Table 1 Baseline demographic and clinical features of the observation and control groups

Age, years, mean ± SD

74.90 ± 2.079

73.93 ± 1.775

0.721

Sex (M/F), n (%)

14/7(66.7/33.3)

19/8(70.4/29.6)

0.784

Temperature, °C, mean ± S D

38.05 ± 0.95

37.89 ± 0.79

0.361

PaO2/FiO2 ratio, mmHg, mean ± SD

201.19 ± 14.21

209.25 ± 11.08

0.65

White blood cell, 109/L, mean ± SD

6.629 ± 0.807

6.613 ± 0.816

0.990

Neutrophils, 109/L, mean ± SD

4.99 ± 0.78

5.43 ± 0.78

0.697

Lymphocyte, 109/L, mean ± SD

0.67 ± 0.06

0.79 ± 0.08

0.17

Platelet, 109/L, mean ± SD

178.57 ± 14.95

186.74 ± 14.93

0.69

CRP, mg/L, mean ± SD

94.98 ± 13.69

88.76 ± 7.74

0.43

IL-6,pg/ml, mean ± SD

60.69 ± 14.08

32.09 ± 7.37

0.06

Ferritin,μg/L, mean ± SD

301.30 ± 60.75

220.43 ± 42.4

0.25

Creatine kinase, U/L, mean ± SD

1.56 ± 0.15

1.75 ± 0.21

0.49

Creatinine, U/L, mean ± SD

64.11 ± 3.61

73.89 ± 5.56

0.17

Alanine aminotransferase, U/L,mean ± SD

25.37 ± 3.2

33.51 ± 5.2

0.22

Glutamate aminotransferase, mean ± SD

27.13 ± 1.83

27.37 ± 2.37

0.93

Blood sugar, mmol/L, mean ± SD

8.61 ± 0.87

8.53 ± 0.34

0.95

Cardiovascular disease, n (%)

10(47.6%)

13(48.1%)

0.82

Diabetes, n (%)

8(38.1%)

10(37.0%)

0.85

Respiratory disease, n (%)

4(19.0%)

5(18.5%)

0.78

Neurologic disorder, n (%)

6(28.6%)

8(37.0%)

0.70

hypertension, n (%)

8(38.1%)

14(51.8%)

0.20