Basic characteristics of patients with COPD and controls*
| Variable | COPD (n = 47)M = 28/F = 19 | Controls (n = 48)M = 29/F = 19 | T test for independent samples (p value) |
|---|---|---|---|
| NA, not available; NS, not significant; BMI, body mass index; FEV1, forced expiratory volume in 1 s; TLC, total lung capacity; RV, residual volume; Tlco, carbon monoxide transfer factor; MRC, Medical Research Council; 6MWD, 6-minute walk distance; SGRQ, St George’s Respiratory Disease Questionnaire; BODE, body mass index (B), obstruction (O), dyspnoea (D) and exercise endurance (E). | |||
| Data presented as mean (SD). | |||
| *Log transformation was performed on variables with non-normal distribution. | |||
| Age | 64 (8) | 64 (7) | NS |
| BMI (kg/m2) | 26.6 (5.2) | 27.6 (4.8) | NS |
| Smoking history (pack-years) | 70 (40) | 23 (3) | <0.001 |
| Pre-bronchodilator FEV1 (l) | 0.87 (0.33) | 2.46 (0.61) | <0.001 |
| Pre-bronchodilator FEV1 (% predicted) | 32 (10) | 90 (15) | <0.001 |
| Post-bronchodilator FEV1 (l) | 0.94 (0.36) | NA | |
| Post-bronchodilator FEV1 (% predicted) | 35 (11) | NA | |
| TLC (l) | 7.00 (1.57) | 5.33 (1.48) | <0.001 |
| TLC (% predicted) | 126 (2) | 95 (19) | <0.001 |
| RV (l) | 4.46 (1.36) | 2.07 (0.81) | <0.001 |
| RV (% predicted) | 211 (60) | 96 (33) | <0.001 |
| Tlco (ml/min/mmHg) | 9.9 (3.8) | 19.5 (6) | <0.001 |
| Tlco (% predicted) | 48 (5) | 92 (24) | <0.001 |
| MRC dyspnoea | 2.5 (0.8) | 0.08 (0.3)* | <0.001 |
| 6MWD (m) | 365 (109) | 540 (95) | <0.001 |
| SGRQ composite score | 53 (18) | 4.8 (2.6)* | <0.001 |
| BODE index | 4.7 (1.8) | 2.2 (1.8) | <0.001 |