Table 1.
Main characteristics of the two study groups. Data are presented as means ± SD for continuous variables; percentages are reported for categorical variables. ALT: Alanine aminotransferase; AST: aspartate aminotransferase; BUN: blood urea nitrogen; CPAP: continuous positive airway pressure; CRP: C Reactive Protein; HFNC: high-flow nasal cannula; LMWH: low molecular weight heparin; LTOT: long-term oxygen therapy; NIV: non-invasive ventilation.
| Placebo (n = 84) |
L-Arginine (n = 85) |
p | |
|---|---|---|---|
| Gender (M/F, %) | 75.3/34.7 | 64.7/35.3 | 0.137 |
| Age (years) | 62.0 ± 11.9 | 61.1 ± 13.2 | 0.634 |
| Hypertension (%) | 46.9 | 37.6 | 0.227 |
| Coronary artery disease (%) | 14.8 | 17.6 | 0.621 |
| Smokers (%) | 13.6 | 11.8 | 0.725 |
| Obesity (% | 9.9 | 10.6 | 0.880 |
| Diabetes (%) | 11.1 | 11.8 | 0.895 |
| Time between onset of symptoms and admission (days) | 7.9 ± 3.1 | 7.9 ± 3.3 | 0.982 |
| White blood cells (n/mL) | 8521.4 ± 5103.6 | 7709.4 ± 4222.2 | 0.265 |
| Lymphocytes (n/mL) | 796.8 ± 362.4 | 782.1 ± 329.4 | 0.788 |
| CRP (mg/L) | 8.0 ± 6.7 | 11.1 ± 10.4 | 0.029 |
| D-dimer (ng/mL) | 945.5 ± 1660.6 | 709.7 ± 1157.2 | 0.295 |
| ALT (U/L | 62.9 ± 82.7 | 53.2 ± 44.5 | 0.351 |
| AST (U/L) | 46.3 ± 40.1 | 40.8 ± 29.0 | 0.312 |
| Creatinine (mg/dL) | 0.89 ± 0.7 | 0.78 ± 0.2 | 0.100 |
| Sodium (mmol/L) | 138.5 ± 4.1 | 138.5 ± 4.6 | 0.946 |
| Potassium (mmol/L) | 4.44 ± 0.7 | 4.40 ± 0.5 | 0.690 |
| Asthenia (%) | 63.0 | 63.5 | 0.940 |
| Dyspnea (%) | 91.4 | 89.4 | 0.671 |
| Cough (%) | 37.0 | 32.9 | 0.580 |
| Fever (%) | 67.9 | 75.3 | 0.291 |
| Sputum (%) | 8.6 | 2.4 | 0.074 |
| Remdesivir (%) | 39.5 | 44.7 | 0.498 |
| LMWH (%) | 95.1 | 92.9 | 0.566 |
| Steroids (%) | 86.4 | 92.9 | 0.166 |
| Monoclonal antibodies (%) | 15.4 | 10.0 | 0.472 |
| Anti-COVID vaccine (%) | 45.7 | 47.1 | 0.859 |
| P/F (PaO2/FiO2- baseline) | 132.0 ± 57.5 | 148.6 ± 66.1 | 0.086 |
| P/F (PaO2/FiO2- day 10) | 190.5 ± 116.3 | 216.8 ± 96.0 | 0.281 |
| P/F (PaO2/FiO2- day 20) | 255.5 ± 103.4 | 258.8 ± 89.0 | 0.857 |
| Hospitalization (days) | 35.9 ± 15.4 | 21.9 ± 7.7 | 0.0001 |
| Death | 13 (13.8%) | 3 (3.4%) | 0.013 |
| Respiratory support (baseline) | |||
| None (%) | 1.2 | 0 | 0.500 |
| LTOT (%) | 3.7 | 9.4 | |
| HFNC (%) | 77.8 | 71.8 | |
| CPAP (%) | 11.1 | 11.8 | |
| NIV (%) | 6.2 | 7.1 | |
| Respiratory support (day 10) | |||
| None (%) | 7.4 | 49.4 | < 0.0001 |
| LTOT (%) | 14.8 | 28.2 | |
| HFNC (%) | 67.9 | 20.0 | |
| CPAP (%) | 1.2 | 1.2 | |
| NIV (%) | 8.6 | 1.2 | |
| Respiratory support (day 20) | |||
| None (%) | 22.2 | 81.0 | < 0.0001 |
| LTOT (%) | 9.9 | 9.5 | |
| HFNC (%) | 65.4 | 9.5 | |
| CPAP (%) | 2.5 | 0 | |
| NIV (%) | 0 | 0 | |