Table 2 Comparisons of patients’ characteristics between patients with normonatremia and patients with hyponatremia during hospitalization

Age (yrs)

54.2 ± 15.3

52.1 ± 12.9

0.162

Sex (Male)

53.6 %

50.9 %

0.641

Ejection fraction (%) *

39.3 ± 18.4

39.9 ± 20.1

0.846

Ischemia as cause of HF

58.3 %

51.9 %

0.254

 SBP

129.4 ± 27.4

117.8 ± 24.1

<0.001

 DBP

83.1 ± 18.2

76.9 ± 16.8

0.002

 Heart rate

94.8 ± 17.6

97.4 ± 18.9

0.212

 Respiratory rate

26.7 ± 5.9

27.6 ± 6.1

0.181

 Orthopnea

69.6 %

71.6 %

0.703

 PND

52.5 %

58.8 %

0.257

 Cough

18.8 %

18.6 %

0.971

 Chest pain

20.7 %

7.8 %

0.003

 Peripheral oedema

61.1 %

72.5 %

0.033

 Ascites

8.8 %

21.6 %

<0.001

 Fatigue

21.5 %

50.9 %

<0.001

Medical history

 Hypertension

45.1 %

31.4 %

0.014

 Diabetes mellitus

22.7 %

24.5 %

0.694

 Chronic obstructive pulmonary disease

4.1 %

7.8 %

0.128

 Stroke

3.9 %

1.9 %

0.351

 Tuberculosis

4.7 %

7.8 %

0.214

 Asthma

2.2 %

2.9 %

0.509

 Previous hospitalization for cardiac disease

40.9 %

51.9 %

0.046

Concomitant diagnosis

 Atrial fibrillation

15.5 %

12.7 %

0.495

 Pneumonia

15.7 %

20.6 %

0.248

 Renal failure

17.7 %

33.3 %

0.001

 Cardiac arrhythmia

4.9 %

5.9 %

0.714

 Infectious diseases (other than pneumonia)

4.1 %

5.9 %

0.456

Blood chemistry at admission

 Sodium (mEq/L)

139.9 ± 4.5

133.1 ± 6.2

<0.001

 Potassium (mEq/L)

4.4 ± 0.4

4.2 ± 0.9

0.824

 Chloride (mEq/L)

102. 9 ± 7.4

96.2 ± 8.1

<0.001

 Blood glucose (mg/dL)

142.1 ± 73.2

137.1 ± 76.7

0.555

 Blood urea nitrogen (mg/dL)

50.7 ± 33.7

73.1 ± 50.9

<0.001

 Creatinine (mg/dL)

1.4 ± 1.1

1.7 ± 1.4

0.075

 Uric acid (mg/dL)

9.4 ± 5.7

9.0 ± 4.0

0.633

 Total cholesterol (mg/dL)

158.0 ± 48.3

137.9 ± 43.1

<0.001

 HDL (mg/dL)

35.5 ± 17.9

27.4 ± 12.6

<0.001

 Protein total (g/dL)

6.5 ± 0.9

6.3 ± 1.2

0.097

 Albumin (g/dL)

3.4 ± 0.6

3.2 ± 0.5

<0.001

 Hemoglobin (g/dL)

12.7 ± 2.5

12.8 ± 2.3

0.919

 Erythrocyte (x10¹²/L)

4.61 ± 2.16

4.61 ± 1.23

0.996

 Hematocrit (%)

39.5 ± 7.0

40.2 ± 6.9

0.544

 Leucocyte (x10⁹/L)

8.3 (6.7–10.5)

8.7 (7.0–12.3)

0.187

 AST (IU/L)

34 (25–55)

40 (28–83)

0.012

 ALT (IU/L)

26 (16–51)

34 (18–88)

0.011