Table 1 Comparison of baseline characteristics between patients with long COVID-19 syndrome and healthy subjects

Age (years)

51 ± 11

45 ± 13

0.20

BMI (kg/m²)

25 ± 3

26 ± 4

0.42

Male, n (%)

6 (60)

9 (47)

0.52

Duration of symptoms at time of assessment (days)

n/a

163 [142,185]

n/a

Heart rate (beats per minute)

61 ± 6

68 ± 12

0.17

Systolic blood pressure (mmHg)

126 ± 27

119 ± 17

0.49

Diastolic blood pressure (mmHg)

70 ± 10

74 ± 9

0.30

Laboratory findings

 C-Reactive Protein at diagnosis (mg/L)

n/a

141 ± 11

n/a

 White Blood Cell count at study visit (10⁹/L)

6.4 [4.8–8.9]

7.2 [5.9–8.6]

0.36

 Lymphocyte count at study visit (10⁹/L)

2.0 ± 0.8

1.0 ± 2.5

0.28

 Neutrophil count at study visit (10⁹/L)

3.6 [2.8–5.2]

4.4 [3.2–5.0]

0.35

 Monocyte count at study visit (10⁹/L)

0.39 ± 0.15

0.46 ± 0.16

0.30

 Platelet count at study visit (10⁹/L)

226 ± 54

260 ± 57

0.14

 Haemoglobin at study visit (g/L)

145 [139–156]

147 [130–150]

0.71

 Creatinine at study visit (µmol/L)

66 ± 14

68 ± 17

0.69

 eGFR at study visit (ml/min/1.73m²)

90 [86–90]

90 [82–90]

0.31

 NT-proBNP at study visit (ng/L)

35 [35–71]

56 [38–68]

0.24

Chest X-ray findings at index diagnosis

 Normal, n (%)

n/a

2(11)

n/a

 COVID-19 changes, n (%)

n/a

3(16)

n/a

Chest X-ray findings at ≥ 12 weeks

 Normal, n (%)

n/a

4(21)

n/a

 COVID-19 changes, n (%)

n/a

0(0)

n/a

Cardiovascular symptoms

 Fatigue, n (%)

n/a

16 (84)

n/a

 Chest pain, n (%)

n/a

2 (11)

n/a

 Dyspnoea, n (%)

n/a

10 (53)

n/a

 Palpitations, n (%)

n/a

13 (69)

n/a