RT Journal Article
SR Electronic
T1 Mechanisms of exercise limitation in patients with chronic hypersensitivity pneumonitis
JF ERJ Open Research
JO erjor
FD European Respiratory Society
SP 00043-2018
DO 10.1183/23120541.00043-2018
VO 4
IS 3
A1 Olívia Meira Dias
A1 Bruno Guedes Baldi
A1 Jeferson George Ferreira
A1 Letícia Zumpano Cardenas
A1 Francesca Pennati
A1 Caterina Salito
A1 Carlos Roberto Ribeiro Carvalho
A1 Andrea Aliverti
A1 André Luis Pereira de Albuquerque
YR 2018
UL http://openres.ersjournals.com/content/4/3/00043-2018.abstract
AB Small airway and interstitial pulmonary involvements are prominent in chronic hypersensitivity pneumonitis (cHP). However, their roles on exercise limitation and the relationship with functional lung tests have not been studied in detail.Our aim was to evaluate exercise performance and its determinants in cHP. We evaluated maximal cardiopulmonary exercise testing performance in 28 cHP patients (forced vital capacity 57±17% pred) and 18 healthy controls during cycling.Patients had reduced exercise performance with lower peak oxygen production (16.6 (12.3–19.98) mL·kg−1·min−1 versus 25.1 (16.9–32.0), p=0.003), diminished breathing reserve (% maximal voluntary ventilation) (12 (6.4–34.8)% versus 41 (32.7–50.8)%, p<0.001) and hyperventilation (minute ventilation/carbon dioxide production slope 37±5 versus 31±4, p<0.001). All patients presented oxygen desaturation and augmented Borg dyspnoea scores (8 (5–10) versus 4 (1–7), p=0.004). The prevalence of dynamic hyperinflation was found in only 18% of patients. When comparing cHP patients with normal and low peak oxygen production (<84% pred, lower limit of normal), the latter exhibited a higher minute ventilation/carbon dioxide production slope (39±5.0 versus 34±3.6, p=0.004), lower tidal volume (0.84 (0.78–0.90) L versus 1.15 (0.97–1.67) L, p=0.002), and poorer physical functioning score on the Short form-36 health survey. Receiver operating characteristic curve analysis showed that reduced lung volumes (forced vital capacity %, total lung capacity % and diffusing capacity of the lung for carbon dioxide %) were high predictors of poor exercise capacity.Reduced exercise capacity was prevalent in patients because of ventilatory limitation and not due to dynamic hyperinflation. Reduced lung volumes were reliable predictors of lower performance during exercise.Besides significant small airway involvement, reduced exercise capacity is due to ventilatory limitation and not due to dynamic hyperinflation in chronic hypersensitivity pneumonitis http://ow.ly/Ou9230kSBQz