Table E7.
Demographics and both clinical CT and QCT of clusters in a combined cohort of asthmatic patients and patients with COPD
| Cluster 1: asthmatic patients, n = 42; patients with COPD, n = 2 | Cluster 2: asthmatic patients, n = 94; patients with COPD, n = 24 | Cluster 3: asthmatic patients, n = 25; patients with COPD, n = 47 | Significance (P value) | |
|---|---|---|---|---|
| Age (y) | 49.7 (13.1) | 58.0 (12.4) | 62.8 (12.5) |
6E-7* .03† .001‡ |
| Sex§ | ||||
| Female | 73.8% | 27.8% | 45.8% | 1E-5 |
| Male | 26.2% | 72.2% | 54.2% | |
| BMI (kg/m2) | 29.0 (6.0) | 28.9 (5.7) | 28.7 (6.3) | .97 |
| Smoking status‖ | ||||
| Current smoker | 4.8% | 9.7% | 9.3% | 2E-4 |
| Exsmoker | 31% | 68.1% | 44.9% | |
| Never smoked | 64.3% | 22.2% | 45.7% | |
| Pack years (if smoked) | 4.8 (10.6) | 13.8 (28.0) | 34.3 (36.7) |
2E-7* 3E-6† .2‡ |
| Severe exacerbations per year | 2 (3) | 2 (2) | 2 (2) | .51 |
| Blood eosinophil count (×109/L)§ | 0.28 (0.14-0.42) | 0.25 (0.15-0.36) | 0.23 (0.14-0.29) | .29 |
| Blood neutrophil count (×109/L)§ | 4.6 (3.4-5.7) | 4.4 (3.6-5.7) | 4.6 (3.6-5.7) | 1 |
| Total sputum cell count (106/g)§ | 1.77 (0.92-7.84) | 2.33 (1.01-5.10) | 3.37 (1.23-7.00) | .27 |
| Sputum neutrophils (%)§ | 44.8 (19.3-73.0) | 49.3 (22.0-71.3) | 61.5 (17.0-88.5) | .21 |
| Sputum eosinophils (%)§ | 0.5 (0-2.3) | 1.9 (0.3-6.3) | 1.0 (0.3-2.5) | .08 |
| Pre-BD FEV1 (% predicted) | 82.3 (24.4) | 77.6 (23.3) | 52.2 (21.7) |
5E-10* 2E-11† .77‡ |
| Post-BD FEV1 (% predicted) | 89.2 (21.9) | 82.7 (23.5) | 57.8 (24.0) |
1E-10* 4E-11† .38‡ |
| Pre-BD FEV1/FVC ratio (%) | 72.7 (9.8) | 67.0 (12.0) | 50.3 (12.5) |
4E-18* 3E-17† .28‡ |
| Post-BD FEV1/FVC ratio (%) | 76.1 (9.6) | 68.5 (11.4) | 52.2 (12.7) |
4E-21* 2E-17† .001‡ |
| BD response | 0.19 (0.24) | 0.16 (0.21) | 0.18 (0.23) | .79 |
| KCO (% predicted) | 107 (18.5) | 101 (20.3) | 79.7 (29.6) |
2E-6* 1E-7† .82‡ |
| RV/TLC (%) | 37.7 (12) | 41.2 (11) | 32.7 (12) |
3E-8* 2E-8† .40‡ |
| Mean LA/BSA (mm2/m2) | 10.7 (2.94) | 11.4 (2.46) | 11.0 (3.05) | .29 |
| Mean TA/BSA (mm2/m2) | 27.9 (6.19) | 29.6 (5.13) | 28.5 (6.16) | .19 |
| Mean WA/BSA (mm2/m2) | 17.2 (3.32) | 18.2 (2.78) | 17.4 (3.20) | .12 |
| Mean %WA | 62.7 (2.21) | 62.2 (2.05) | 62.6 (2.36) | .3 |
| MLDE/I | 0.866 (0.056) | 0.856 (0.061) | 0.910 (0.058) |
5E-4* 1E-8† 1.00‡ |
| RVC | −12.93 (11.34) | −23.96 (10.47) | −30.59 (12.22) |
4E-16* 9E-20† .71‡ |
| Insp VI−950 | 4.6 (2.0) | 13.0 (3.2) | 26.6 (6.13) |
1E-72* 6E-57† 1E-22‡ |
| Exp VI−856 | 13.3 (8.3) | 21.7 (12.6) | 45.8 (18.8) |
1E-22* 5E-20† .004‡ |
| CTLVE/I | 0.65 (0.09) | 0.58 (0.11) | 0.66 (0.13) | 1.00* 4E-5† .004‡ |
| Perc15 (HU) | −905 (14.7) | −943 (8.7) | −972 (11.1) |
5E-86* 1E-43† 1E-51‡ |
| LAC-D−950 | −1.92 (0.20) | −1.84 (0.12) | −1.80 (0.13) | .22 |
| Pi10 (mm2) | 14.9 (1.28) | 15.0 (1.41) | 14.8 (1.28) | .73 |
| Po20 %WA | 56.2 (2.37) | 56.0 (2.34) | 56.0 (2.83) | .88 |
| %WA (no. [%])§# | 6 (14.3) | 15 (12.7) | 11 (15.3) | .88 |
| MLDE/I (no. [%])§# | 2 (4.8) | 8 (6.8) | 20 (27.8) | 8E-5 |
| Perc15 (no. [%])‖ | 0 (0) | 0 (0) | 31 (43.1) | 6E-19 |
BD, Bronchodilator; BMI, body mass index; CTLVE/I, computed tomographic lung volume expiratory/inspiratory ratio; Exp VI−856, expiratory voxel index less than −856 HU; FVC, forced vital capacity; Insp VI−950, inspiratory voxel index less than −950 HU; Pi10, wall area of theoretical airway with an internal perimeter of 10 mm; Po20 %WA, percentage wall area of a theoretical airway with an external perimeter of 20 mm; RVC, relative voxel change; RV/TLC, residual volume/total lung capacity.
Intergroup comparison, parametric (nonparametric) data: The P value for 1-way ANOVA (Kruskal-Wallis test) has been presented unless the ANOVA (Kruskal-Wallis test) result was significant (P < .05), in which case the P value has been presented for the Tukey (Dunn) test pairwise comparisons: *asthmatic patients versus patients with COPD, †asthmatic patients versus healthy subjects, and ‡patients with COPD versus healthy subjects. Differences in proportions were tested by using the χ2 test. Data are expressed as means (SDs), §medians (interquartile ranges), or §proportions. #Greater than 2 SDs of healthy control subjects. ‖Less than 2 SDs of healthy control subjects.