Table 4.
Comparison of lung function parameters between children with asthma and age matched non-asthmatic group.
| Variable | Asthma (n=27) | Healthy controls (n=13) | P-value | Adjusted P* |
|---|---|---|---|---|
| X 5 Hz z-score | 0.56 ± 0.45 | 0.93 ± 0.53 | 0.028 | 0.043 |
| X10 Hz z-score | 0.63 (-0.18, 0.83) | 0.96 (0.64, 1.61) | 0.031 | 0.034 |
| X15 Hz z-score | 1.47 (0.65, 2.23) | 2.28 (1.87, 2.72) | 0.009 | 0.012 |
| X20 Hz z-score | -0.23 ± 1.24 | 0.64 ± 1.06 | 0.036 | 0.023 |
| R 5 Hz z-score | -0.37 ± 0.91 | -0.52 ± 0.83 | 0.624 | 0.622 |
| R10 Hz z-score | -0.22 ± 0.99 | -0.30 ± 0.73 | 0.810 | 0.713 |
| R15 Hz z-score | -0.39 (-0.89, 0.30) | -0.35 (-0.63, 0.49) | 0.711 | 0.986 |
| R20 Hz z-score | -0.04 ± 1.06 | 0.12 ± 0.61 | 0.601 | 0.664 |
| R5-R20 | -0.33 ± 0.51 | -0.65 ± 0.44 | 0.064 | 0.036 |
| Z 5 Hz z-score | -0.42 ± 0.87 | -0.60 ± 0.80 | 0.533 | 0.535 |
| Ax (kPas/L) | 1.01 (0.57, 1.67) | 0.57 (0.20, 0.73) | 0.013 | 0.085 |
| LCI2.5 | 7.65 ± 1.36 | 6.56 ± 0.56 | 0.034 | 0.006 |
| FRC | 1.27 (0.88, 1.54) | 1.16 (1.07, 1.34) | 0.953 | 0.385 |
Lung function was measured using Impulse Oscillometry and Nitrogen Multiple- Breath washout. Data are presented as mean ± SD or median (IQR). Difference between groups analysed by Wilcoxon Rank Sum test (non-parametric data) or two-sample t-test (parametric data). Patients with missing and/or invalid data were excluded for each variable. *Age, weight and height were adjusted using General Linear Model. P<0.05 considered statistically significant. X, respiratory reactance; R, respiratory resistance; Z, respiratory impedance; AX, area of reactance; LCI, lung clearance index; FRC, Functional residual capacity. Bold values indicate statistically significant difference (P<0.05) noted between the two groups.