Airway function and inflammatory markers in RSV versus control subjects with or without current asthma/RW at age 18 years
| Current asthma/RW | No current asthma/RW | |||||
| RSV (n=18) | Controls (n=8) | 95% CI for difference | RSV (n=24) | Controls (n=78) | 95% CI for difference | |
| Resting | ||||||
| FEV1 (z-score) | −0.64 (0.85) | 0.05 (0.77) | −0.03 to 1.42 | 0.00 (0.91) | 0.11 (1.11) | 0.00 to 0.77* |
| FEV1/FVC (z-score) | −0.89 (0.82) | 0.08 (1.37) | 0.09 to 1.86* | −0.53 (0.86) | −0.10 (1.00) | 0.24 to 0.97** |
| FEF25–75 (z-score) | −0.89 (0.71) | −0.06 (0.86) | 0.17 to 1.50* | −0.38 (0.75) | −0.05 (0.85) | 0.25 to 0.86*** |
| LCI | 6.88 (0.63) | 6.89 (0.25) | −0.46 to 0.49 | 6.44 (0.31) | 6.56 (0.43) | −0.21 to 1.29 |
| Challenge (DACh) | ||||||
| Fall in FEV1 (%) | 8.5 (0.0–37.8) | 7.5 (0.3–42.8) | −5.5 to 11.5 | 3.6 (0.0–9.3) | 3.1 (0.0–22.1) | −0.9 to 1.8 |
| Post-bronchodilation | ||||||
| Rise in FEV1 (%) | 6.5 (0.0–10.2) | 2.5 (0.0–9.9) | −0.3 to 6.3 | 5.4 (0.0–10.5) | 3.1 (0.0–10.4) | −0.0 to 3.2** |
| FEV1 (z-score) | −0.18 (0.79) | 0.25 (1.05) | −0.34 to 1.20 | 0.41 (0.81) | 0.39 (1.15) | −0.18 to 0.61 |
| FEV1/FVC (z-score) | −0.23 (0.83) | 0.48 (1.06) | −0.09 to 1.50 | 0.11 (0.90) | 0.41 (0.95) | 0.11 to 0.80** |
| FEF25–75 (z-score) | −0.29 (0.76) | 0.48 (0.72) | 0.11 to 1.43* | 0.19 (0.74) | 0.37 (0.84) | 0.11 to 0.69* |
| Inflammatory markers | ||||||
| FeNO (ppb) | 22 (6–84) | 15 (7–51) | −7 to 26 | 13 (6–54) | 12 (5–74) | −3 to 3 |
| Blood eosinophils (×109/l) | 0.33 (0.06–0.57) | 0.16 (0.04–0.31) | 0.01 to 0.27* | 0.16 (0.04–0.37) | 0.14 (0.01–0.79) | −0.02 to 0.06 |
Data are shown as mean (SD) or median (range).
For normally distributed data differences between the two groups are shown with 95% CI for the mean values and for non-normally distributed data as the 95% CI for the medians.
↵* p<0.05
↵** p<0.01
↵*** p<0.001.
DACh, isocapnic dry air hyperventilation challenge; FEF25–75, forced expiratory fraction at 25–75% forced vital capacity; FeNO, fraction exhaled nitric oxide; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; LCI, lung clearance index; ppb, parts per billion; RSV, respiratory syncytial virus; RW, recurrent wheeze.