Sex‐Specific Heart Rate Responses to Apneic Manipulations in Young Healthy Subjects
Bibliographic record
Abstract
Contributions of lung stretch and chemoreflex stimulation to heart rate (HR) responses to apnea have not been elucidated independently in men and women. We tested the hypothesis that HR responses to apnea would be exaggerated in men relative to women. Relative changes in HR (ECG) were analyzed during 4 maximal apneic maneuvers: 1) end‐inspiratory (INSP), 2) end‐tidal expiratory (ETE), 3) INSP following hyperoxic breathing (HX), and 4) INSP following hyperventilation (HV). HR data from all apneas were analyzed in 10s bins. The first 5 bins (50s) of each apnea were compared between sexes in these analyses. INSP caused similar changes in HR between sexes (‐8 ± 11 and ‐7 ± 6 bpm, P=0.8), and the time courses of the changes in HR were also similar. Although the nadir bradycardic response to ETE (designed to unload lung stretch receptors) was similar between men and women (‐9 ± 7 and ‐9 ± 8 bpm, P=0.9) onset of bradycardia was delayed in women (30s bin) compared with men, in whom the bradycardia was immediate (10s bin). During HX (eliminating the influence of O 2 ) and HV (eliminating the influence of CO 2 ) both the time courses of the HR responses and the HR nadirs (HX: ‐17 ± 13 and ‐14 ± 11 bpm, P=0.6; HV: ‐33 ± 12 and ‐35 ± 17 bpm, P=0.9) were similar between men and women, respectively. These data suggest that sex differences in HR responses to apnea are not dependent on changes in O 2 or CO 2 but, rather, are unveiled during the unloading of lung stretch receptors. Supported by NSERC, AIHS, Mount Royal University Innovation Grant, and the University of Alberta Human Performance Scholarship Fund.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| 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".