Sleep macro-architecture, nocturnal hypoxemia, and Alzheimer's disease-related MRI patterns among diverse older adults

Abstract

Introduction: Sleep patterns change with aging, yet their relationship with brain health, particularly Alzheimer's disease (AD)-related MRI patterns among diverse older adults is not clear.

Methods: We cross-sectionally studied community-dwelling Non-Hispanic White (NHW), Hispanic, and Black participants recruited from the Health and Aging Brain Study-Health Disparities (HABS-HD)-Dormir Study, who underwent WatchPAT and brain MRI.

Results: A total of 842 participants (34% male; 42% NHW, 33% Hispanic, and 25% Black; mean age 66.1 ± 8.6 years) were included. Greater light sleep percentage and longer rapid-eye movement (REM) sleep latency were independently associated with thinner cortex in AD-signature regions, while inverse pattern was observed for greater deep sleep percentage. Higher Apnea-Hypopnea Index (AHI) in REM sleep was independently associated with greater white matter hyperintensities volume. There were no ethnoracial interactions for these associations.

Discussion: Light and deep sleep percentage, REM sleep latency, and AHI in REM sleep were associated with AD-related MRI patterns.

Highlights: Greater light sleep percentage and longer rapid-eye movement sleep latency were associated with thinner cortex in the Alzheimer's Disease-siganture regions, while greater deep sleep percentage was associated with thicker cortex in those regions. Higher apnea hypoonea index in rapid eye movement sleep was associated with greater white matter hyperintensities volume. No moderation effects by race/ethnicity were observed among Non-Hispanic White/Hispanic/Black adults.

Keywords: Alzheimer's disease; dementia; magnetic resonance imaging; sleep; sleep apnea.