Table E7.
Asthma phenotypes (subjects with a smoking history of >10 pack years were excluded)
| Asthma cluster 1: Severe air trapping, bronchial wall thickening, and bronchial lumen dilatation (n = 10) | Asthma cluster 2: Moderate air trapping (n = 33) | Asthma cluster 3: Severe air trapping and bronchial lumen narrowing (n = 15) | Significance (P value) | |
|---|---|---|---|---|
| Age (y) | 52.1 (10.1) | 49.2 (13.3) | 54.3 (8.9) | .4 |
| Sex (M/F) | 7/3 | 17/16 | 6/9 | .8 |
| Postbronchodilator FEV1 (% predicted) | 61.4 (17.0) | 84.2 (20.2) | 72.2 (16.3) | .005* |
| Postbronchodilator FEV1/FVC ratio (%) | 65.6 (13.3) | 72.8 (10.6) | 68.4 (9.5) | .2 |
| Midexpiratory flow (L/s) | 1.7 (1.2) | 2.1 (0.9) | 1.9 (0.9) | .6 |
| RV (L) | 2.9 (0.8) | 1.7 (0.7) | 2.0 (0.9) | .006* |
| TLC (L) | 6.4 (1.4) | 5.8 (1.4) | 5.7 (2.1) | .6 |
| RV/TLC (%) | 45.2 (11.0) | 29.2 (6.5) | 35.4 (9.6) | <.005* |
| RB1 % wall volume | 57.9 (2.9) | 62.0 (2.6) | 64.9 (2.9) | <.005*†‡ |
| RB1 wall volume (mm3) | 544.7 (96.8) | 455.7 (121.3) | 331.3 (107.3) | <.005†‡ |
| RB1 wall volume (% greater than upper 95% CI of healthy control subjects) | 30 | 15 | 7 | .3 |
| RB1 LV (mm3) | 397.0 (81.1) | 280.1 (78.2) | 179.6 (56.7) | <.005*†‡ |
| RB1 LV (% less than lower 95% CI of healthy control subjects) | 10 | 64 | 93 | <.005 |
| Expiratory VI −850 (%) | 24.9 (16.4) | 17.5 (11.9) | 23.4 (11.5) | .2 |
| Expiratory VI −850 (% greater than upper 95% CI of healthy control subjects) | 70 | 30 | 60 | .03 |
| MLD E/I | 0.881 (0.06) | 0.858 (0.06) | 0.861 (0.05) | .5 |
| MLD E/I (% greater than upper 95% CI of healthy control subjects) | 80 | 55 | 67 | .3 |
Data are expressed as means (SDs). Pearson χ2 and Fisher exact tests were used to compare ratios.
FVC, Forced vital capacity.
Intergroup comparisons
One-way ANOVA with the Tukey test to compare all pairs of columns: *P < .05, asthma cluster 1 versus asthma cluster 2; †P < .05, asthma cluster 1 versus asthma cluster 3; and ‡P < .05, asthma cluster 2 versus asthma cluster 3.