Table 1.
Subjects’ characteristics.
| Variables | Healthy Controls (No. 40) |
Long COVID Patients (No. 42) |
p |
|---|---|---|---|
| Age (years) | 47 ± 11 | 49 ± 12 | 0.494 |
| Sex (F/M) | 22/18 | 23/19 | 0.983 |
| BMI (Kg/m2) | 25 ± 4 | 26 ± 3 | 0.121 |
| FVC (% pred) | 108 ± 15 | 101 ± 17 | 0.066 |
| FEV1 (% pred) | 106 ± 12 | 99 ± 15 | 0.025 |
| FEV1/FVC (%) | 82 ± 6 | 81 ± 6 | 0.255 |
| VO2 peak (mL/kg/min) | 31 ± 10 | 23 ± 8 | 0.001 |
| VO2 peak (% pred) | 105 ± 27 | 84 ± 21 | 0.001 |
| Workload (Watts) | 181 ± 65 | 123 ± 43 | 0.001 |
| Workload (% pred) | 117 ± 36 | 82 ± 22 | 0.001 |
| AT (mL/kg/min) | 21 ± 10 | 16 ± 8 | 0.030 |
| O2 Pulse rest (mL/bpm) | 4.9 ± 2.4 | 4.1 ± 1.3 | 0.069 |
| O2 Pulse peak (mL/bpm) | 14.6 ± 4.5 | 11.7 ± 3.6 | 0.002 |
| OUES (mL/min) | 2288 ± 687 | 1688 ± 686 | 0.001 |
| HR rest (bpm) | 75 ± 14 | 85 ± 15 | 0.002 |
| HR peak (bpm) | 152 ± 19 | 147 ± 15 | 0.217 |
| HR peak (% pred) | 88 ± 9 | 86 ± 8 | 0.377 |
| HR recovery (bpm) | 25 ± 9 | 20 ± 10 | 0.009 |
| BR (%) | 50 ± 11 | 51 ± 14 | 0.768 |
| VE peak (L/min) | 72 ± 26 | 59 ± 21 | 0.023 |
| Vt rest (L) | 0.74 ± 0.3 | 0.74 ± 0.3 | 0.994 |
| Vt peak (L) | 2.37 ± 0.8 | 1.97 ± 0.5 | 0.007 |
| RR rest (bpm) | 14 ±5 | 14 ± 6 | 0.770 |
| RR peak (bpm) | 31 ± 7 | 31 ± 9 | 0.847 |
| PETCO2 rest (mmHg) | 33 ± 6 | 34 ± 4 | 0.319 |
| PETCO2 peak (mmHg) | 41 ± 5 | 41 ± 5 | 0.921 |
| Δ PETCO2 (mmHg) | 8 ± 6 | 7 ± 5 | 0.468 |
| VE/VCO2 Slope (L) | 26 ± 4 | 30 ± 4 | 0.001 |
| TI/TTot rest | 0.29 ± 0.09 | 0.36 ± 0.09 | 0.001 |
| TI/TTot peak | 0.39 ± 0.05 | 0.42 ± 0.06 | 0.034 |
| VT/TI rest (mL/s) | 685 ± 397 | 605 ± 262 | 0.286 |
| VT/TI peak (mL/s) | 3155 ± 1101 | 2560 ± 850 | 0.008 |
| VAS dyspnoea (mm/watts) | 0.48 ± 0.19 | 0.64 ± 0.22 | 0.022 |
Values are expressed as mean ± SD. Abbreviations: BMI: Body Mass Index, FVC: Forced Vital Capacity, FEV1: Forced Expiratory Volume at 1st Second, VO2: O2 uptake, AT: Anaerobic Threshold, OUES: O2 Uptake Efficiency Slope, HR: Heart Rate, BR: Breathing Reserve, VE: Minute Ventilation, RR: Respiratory Rate, PETCO2: End-Tidal pressure of CO2, TI: Inspiratory Time, TTOT: Tidal Volume duration, VT: Tidal Volume, VAS: Visual Analogue Scale. Bold values indicate statistical significance.