Exercise ventilatory inefficiency in mild to end-stage COPD

dc.contributor.authorAlberto Neder, J.
dc.contributor.authorArbex, Flavio F. [UNIFESP]
dc.contributor.authorAlencar, Maria Clara N. [UNIFESP]
dc.contributor.authorO'Donnell, Cpnor D. J.
dc.contributor.authorCory, Julia
dc.contributor.authorWebb, Kathy A.
dc.contributor.authorO'Donnell, Denis E.
dc.contributor.institutionQueens Univ
dc.contributor.institutionKingston Gen Hosp
dc.contributor.institutionUniversidade Federal de São Paulo (UNIFESP)
dc.description.abstractVentilatory inefficiency during exercise is a key pathophysiological feature of chronic obstructive pulmonary disease. Currently, it is unknown how this physiological marker relates to clinically relevant outcomes as resting ventilatory impairment progresses across disease stages.Slope and intercept of the linear region of the ventilation-carbon dioxide output relationship and the ratio between these variables, at the lowest point (nadir), were contrasted in 316 patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages 1-4 (forced expiratory volume in 1 s, ranging from 148% pred to 12% pred) and 69 aged- and gender-matched controls,Compared to controls, slope and intercept were higher in GOLD stages 1 and 2, leading to higher nadirs (p<0.05). Despite even larger intercepts in GOLD stages 3 and 4, slopes diminished as disease evolved (from mean +/- SD 35 +/- 6 in GOLD stage 1 to 24 +/- 5 in GOLD stage 3, p<0.05). As a result, there were no significant differences in nadirs among patient groups. Higher intercepts, across all stages (p<0.01), and to a lesser extent lower slopes in GOLD stages 2-4 (p<0.05), were related to greater mechanical constraints, worsening pulmonary gas exchange, higher dyspnoea scores, and poorer exercise capacity.Increases in the ventilation intercept best indicate the progression of exercise ventilatory inefficiency across the whole spectrum of chronic obstructive pulmonary disease severity.en
dc.description.affiliationQueens Univ, Resp Invest Unit, Kingston, ON, Canada
dc.description.affiliationQueens Univ, Lab Clin Exercise Physiol, Kingston, ON, Canada
dc.description.affiliationKingston Gen Hosp, Kingston, ON K7L 2V7, Canada
dc.description.affiliationUniversidade Federal de São Paulo, Div Respirol, Clin Exercise Physiol Unit SEFICE, São Paulo, Brazil
dc.description.affiliationUnifespUniversidade Federal de São Paulo, Div Respirol, Clin Exercise Physiol Unit SEFICE, São Paulo, Brazil
dc.description.sourceWeb of Science
dc.identifier.citationEuropean Respiratory Journal. Sheffield: European Respiratory Soc Journals Ltd, v. 45, n. 2, p. 377-387, 2015.
dc.publisherEuropean Respiratory Soc Journals Ltd
dc.relation.ispartofEuropean Respiratory Journal
dc.rightsAcesso restrito
dc.titleExercise ventilatory inefficiency in mild to end-stage COPDen