Catecholamines in Alzheimer's Disease: A Systematic Review and Meta-Analysis
Bibliographic record
Abstract
Background and Purpose: Previous studies found inconsistent results regarding the relationship between AD and catecholamines, such as dopamine (DA), norepinephrine (NE), and epinephrine (EPI). Our study performed a systematic review and meta-analysis to evaluate previous studies’ results on this relationship. Method: Literature retrieval of eligible studies was performed in 4 databases (Web of Science, PubMed, Embase, and Psyc-ARTICLES). Standardized mean differences (SMD) were calculated to assess differences in catecholamines between the AD groups and controls. Results: Thirteen studies met the eligibility criteria. Compared with the controls, significant lower levels of NE (SMD=-1.10, 95% CI: -2.01 to -0.18, p=0.019) and DA (SMD =-1.12, 95% CI: -1.88 to -0.37, p=0.003) concentrations were observed in patients with AD. No difference was found in EPI (SMD=-0.74, 95% CI: -1.85 to 0.37, p=0.189) between the two groups. Conclusion: Overall, these findings are in line with the hypothesis that reduced NE and DA may be an important indicator for AD. (Registration number CRD42018112816)
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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 | 0.011 | 0.026 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.015 | 0.022 |
| Bibliometrics | 0.008 | 0.009 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".