Association of Obstructive Apnea with Thoracic Fluid Shift and Small Airways Narrowing in Asthma During Sleep
Bibliographic record
Abstract
Xiaoshu Cao,1,2 Cristina de Oliveira Francisco,2 T Douglas Bradley,2– 4 Nasim Montazeri Ghahjaverestan,1,2 Susan M Tarlo,3,5,6 Matthew B Stanbrook,3,5 Kenneth R Chapman,3,5 Mark Inman,7 Azadeh Yadollahi1,2 1Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada; 2KITE, Toronto Rehabilitation Institute - University Health Network, Toronto, ON, Canada; 3Department of Medicine, University of Toronto, Toronto, ON, Canada; 4Department of Medicine, University Health Network Toronto General Hospital, Toronto, ON, Canada; 5Department of Medicine, University Health Network Toronto Western Hospital, Toronto, ON, Canada; 6Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada; 7Faculty of Medicine (Respirology), McMaster University, Hamilton, ON, CanadaCorrespondence: Azadeh Yadollahi, KITE, Toronto Rehabilitation Institute - University Health Network, Room 12-106, 550 University Avenue, Toronto, ON, M5G 2A2, Canada, Email azadeh.yadollahi@uhn.caRationale: Obstructive sleep apnea (OSA) is highly prevalent among patients with asthma, suggesting a pathophysiological link between the two, but a mechanism for this has not been identified.Hypothesis: Among patients with asthma, those with OSA will have greater overnight increases in thoracic fluid volume and small airways narrowing than those without OSA.Methods: We enrolled 19 participants with asthma: 9 with OSA (apnea-hypopnea index (AHI) ≥ 10) and 10 without OSA (AHI < 10). All participants underwent overnight polysomnography. Before and after sleep, thoracic fluid volume was measured by bioelectrical impedance and small airways narrowing was primarily assessed by respiratory system reactance at 5Hz using oscillometry.Results: Patients with asthma and OSA (OSA group) had a greater overnight increase in thoracic fluid volume by 120.5 mL than patients without OSA (non-OSA group) (164.4 ± 44.0 vs 43.9 ± 47.3 mL, p=0.006). Compared to the non-OSA group, the OSA group had greater overnight decrease in reactance at 5Hz (− 1.08 ± 0.75 vs 0.21 ± 0.27 cmH2O/L/s, p=0.02), and overnight increase in reactance area (14.81 ± 11.09 vs − 1.20 ± 2.46 cmH2O/L, p=0.04), frequency dependence of resistance (1.02 ± 0.68 vs 0.05 ± 0.18 cmH2O/L/s, p=0.04), and resonance frequency (2.80 ± 4.14 vs − 1.42 ± 2.13 cmH2O/L/s, p=0.04).Conclusion: Patients with asthma and co-existing OSA had greater overnight accumulation of fluid in the thorax in association with greater small airways narrowing than those without OSA. This suggests OSA could contribute to worsening of asthma at night by increasing fluid accumulation in the thorax.Keywords: asthma, obstructive sleep apnea, small airway narrowing, thoracic fluid volume
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".