Clinical characteristics of study participants
| Lifelong non- smokers without chronic lung disease | Former smokers without chronic lung disease | Patients with COPD arranged by GOLD criteria6 7 | ||||
| COPD I | COPD II | COPD III | COPD IV | |||
| Number of study participants | 8 | 10 | 7 | 14 | 10 | 24 |
| FEV1 (% of predicted) | 103 (88–109) | 98 (86–114) | 84 (81–95) | 65 (53–74) | 36 (30–48) | 21 (12–29) |
| FEV1/FVC (% of FVC) | 79 (74–84) | 79 (75–84) | 66 (58–68) | 55 (40–66) | 39 (32–53) | 28 (21–48) |
| Age (years) | 62 (55–69) | 60 (35–66) | 64 (59–74) | 67 (58–77) | 63 (49–71) | 55 (43–65) |
| Sex | ||||||
| Male | 5 | 5 | 3 | 8 | 6 | 9 |
| Female | 3 | 5 | 4 | 6 | 4 | 15 |
| Smoking history | ||||||
| Pack-years | N/A | 36 (9–88) | 50 (30–74) | 67 (20–100) | 50 (20–84) | 39 (20–80) |
| Smoke free (years) | N/A | 11 (3–18) | 4 (2–9) | 8 (2–37) | 5 (2–21) | 5 (2–15) |
| Number of airways examined (per study participant) | 4.5±0.8 | 8.9±1.8 | 7.6±1.9 | 7.6±1.3 | 8.0±1.1 | 9.8±1.2 |
| Basement membrane length (mm) | 2.2±0.2 | 2.3±0.2 | 1.8±0.2 | 2.0±0.1 | 2.3±0.2 | 2.0±0.1 |
Median and range (minimum and maximum) are indicated for each clinical parameter. Number of airways examined per study participant and basement membrane length are indicated as mean±SE.