Measurements at highest common work rate (80 W) in subjects with mild asymptomatic airway obstruction, patients with mild COPD and healthy controls
| Asymptomatic airway obstruction (n=20) | COPD (n=20) | Healthy controls (n=20) | |
|---|---|---|---|
| Dyspnoea, Borg scale | 3.3±2.1♯ | 4.6±2.7♯ | 1.6±1.3 |
| Leg discomfort, Borg scale | 3.7±3.0 | 5.1±2.7 | 3.0±3.0 |
| V′O2, L/min | 1.19±0.18 | 1.20±0.20 | 1.27±0.17 |
| HR, % predicted maximum | 73.3±8.0 | 73.0±9.1 | 71.2±7.1 |
| O2 pulse, mL O2/beat | 10.2±2.8 | 10.3±3.6 | 11.2±3.4 |
| V′E, L/min | 38.8±6.9 | 39.7±11.9 | 36.7±6.9 |
| f, breaths/min | 21.6±6.1 | 23.1±9.1 | 19.7±4.0 |
| VT, L | 1.80±0.29 | 1.72±0.46 | 1.86±0.38 |
| IRV, L | 1.42±0.63 | 1.29±0.56♯ | 1.78±0.69 |
| IC, L | 3.22±0.61♯ | 3.01±0.76♯ | 3.64±0.74 |
Values are means±SD. ♯p<0.05 versus controls.
f, respiratory rate; HR, heart rate; IC, inspiratory capacity; IRV, inspiratory reserve volume; V′O2, oxygen uptake; V′E, minute ventilation; V′E/V′CO2, ventilatory equivalents for carbon dioxide; VT, tidal volume.