All patients | Comorbidity categories | p-value | |||
0 | 1 | ≥2 | |||
Patients n | 316 | 120 | 109 | 87 | |
Age yrs | 68.3±7.6 | 67.5±7.0 | 68.5±7.1 | 69.1±8.8 | 0.357 |
Males/females n | 235/81 | 87/33 | 77/32 | 71/16 | 0.107 |
Charlson score | 2.66±1.22 | 2.20±0.76 | 2.63±1.07 | 3.30±1.56 | 0.001 |
BMI kg·m−2 | 27.2±5.2 | 26.3±3.8 | 28.0±4.8 | 27.3±7.1 | 0.093 |
Pa,CO2 mmHg | 41.4±5.1 | 40.8±5.4 | 42.1±5.4 | 41.5±5.4 | 0.232 |
Pa,O2 mmHg | 71.9±9.7 | 72.8±10.2 | 71.5±9.8 | 71.1±9.1 | 0.450 |
FEV1 % pred | 49.6±14.0 | 50.2±15.2 | 50.5±14.1 | 47.5±11.9 | 0.268 |
COPD stage# | 0.421 | ||||
Mild | 14 (4.4) | 7 (5.8) | 4 (3.6) | 3 (3.4) | |
Moderate | 147 (46.5) | 48 (40.0) | 57 (52.2) | 42 (48.2) | |
Severe | 127 (40.1) | 52 (43.3) | 41 (37.6) | 34 (39.0) | |
Very severe | 28 (8.8) | 13 (10.8) | 7 (6.4) | 8 (9.1) | |
6MWD m | 396.9±82.5 | 409.7±82.3 | 390.9±71.1 | 386.6±94.0 | 0.096 |
MRC score | 3.21±0.85 | 3.14±0.86 | 3.34±0.79 | 3.14±0.88 | 0.136 |
SGRQ score | 42.7±15.8 | 42.7±16.0 | 43.1±16.3 | 42.2±15.2 | 0.948 |
Data are presented as mean±sd or n (%), unless otherwise stated. BMI: body mass index; Pa,CO2: arterial carbon dioxide tension; Pa,O2: arterial oxygen tension; FEV1: forced expiratory volume in 1 s; % pred: % predicted; COPD: chronic obstructive pulmonary disease; 6MWD: 6-min walk distance; MRC: Medical Research Council dyspnoea scale; SGRQ: St George's Respiratory Questionnaire. #: mild COPD is defined as FEV1/forced vital capacity (FVC) ratio ≤0.7 and FEV1 ≥80% pred, moderate COPD as FEV1/FVC ratio ≤0.7 and FEV1 50–80% pred, severe COPD as FEV1/FVC ratio ≤0.7 and FEV1 30–50% pred, and very severe COPD FEV1/FVC ratio ≤0.7 and FEV1 <30% pred. Bold indicates statistically significant p-value.