Characteristics of subjects stratified by reduced post-bronchodilator carbon monoxide transfer coefficient (Kco) at visit 2 (n=165)
| No reduced Kco (n=127) | Reduced Kco (n=38)† | |
|---|---|---|
| BHR=bronchial hyperresponsiveness; FEV1=forced expiratory volume in 1 second; VC=vital capacity; RV=residual volume; bd=bronchodilator. | ||
| *p <0.05. | ||
| †Reduced Kco=Tlco/Va <80% predicted. | ||
| Median (range) age at visit 1 (years) | 22 (13–40) | 27 (14–44) |
| Sex (% male) | 63.8* | 44.7* |
| Median (range) age of onset of asthma (years) | 4 (0–37) | 6 (0–39) |
| Median (range) untreated period (years) | 14 (0–38) | 10.5 (0–40) |
| Smoking visit 1, non/ex/current (%) | 58.3/8.7/33.1* | 39.5/7.9/52.6* |
| Smoking visit 2, non/ex/current (%) | 43.3/32.3/24.4 | 26.3/34.2/39.5 |
| Median (range) pack years of smoking at visit 2 | 2.5 (0–80)* | 8.0 (0–58)* |
| ≥1 positive skin test at visit 1 (%) | 93.7 | 94.7 |
| ≥1 positive skin test at visit 2 (%) | 82.7 | 78.9 |
| Geometric mean (SD) IgE at visit 2 (IU) | 87.1 (3.9) | 85.1 (4.5) |
| Geometric mean (SD) slope BHR at visit 1 | 6.0 (3.4) | 7.2 (3.7) |
| Geometric mean (SD) slope BHR at visit 2 | 3.0 (4.1) | 3.5 (6.8) |
| BHR ≤4 mg/ml visit 1 (%) | 48.0 | 52.6 |
| BHR ≤32 m/ml visit 2 (%) | 85.0 | 72.7 |
| BHR ≤4 mg/ml visit 2 (%) | 42.5 | 54.5 |
| Mean (SD) FEV1 pre-bd at visit 1 (% pred) | 65.4 (23.1) | 63.2 (24.0) |
| Mean (SD) FEV1 post-bd at visit 1 (% pred) | 89.6 (19.9) | 88.3 (21.6) |
| Mean (SD) FEV1 pre-bd at visit 2 (% pred) | 73.5 (23.2) | 69.7 (24.0) |
| Mean (SD) FEV1 post-bd at visit 2 (% pred) | 86.2 (21.5) | 80.6 (23.5) |
| Mean (SD) FEV1 reversibility at visit 1 (% pred) | 24.2 (12.6) | 25.2 (15.7) |
| Mean (SD) FEV1 reversibility at visit 2 (% pred) | 12.7 (7.9) | 10.9 (8.5) |
| Mean (SD) VC post-bd at visit 1 (% pred) | 103.4 (13.2) | 105.9 (16.2) |
| Mean (SD) VC post-bd at visit 2 (% pred) | 102.9 (14.6) | 107.5 (16.9) |
| Median (range) TLC post-bd at visit 1 (% pred) | 106.1 (77.3–148.9) | 110.5 (78.5–147.5) |
| Median (range) TLC post-bd at visit 2 (% pred) | 100.1 (70.8–123.8)* | 106.2 (78.8–147.7)* |
| Median (range) RV post-bd at visit 1 (% pred) | 114.2 (53.7–228.5)* | 134.9 (71.8–219.5)* |
| Median (range) RV post-bd at visit 2 (% pred) | 98.5 (51.8–184.6)* | 116.12(59.0–213.8)* |
| Pulmonary medication use at visit 2 (%) | 60.6 | 73.7 |
| Inhaled corticosteroid use at visit 2 (%) | 42.5 | 57.9 |
| Oral corticosteroid use at visit 2 (%) | 7.9 | 2.6 |