Limitation in tidal volume expansion partially determines the intensity of physical activity in COPD.
In patients with chronic obstructive pulmonary disease (COPD), reduced levels of daily physical activity are associated with the degree of impairment in lung, peripheral muscle, and central hemodynamic function. There is, however, limited evidence as to whether limitations in tidal volume expansion also, importantly, determine daily physical activity levels in COPD. Eighteen consecutive patients with COPD [9 active (forced expiratory volume in 1 s, FEV1: 1.59 ± 0.64 l) with an average daily movement intensity >1.88 m/s(2) and 9 less active patients (FEV1: 1.16 ± 0.41 l) with an average intensity <1.88 m/s(2)] underwent a 4-min treadmill test at a constant speed corresponding to each individual patient's average movement intensity, captured by a triaxial accelerometer during a preceding 7-day period. When chest wall volumes, captured by optoelectronic plethysmography, were expressed relative to comparable levels of minute ventilation (ranging between 14.5 ± 4.3 to 33.5 ± 4.4 l/min), active patients differed from the less active ones in terms of the lower increase in end-expiratory chest wall volume (by 0.15 ± 0.17 vs. 0.45 ± 0.21 l), the greater expansion in tidal volume (by 1.76 ± 0.58 vs. 1.36 ± 0.24 l), and the larger inspiratory reserve chest wall volume (IRVcw: by 0.81 ± 0.25 vs. 0.39 ± 0.27 l). IRVcw (r(2) = 0.420), expiratory flow (r(2) change = 0.174), and Borg dyspnea score (r(2) change = 0.123) emerged as the best contributors, accounting for 71.7% of the explained variance in daily movement intensity. Patients with COPD exhibiting greater ability to expand tidal volume and to maintain adequate inspiratory reserve volume tend to be more physically active. Thus interventions aiming at mitigating restrictions on operational chest wall volumes are expected to enhance daily physical activity levels in COPD.
National and Kapodistrian University of Athens, Department of Physical Education and Sports Sciences, Athens, Greece; National and Kapodistrian University of Athens, 1st Department of Critical Care Medicine, Evangelismos Hospital, Athens, Greece; Technological Educational Institute of Central Greece, Department of Physiotherapy, Lamia, Greece;
Eleni A
EA
Kortianou
Dipartimento di Elettronica, Informazione e Bioingeneria, Politecnico di Milano, Italy.
Andrea
A
Aliverti
National and Kapodistrian University of Athens, Department of Physical Education and Sports Sciences, Athens, Greece;
Zafeiris
Z
Louvaris
National and Kapodistrian University of Athens, Department of Physical Education and Sports Sciences, Athens, Greece;
Maroula
M
Vasilopoulou
National and Kapodistrian University of Athens, Department of Physical Education and Sports Sciences, Athens, Greece;
Ioannis
I
Nasis
National and Kapodistrian University of Athens, 1st Department of Critical Care Medicine, Evangelismos Hospital, Athens, Greece;
Andreas
A
Asimakos
National and Kapodistrian University of Athens, 1st Department of Critical Care Medicine, Evangelismos Hospital, Athens, Greece;
Spyros
S
Zakynthinos
National and Kapodistrian University of Athens, Department of Physical Education and Sports Sciences, Athens, Greece; National and Kapodistrian University of Athens, 1st Department of Critical Care Medicine, Evangelismos Hospital, Athens, Greece; gianvog@phed.uoa.gr.
Ioannis
I
Vogiatzis
D061725:Accelerometry; D000368:Aged; D004417:Dyspnea / Q000503:physiopathology; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D015656:Respiratory Mechanics / Q000502:physiology; D013990:Tidal Volume / Q000502:physiology*
activity monitoring; chronic obstructive pulmonary disease; dynamic hyperinflation; lung volumes; respiratory muscle kinetics; walking intensity