Sleep efficiency is associated with amyloid burden, cerebral blood flow, and cognition in healthy older adults
Bibliographic record
Abstract
Abstract Background Prior work has identified associations between sleep quality and amyloid‐beta (Aβ). However, how sleep efficiency relates to Aβ, cerebral blood flow (CBF), and cognition are not well understood. The objective of this study was to evaluate these relationships and the modifying role of APOE4 status. Method Objective sleep efficiency, Aβ, CBF, and cognitive performance on neuropsychological assessments (MoCA, Flanker, CVLT, and Complex Figure) were examined in a sample of 52 non‐demented, older adults (age=66.5+6.82, 67% female, 27% APOE4 carriers). Sleep efficiency, defined as the percentage of time asleep within a given sleep period, was objectively measured using the GENEActiv tri‐axis accelerometer for an average of 30.25 days. Aβ was measured in vivo using positron emission tomography and the F‐18 florbetaben tracer to calculate composite SUVR scores. Global gray matter CBF was quantified using a pseudo‐continuous arterial spin labeling MRI scan. All analyses were adjusted for age, sex, and education (for cognitive measures). Result Overall, higher sleep efficiency was associated with lower Aβ burden (p=.04), higher CBF (p=.03), higher MoCA scores (p=.05) and a trend for better Complex Figure Test recall (p=.07). There was a significant moderating effect of APOE4 status on the association between sleep and Aβ, such that poorer sleep efficiency was associated with higher Aβ burden in APOE4 carriers only (p=.01). APOE4 moderation was not observed for CBF. When stratified by high and low sleep efficiency levels (median split), APOE4 carrier status predicted Aβ burden only in individuals with low sleep efficiency (p =.02). Additionally, sleep efficiency predicted performance on long delay free recall of the CVLT and Complex Figure Test (p=.01) in the low sleep efficiency group only. No association between sleep efficiency and Flanker were observed. Conclusion These results provide evidence that sleep efficiency is associated with brain health and cognition, and suggest a modifying effect of APOE4 on the relationship between sleep and amyloid. Mechanistic evidence from animal models and human studies suggests that impaired slow wave activity during NREM sleep may disrupt dynamic fluid oscillations important for amyloid clearance and brain blood flow. Future work is needed to understand the causal and temporal relationships between these processes.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".