Nighttime behaviors, but not insomnia, correlates with cognition and biomarkers of dementia
Bibliographic record
Abstract
Abstract Background While sleep disturbances appear to be risk factors in the progression of Alzheimer’s disease (AD) and other dementias, little is known about the prevalence across dementia severity and the potential influence on the trajectory of cognitive decline. Method We used the prospective National Alzheimer Coordinating Center Uniform Data Set to evaluate the hypotheses that the prevalence of insomnia differs by definition and by stage of cognitive impairment, that certain sleep features track with established biomarkers of AD, and that longitudinal changes in sleep disorders affect cognition and AD biomarkers. We conducted cross‐sectional analyses to determine the prevalence of clinician‐determined insomnia and nighttime behaviors (nighttime restlessness, agitation, daytime sleepiness) in normal, mild cognitive impairment (MCI), and demented individuals, as defined by Montreal Cognitive Assessment (MoCA) cut‐off scores obtained during the patient’s first visit. We evaluated mean MoCA scores, hippocampal volumes, and CSF phosphorylated tau:beta amyloid ratios obtained near the first visit using Analysis of Variance (ANOVA) with age as a covariate. In longitudinal evaluations, we classified changes in insomnia and nighttime behaviors as “none”, “remitted”, “acquired”, or “steady” between the first and last visits. Similar changes in MoCA scores and hippocampal volumes were assessed with repeated‐measure ANOVA. Result The prevalence of clinician‐identified insomnia at initial visits was 15%, 17%, and 13% for normal, MCI, and dementia groups respectively. Prevalence of clinician‐identified nighttime behaviors was 13%, 19%, and 27% respectively. Insomnia was significantly associated with higher MoCA scores, larger hippocampal volumes, and higher pTau:Beta values, indicating those with clinician‐identified insomnia had better cognition and less neurodegeneration than individuals who clinicians identified to be without insomnia. In contrast, the presence of nighttime behaviors were associated with significantly worse cognition, smaller hippocampal volumes, and lower pTau:Beta. Similar findings were seen between longitudinal associations of sleep disorders and cognition and hippocampal volumes. Conclusion Our findings suggest that the clinician determination of insomnia may be under‐recognized in patients with cognitive impairment seen in memory disorders clinics, and that nighttime behaviors especially when reported by family members may better reflect sleep disturbances, the biological underpinnings of AD, and have diagnostic specificity in AD over insomnia.
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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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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".