Table 3. Spirometric and IOS data of smokers and non-smokers in male subjects (n=87).
| Parameters | Smokers (n=24) | Non-smokers (n=63) | P value |
|---|---|---|---|
| Spirometry | |||
| % predicted FVC | 96.1±11.3 | 101.6±14.8 | 0.104 |
| z-score of FVC | −0.020 (−0.883, 0.259) | 0.135 (−0.521, 0.884) | 0.171 |
| % predicted FEV1 | 97.4±10.0 | 99.6±13.7 | 0.476 |
| z-score of FEV1 | −0.095 (0.779, 0.486) | 0.081 (−0.716, 0.748) | 0.314 |
| FEV1/FVC, % | 83.4±5.1 | 81.9±6.0 | 0.280 |
| z-score of FEV1/FVC | 0.030 (−0.612, 0.694) | −0.208 (−0.708, 0.175) | 0.301 |
| % predicted FEF25–75% | 105.2±25.4 | 102.2±23.7 | 0.616 |
| z-score of FEF25–75% | −0.109 (−0.565, 0.672) | 0.088 (−0.649, 0.559) | 0.613 |
| IOS | |||
| R5, cmH2O/L/s | 3.47±1.04 | 3.22±0.97 | 0.287 |
| R20, cmH2O/L/s | 2.85±0.92 | 2.76±0.75 | 0.624 |
| R5–R20, cmH2O/L/s, median (IQR) | 0.43 (0.30, 0.89) | 0.34 (0.17, 0.70) | 0.145 |
| X5, cmH2O/L/s | −0.99±0.48 | −0.87±0.42 | 0.259 |
| Fres, Hz | 12.74±3.58 | 12.23±3.77 | 0.575 |
| AX, cmH2O/L, median (IQR) | 2.15 (1.41, 6.16) | 2.12 (1.22, 3.87) | 0.314 |
Data are mean ± SD unless otherwise stated. IOS, impulse oscillometry; FVC, forced vital capacity; FEV1, forced expiratory volume in the first second; FEF25–75%, forced expiratory flow at 25–75% of FVC; R5, resistance at 5 Hz; R20, resistance at 20 Hz; R5–R20, heterogeneity of resistance between R5 and R20; X5, reactance at 5 Hz; Fres, resonant frequency; AX, the area under reactance curve between 5 Hz and resonant frequency; SD, standard deviation.