Table 2.
Lung function
| Female patients with asthma | Male patients with asthma | P value | |
| N | 450 | 323 | |
| Spirometry | |||
| Prebronchodilator FEV1 % predicted (mean (SD)) | 82.09 (17.63) | 79.90 (17.67) | 0.092 |
| FEV1 reversibility, % change from baseline (median (IQR)) | 8.47 (4.58, 16.24) | 9.84 (4.73, 17.31) | 0.178 |
| Postbronchodilator FEV1 % predicted (mean (SD)) | 89.88 (15.76) | 88.64 (16.24) | 0.295 |
| Postbronchodilator FVC % predicted (mean (SD)) | 98.01 (15.00) | 100.90 (14.37) | 0.008 |
| Prebronchodilator FEV1/FVC (mean (SD)) | 0.71 (0.11) | 0.67 (0.11) | <0.001 |
| Prebronchodilator FEV1/FVC % predicted (mean (SD)) | 86.31 (12.10) | 82.71 (12.57) | <0.001 |
| Postbronchodilator FEV1/FVC (mean (SD)) | 0.76 (0.10) | 0.71 (0.11) | <0.001 |
| Postbronchodilator FEV1/FVC % predicted (mean (SD)) | 91.95 (11.38) | 88.33 (12.42) | <0.001 |
| Postbronchodilator FEF25-75 % predicted (mean (SD)) | 67.21 (32.17) | 64.97 (29.06) | 0.338 |
| Postbronchodilator FEF50 % predicted (mean (SD)) | 82.54 (32.62) | 79.81 (30.88) | 0.268 |
| PAL (%) | 122 (27.11) | 126 (39.00) | <0.001 |
| Body plethysmography | |||
| TLC, % of predicted (mean (SD)) | 105.41 (15.47) | 103.40 (11.90) | 0.065 |
| RV, % predicted (mean (SD)) | 110.96 (28.78) | 110.78 (27.77) | 0.938 |
| RV/TLC, (mean (SD)) | 0.35 (0.09) | 0.31 (0.08) | <0.001 |
| RV/TLC, % predicted (mean (SD)) | 101.43 (23.69) | 98.79 (24.23) | 0.153 |
| Airway hyperresponsiveness | |||
| Airway hyperresponsiveness category (%) | 0.017 | ||
| Very mild (PC20 ≥4 and <16 mg/mL, PD20 ≥0.5 and <2 mg) | 70 (21.3) | 76 (33.2) | |
| Mild (PC20 ≥1 and <4 mg/mL, PD20 ≥0.13 and <0.5 mg) | 105 (31.9) | 62 (27.1) | |
| Moderate (PC20 ≥0.25 and <1 mg/mL, PD20 ≥0.03 and <0.13 mg) | 83 (25.2) | 52 (22.7) | |
| Severe (PC20 <0.25 mg/mL, PD20 <0.03 mg) | 71 (21.6) | 39 (17.0) | |
| Impulse oscillometry | |||
| X5, kPa/L/s (median (IQR)) | −0.12 (−0.17,–0.09) | −0.08 (−0.12,–0.06) | <0.001 |
| X5 % predicted* (mean (SD)) | 103.55 (42.16) | 103.62 (52.10) | 0.984 |
| AX, Hz*kPa/L/s (median (IQR)) | 0.41 (0.22, 0.86) | 0.23 (0.12, 0.54) | <0.001 |
| AX % predicted* (mean (SD)) | 178.24 (173.01) | 214.27 (291.26) | 0.077 |
| R5, kPa/L/s (mean (SD)) | 0.42 (0.14) | 0.35 (0.14) | <0.001 |
| R5 % predicted* (mean (SD)) | 125.16 (38.24) | 131.51 (48.08) | 0.065 |
| R20, kPa/L/s (mean (SD)) | 0.35 (0.09) | 0.30 (0.08) | <0.001 |
| R20 % predicted* (mean (SD)) | 103.02 (24.98) | 231.60 (65.75) | <0.001 |
| R5-20 kPa/L/s (median (IQR)) | 0.06 (0.02, 0.11) | 0.04 (0.02, 0.08) | 0.002 |
| Multiple breath nitrogen washout and FeNO | |||
| Scond, 1/L (median (IQR)) | 0.03 (0.02, 0.05) | 0.03 (0.02, 0.04) | 0.138 |
| Scond, % predicted (median (IQR)) | 86.73 (44.93, 136.10) | 75.64 (45.42, 114.21) | 0.183 |
| Sacin, 1/L (median (IQR)) | 0.10 (0.06, 0.15) | 0.10 (0.06, 0.15) | 0.33 |
| Sacin, % predicted (median (IQR)) | 121.44 (73.11, 172.51) | 106.63 (66.84, 143.50) | 0.16 |
| FeNO, ppb (median (IQR)) | 23.00 (15.00, 36.50) | 26.00 (16.75, 40.00) | 0.069 |
Univariable analyses of lung function results at baseline of subjects with asthma in the ATLANTIS study, stratified by sex.
PAL was defined as postbronchodilator FEV1/FVC lower than the lower limit of normal.
*Calculated using the IOS reference values proposed by Oostveen et al. 16
AX, area of reactance; FEF50, forced expiratory flow at 50% of FVC; FEF25-75, forced expiratory flow at 25%–75% of FVC; FeNO, ractional exhaled nitric oxide; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; IOS, impulse oscillometry; PAL, persistent airflow limitation; R5, resistance at 5 Hz; R20, resistance at 20 Hz; R5-20, resistance at 5 Hz–resistance at 20 Hz; RV, residual volume; Sacin, ventilation homogeneity of the acinar zone of the lungs corrected for tidal volume; Scond, ventilation heterogeneity in the conductive zone of the lungs corrected for tidal volume; TLC, total lung capacity; X5, reactance at Hz.