Relations between cardiopulmonary function during exercise and exercise tolerance in patients with COPD

Abstract

Methods: In part 1, a cross-sectional study took place. Sixty COPD patients performed a spirometry and a cardiopulmonary exercise test (CPET). Predictors of exercise tolerance were examined. In part 2, a longitudinal observational study took place. Twelve COPD patients completed an exercise training intervention. A study on relations between changes in cardiopulmonary function and changes in exercise tolerance was performed.

Results: Significant predictors of VO2peak are peak carbon dioxide output (VCO2peak), peak respiratory exchange ratio (RERpeak), peak oxygen pulse (O2/HRpeak), peak heart rate (HRpeak) and total lung capacity %predicted (TLC %pred). Significant predictors of Wpeak are VCO2peak and body mass index (BMI). Significant predictors of 'VO2peak during follow-up are the change in peak inspiratory tidal volume ('Vtinpeak) and the change in peak inspiratory time/total respiratory cycle time ('Ti/Ttot). Significant predictors of 'Wpeak are 'O2/HRpeak and 'RERpeak.

Conclusions: Resting lung function test has a limited predictability on exercise capacity, but certain CPET variables are predictive of (changes in) exercise tolerance in COPD patients. Physicians and physical therapists should strive for an optimization of pulmonary, muscle and cardiac function to enhance exercise tolerance in COPD patients.