour ABPM (to measure NDBP) and repeat portable sleep studies 10-years after Visit 1. Analyses will adjust for anthropometric, socioeconomic, racial, and medical confounders.