TABLE 1.
Participant demographic, pulmonary function test (PFT)# and magnetic resonance imaging (MRI) measurements
|
COVID-negative
(n=28) |
Recovered
(n=34) |
Long COVID
(n=73) |
p-value ¶ | |
| Age (years) | 40±16 | 42±14 | 49±12§ | 0.004 |
| Female | 16 (57) | 20 (59) | 44 (60) | 1.0 |
| Caucasian | 22 (79) | 28 (82) | 62 (85) | 0.3 |
| BMI (kg·m−2) | 27±4 | 27±5 | 29±6 | 0.2 |
| Hospitalised for COVID-19 during acute infection | 4 (12) | 18 (25) | 0.2 | |
| Time between COVID-19 diagnosis and MRI (days) | 424±243 | 414±226 | 0.8 | |
| SGRQ Total + | 5±5 | 7±7 | 36±20§,ƒ | <0.001 |
| SGRQ Symptom + | 5±7 | 11±14 | 42±22§,ƒ | <0.001 |
| SGRQ Activity + | 10±12 | 12±11 | 51±26§,ƒ | <0.001 |
| SGRQ Impact + | 1±3 | 3±6 | 26±21§,ƒ | <0.001 |
| FEV1 (% pred) | 105±15 | 109±16 | 99±18ƒ | 0.04 |
| FVC (% pred) | 107±13 | 112±15 | 102±20 | 0.06 |
| FEV1/FVC (%) | 81±8 | 80±7 | 79±6 | 0.5 |
| RV (% pred) | 108±25 | 110±21 | 106±30 | 0.8 |
| TLC (% pred) | 99±13 | 102±11 | 94±18 | 0.09 |
| RV/TLC (% pred) | 107±19 | 109±19 | 112±22 | 0.6 |
| DLCO (% pred) | 103±14 | 108±10 | 99±24 | 0.1 |
| VDP (%) | 0±1 | 0±1 | 1±2 | 0.2 |
| Mem/Gas (×10−2) | 0.71±0.15 | 0.73±0.18 | 0.77±0.24 | 0.4 |
| RBC/Mem | 0.47±0.13 | 0.43±0.11 | 0.40±0.12§ | 0.03 |
| RBC/Gas (×10−2) | 0.35±0.12 | 0.32±0.09 | 0.31±0.09 | 0.2 |
Data are presented as mean±sd or n (%), unless otherwise stated. BMI: body mass index; COVID-19: coronavirus disease 2019; SGRQ: St George's Respiratory Questionnaire; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; RV: residual volume; TLC: total lung capacity; DLCO: diffusing capacity of the lung for carbon monoxide; VDP: ventilation defect percent; Mem/Gas: membrane-to-gas ratio (membrane uptake); RBC/Mem: red blood cell-to-membrane ratio; RBC/Gas: red blood cell-to-gas ratio (red blood cell transfer). #: PFT measurements included where available (COVID-negative: n=27 for FEV1 and FVC, n=15 for RV, n=20 for TLC, n=21 for DLCO; recovered: n=27 for all PFTs; long COVID: n=66 for FEV1 and FVC, n=57 for RV, n=61 for TLC, n=62 for DLCO); ¶: using one-way ANOVA for parametric variables, Kruskal–Wallis tests for non-parametric variables or Fisher's exact test for categorial variables (bold p-values indicate p<0.05); +: SGRQ administered at Site 1 only (n=11 COVID-negative, n=26 recovered, n=36 long COVID); §: significantly different from COVID-negative (p<0.05); ƒ: significantly different from recovered (p<0.05).