P1‐032: Disruption of the Presumed Circadian Sleep Maintenance Zone Predicts Cognitive Impairment in Older Adults
Bibliographic record
Abstract
Age-related changes in sleep quality are associated with cognitive impairment in older adults and may play a role in the trajectory of cognitive decline in Alzheimer’s disease. Circadian dysregulation of the sleep maintenance zone could in part explain these changes in sleep quality and might be associated with cognitive impairment observed in older adults. Community dwelling older adults (N = 112; mean age = 71.6, SD = 7.4; 63% female) with Mini-Mental State Examination scores > 24/30 participated in the study. MCI status was determined using the Montreal Cognitive Assessment (MCI: MoCA < 26/30). Circadian regulation and sleep quality was assessed using the MotionWatch 8© actigraphy system (MW8; camntech). Following 14d actigraphy, cognitive function was assessed using the cognitive subscale of the Alzheimer’s disease assessment scale (ADAS-Cog). Partial correlations, controlling for age, sex, time of cognitive testing, and number of days of actigraphy, determined whether circadian regulation and sleep parameters were associated with cognitive performance. We operationally defined the sleep maintenance zone as the early morning hours prior to habitual wake-up (i.e., 3:00 to 5:59). Age was fairly strongly related to ADAS-Cog performance (r = .46, p < .001). Older age was also associated with greater nocturnality of activity (r = .19, p < .05); more specifically, older age was associated with a greater proportion of activity occurring between 3:00 and 5:59 (r = .21, p < .05) and with a lower proportion of activity occurring between 18:00 and 20:59 (r = -.24, p < .05). Poorer ADAS-Cog performance was associated with greater nocturnality of activity (r = .32, p < .001), with a greater proportion of activity occurring from 3:00 to 5:59 (r = .22, p < .05) and from 6:00 to 8:59 (r = .33, p < .001), and with a lower proportion of activity occurring from12:00 to 14:59 (r = -.19, p < .05), 18:00 to 20:59 (r = -.29, p < .01), and 21:00 to 23:59 (r = -.19, p < .05). Our results support the hypothesis that circadian dysregulation of the sleep maintenance zone is associated with cognitive impairment.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".