Table 1. Baseline demographics.
| Control (n = 11) | Mild-to-moderate asthma (n = 12) | Refractory asthma (n = 14) | Eosinophilic bronchitis (n = 10) | Significance | |
|---|---|---|---|---|---|
| Age (years) | 60.1 (10.4) | 46.3 (18.0) | 51.3 (8.1) | 57.1 (12.3) | ns* |
| Gender M : F | 7 : 4 | 8 : 4 | 9 : 5 | 5 : 5 | ns‡ |
| Atopy (%) | 36 | 58 | 57 | 60 | ns‡ |
| Disease duration (years) | NA | 22.8 (17.0) | 21.7 (16.9) | 10.6 (10.9) | ns* |
| BMI (kg/m2) | 25.4 (3.6) | 27.9 (3.6) | 29.1 (7.4) | 26.5 (6.4) | ns* |
| BDP equivalent (mcg/24 h) | 0 692 (748) | 1829 (760) | 1460 (776) | P = 0.002* | P < 0.01† |
| Oral CS (mg/24 day): n | 0 | 0 | 9.6 (4.7):14/14 | 0 | – |
| Total IgE (KU)§ | 20 [9–44] | 106 [36–314] | 169 [72–395] | 116 [56–242] |
P = 0.004* P < 0.05 vs control |
| Peripheral blood eosinophils§ | 0.14 [0.08–0.24] | 0.16 [0.1–0.25] | 0.27 [0.16–0.44] | 0.29 [0.17–0.47] | ns* |
| FEV1% postbronchodilator | 106.1 (13.8) | 87.4 (21.6) | 79.9 (29) | 108.4 (15.4) |
P = 0.0047* (P < 0.05 EB/control vs refractory asthma) |
| FEV1/FVC | 75.4 (6.2) | 72.4 (10.4) | 65.5 (22.5) | 79.8 (10.3) | ns* |
| %Bronchodilator response FEV1 | 0.44 (6.2) | 9.4 (20.2) | 10.6 (17.4) | 4.4 (5.4) | ns* |
| PC20 (mg/ml)§ | >16 | 0.26 [0.1–0.72] | 2.9 [0.17–48] | >16 | P < 0.0001* |
| Sputum eosinophils %§ | 0.42 [020–0.88] | 1.2 [0.31–4.3] | 5.6 [1.7–18.1] | 4.0 [1.2–13.3] |
P = 0.004 P < 0.05 EB/severe asthma vs control |
| Sputum neutrophils % | 67.8 (26.9) | 49.1 (31.3) | 55.4 (30.5) | 52 (24.0’ | ns |
| eNO (50 mls/s) ppb§ | 16.5 [12.4–21.0] | 20.5 [12.5–33.7] | 31 [15.8–62.0] | 34.5 [22.7–53.6] | ns* P = 0.07 |
Data expressed as mean (SD). Intergroup comparisons: t-test and one-way ANOVA with Bonferroni correction for multiple comparisons.
BMI, body mass index; BDP, beclamethasone diproprionante equivalents; fluticasone 2 : 1, budesonide 1.25 : 1, mometasone 1 : 1; CS, corticosteroid; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; eNO, exhaled nitric oxide.
*
ANOVA.
†
Mild asthma vs severe asthma.
‡
Chi-squared test.
§
Geometric mean [95% CI].