The Effects of Acute Ozone Pollution Exposure on Muscle Sympathetic Activity and Cardiac-Autonomic Control
Notice bibliographique
Résumé
Background: Ground level ozone (O 3 ) is a respiratory irritant well established to cause reductions in lung function. O 3 exposure may also promote progressive autonomic imbalance to the cardiovascular system as previously indicated by reductions in heart rate variability (HRV) and elevated basal blood pressure. However, no studies have directly assessed whether muscle sympathetic activity (MSNA) increases in this context. This study investigated whether short-term O 3 exposure promotes autonomic imbalance (via MSNA and HRV), with O 3 exposure being hypothesized to both decrease HRV and increase MSNA. Our secondary objective was to validate O 3 induced reductions in lung function as shown in previous studies. Methods: Twenty-eight healthy adults (female N. = 12; 23 ± 4 years [mean ± SD]) were randomized to a single 90 minute, double-blinded exposure of either: (i) artificial O 3 (0.75 parts per million [ppm]; N.14) or (ii) room air (RA) (naturally occurring O 3 <0.01 ppm). Spirometry was performed pre/post exposure, while blood pressure (finger photoplethysmography), MSNA (microneurography [N. 25]), and HRV (Lead~II ECG) were measured at several points during exposure. MSNA was quantified as burst frequency (burst/min) and burst incidence (burst/100 heart beats [hb]). HRV was averaged (5-minute bins) and assessed through time-domain (mean and standard deviation RR interval, root squared mean successive differences, percentage of RR interval differences >50ms) and frequency-domain (high frequency [ 0.15-0.4 Hz), low frequency [0.04-0.15 Hz], low/high frequency ratio) indices. Delta MSNA,HRV, and blood pressure were analyzed during exposure using two-way repeated measures ANOVA model. Pre/post exposure spirometry was assessed through students t-test. Results: O 3 and RA groups showed no difference in baseline lung function (forced expiratory volume [FEV 1 ] ~ 4.58 ± 0.98 vs 4.3 ± 0.84 L), heart rate (62 ± 8 vs 61 ± 6 beats/min), arterial pressure (MAP~87 ± 9 vs 81 ± 5 mmHg, p=0.06), burst frequency (16 ± 5 vs 16 ± 5 bursts/min), burst incidence (25 ± 10 vs 25 ± 10 bursts/100hb) and HRV time/frequency domain measures. O 3 group, but not RA, saw a reduced post-exposure FEV 1 (-8 ± 9% p<0.01 vs baseline). MAP response was unchanged between groups during exposure, while O 3 group showed greater time-dependent increases than RA group in burst frequency (+7 ± 4 vs +2 ± 3 bursts/min at 90 minutes exposure, p<0.05) and incidence (+10 ± 7 vs +3 ± 5 bursts/100hb at 90 minutes exposure, p<0.05). No differences were found in HRV time and frequency domain responses between O 3 and RA groups during exposure. Conclusion: These findings provide evidence of short-term O 3 induced sympathetic vasomotor activation that accompanies reductions in lung function. The increase of MSNA demonstrates sympathetic activation is present during initial O 3 exposure, and may partly contribute to early autonomic imbalance in the absence of observable changes to blood pressure and HRV. Supported by the Natural Sciences and Engineering Research Council of Canada (AWS; SAB) and a Killam Laureate Doctoral Scholarship (SAB). This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
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 | 0,000 | 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) | 0,001 | 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 ».