Home-based sleep monitoring reveals associations between amyloid accumulation and sleep alterations in individuals with subjective and mild cognitive impairment.

INTRODUCTION

Sleep disturbances have been associated with Alzheimer's disease (AD), but their relevance in preclinical stages, such as subjective cognitive decline (SCD), and their relationship with brain pathology remain unclear.

METHODS

We used a portable sleep-monitoring headband over four consecutive nights to assess sleep in 19 cognitively unimpaired (CU), 15 SCD, and 20 mild cognitive impairment (MCI) participants with available amyloid positron emission tomography (PET). Linear-mixed-effects models compared sleep parameters across groups, accounting for amyloid burden, age, sex, education, and recording. Regional and voxel-wise analyses examined regional associations between sleep parameters and amyloid burden.

RESULTS

MCI patients presented reduced N3 (i.e., deep sleep), while SCD individuals showed longer N1 (i.e., light sleep) duration compared to CU. Regional amyloid burden was associated with longer light and deep sleep in amyloid-positive individuals. Higher education was linked to better sleep efficiency.

DISCUSSION: Sleep changes may serve as early indicators of cognitive dysfunction and regional amyloid accumulation.