Effect of 4 days of intermittent hypoxia on oxidative stress in healthy men
Bibliographic record
Abstract
Periodic occlusion of the upper airway in patients with obstructive sleep apnea (OSA) leads to intermittent hypoxia (IH). IH is characterized by repeated episodes of hypoxia/reoxygenation, which is known to increase the production of reactive oxygen species (ROS). Causal relationships between OSA, IH and oxidative stress have not been established because of confounding effects of medical co‐morbidities and obesity which are frequently associated with OSA. The aim of this study was to determine if IH changes oxidative stress in healthy volunteers. Nine men (29.3 ± 1.7 years; BMI, 25.0 ± 0.4 kg.m −2 ; mean±SD) were studied. Following baseline measurements breathing room air (day zero (D0)), all subjects were exposed to 4 days (D1 to D4) of IH while awake (2 min at P et O 2 = 45 Torr and 2 min at P et O 2 = 88 Torr) 6 hours.d −1 . Lipid peroxidation (malondialdehides, MDA), DNA oxidation (8‐Hydroxy‐2′‐deoxyguanosine, 8‐OHdG) and oxidation protein products (AOPP) were assessed in plasma. MDA increased significantly between baseline (D0) and D1 (+39%: 3.48 ± 1.17 vs 4.85 ± 0.90 μmol.l −1 ) and then tended to return to baseline l evels. 8‐OHdG increased significantly between D0 and D1 (+51%: 53.84 ± 54.63 vs 83.30 ± 45.49 μmol.l −1 ) and remained elevated until D4 (+67%: 53.84 ± 54.63 vs 89.71 ± 36.06 μmol.l −1 ). These findings demonstrate that IH increases oxidative stress and suggest that IH may contribute to ROS overproduction in OSA. Supported by the Alberta Heritage Foundation for Medical Research and the Heart & Stroke Foundation of Canada.
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 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 | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| 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 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".