Characteristics of subjects with persistent asthma at follow-up, by asthma control classified according to Global Initiative for Asthma 2006 [29] criteria
| Controlled asthma | Partly controlled asthma | Uncontrolled asthma | p-value | |
| Subjects n | 100 | 58 | 24 | |
| Female sex | 63 (63.0) | 40 (69.0) | 18 (75.0) | 0.476 |
| Age at follow-up | 53.7±9.7 | 55.7±10.4 | 56.3±10.1 | 0.327 |
| Age at asthma onset | 38.2±10.0 | 40.7±10.5 | 41.1±10.3 | 0.232 |
| BMI | 28.8±5.1 | 29.3±6.0 | 28.0±3.5 | 0.579 |
| BMI classification | ||||
| Normal weight | 19 (19.0) | 13 (22.4) | 7 (29.2) | |
| Overweight | 50 (50.0) | 19 (32.8) | 10 (41.7) | |
| Obesity | 31 (31.0) | 26 (44.8) | 7 (29.2) | 0.216+ |
| Smoking habits and occupational exposure | ||||
| Nonsmoker | 50 (50.0) | 28 (48.3) | 12 (50.0) | |
| Ex-smoker | 45 (45.0) | 27 (46.6) | 11 (45.8) | |
| Current smoker | 5 (5.0) | 3 (5.2) | 1 (4.2) | 0.999§ |
| Pack-years | 11.3±12.0 | 12.1±11.1 | 9.8±12.5 | 0.846 |
| Occupational exposure to gas, dust or fumes | 36 (37.1) | 14 (24.6) | 11 (52.4) | 0.057 |
| Lung function | ||||
| Pre-bronchodilator FEV1 pp | 91.9±11.4 | 85.0±15.4 | 86.6±17.6 | 0.008 |
| Pre-bronchodilator FVC pp | 97.4±12.6 | 91.1±15.1 | 91.7±16.1 | 0.015 |
| Pre-bronchodilator FEV1/FVC <0.70 | 29 (29.9) | 22 (37.9) | 8 (33.3) | 0.588 |
| AfterFEV1/FVC <0.70 | 13 (14.0) | 15 (26.8) | 4 (19.0) | 0.153 |
| FEV1 reversibility ≥12% and ≥200 mL | 5 (5.4) | 6 (10.7) | 1 (4.8) | 0.425 |
| Comorbidities | ||||
| Current allergic rhinitis | 37 (37.0) | 29 (50.0) | 10 (41.7) | 0.279 |
| Current eczema | 18 (18.0) | 11 (19.0) | 5 (20.8) | 0.948 |
| Reflux | 39 (39.0) | 25 (43.1) | 10 (41.7) | 0.875 |
| Nasal polyps | 8 (7.1) | 5 (8.6) | 0 | 0.350 |
| Blood neutrophils 109·L−1# | ||||
| ≥4 | 34 (37.4) | 18 (32.1) | 15 (65.2) | 0.020 |
| ≥5 | 10 (11.0) | 5 (8.9) | 6 (26.1) | 0.092 |
| ≥6 | 3 (3.3) | 3 (5.4) | 3 (13.0) | 0.176 |
| mean±sd | 3.7 (1.1) | 3.6 (1.2) | 4.4 (1.5) | 0.017 |
| Blood eosinophils 109·L−1# | ||||
| ≥ 0.2 | 40 (44.0) | 30 (53.6) | 10 (43.5) | 0.491 |
| ≥0.3 | 16 (17.6) | 17 (30.4) | 6 (26.1) | 0.187 |
| ≥0.4 | 8 (8.8) | 11 (19.6) | 4 (17.4) | 0.147 |
| mean±sd | 0.2 (0.1) | 0.2 (0.2) | 0.2 (0.2) | 0.146 |
| Allergic sensitisation¶ | ||||
| Specific IgE >0.35 IU·mL−1 | 27 (27.8) | 18 (32.7) | 5 (20.8) | 0.550 |
| Sensitisation to any pollen | 19 (19.6) | 15 (27.3) | 3 (12.5) | 0.292 |
| Sensitisation to any furred animal | 17 (17.5) | 10 (18.2) | 3 (12.5) | 0.812 |
Data are presented as n (%) or mean±sd, unless otherwise stated. BMI: body mass index; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; Ig: immunoglobulin. #: among the 170 participating in blood sampling for cell count; ¶: among the 176 participating in blood sampling for IgE; +: analysis performed in a 3×3 table. Bold values indicate p<0.05.