[Maximal respiratory pressures and exercise tolerance in patients with COPD].
Many authors reported respiratory muscle function impairment in patients with chronic obstructive pulmonary disease (COPD). Impaired respiratory muscle function may contribute exercise intolerance which is frequently observed in this disease.


OBJECTIVE
was to determine the influence of respiratory muscle function on exercise capacity in patients with COPD.


METHODS
23 patients with stable COPD aged 62.7 +/- 9.3 years (6F, 17M; mean post-bronchodilator FEV1 = 47.9 +/-12.4% value predicted) participated in the study. Exercise capacity was assessed by the six-minute walk test and the incremental cardiopulmonary exercise test (CPET) on a treadmill. Maximal respiratory pressures (PImax, PEmax) were evaluated before and directly after CPET.


RESULTS
The mean peak oxygen uptake (VO max) was 27.2 +/- 6.1 mlO2/min/kg and the mean distance walked during the 6MWT was 569.4 +/- 101.7 m. Both PIMax and PE max decreased significantly after maximal exercise (71.4 +/-23.0 vs 63.6 +/- 22.2 cmH2O, p = 0.001 and 124.9 +/- 46.5 vs 112.3 +/- 46.6 cm H2O, p = 0.02 respectively). No correlation between VO2max and the 6-minute walk distance and the maximal respiratory pressures was found. We observed a negative correlation between the 6-minute walk distance and the difference between the pre- and post CPET maximal inspiratory pressure.


CONCLUSIONS
respiratory muscle function is impaired in patients with COPD but this does not affect exercise performance. Exercise causes a decrease of the respiratory muscle strength.
Maskey-Warzechowska
Marta
M
Katedra i Klinika Chorób Wewnetrznych, Pneumonologii i Alergologii AM w Warszawie.
Przybyłowski
Tadeusz
T
Hildebrand
Katarzyna
K
Wrotek
Katarzyna
K
Wiwała
Joanna
J
Kościuch
Justyna
J
Chazan
Ryszarda
R
D000368:Aged; D004417:Dyspnea / Q000209:etiology / Q000503:physiopathology; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011312:Pressure; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000503:physiopathology*; D012129:Respiratory Function Tests; D012132:Respiratory Muscles / Q000503:physiopathology*; D013147:Spirometry; D014109:Total Lung Capacity; D016138:Walking