O011 Associations between sleep and Alzheimer’s disease biomarkers within the EPAD cohort

BACKGROUND: Changes in sleep quality are common in Alzheimer’s Disease (AD) and may contribute to the onset and accumulation of disease. However, in preclinical stages, it is unclear whether sleep quality or sleep disturbance relate to disease pathology after controlling for known AD risk factors. This study aimed to determine if self-reported sleep quality is associated with AD biomarkers after accounting for such factors. METHOD: Data were obtained from the European Prevention of Alzheimer’s Disease (EPAD) Longitudinal Cohort Study (LCS; v1500.0). CSF samples were collected for measurement of β-amyloid (Aβ42) and phosphorylated tau (p-tau). Self-reported sleep quality was assessed by the PSQI. Linear regression was used to determine whether p-tau/Aβ42 was associated with PSQI component scores when controlling demographics, ApoE4, depressive symptoms, BMI, vascular risks, smoking status, use of psychotropics, white matter lesions, and hippocampal volume. PSQI component scores of 2 or 3 were combined due to small numbers of component scores of 3. RESULTS: A total of 1239 participants were included (mean age=65.30 years, SD=7.11; mean PSQI total score=5.31, SD=3.38). After adjustment for all covariates, higher p-tau/Aβ42 was found to be associated with longer sleep latency (component score of 1: β=0.16, p=0.007; component score of 2/3: β=0.12, p=0.134) and better sleep efficiency (component score of 1: β=-0.22, p=0.04; component score of 2/3: β=-0.31, p=0.009) CONCLUSION: These findings contribute to growing evidence suggesting sleep is an important early marker of underlying neurodegeneration. Longitudinal assessment of EPAD-LCS participants will allow for evaluation of self-reported sleep as a predictive marker of neurodegeneration.