TY - JOUR
T1 - Intensity of daily physical activity is associated with central hemodynamic and leg muscle oxygen availability in COPD
AU - Louvaris, Zafeiris
AU - Kortianou, Eleni A.
AU - Spetsioti, Stavroula
AU - Vasilopoulou, Maroula
AU - Nasis, Ioannis
AU - Asimakos, Andreas
AU - Zakynthinos, Spyros
AU - Vogiatzis, Ioannis
PY - 2013/9/15
Y1 - 2013/9/15
N2 - In chronic obstructive pulmonary disease (COPD), daily physical activity is reported to be adversely associated with the magnitude of exerciseinduced dynamic hyperinflation and peripheral muscle weakness. There is limited evidence whether central hemodynamic, oxygen transport, and peripheral muscle oxygenation capacities also contribute to reduced daily physical activity. Nineteen patients with COPD (FEV1, 48 ± 14% predicted) underwent a treadmill walking test at a speed corresponding to the individual patient's mean walking intensity, captured by a triaxial accelerometer during a preceding 7-day period. During the indoor treadmill test, the individual patient mean walking intensity (range, 1.5 to 2.3 m/s2) was significantly correlated with changes from baseline in cardiac output recorded by impedance cardiography (range, 1.2 to 4.2 L/min; r = 0.73), systemic vascular conductance (range, 7.9 to 33.7 ml•min-1•mmHg-1; r = 0.77), systemic oxygen delivery estimated from cardiac output and arterial pulse-oxymetry saturation (range, 0.15 to 0.99 L/min; r = 0.70), arterio-venous oxygen content difference calculated from oxygen uptake and cardiac output (range, 3.7 to 11.8 mlO2/100 ml; r =-0.73), and quadriceps muscle fractional oxygen saturation assessed by near-infrared spectrometry (range,-6 to 23%; r = 0.77). In addition, mean walking intensity significantly correlated with the quadriceps muscle force adjusted for body weight (range, 0.28 to 0.60; r = 0.74) and the ratio of minute ventilation over maximal voluntary ventilation (range, 38 to 89%, r =-0.58). In COPD, in addition to ventilatory limitations and peripheral muscle weakness, intensity of daily physical activity is associated with both central hemodynamic and peripheral muscle oxygenation capacities regulating the adequacy of matching peripheral muscle oxygen availability by systemic oxygen transport.
AB - In chronic obstructive pulmonary disease (COPD), daily physical activity is reported to be adversely associated with the magnitude of exerciseinduced dynamic hyperinflation and peripheral muscle weakness. There is limited evidence whether central hemodynamic, oxygen transport, and peripheral muscle oxygenation capacities also contribute to reduced daily physical activity. Nineteen patients with COPD (FEV1, 48 ± 14% predicted) underwent a treadmill walking test at a speed corresponding to the individual patient's mean walking intensity, captured by a triaxial accelerometer during a preceding 7-day period. During the indoor treadmill test, the individual patient mean walking intensity (range, 1.5 to 2.3 m/s2) was significantly correlated with changes from baseline in cardiac output recorded by impedance cardiography (range, 1.2 to 4.2 L/min; r = 0.73), systemic vascular conductance (range, 7.9 to 33.7 ml•min-1•mmHg-1; r = 0.77), systemic oxygen delivery estimated from cardiac output and arterial pulse-oxymetry saturation (range, 0.15 to 0.99 L/min; r = 0.70), arterio-venous oxygen content difference calculated from oxygen uptake and cardiac output (range, 3.7 to 11.8 mlO2/100 ml; r =-0.73), and quadriceps muscle fractional oxygen saturation assessed by near-infrared spectrometry (range,-6 to 23%; r = 0.77). In addition, mean walking intensity significantly correlated with the quadriceps muscle force adjusted for body weight (range, 0.28 to 0.60; r = 0.74) and the ratio of minute ventilation over maximal voluntary ventilation (range, 38 to 89%, r =-0.58). In COPD, in addition to ventilatory limitations and peripheral muscle weakness, intensity of daily physical activity is associated with both central hemodynamic and peripheral muscle oxygenation capacities regulating the adequacy of matching peripheral muscle oxygen availability by systemic oxygen transport.
KW - Activity monitoring
KW - Chronic obstructive pulmonary disease
KW - Nearinfrared spectroscopy
KW - Quadriceps muscle oxygenation
KW - Walking intensity
UR - http://www.scopus.com/inward/record.url?scp=84884324421&partnerID=8YFLogxK
U2 - 10.1152/japplphysiol.00379.2013
DO - 10.1152/japplphysiol.00379.2013
M3 - Article
C2 - 23845982
AN - SCOPUS:84884324421
SN - 8750-7587
VL - 115
SP - 794
EP - 802
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 6
ER -