RT Journal Article
SR Electronic
T1 What is the relationship between inspiratory capacity and different measures of exercise capacity in patients with COPD?
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P4154
VO 40
IS Suppl 56
A1 Leila Donária
A1 Rafael Mesquita
A1 Camila Monteiro Mazzarin
A1 Isabel Cristina Hilzert Genz
A1 Vanessa Suziane Probst
A1 Nidia Aparecida Hernandes
A1 Fábio Pitta
YR 2012
UL http://erj.ersjournals.com/content/40/Suppl_56/P4154.abstract
AB Background: Inspiratory capacity (IC) is an indirect measure of pulmonary hyperinflation in patients with chronic obstructive pulmonary disease (COPD), and may be a limiting factor to exercise capacity in this population. However, the relationship of IC with exercise capacity still needs to be better explored. Objective: To investigate the relationship between inspiratory capacity and different measures of exercise capacity in subjects with COPD. Methods: Thirty patients with COPD (16 men, 66±8 years, forced expiratory volume in the first second [FEV1] 40±14% pred) were studied. Inspiratory capacity was assessed by post-bronchodilator spirometry, whereas exercise capacity was assessed by the following three tests: six-minute walking test (6MWT), incremental symptom-limited cycle ergometry test (ISL) and constant work rate cycle ergometry test (CWR), all tests performed according to international guidelines. Results: In the 6MWT, IC (in liters) explained 18% (p=0.02) of the distance walked, whereas in the ISL it explained 23% (p=0.008) of maximum work load and 19% (p=0.02) of heart rate reached at the end of the test. In the CWR, IC showed only a simple negative correlation with oxygen saturation at the end of the test (r=-0.48). Conclusion: The inspiratory capacity significantly contributes, albeit modestly, to some key variables of exercise capacity tests. This indicates that a greater ventilatory reserve may be related to better physical fitness, and hence to a lower chance of hyperinflation.