Genetic Variability in Caffeine Acute Effects and Withdrawal Symptoms
Bibliographic record
Abstract
The mechanisms underlying caffeine’s acute effects and withdrawal symptoms are not entirely understood. The purpose was to determine whether the clusters of acute effects or withdrawal symptoms are associated with genetic polymorphisms in DARPP-32 and COMT, which mediate some of caffeine’s physiological effects. Subjects (n=1135) were from the Toronto Nutrigenomics and Healthy Study. Fourteen well-described acute effects of caffeine co-exist in six groups, while fourteen well-characterized withdrawal symptoms co-exist in three groups. Neither the rs907094 C>T polymorphism in the PPP1R1B gene encoding DARPP-32, nor the COMT Val158Met affected the odds of reporting any acute effects or withdrawal symptoms cluster. Among individuals consuming ≥ 200 mg/d of caffeine, Met/Met homozygotes were more likely to report the “increased heart rate” acute effects cluster. These results suggest that ‘slow’ COMT activity, conferred by the Met allele, may explain part of the inter-individual variability in the risk for increased heart rate among heavy caffeine consumers.
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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 | 0.002 |
| 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 | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".