Characteristics of study subjects, pulmonary function tests, and peak exercise data
|
Normal subjects (n=15) |
COPD (n=57) | |
| Age (years) | 62 (5) | 66 (7) |
| Body mass index (kg/m2) | 26 (4) | 25 (5) |
| FEV1(l) | 2.88 (0.28)a | 1.04 (0.41)b |
| FEV1 (% pred) | 106 (9)a | 39 (15)b |
| FVC (l) | 3.68 (0.40)a | 2.57 (0.70)b |
| FVC (% pred) | 94 (8)a | 64 (16)b |
| TLC (% pred) | –- | 117 (18) |
| Tlco (% pred) | –- | 66 (24) |
| V˙o 2 (ml/kg/min) | 29 (8)a | 14 (4)b |
| Work rate (watt) | 156 (39)a | 52 (28)b |
| V˙e (l/min) | 75 (19)a | 36 (13)b |
| V˙e/MVV (%) | 74 (18) | 90 (23) |
| Heart rate (beats/min) | 156 (10)a | 131 (19)b |
| Heart rate (% max pred) | 92 (7)a | 79 (11)b |
| Borg scores | ||
| Dyspnoea | 5.0 (3.1) | 7.3 (2.1) |
| Leg fatigue | 5.2 (3.5) | 5.7 (3.0) |
| Sao 2 | ||
| Rest | 0.98 (0.01)a | 0.96 (0.04)b |
| Peak exercise | 0.98 (0.01)a | 0.90 (0.07)b |
| Paco 2(kPa) | ||
| Rest | 5.2 (0.5) | 5.6 (0.9) |
| Peak exercise | 4.9 (0.7)a | 6.4 (1.2)b |
| Lactate (mmol/l) | ||
| Rest | 0.75 (0.40) | 0.98 (0.63) |
| Peak exercise | 8.06 (2.38)a | 3.91 (2.02)b |
FEV1 = forced expiratory volume in one second; FVC = forced vital capacity; TLC = total lung capacity; Tlco = carbon monoxide transfer factor; V˙o 2 = oxygen output; V˙e = minute ventilation.
Values are mean (SD). Values followed by different letters are significantly different.