Reduced Exercise Tolerance in Long-COVID Patients
Notice bibliographique
Résumé
Introduction: Because many patients report long-term symptoms including dyspnea and fatigue after an acute COVID-19 infection, we recently developed a comprehensive follow-up clinic to understand and manage these patients. We conducted cardiopulmonary exercise tests (CPET) to characterize the respiratory responses to exercise as a potential cause of dyspnea in long-COVID patients. Methods: Seven long-COVID patients (mean age 53±4 years, 100% female) and seven age, sex and height-matched healthy controls (mean age 55±10 years) completed a pulmonary function test and an incremental CPET to exhaustion. These seven long-COVID patients were assessed due to persistent dyspnea after recovery from the acute infection;three long-COVID patients required hospitalization during the acute infection. The CPET was performed on average 158±59 days since COVID-19 diagnosis. Arterial saturation (SpO2) and breath-by-breath respiratory data, including ventilatory equivalents for carbon dioxide (VE/VCO2), were collected continuously, while inspiratory capacity (IC), inspiratory reserve volume (IRV), and dyspnea (modified Borg scale) were evaluated throughout exercise. Statistical analyses were performed using unpaired t-tests with a significance level of 0.05. Results: Prior to testing, COVID-19 patients reported resting dyspnea (mean modified Medical Research Council Dyspnea scale 2.1±0.7) and elevated post-COVID functional scale (mean 2.1±1.2), revealing persistent symptoms. Spirometric assessment at rest was within expected normal limits, though a reduction in FEV1 was seen in the COVID-19 patients (88.9±16.6% predicted) compared to matched controls (111.1±13.2% predicted;p = 0.02). Lung volumes and diffusion capacity were similar between both groups. Most notably, COVID-19 patients (19.6±7.4 mL/kg/min) had a reduced VO2peak when compared to controls (29.1±8.3 mL/kg/min, p<0.01). As well, VE/VCO2 at rest and anaerobic threshold were elevated in COVID-19 patients as compared to controls. SpO2 at peak exercise was not different between COVID-19 patients and controls (95±4% vs. 94±3%, p=0.57). At peak exercise, there were no between-group differences in tidal volume, breathing frequency, IC, IRV observed. Patient-reported dyspnea and leg fatigue at peak exercise were also similar between groups. Conclusion: Initial results suggest that long-COVID patients demonstrate reduced exercise tolerance and elevated VE/VCO2;however, SpO2, operating lung volumes and dyspnea responses to exercise are similar to healthy controls, suggesting that there may be a non-pulmonary cause for the observed exercise intolerance. Further investigation is required to understand this limitation and its relationship to symptoms in long-COVID patients.
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Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».