TY - JOUR
T1 - Activity monitoring reflects cardiovascular and metabolic variations in COPD patients across GOLD stages II to IV
AU - Kortianou, E. A.
AU - Louvaris, Z.
AU - Vasilopoulou, M.
AU - Nasis, I.
AU - Kaltsakas, G.
AU - Koulouris, N. G.
AU - Vogiatzis, I.
PY - 2013/12/1
Y1 - 2013/12/1
N2 - We investigated whether activity monitoring reliably reflects variations in oxygen transport and utilization during walking in COPD patients. Forty-two patients (14 in each GOLD stage II, III and IV) performed an incremental treadmill protocol to the limit of tolerance. Breath-by-breath gas exchange, central hemodynamic variables and activity monitoring were simultaneously recorded. Physiological variables and accelerometer outputs rose linearly with walking speeds. Strong correlations (r[interquartile range, IQR]) were found between treadmill walking intensity (WI: range 0.8-2.0ms-2) and oxygen consumption (0.95 [IQR 0.87-0.97]), (range 7.6-15.5mlkg-1min-1); minute ventilation (0.95 [IQR 0.86-0.98]), (range 20-37lmin-1); cardiac output (0.89 [IQR 0.73-0.94]), (range 6.8-11.5lmin-1) and arteriovenous oxygen concentration difference (0.84 [IQR 0.76-0.90]), (range 7.7-12.1ml O2100ml-1). Correlations between WI and gas exchange or central hemodynamic parameters were not different across GOLD stages. In conclusion, central hemodynamic, respiratory and muscle metabolic variations during incremental treadmill exercise are tightly associated to changes in walking intensity as recorded by accelerometry across GOLD stages II to IV. Interestingly, the magnitude of these associations is not different across GOLD stages.
AB - We investigated whether activity monitoring reliably reflects variations in oxygen transport and utilization during walking in COPD patients. Forty-two patients (14 in each GOLD stage II, III and IV) performed an incremental treadmill protocol to the limit of tolerance. Breath-by-breath gas exchange, central hemodynamic variables and activity monitoring were simultaneously recorded. Physiological variables and accelerometer outputs rose linearly with walking speeds. Strong correlations (r[interquartile range, IQR]) were found between treadmill walking intensity (WI: range 0.8-2.0ms-2) and oxygen consumption (0.95 [IQR 0.87-0.97]), (range 7.6-15.5mlkg-1min-1); minute ventilation (0.95 [IQR 0.86-0.98]), (range 20-37lmin-1); cardiac output (0.89 [IQR 0.73-0.94]), (range 6.8-11.5lmin-1) and arteriovenous oxygen concentration difference (0.84 [IQR 0.76-0.90]), (range 7.7-12.1ml O2100ml-1). Correlations between WI and gas exchange or central hemodynamic parameters were not different across GOLD stages. In conclusion, central hemodynamic, respiratory and muscle metabolic variations during incremental treadmill exercise are tightly associated to changes in walking intensity as recorded by accelerometry across GOLD stages II to IV. Interestingly, the magnitude of these associations is not different across GOLD stages.
KW - Activity monitoring
KW - Cardiac output
KW - COPD
KW - Indirect calorimetry
KW - Physical activity
KW - Walking
UR - http://www.scopus.com/inward/record.url?scp=84888006614&partnerID=8YFLogxK
U2 - 10.1016/j.resp.2013.08.014
DO - 10.1016/j.resp.2013.08.014
M3 - Article
C2 - 24013005
AN - SCOPUS:84888006614
SN - 1569-9048
VL - 189
SP - 513
EP - 520
JO - Respiratory Physiology and Neurobiology
JF - Respiratory Physiology and Neurobiology
IS - 3
ER -