Alzheimer’s disease is characterized by an accumulation of amyloid β proteins (pAβ) in the brain. Recent studies indicate that brain protein extrusion is a physiological phenomenon that takes place during deep sleep phases. The relationship between the accumulation of pAβ and the quality of sleep in the elderly is still poorly understood. Our study therefore focuses on the possible links between the quality of deep sleep, which is mostly present at the start of the night, and the accumulation of pAβ in brain tissue.
A total of 40 women and 41 men from the 3C and AMI cohorts (80.2 ± 5.4 years) were recruited. Imaging examinations were performed (3T MRI, PET [18F] -Flutemetamol) as well as objective and ecological monitoring of sleep over 8 days by actimetry (MotionWatch 8). The quality of deep sleep is measured by the Fragmentation Index (IF) of the first part of the night with MotionWare. The segmentation of the gray matter images was performed with FreeSurfer 5.3 and the reconstruction of the pAβ images was performed on PMOD 3.5. Linear regression models were performed between the IF and the pAβ images on SPM12.
In women, poorer quality of sleep was associated with a higher frontal region pAβ load (CFT, corrected FWE, p <.05), while this relationship was not observed in men.
We confirm a relationship between amyloid load and sleep quality in women and continue analyzes of the variability of FI.