Table 2.
Small airway characteristics
| Non-smoker n = 15 | Smoker n = 32 | COPD stage I-II n = 35 | COPD stage IV n = 8 | p-value ANOVA | |
|---|---|---|---|---|---|
| Airway diameter, mm | |||||
| Longest | 0.89 (0.70) | 0.72 (0.36) | 0.84 (0.60) | 0.70 (0.40) | 0.759 |
| Shortest | 0.40 (0.50) | 0.26 (0.174) | 0.30 (0.21) | 0.07 (0.03) | 0.085 |
| Average | 0.64 (0.54) | 0.49 (0.24) | 0.48 (0.27) | 0.40 (0.21) | 0.503 |
| Internal lumen | |||||
| perimeter, mm | 3.17 (2.14) | 2.60 (1.45) | 2.48 (1.25) | 2.17 (1.04) | 0.587 |
| Area, mm2 | 0.45 (0.85) | 0.17 (0.16) | 0.26 (0.28) | 0.09 (0.14) | 0.248 |
| Basement membrane | |||||
| Perimeter, mm | 3.30 (2.25) | 2.72 (1.46) | 2.47 (1.22) | 2.34 (1.11) | 0.591 |
| Area, mm2 | 0.56 (0.93) | 0.26 (0.21) | 0.29 (0.30) | 0.17 (0.17) | 0.239 |
| Epithelial area, mm2 | 0.11 (0.10) | 0.09 (0.08) | 0.09 (0.09) | 0.08 (0.06) | 0.938 |
| Thickness of airway wall within RBM** (μm) | 23.3 (12.3) | 26.1 (9.6) | 30.9 (11.1) | 22.0 (4.7) | 0.029 |
mean (SD)
n = number of bronchioli studied
*statistically significant difference compared to stage IV COPD
**RBM = reticular basement membrane, including the membrane itself