Table 1. Baseline characteristics of the study patients according to the baseline mMRC dyspnea scale.
| Characteristics | mMRC 0 or 1 (n=62) | mMRC ≥2 (n=40) | P value |
|---|---|---|---|
| Age (years) | 67.2±0.8 | 66.9±1.2 | 0.863 |
| BMI (kg/m2) | 23.8±0.3 | 23.1±0.5 | 0.225 |
| Current smoker/ex-smoker (n) | 19/43 | 10/30 | 0.537 |
| Smoking pack years | 37.2±2.2 | 48.1±3.4 | 0.005 |
| CAT score | 13.7±0.7 | 17.1±0.8 | 0.002 |
| SGRQ total score | 19.7±1.0 | 31.2±2.2 | <0.001 |
| FEV1% predicted | 55.9±1.6 | 48.4±2.4 | 0.008 |
| FVC% predicted | 85.9±1.6 | 80.0±2.3 | 0.030 |
| FEV1/FVC (%) | 46.8±1.3 | 43.2±1.8 | 0.095 |
| DLco% predicted | 75.5±2.4 | 60.0±3.1 | <0.001 |
| TLC% predicted | 95.8±2.1 | 100.1±3.4 | 0.245 |
| IC/TLC% | 34.2±1.5 | 32.9±2.0 | 0.600 |
| FRC% predicted | 111.4±4.2 | 120.4±6.2 | 0.217 |
| RV% predicted | 91.0±4.5 | 113.3±9.2 | 0.018 |
| 6-minute walk distance (m) | 458±10 | 438±13 | 0.247 |
Data are presented as the mean ± SEM. mMRC, Modified Medical Research Council; BMI, body mass index; CAT, COPD Assessment Test; SGRQ, St. George’s Respiratory questionnaire; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; DLco, diffusing capacity for carbon monoxide; TLC, total lung capacity; IC, inspiratory capacity; FRC, functional residual capacity; RV, residual volume.