Catechol- <i>O</i> -Methyltransferase Genotype Is Associated with Self-Reported Increased Heart Rate Following Caffeine Consumption
Bibliographic record
Abstract
Rationale: The mechanisms underlying the various acute effects of caffeine are not clear. Some of the physiological effects of caffeine may be mediated through increased catecholamines, which are metabolized by catechol-O-methyltransferase (COMT). A Val158Met polymorphism in COMT affects enzyme activity with Val/Val homozygotes having a 3–4-fold greater activity than Met/Met homozygotes. Objective: To determine whether the self-reported acute effects of caffeine are associated with the COMT Val158Met polymorphism (rs4680). Methods: Subjects were men (n=344) and women (n=801) aged 20–29 years who were participants of the Toronto Nutrigenomics and Health Study. Acute effects were assessed by questionnaire, and caffeine intake was assessed using a semiquantitative food frequency questionnaire. Odds ratios (OR) and 95% confidence intervals (CI) were calculated to determine if the likelihood of reporting an acute effect was associated with COMT genotype. Results: Among individuals consuming more than 200 mg/day of caffeine, COMT genotype was associated with self-reported increased heart rate. Compared to the Val/Val genotype, the adjusted OR (95% CI) of reporting increased heart rate for the Val/Met and the Met/Met genotypes was 1.43 (0.64, 3.20) and 2.98 (1.04, 8.51), respectively. Conclusions: These findings show that the Met/Met genotype, conferring slow COMT activity, is associated with self-reported increased heart rate after caffeine intake. This observation suggests that caffeine may increase heart rate in a genetic subset of the population who have an impaired ability to breakdown catecholamines such as epinephrine and norepinephrine.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.010 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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 | 0.002 |
| 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 teacher head, 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".