Table 1.
Characteristics of the 20 included patients with moderate-to-very severe COPDa.
| Characteristics | Mean (SD) |
| Age (years) | 63 (8) |
| Body mass index (kg/m²) | 26 (4) |
| Forced expiratory volume in 1 second (L) | 1.4 (0.5) |
| Forced expiratory volume in 1 second (% predicted) | 48 (15) |
| Forced vital capacity (L) | 3.8 (1.1) |
| Forced vital capacity (% predicted) | 97 (20) |
| Transfer factor for carbon monoxide (% predicted) | 50 (16) |
| Partial pressure of oxygen (kPa) | 8.7 (1.7) |
| Partial pressure of carbon dioxide (kPa) | 5.2 (0.6) |
| 6-minute walking distance (m) | 411 (59) |
| COPD assessment test score | 21 (5) |
| Total night sleeping time (min) | 411 (72) |
| Wake time after sleep onset (min) | 74 (36) |
| Sleep efficiency (%) | 83 (8) |
aCOPD: chronic obstructive pulmonary disease.