title: Asymptomatic subjects with airway obstruction have significant impairment at exercise.
abstract: The relevance of screening for airway obstruction in subjects not complaining of COPD symptoms may depend on the definition of airway obstruction. Response to exercise in asymptomatic subjects with persistent airway obstruction as defined by a postbronchodilator FEV1/FVC <5th centile lower limit of normal (LLN) remains unknown.
  
  
  
  Dyspnoea (Borg scale), exercise tolerance and ventilatory constraints on tidal volume expansion were assessed in 20 consecutive asymptomatic subjects with persistent mild airway obstruction detected by screening (postbronchodilator FEV1/FVC z-score: -2.14±0.29; FEV1 z-score: -1.02±0.64) undergoing incremental cycle cardiopulmonary exercise testing, compared with 20 healthy controls with normal spirometry matched for age, sex, body mass index and smoking history (FEV1/FVC z-score: -0.13±0.57; FEV1 z-score: 0.32±0.67) and with 20 symptomatic patients with COPD matched for the same characteristics (FEV1/FVC z-score: -2.36±0.51; FEV1 z-score: -1.02±0.48).
  
  
  
  Asymptomatic subjects with airway obstruction had higher dyspnoea ratings than controls during incremental exercise. Asymptomatic subjects with airway obstruction had also peak oxygen consumption and peak power output that were lower than controls, and similar to those observed in patients with COPD. Although less frequent than in COPD, dynamic hyperinflation was more frequent in asymptomatic subjects with airway obstruction than in controls (85%, 50% and 10%, respectively; p=0.01 in asymptomatic subjects vs controls and p=0.04 vs COPD).
  
  
  
  Although they did not present with chronic activity-related dyspnoea, subjects with a postbronchodilator FEV1/FVC<LLN as detected by screening had poorer exercise tolerance than healthy controls on exertion, and a significant proportion of them had dynamic hyperinflation. These subjects may, therefore, deserve further attention and may warrant regular follow-up.
authors.affiliation: Service de Physiologie-Explorations Fonctionnelles, Besançon, France Service de Pneumologie, Besançon, France.
authors.forename: Thibaud
authors.initials: T
authors.lastname: Soumagne
authors.affiliation: Sorbonne Universités, INSERM, UMR_S 1158, Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service des Explorations Fonctionnelles de la Respiration, de l'Exercice et de la Dyspnée, Paris, France.
authors.forename: Pierantonio
authors.initials: P
authors.lastname: Laveneziana
authors.affiliation: Service de Physiologie-Explorations Fonctionnelles, Besançon, France Service de Pneumologie, Besançon, France.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Veil-Picard
authors.affiliation: Service de Physiologie-Explorations Fonctionnelles, Besançon, France EA 3920, Université de Franche-Comté, Besançon, France.
authors.forename: Alicia
authors.initials: A
authors.lastname: Guillien
authors.affiliation: Service de Physiologie-Explorations Fonctionnelles, Besançon, France Service de Pneumologie, Besançon, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Claudé
authors.affiliation: Centre de Méthodologie Clinique, CHU Besançon, Besançon, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Puyraveau
authors.affiliation: Epidémiologie des Maladies Respiratoires et Allergiques i-PLESP INSERM et UPMC, Paris, France.
authors.forename: Isabella
authors.initials: I
authors.lastname: Annesi-Maesano
authors.affiliation: Service de Pneumologie et Soins Intensifs Respiratoires, Groupe Hospitalier Cochin, Site Val de Grâce, AP-HP et Université Paris Descartes (EA2511), Sorbonne-Paris-Cité, Paris, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Roche
authors.affiliation: Service de Pneumologie, Besançon, France UMR CNRS Chrono Environnement, Université de Franche-Comté, Besançon, France.
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Dalphin
authors.affiliation: Service de Physiologie-Explorations Fonctionnelles, Besançon, France EA 3920, Université de Franche-Comté, Besançon, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Degano
mesh_terms: D000328:Adult; D000368:Aged; D001985:Bronchial Provocation Tests / Q000379:methods; D016022:Case-Control Studies; D004417:Dyspnea / Q000209:etiology / Q000503:physiopathology; D005080:Exercise Test / Q000379:methods; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D013147:Spirometry / Q000379:methods; D013990:Tidal Volume / Q000502:physiology
keywords: COPD ÀÜ Mechanisms; Exercise; Lung Physiology