Table 1 Baseline characteristics of the study patients according to the optimal cutoff point of total indoxyl sulfate (tIS)

Age, years

58(47–68)

58(47–68)

61(51–71)

0.11

Male, n (%)

268(53.6)

238(53.1)

30(57.7)

0.53

Time on dialysis, months

49(24–74)

49(24–73)

50(24–85)

0.74

Cause of end–stage renal disease, n (%)

0.84

 Diabetic nephropathy

134(26.8)

117(26.1)

17(32.7)

0.31

 Glomerulonephritis

210(42.0)

191(42.6)

19(36.5)

0.40

 Hypertensive benign renal arteriosclerosis

101(20.2)

89(19.9)

12(23.1)

0.59

 Polycystic kidney

31(6.2)

29(6.5)

2(3.9)

0.46

 Chronic interstitial nephritis

11(2.2)

10(2.2)

1(1.9)

0.89

 Other

13(2.6)

12(2.7)

1(1.9)

0.75

Hemoglobin, g/l

109(100–117)

109.5(100–117)

107(98–118)

0.66

Alanine aminotransferase,u/L

11(8–15)

11(8–15)

10(8–16)

0.82

Albumin, g/l

41(39–42)

40.6(39.0–42.2)

40.8(39.5–42.3)

0.57

Alkaline phosphatase, u/l

84(68–114.5)

82.5(68.0–112.5)

88(73–117.5)

0.20

Urea nitrogen, mmol/L

25.7(21.7–29)

25.4(21.4–28.8)

27.6(24.8–31.7)

< 0.01

Creatinine, umol/L

928.5(752.5–1096)

925.0(750.0–1092.5)

960.5(791–1111)

0.24

Kt/V

1.36(1.21–1.53)

1.36(1.21–1.53)

1.30(1.23–1.49)

0.54

Platelet, (×10⁹/L)

191(156.5–228)

193.50(157–229)

184.5(150.5–222)

0.34

Potassium, mmol/L

5.0(4.5–5.6)

5.0(4.4–5.5)

5.3(4.6–5.9)

0.07

Sodium, mmol/l

133.9(131.7–136.4)

133.9(131.8–136.4)

133.9(131.5–136.4)

0.55

Calcium, mmol/l

2.36 ± 0.17

2.36 ± 0.17

2.34 ± 0.18

0.46

Phosphorus, mmol/l

2.0(1.6–2.4)

2.0(1.6–2.4)

2.2(1.8–2.6)

0.04

Chlorine, mmol/l

97.08 ± 4.12

97.15 ± 4.16

96.48 ± 3.73

0.27