Table 1. Main baseline characteristics of the two study groups; data are mean (SD) for normally divided parameters and median (IQR, µ = mean) for non-normal parameters; DLCO − diffusing capacity for carbon monoxide; FEV1 – forced expiratory volume in one second; FVC – forced vital capacity; HRmax – maximum heart rate; IQR – interquartile range; SD – standard deviation; TLC – total lung capacity; VC – vital capacity; eVO2max − estimated maximum rate of oxygen consumption .
| Parameter | COVID+ (n = 51) | CONTROL (n = 125) | P |
| Age | 30.00 (IQR 8, μ = 31.78) | 31.00 (IQR 11, μ = 32.66) | 0.497 |
| Male | 49 (96.1%) | 123 (98.4%) | 0.581 |
| Female | 2 (3.9%) | 2 (1.6%) | |
| Height (cm) | 183 (SD 7.6) | 184 (SD 6.8) | 0.726 |
| Weight (kg) | 86.0 (SD 12.5) | 86.6 (SD 11.5) | 0.767 |
| Body mass index (kg·m-2) | 25.4 (SD 2.4) | 25.6 (SD 2.7) | 0.962 |
| Fat percentage | 15.8 (IQR 5.5, μ = 16.4) | 15.8 (IQR 6.2, μ = 16.5) | 0.754 |
| n | 48 | 111 | |
| Occupation | 0.804 | ||
| Diver | 32 (62.7%) | 77 (61.6%) | |
| Submariner | 10 (19.6%) | 27 (21.6%) | |
| Special forces | 7 (13.7%) | 19 (15.2%) | |
| Smoking status | 0.527 | ||
| Never | 32 (62.7%) | 71 (56.8%) | |
| Active | 10 (19.6%) | 22 (17.6%) | |
| Former | 9 (17.6%) | 32 (25.6%) | |
| Smoking pack years | 3.5 (IQR 6.45, μ = 4.19) | 4.05 (IQR 5.63, μ = 5.33) | 0.330 |
| n | 19 | 54 | |
| FEV1 (L) | 4.63 (SD 0.58) | 4.74 (SD 0.61) | 0.316 |
| FEV1 Z-score | -0.14 (SD 0.78) | 0.0 (SD 0.80) | 0.275 |
| n | 51 | 123 | |
| FVC (L) | 5.96 (SD 0.82) | 6.01 (SD 0.76) | 0.679 |
| FVC Z-score | 0.25 (SD 0.82) | 0.27 (SD 0.83) | 0.841 |
| n | 51 | 123 | |
| FEV1/FVC | 77.78 (SD 4.48) | 78.90 (SD 4.55) | 0.141 |
| FEV1/FVC Z-score | 0.65 (SD 0.64) | -0.48 (SD 0.68) | 0.118 |
| n | 51 | 123 | |
| RV (L) | 1.65 (SD 0.48) | 1.53 (SD 0.31) | 0.314 |
| n | 27 | 21 | |
| VCmax (L) | 30 | 21 | 0.138 |
| n | 30 | 21 | |
| TLC (L) | 7.90 (SD 1.09) | 8.03 (SD 1.00) | 0.666 |
| n | 27 | 21 | |
| TLC % of predicted | 105.5 (IQR 14.6, μ = 104.9) | 104.6 (IQR 17.0, μ = 105.0) | 0.856 |
| n | 26 | 21 | |
| DLCO (mmol·min-1·kPa-1) | 11.67 (SD 1.90) | 12.13 (SD 1.68) | 0.306 |
| DLCO % of predicted | 101.7 (SD 14.4) | 102.3 (SD 8.7) | 0.838 |
| n | 32 | 33 | |
| Wmax (watt) | 324 (SD 50) | 324 (SD 45) | 0.920 |
| n | 50 | 122 | |
| eVO2-max (ml·kg-1·min-1) | 43.69 (IQR 6.52, μ = 43.78) | 42.68 (IQR 6.63, μ = 43.10) | 0.284 |
| n | 50 | 122 | |
| HRmax (beats·min-1) | 186 (IQR 20, μ = 184) | 185 (IQR 11, μ = 186) | 0.550 |
| n | 50 | 122 |