Table 1. Demographic and clinical characteristics of control subjects and COPD patients grouped according to GOLD stage of disease severity.
| Controls (N = 5) | GOLD1 (N = 5) | GOLD2 (N = 5) | GOLD 3 (N = 5) | GOLD4 (N = 5) | P | |
| Age; mean (SD) | 73.9 (3.8) | 74.4 (8.9) | 75.6 (3.2) | 78.8 (4.5) | 73.2 (6.3) | 0.128 |
| Males, n (%) | 2 (40) | 3 (60) | 4 (80) | 5 (100) | 3 (60) | 0.439 |
| BMI; mean (SD) | 25.1 (4.2) | 23.6 (4.4) | 28.0 (3.5) | 26.2 (3.9) | 29.8 (3.8) | 0.186 |
| Smoking status, n (%) | 0.081 | |||||
| Current | 0 (0) | 1 (20) | 0 (0) | 2 (40) | 1 (20) | |
| Former | 1 (20) | 2 (40) | 5 (100) | 3 (60) | 2 (40) | |
| Never | 4 (80) | 2 (40) | 0 (0) | 0 (0) | 2 (40) | |
| Pack/Year; mean (SD) | 5.0 (11.2) | 23.0 (22.2) | 55.5 (33.0) | 49.0 (17.5) | 41.2 (56.6) | 0.099 |
| MRC dyspnea score; mean (SD) | 0.40 (0.9) | 1.4 (1.3) | 1.0 (1.2) | 3.0 (0.2) | 2.2 (0.8) | 0.004 |
| 6 MWD in meters; mean (SD) | 569 (97) | 387 (61) | 323 (54) | 323 (147) | 307 (96) | 0.004 |
| Diabetes mellitus, n (%) | 1 (20) | 1 (20) | 2 (40) | 2 (40) | 0 (0) | 0.381 |
| Ischemic heart disease (%) | 0 (0) | 1 (20) | 1 (20) | 2 (40) | 1 (20) | 0.711 |
| Pulmonary hypertension/cor pulmonare, n (%) | 0 (0) | 1 (20) | 0 (0) | 1 (20) | 1 (20) | 0.684 |
| Bronchiectasis, n (%) | 0 (0) | 0 (0) | 0 (0) | 1 (20) | 0 (0) | 0.439 |
| Obstructive sleep apnoea, n (%) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 2 (40) | 0.034 |
| Number of inhaled medications; mean (SD) | 0 | 2.0 (0.7) | 2.2 (1.3) | 2.8 (0.4) | 3.0 (1.2) | 0.005 |
| Oxygen therapy, n (%) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 5 (100) | <0.001 |
| Barthel's total Score; mean (SD) | 102 (0) | 98.6 (2.3) | 93.4 (11.1) | 85.0 (7.3) | 84.0 (7.6) | 0.001 |
| Barthel's selfcare subscore; mean (SD) | 51.0 (0) | 49.6 (2.2) | 47.8 (5.6) | 47.2 (5.0) | 46.6 (4.9) | 0.450 |
| Barthel's mobility subscore; mean (SD) | 51.0 (0) | 49.0 (2.7) | 45.0 (6.2) | 37.8 (2.9) | 37.6 (3.8) | <0.001 |
| Number of acute exacerbation of COPD in the past year; mean (SD) | 0 | 0.8 (0.8) | 1.0 (1.4) | 2.6 (1.7) | 3.0 (0.7) | 0.02 |
| White blood cell count × 103 ; mean (SD) | 5.27 (0.69) | 7.91 (1.30) | 7.55 (2.11) | 8.46 (1.82) | 7.32 (1.77) | 0.052 |
| Erytrocyte sedimentation rate; mean (SD) | 12.7 (18.2) | 32.8 (13.8) | 22.2 (8.4) | 40.0 (45.2) | 28.6 (13.6) | 0.355 |
| C-reactive protein; mean (SD) | 1.6 (0.3) | 2.1 (2.7) | 1.95 (2.1) | 7.82 (12.8) | 3.93 (2.5) | 0.395 |
Comparisons between groups were performed by χ-square test for categorical variables, and one-way ANOVA analyses (followed by Bonferroni post-hoc multiple comparison adjustment) for continuous variables.