Table 1.

Baseline demographic, clinical, and biochemical characteristics of 258 patients on hemodialysis

CharacteristicAll Patients (n=258)Low-IS Group (IS≤32.35 μg/ml; n=129)High-IS Group (IS>32.35 μg/ml; n=129)P value
Age (yr)57.0±14.658.0±13.356.0±15.90.28
Sex (men/women)145/11367/6278/510.17
Height (m)1.65±0.091.63±0.081.66±0.090.05
Weight (kg)60.1±11.260.5±12.359.6±10.00.52
Body mass index (kg/m2)22.1±3.422.6±3.821.7±2.90.03
Interdialytic weight gain (%)3.2±1.23.2±1.03.2±0.90.56
Ultrafiltration volume (ml)2001±7521981±8022022±6990.66
Systolic BP (mmHg)136.6±17.8135.9±18.3137.3±17.30.54
Diastolic BP (mmHg)82.2±10.581.7±10.782.7±10.40.44
Dialysis duration (mo)43.2 (19.7–73.2)42.0 (15.0–73.5)44.0 (26.5–74.0)0.12
Single-pool Kt/V1.4±0.41.4±0.041.4±0.30.92
Urinary volume (ml/kg per 24 h)0 (0–5.3)1.8 (0–7.3)0 (0–4.2)0.03
Residual renal function (ml/min per 1.73 m2)0 (0–0.5)0 (0–0.8)0 (0–0.4)0.02
Normalized protein nitrogen appearance rate (g/kg per day)2.2±0.52.1±0.52.3±0.6<0.01
Smoking history (%)94 (36.4%)44 (34.1%)50 (38.8%)0.44
Underlying kidney disease (%)0.75
 Glomerular disease114 (44.2%)56 (43.4%)58 (45.0%)
 Diabetic nephropathy23 (8.9%)12 (9.3%)11 (8.5%)
 Hypertensive nephropathy23 (8.9%)11 (8.5%)12 (9.3%)
 Polycystic kidney disease18 (7.0%)12 (9.3%)6 (4.7%)
 Others35 (13.6%)18 (14.0%)17 (13.2%)
 Unknown45 (17.4%)20 (15.5%)25 (19.4%)
Comorbidity (%)
 Primary hypertension79 (30.6%)38 (29.5%)41 (31.8%)0.69
 Coronary heart disease17 (6.6%)7 (5.4%)10 (7.8%)0.45
 Diabetes33 (12.8%)18 (14.0%)15 (11.6%)0.58
 Cerebral infarction37 (14.3%)21 (16.3%)16 (12.4%)0.37
 Cerebral hemorrhage8 (3.1%)6 (4.7%)2 (1.6%)0.15
Medications (%)
 Calcium channel blocker159 (61.6%)84 (65.1%)75 (58.1%)0.25
 Angiotensin conversion enzyme inhibitor43 (16.7%)18 (14.0%)25 (19.4%)0.24
 Angiotensin receptor blocker68 (26.4%)38 (29.5%)30 (23.3%)0.29
β-Blocker42 (16.3%)27 (20.9%)15 (11.6%)0.04
α-Blocker48 (18.6%)26 (20.2%)22 (17.1%)0.52
 Aspirin53 (20.5%)28 (21.7%)25 (19.4%)0.64
 Statin15 (5.8%)8 (6.2%)7 (5.4%)0.79
 25-hydroxy vitamin D140 (54.3%)68 (52.7%)72 (55.8%)0.62
Albumin (g/L)39.2±3.838.7±3.639.8±3.80.02
Prealbumin (g/L)0.33±0.080.32±0.080.34±0.080.03
Hemoglobin (g/L)103.4±16.0102.1±17.0104.8±15.00.18
BUN (mg/dl)142.4±32.1137.1±30.5147.7±33.0<0.01
Serum creatinine (mg/dl)11.5±3.010.6±2.912.5±2.8<0.001
Uric acid (mg/dl)7.3±1.57.2±1.57.4±1.50.37
Alkaline phosphatase (U/L)72 (55–91)73 (57–94)69 (53–91)0.41
25-Hydroxy vitamin D (ng/ml)28.5±8.428.3±7.928.8±9.00.66
Ca (mg/dl)8.88±0.818.87±0.798.90±0.840.78
P (mg/dl)6.7±2.06.6±2.06.8±2.00.50
Ca×P (mg2/dl2)59.7±19.158.9±19.260.5±19.00.50
Intact parathyroid hormone (pg/ml)252.3 (129.7–561.4)224.7 (114.0–518.9)281.0 (136.9–607.7)0.16
Unsaturated iron binding capacity (μg/dl)139.4±43.8140.8±43.7138.1±44.00.49
Total iron binding capacity (μg/dl)205.0±39.9204.8±38.1205.0±41.70.96
Iron (μg/dl)65.2±32.263.8±31.166.6±33.20.51
Transferrin (g/L)1.9±0.51.9±0.51.9±0.40.58
Ferritin (ng/ml)130.0 (69.8–276.1)126.4 (68.8–258.1)133.7 (70.6–290.5)0.81
High-sensitivity C-reactive protein (mg/L)2.1 (0.7–6.1)1.5 (0.6–5.2)2.7 (0.7–6.3)0.06
Triglyceride (mg/dl)125.7 (94.9–169.2)132.3 (98.2–182.5)120.4 (93.4–166.6)0.24
Total cholesterol (mg/dl)169.8±43.9170.4±45.2169.2±42.90.84
HDL-cholesterol (mg/dl)44.6±12.945.6±12.843.6±12.90.25
LDL-cholesterol (mg/dl)95.0±35.591.4±34.898.3±35.90.15
Apoprotein-A (g/L)1.2±0.31.3±0.31.2±0.20.06
Apoprotein-B (g/L)0.8±0.20.8±0.20.8±0.20.99
Lipoprotein (a) (mg/L)169 (116–288)163 (120–281)177 (111–291)0.93
Homocysteine (μg/ml)4.8 (3.8–6.2)4.7 (3.5–5.7)4.9 (4.0–6.2)0.04
β2-Microglobulin (mg/L)35.8±11.034.3±11.837.3±10.00.04
Indoxyl sulfate (μg/ml)35.0±18.021.3±7.448.5±14.7<0.001
Left ventricular mass index (g/m2.7)58.2±20.559.2±19.557.3±21.30.51
Left ventricular ejection fraction (%)66.6±7.166.3±7.466.8±6.80.64
  • Data are presented as means±SDs or medians (interquartile ranges) for continuous variables as appropriate and n (%) for categorical variables. Ca, calcium; P, phosphorus.