P1–251: 25‐Hydroxyvitamin D, cognition and Alzheimer's disease
Bibliographic record
Abstract
Blood concentration of vitamin D could be related to cognitive impairments and may be a risk factor for disorders such as Alzheimer's disease (AD). In the current study, we examined the relationship between 25(OH)D, cognition and AD in persons aged 65 years or over in the Canadian Study on Health and Aging (CSHA). Study 1 included 327 participants from the CSHA. These participants were diagnosed as normal or cognitively impaired not demented at baseline. 25-hydroxyvitamin D3 (25(OH)D3) was measured at baseline. Serum 25(OH)D3 was measured by an automated Elecsys vitamin D3 method. Cognition was measured using the Mini-Mental State Examination (MMSE). We used multiple linear regression to examine whether participants' MMSE scores differed in groups with 25(OH)D3 concentration above or below 75 nmol/L at baseline, adjusting for age, education, and sex. Study 2 was a nested case-control study of CSHA participants, wherein we compared persons diagnosed with AD (n = 60) and time-matched controls (n = 120). We conducted Study 2 to examine the association between 25(OH)D3 concentrations and AD. Baseline 25(OH)D3 concentrations in Study 2 were categorized by quartiles and entered into a conditional logistic regression model adjusted for baseline MMSE, education, and sex. Mean MMSE scores after 5 or 10 years of follow-up did not differ according to baseline concentration of 25(OH)D3 before or after adjustment for age, education and sex (p > 0.05). Baseline 25(OH)D3 concentrations were also not associated with the odds of developing AD before or after adjustment for baseline MMSE, education, and sex (p > 0.05). Our findings do not suggest associations between lower 25(OH)D3 concentrations and lower cognition in nondemented CSHA participants, nor did we find an association between baseline 25(OH)D3 and AD.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.017 | 0.002 |
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".