General characteristics of the patients
| Total (n=103) | Intermittent asthma (n=22) | Mild persistent asthma (n=45) | Moderate persistent asthma (n=32) | Severe persistent asthma (n=4) | p Value | |
| Females, n (%) | 77 (75) | 18 (82) | 36 (80) | 19 (59) | 4 (100) | 0.212 |
| Age, years | 41±16 | 36±20 | 40±16 | 47±13 | 26±1 | 0.014 |
| BMI, kg/m2 | 25.0±4.5 | 25.4±4.9 | 23.9±3.4 | 26.6±3.4 | 22.9±2.2 | 0.044 |
| Current smoker, n (%) | 15 (15) | 4 (18) | 10 (22) | 1 (3) | 0 (0) | 0.110 |
| Atopy, n (%) | 54 (53) | 15 (68) | 24 (56) | 11 (34) | 4 (100) | 0.017 |
| Years since diagnosis | 9±8 | 10±11 | 6±6 | 11±9 | 11±6 | 0.083 |
| Active population, n (%) | 57 (55) | 12 (54) | 26 (58) | 17 (53) | 2 (50) | 0.814 |
| Exacerbations last year | 0.7±0.9 | 0.4±0.7 | 0.8±0.7 | 0.6±1.3 | 1.5±0.6 | 0.094 |
| Hospitalisations last year | 0.3±0.8 | 0.2±0.6 | 0.0±0.0 | 0.6±1.2 | 0.5±0.6 | 0.003 |
| Long-acting β-agonist, n (%) | 61 (59) | 4 (18) | 24 (53) | 29 (91) | 4 (100) | <0.001 |
| Inhaled corticosteroids, n (%) | 81 (79) | 4 (18) | 41 (91) | 32 (100) | 4 (100) | <0.001 |
| Leukotriene receptor antagonist, n (%) | 18 (17) | 4 (18) | 6 (13) | 8 (25) | 4 (100) | 0.449 |
| Antihistamine, n (%) | 4 (4) | 2 (9) | 0 (0) | 2 (6) | 0 (0) | 0.255 |
| FVC, litres | 3.54±0.95 | 3.61±0.97 | 3.75±1.06 | 3.24±0.76 | 3.35±0.33 | 0.128 |
| FVC, % predicted | 105±16 | 111±16 | 109±15 | 96±15 | 93±6 | 0.000 |
| FEV1, litres | 2.89±0.86 | 3.08±1.07 | 3.04±0.86 | 2.56±0.63 | 2.74±0.44 | 0.065 |
| FEV1, % predicted | 100±16 | 109±18 | 104±14 | 91±14 | 87±11 | 0.000 |
| FEV1/FVC | 0.81±0.07 | 0.84±0.09 | 0.81±0.07 | 0.79±0.06 | 0.81±0.05 | 0.132 |
| PEF, l/s | 6.95±1.70 | 7.34±1.99 | 7.10±1.58 | 6.55±1.65 | 6.29±1.32 | 0.281 |
| FEF75%, l/s | 3.03±2.70 | 2.72±2.51 | 3.85±3.11 | 2.10±1.94 | 2.98±1.37 | 0.038 |
| FEF50%, l/s | 3.19±1.56 | 3.72±2.12 | 3.35±1.32 | 2.53±1.23 | 3.73±1.82 | 0.026 |
| FEF25%, l/s | 3.71±2.48 | 4.71±2.63 | 3.28±2.21 | 3.58±2.47 | 4.07±3.80 | 0.160 |
| FEF25–75%, l/s | 2.63±1.56 | 3.33±2.28 | 2.72±1.20 | 1.99±1.19 | 3.04±1.42 | 0.015 |
| VCIN, litres | 3.56±0.91 | 3.60±0.91 | 3.73±0.98 | 3.31±0.78 | 3.16±0.00 | 0.273 |
| IC, litres | 2.67±0.59 | 2.55±0.42 | 2.65±0.60 | 2.81±0.66 | 2.32±0.00 | 0.491 |
| FIV1, litres | 3.24±0.84 | 3.37±0.92 | 3.35±0.83 | 3.03±0.83 | 2.90±0.20 | 0.259 |
p Values were tested by analysis of variance with the Bonferroni posthoc test if the variable is stated as mean (SD) or by χ2 test if the variable is stated as n (%).
BMI, body mass index; FEV1, forced expiratory volume in 1 s; FEF75%, FEF50% and FEF25%, forced expiratory flow at 75, 50 and 25% of the FVC, respectively; FEF25–75%, forced mid-expiratory flow; FIV1, forced inspiratory volume in 1 s; FVC, forced vital capacity; IC, inspiratory capacity; PEF, peak expiratory flow; VCIN, inspiratory vital capacity.