Table 1 Baseline characteristics of patients with low serum bicarbonate level in comparison with those of control group

N (%)

113

28

85

Age (years)

70.4 ± 6.6

71.0 ± 6.9

70.2 ± 6.5

0.59

Female (%)

41 (36.3)

5 (17.9)

36 (42.4)

0.019

Diabetes mellitus (%)

38 (33.6)

5 (17.9)

33 (38.8)

0.042

Hypertension (%)

45 (39.8)

3 (10.7)

42 (49.4)

0.0003

Height (cm)

160.6 ± 8.9

164.8 ± 8.1

159.2 ± 8.7

0.005

Weight (kg)

58.3 ± 8.9

60.9 ± 9.4

57.4 ± 8.6

0.08

BMI (kg/m²)

22.5 ± 2.5

22.3 ± 2.2

22.6 ± 2.5

0.61

eGFR (ml/min/1.73 m²)

25.7 ± 13.6

15.1 ± 5.9

29.1 ± 13.6

0.0001

CKD Stage (%)

0.0001

3

40 (35.4)

1 (3.5)

39 (45.9)

4

44 (38.9)

12 (42.9)

32 (37.7)

5

29 (25.7)

15 (53.6)

14 (16.5)

Albumin level (g/dl)

3.7 ± 0.3

3.7 ± 0.3

3.7 ± 0.4

0.99

Sodium level (mEq/l)

140.7 ± 2.3

140.9 ± 2.2

140.7 ± 2.4

0.63

Potassium level (mEq/l)

4.8 ± 0.5

5.0 ± 0.5

4.7 ± 0.5

0.004

Bicarbonate level (mEq/l)

27.4 ± 3.2

23.4 ± 1.8

28.8 ± 2.3

0.0001

24-hour urine protein excretion level (g/day)

0.93 ± 1.01

1.25 ± 1.19

0.83 ± 0.93

0.063

0.52 (IQR, 0.25, 1.18)

1.04 (IQR, 0.35, 1.66)

0.44 (IQR, 0.24, 1.11)

RAAS inhibitor use (%)

98 (86.7)

20 (71.4)

78 (91.8)

0.006

ACEI use

51 (45.1)

12 (42.9)

39 (45.9)

ARB use

86 (76.1)

18 (64.3)

68 (80.0)

Direct renin inhibitor use

34 (30.4)

9 (32.1)

25 (29.8)

Loop diuretic use (%)

37 (32.7)

11 (39.3)

26 (30.6)

0.40

Sodium bicarbonate use (%)

23 (20.3)

12 (42.9)

11 (12.9)

0.0006

Dose of sodium bicarbonate (g/day)

0.54 ± 1.29

1.28 ± 2.03

0.28 ± 0.78

0.0006

0 (IQR, 0, 0)

0 (IQR, 0, 2)

0 (IQR, 0, 0)

Decrease of 25% or more in eGFR (%)

46 (40.7)

19 (67.9)

27 (31.8)

0.0007

Dialysis (%)

10 (8.9)

6 (21.4)

4 (4.7)

0.007

Outcome (%)

46 (40.7)

19 (67.9)

27 (31.8)

0.0007

Follow-up days (days)

449.3 ± 162.7

360.4 ± 184.6

478.6 ± 144.4

0.0007