TABLE 5.
Pulmonary function parameters.
| COVID-19 patients |
Controls |
|||||
| All | Symptomatic infection within the past 6 months | Asymptomatic infection within the past 6 months | All | Any other infection within the past 6 months | No infection within the past 6 months | |
| Pulmonary function testing | ||||||
| N | 73 | 27 | 46 | 45 | 14 | 31 |
| Abnormal pulmonary function* | 12 (16.44) | 4 (14.81) | 8 (17.39) | 12 (26.67) | 5 (35.71) | 7 (22.58) |
| N2 Multiple-breath washout | ||||||
| N | 68 | 27 | 41 | 40 | 11 | 29 |
| LCI2.5, absolute | 6.75 ± 0.73 | 6.79 ± 0.62 | 6.72 ± 0.81 | 6.88 ± 0.61 | 6.79 ± 0.47 | 6.91 ± 0.66 |
| Abnormal values | 3 (4.4) | 1 (3.7) | 2 (4.9) | 3 (7.5) | 0 | 3 (10.3) |
| Body plethysmography | ||||||
| N | 71 | 26 | 45 | 45 | 14 | 31 |
| FVC, Z-score | −0.21 ± 1.06 | −0.26 ± 1.04 | −0.19 ± 1.08 | −0.21 ± 1.22 | −0.25 ± 1.53 | −0.19 ± 1.08 |
| Abnormal values | 5 (7) | 1 (3.9) | 4 (8.9) | 5 (11.1) | 2 (14.3) | 3 (9.7) |
| FEV1, Z-score | 0.3 ± 1.04 | 0.34 ± 1.04 | 0.28 ± 1.05 | 0.27 ± 1.19 | 0.2 ± 1.34 | 0.3 ± 1.13 |
| Abnormal values | 0 | 0 | 0 | 1 (2.2) | 1 (7.1) | 0 |
| MEF75, Z-score | 0.28 ± 1.1 | −0.03 ± 1.13 | 0.46 ± 1.05 | 0.12 ± 1.09 | −0.35 ± 1.38 | 0.34 ± 0.87 |
| Abnormal values | 3 (4.2) | 2 (7.7) | 1 (2.2) | 1 (2.2) | 1 (7.1) | 0 |
| MEF25, Z-score | 0.86 ± 0.94 | 0.91 ± 0.68 | 0.83 ± 1.07 | 1.19 ± 1 | 1.04 ± 0.88 | 1.26 ± 1.06 |
| Abnormal values | 0 | 0 | 0 | 0 | 0 | 0 |
| Diffusion capacity | ||||||
| N | 38 | 10 | 28 | 27 | 4 | 23 |
| DLCO, Z-score | 2.03 ± 2.35 | 2.56 ± 2.27 | 1.84 ± 2.39 | 1.55 ± 1.91 | 2.74 ± 2.7 | 1.35 ± 1.74 |
| Abnormal values | 2 (5.3) | 0 | 2 (7.1) | 1 (3.7) | 0 | 1 (4.4) |
| DLCO/VA, Z-score | 0.02 ± 0.76 | −0.11 ± 1.09 | 0.07 ± 0.62 | −0.21 ± 0.94 | 0.05 ± 1.39 | −0.25 ± 0.88 |
| Abnormal values | 0 | 0 | 0 | 0 | 0 | 0 |
LCI2.5%, lung clearance index at 2.5% of starting concentration; FVC, forced vital capacity; FEV1, forced expiratory volume in the first second; MEF, mean expiratory flow at different pulmonary volume levels (75, 25); DLCO, diffusing capacity of the lungs for carbon monoxide; VA, alveolar volume.
All pulmonary function parameters are presented as the mean ± standard deviation. Abnormal values were presented as n (%).
*Abnormal pulmonary function defined as at least one measured parameter being pathological (LCI2.5% > 7.9, FVC Z-score, FEV1 Z-score, MEF75 Z-score, MEF25 Z-score, DLCO Z-score, DLCO/VA Z-score < −1.96) or at least one borderline parameter (LCI2.5% > 7.0, FVC Z-score, FEV1 Z-score, MEF75 Z-score, MEF25 Z-score, DLCO Z-score, DLCO/VA Z-score < −1 ≥ −1.96) in two different pulmonary function tests (N2 multiple-breath washout, body plethysmography, diffusion capacity).