Oxygen supplementation during exercise improves leg muscle fatigue in chronic fibrotic interstitial lung disease
Bibliographic record
Abstract
Background Exercise-induced hypoxaemia is a hallmark of chronic fibrotic interstitial lung disease ( f -ILD). It remains unclear whether patients’ severe hypoxaemia may exaggerate locomotor muscle fatigue and, if so, to what extent oxygen (O 2 ) supplementation can ameliorate these abnormalities. Methods Fifteen patients (12 males, 9 with idiopathic pulmonary fibrosis) performed a constant-load (60% peak work rate) cycle test to symptom limitation (Tlim) while breathing medical air. Fifteen age-matched and sex-matched controls cycled up to patients’ Tlim. Patients repeated the exercise test on supplemental O 2 (42%±7%) for the same duration. Near-infrared spectroscopy assessed vastus lateralis oxyhaemoglobin concentration ((HbO 2 )). Pre-exercise to postexercise variation in twitch force (∆Tw) induced by femoral nerve magnetic stimulation quantified muscle fatigue. Results Patients showed severe hypoxaemia (lowest O 2 saturation by pulse oximetry=80.0%±7.6%) which was associated with a blunted increase in muscle (HbO 2) during exercise vs controls (+1.3±0.3 µmol vs +4.4±0.4 µmol, respectively; p<0.001). Despite exercising at work rates ∼ one-third lower than controls (42±13 W vs 66±13 W), ∆Tw was greater in patients (∆Tw/external work performed by the leg muscles=−0.59±0.21 %/kJ vs −0.25±0.19 %/kJ; p<0.001). Reversal of exertional hypoxaemia with supplemental O 2 was associated with a significant increase in muscle (HbO 2) , leading to a reduced decrease in ∆Tw in patients (−0.33±0.19 %/kJ; p<0.001 vs air). Supplemental O 2 significantly improved leg discomfort (p=0.005). Conclusion O 2 supplementation during exercise improves leg muscle oxygenation and fatigue in f -ILD. Lessening peripheral muscle fatigue to enhance exercise tolerance is a neglected therapeutic target that deserves clinical attention in this patient population.
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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 | 0.000 | 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) | 0.001 | 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".