Comparison of autonomic nervous system activity between smokers and non-smokers under hypoxic conditions
Bibliographic record
Abstract
It is well known that smoking impairs the autonomic regulation in normoxic conditions. There is no research assessing the autonomic nervous system activity in smokers exposed to acute exogenous hypoxia. Aim: To compare the autonomic nervous (ANS) system activity in smokers and non-smokers exposed to acute exogenous hypoxia via heart rate variability (HRV). Material and methods: Twenty-one healthy non-smoker males aged 28.0 ± 7.4 (mean±SD) and 14 healthy smoker males aged 28.1±4.3 with 9.2±5.6 pack-years were subjected to one-hour hypoxia (FiO2=12,3±1,5%) via hypoxicator (Altitude Tech, AltiPro 8850 Summit+, Canada) with simultaneous recording of electrocardiography and pulse oxymetry. HRV data was derived via specific software (Kubios HRV, Finland) by analyzing the one-hour hypoxic period. Results: There was no difference between pre-hypoxic oxygen saturation (SpO2) of both groups (96.8±1.2 vs 96.3±1.6 p=0.309). During hypoxic exposure smokers had higher SpO2 (91.4±1.4 vs 88.2±5.9 p=0.026) and higher heart rate (77.7±12.9 vs 66.8±10.3 p=0.009), but lower HRV: root mean square of successive differences (RMSSD) (31.3±12.7 vs 60.3±33.1 p=0.001), low frequency (lnLF) (6.5±1.3 vs 7.4±0.9 p=0.018), high frequency (HF) (5.9±0.9 vs 6.8±1.2 p=0.014), as well as Poincaré plot standard deviations SD1 (22.2±9.0 vs 42.9±23.4 p=0.001) and SD2 (85.0±23.9 vs 120.6±39.0 p=0.002). Conclusion: Exposed to exogenous hypoxia smokers have higher SpO2 but lower HRV parameters – RMSSD, lnLF, lnHF and SD1 and SD2. These data suggest that smokers have altered autonomic regulation under hypoxic conditions– diminished parasympathetic activity and sympathetic domination despite having higher SpO2.
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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".