TABLE 1.
Demographic data, spirometric parameters, and values for FeNO in patients with negative and positive methacholine challenge test in the discovery cohort
| Characteristic variables | Negative MCT | Positive MCT | p |
|---|---|---|---|
| <55 years | n 1 = 143 | n 2 = 148 | |
| Male (n/%) | 65 (45.45%) | 60 (40.54%) | 0.397 |
| Age, yearsa | 35.00 (30.00, 47.00) | 40.00 (30.00, 48.00) | 0.248 |
| BMI, kg/m2 a | 22.52 (19.95, 24.92) | 22.31 (20.35, 24.64) | 0.861 |
| Past smoking history (n/%) | 28 (19.58%) | 31 (20.95%) | 0.772 |
| FEF50%, % predicteda | 86.10 (68.60, 103.30) | 65.50 (60.30, 73.65) | <0.001 |
| FEF25%, % predicteda | 101.10 (86.10, 115.60) | 90.40 (75.45, 98.45) | <0.001 |
| FEF75%, % predicteda | 81.70 (61.20, 104.50) | 69.80 (50.20, 86.28) | <0.001 |
| FEF25%–75%, % predicteda | 87.70 (73.80, 99.70) | 68.35 (60.18, 73.35) | <0.001 |
| PEF, % predicteda | 103.60 (93.10, 114.60) | 99.80 (90.30, 111.63) | 0.024 |
| FEV1, % predicteda | 99.90 (94.60, 107.30) | 96.60 (89.65, 103.15) | <0.001 |
| FVC, % predicteda | 101.60 (94.70, 107.10) | 100.70 (93.20, 108.28) | 0.966 |
| FEV1/FVC, %a | 85.23 (80.30, 91.65) | 81.15 (77.61, 85.06) | <0.001 |
| FeNO, ppba | 21.00 (13.00, 41.00) | 53.00 (39.25, 93.00) | <0.001 |
| ≥55 years | n 1 = 115 | n 2 = 128 | |
| Male (n/%) | 30 (26.09%) | 34 (26.56%) | 0.993 |
| Age, yearsa | 61.00 (56.00, 65.00) | 61.00 (56.25, 64.00) | 0.696 |
| BMI, kg/m2 a | 23.31 (21.67, 25.30) | 23.62 (22.06, 25.74) | 0.326 |
| Past smoking history (n/%) | 17 (14.78%) | 14 (10.94%) | 0.370 |
| FEF50%, % predicteda | 77.50 (65.30, 102.70) | 60.90 (56.08, 65.48) | <0.001 |
| FEF25%, % predicteda | 101.00 (88.70, 117.60) | 89.00 (76.30, 103.08) | <0.001 |
| FEF75%, % predicteda | 65.60 (49.10, 82.30) | 53.45 (42.48, 70.78) | <0.001 |
| FEF25%–75%, % predicteda | 77.40 (63.70, 88.90) | 59.55 (50.68, 69.83) | <0.001 |
| PEF, % predictedb | 109.20 ± 18.76 | 103.34 ± 18.87 | 0.008 |
| FEV1, % predicteda | 108.40 (98.50, 118.70) | 97.85 (91.20, 107.98) | <0.001 |
| FVC, % predicteda | 110.90 (99.60, 122.30) | 109.05 (100.85, 116.50) | 0.130 |
| FEV1/FVC, %a | 81.23 (76.91, 85.84) | 76.98 (73.97, 79.72) | <0.001 |
| FeNO, ppba | 24.00 (16.00, 38.00) | 49.00 (22.00, 56.75) | <0.001 |
Note: Bold font indicates statistical significance.
Abbreviations: BMI, body mass index; FEF25%, forced expiratory flow at 25% of forced vital capacity; FEF50%, forced expiratory flow at 50% of forced vital capacity; FEF75%, forced expiratory flow at 75% of forced vital capacity; FEF25%–75%, Forced expiratory flow between 25% and 75%; FeNO, fractional exhaled nitric oxide; FVC, forced vital capacity; FEV1, forced expiratory volume in 1 s; PEF, peak expiratory flow; MCT, methacholine challenge test.
a
median (IQR) values.
b
mean ± SD values.