Table 1.
Characteristics of the study population (n = 119)
| COPD | ||||||
| Healthy (ex)smokers | At Risk (Stage 0) | Mild (Stage I) | Moderate (Stage IIA) | Moderate (Stage IIB) | Severe (Stage III) | |
| N | 44 | 18 | 15 | 20 | 16 | 6 |
| Males (%) | 48 | 33 | 60 | 70 | 81 | 100 |
| Age, yr | 51 (45–71) | 53 (42–61) | 54 (48–66) | 57 (46–73) | 66 (49–74) | 59 (53–69) |
| Pack yr | 24 (4–66) | 29 (2–67) | 31 (20–77) | 35 (15–77) | 36 (10–85) | 34 (12–45) |
| Current smoking(%) | 89 | 100 | 100 | 85 | 75 | 83 |
| FEV1 (%pred) | 101 (62–128) | 105 (82–132) | 93 (81–116) | 69 (51–75) | 41 (30–49) | 24 (22–28) |
Healthy (ex) smokers; normal spirometry, no chronic symptoms (cough, sputum production). COPD classification of COPD by severity according to the GOLD guidelines; Stage 0: normal spirometry, chronic symptoms (cough, sputum production); Stage I: FEV1/FVC < 70%, FEV1 ≥ 80 % predicted, with or without chronic symptoms (cough, sputum production, dyspnea); Stage IIA: FEV1/FVC < 70%, 50% ≥ FEV1 < 80 % predicted; Stage IIB: FEV1/FVC < 70%, 30% ≥ FEV1 < 50 % predicted; Stage III: FEV1/FVC < 70%, FEV1 < 30 % predicted or FEV1 < 50% predicted plus respiratory failure or clinical signs of right heart failure.