Mean (SD) baseline patient characteristics
| Non-smoking asthmatic patients (n=21) | Smoking asthmatic patients (n=17) | p value | |
|---|---|---|---|
| FEV1=forced expiratory volume in 1 second, PEF=peak expiratory flow; PC20=concentration of methacholine provoking a 20% fall in FEV1; NS=not significant. | |||
| *Geometric mean (SD). | |||
| Sex (M/F) | 15/6 | 6/11 | |
| Age (years) | 35.4 (9.7) | 34.6 (9.5) | NS |
| Asthma duration (years) | 17.9 (9.6) | 15.7 (10.6) | NS |
| Smoking pack years | – | 16.5 (10.4) | |
| Baseline FEV1 (% predicted) | 87.9 (15.9) | 87.2 (13.4) | NS |
| Bronchodilator response (% FEV1) | 10.5 (7.4) | 7.5 (5.1) | NS |
| Methacholine PC20 (mg/ml)* | 0.76 (1.3) | 1.5 (1.3) | NS |
| Serum total IgE (IU/ml) | 185.6 (165.1) | 192.4 (301) | NS |
| Serum cotinine (mg/l) | 11.4 (8.4) | 125.7 (13.1) | <0.0001 |
| Sputum eosinophils (%) (median IQR) | 3.8 (0.7–5.5)% | 0.3 (0–0.9)% | 0.005 |
| Run in values | |||
| Morning PEF (l/min) | 472 (113) | 385 (83) | |
| Morning PEF (% pred) | 88 (17) | 84 (17) | NS |
| Evening PEF (l/min) | 491 (117) | 393 (79) | |
| Evening PEF (% predicted) | 92 (18) | 86 (17) | NS |