Blunted parasympathetic reactivation in smokers after exogenous hypoxic provocation
Bibliographic record
Abstract
Introduction: Exogenous hypoxia changes the activity of the autonomic nervous system which could be diminished in patients with dysautonomia. Aim: To assess the effect of smoking on parasympathetic reactivation via heart rate variability (HRV) after exogenous hypoxic exposure. Material and methods: Twenty-one healthy non-smoking males aged 28.0±7.4 (mean±SD) and fourteen male smokers aged 28.1±4.3 with 9.2±5.6 pack-years were subjected to one-hour hypoxic exposure (FiO2=12.3±1.5%) via hypoxicator (Altitude Tech, AltiPro 8850 Summit+, Canada) with simultaneous recording of ECG. HRV data was derived via specific software (Kubios HRV, Finland) by analyzing 5 minute samples during and after the hypoxic exposure. Results: The group of non-smokers compared to smokers had higher root mean square of successive differences (RMSSD) (65.9±40.2 vs 34.3±17.1 ms, p=0.009) and high frequency (lnHF) (6.8±1.4 vs 5.8±1.2 ms2, p=0.029), as well as lower heart rate (MeanHR) (65.1±11.1 vs 77.3±13.8 beat.min-1, p=0.009) in hypoxic conditions. After removing the hypoxia there was a significant increase in RMSSD (65.9±40.2 vs 75.1±46.0 ms, p=0.011), lnHF (6.8±1.4 vs 7.2±1.3 ms2, p=0.014) and a decrease in LF/HF (3.0±2.3 vs 1.9±1.4 p<0.001) and MeanHR (65.1±11.1 vs 61.9±9.0 beat.min-1, p=0.001) in the non-smokers9 group, but not among the smokers - RMSSD (34.3±17.1 vs 34.9±20.1 p=0.914), lnHF (5.8±1.2 vs 5.8±1.14 ms2, p=0.912), LF/HF (3.8±1.6 vs 4.0±1.8 p=0.657). Conclusion: Parasympathetic reactivation is blunted in smokers when shifting from hypoxic to normoxic ambient conditions. Hypoxic exposure test could be applied in clinical practice for early detection of autonomic dysfunction in smokers.
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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 | 0.000 |
| 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".