Clinical characteristics and pulmonary function tests of study subjects
| Controls (n=15) | Mild asthma (n=15) | Moderate asthma (n=15) | Severe asthma (n=15) | |
| Sex (F/M) | 10/5 | 10/5 | 9/6 | 8/7 |
| Age (years)1-150 | 64.2 (10.4) | 57.2 (13.0) | 58.2 (13.3) | 66.3 (7.8) |
| Duration of asthma (years)1-151 | NA | 8.0 (3–22) | 10.0 (4–25) | 15.5 (5–36) |
| Atopic/non-atopic | 0/15 | 8/7 | 8/7 | 8/7 |
| FVC (% pred)1-150 | 111.5 (8.3) | 106.2 (13.7) | 102.5 (19.3) | 94.6 (12.6) |
| FEV1 (% pred)1-150 1-152 | 107.8 (11.4) | 98.6 (10.2) | 71.3 (3.9) | 52.6 (6.2) |
| FEV1/FVC (%)1-150 1-153 | 79.5 (4.2) | 76.6 (9.4) | 61.5 (7.5) | 52.4 (8.5) |
| TLC (% pred)1-150 | 103.8 (6.1) | 108.3 (9.9) | 112.2 (15.0) | 117.5 (13.9) |
| FRC (% pred)1-150 | 97.0 (11.3) | 96.6 (14.9) | 101.5 (20.1) | 107.9 (18.2) |
| RV (% pred)1-150 1-154 | 100.7 (11.6) | 108.0 (16.1) | 121.7 (34.7) | 143.8 (23.9) |
| Tlco (% pred)1-150 | 102.4 (8.2) | 101.8 (12.7) | 102.6 (12.6) | 105.1 (13.4) |
| Tlco/VA (% pred)1-150 | 105.5 (6.0) | 108.6 (15.8) | 111.6 (16.2) | 113.1 (13.7) |
| Medication | ||||
| Inhaled BDP (mg/day)1-150 | NA | 0 | 706 (103) | 1120 (101) |
| Systemic corticosteroids (n) | NA | 0 | 0 | 15 |
FVC = forced vital capacity; % pred = percentage of the predicted value; FEV1 = forced expiratory volume in 1 second; TLC = total lung capacity; FRC = forced residual capacity; RV = residual volume; Tlco = lung transfer factor for carbon monoxide; VA = alveolar volume; BDP = beclomethasone dipropionate; NA = not available.
↵1-150 Values are expressed as mean (SD).
↵1-151 Values are expressed as median (range).
↵1-152 Controls and patients with mild asthma were significantly higher than those with either moderate (p<0.001) or severe (p<0.001) asthma, and those with moderate asthma were significantly higher than severe asthma (p<0.001).
↵1-153 Controls and patients with mild asthma were significantly higher than those with either moderate (p<0.05) or severe (p<0.001) asthma, and those with moderate asthma were significantly higher than severe asthma (p<0.05).
↵1-154 Patients with severe asthma were significantly higher than either controls or those with mild asthma (p<0.01).