Normal subjects | Asthma | COPD | ||
No. of subjects | 96 | 53 | 57 | |
Median (range) age (years) | 38 (20–65) | 51 (22–73) | 65 (45–88) | |
Sex (% male) | 34 | 62 | 75 | |
Smoking habits (%) | ||||
Current smokers | 17 | 17 | 40 | |
Ex-smokers | 20 | 40 | 60 | |
Non-smokers | 63 | 43 | 0 | |
Drug treatment (%) | ||||
β agonists | 0 | 100 | 100 | |
Anticholinergics | 0 | 21 | 83 | |
Theophylline | 0 | 8 | 19 | |
Inhaled corticosteroids | 0 | 100 | 35 | |
Lung function | ||||
Mean (SE) FEV1 (l) | 3.7 (0.48) | 2.1 (0.12) | 1.1 (0.1) | |
Mean (SE) FVC (l) | 4.4 (0.62) | 3.4 (0.16) | 2.6 (0.1) | |
% Predicted FEV1 (SE) | 107 (14) | 71 (3) | 42 (2) | |
Mean (SE) PEF variability (%) | — | 15.9 (1.2) | 17.0 (1.8) | |
(n=53) | (n=18) | |||
Mean (SE) PC20(mg/ml) | — | 1.9 (0.46) | — | |
(n=43) |
FEV1 = forced expiratory volume in one second; FVC = forced vital capacity; PEF = peak expiratory flow; PC20 = concentration of histamine provoking a fall in FEV1 of 20% or more.
Values are numbers of subjects except when otherwise stated.