Table 1 Baseline clinical backgrounds of the patients in the four groups divided by the albumin-corrected serum calcium level at baseline (n = 2869).
Four groups stratified by the baseline albumin-corrected serum calcium level | |||||
|---|---|---|---|---|---|
G1: 5.7–8.9 mg/dL | G2: 9.0–9.4: mg/dL | G3: 9.5–9.9 mg/dL | G4: 10.0–16.5 mg/dL | P for trend | |
n = 787 | n = 754 | n = 703 | n = 625 | ||
Baseline characteristics | |||||
Age, years | 63.7 ± 13.0 | 63.8 ± 13.0 | 63.7 ± 12.7 | 62.9 ± 12.2 | 0.28 |
Sex (male), % | 66 | 59 | 54 | 54 | <0.001 |
Diabetic nephropathy, % | 35 | 31 | 25 | 23 | <0.001 |
History of cardiovascular diseases, % | 32 | 32 | 36 | 30 | 0.11 |
Dialysis vintage, years | 3.0 (0.9–7.4) | 4.7 (1.7–9.5) | 6.9 (3.3–13.1) | 8.5 (3.8–15.3) | <0.001 |
Dialysis time per session, hours | 4.7 ± 0.5 | 4.8 ± 0.5 | 4.7 ± 0.6 | 4.7 ± 0.6 | 0.01 |
Dialysate Ca concentration | |||||
3.0 mEq/L, % | 80 | 84 | 84 | 88 | <0.001 |
2.5 mEq/L, % | 20 | 16 | 16 | 12 | <0.001 |
Kt/V for urea | 1.53 ± 0.29 | 1.58 ± 0.30 | 1.62 ± 0.32 | 1.60 ± 0.30 | <0.001 |
Normalized protein catabolic rate, g/kg/day | 0.95 ± 0.21 | 0.96 ± 0.21 | 0.98 ± 0.21 | 0.96 ± 0.21 | 0.20 |
Body mass index, kg/m2 | 21.5 ± 3.4 | 21.2 ± 3.1 | 21.1 ± 3.1 | 20.9 ± 3.1 | <0.001 |
Systolic blood pressure, mmHg | 155 ± 23 | 155 ± 22 | 154 ± 24 | 153 ± 24 | 0.04 |
Cardiothoracic ratio, % | 50.5 ± 5.7 | 50.4 ± 5.6 | 50.5 ± 5.4 | 50.9 ± 5.5 | 0.17 |
Blood tests | |||||
Blood hemoglobin, g/dL | 10.5 ± 1.2 | 10.5 ± 1.1 | 10.5 ± 1.1 | 10.6 ± 1.2 | 0.19 |
Serum albumin, g/dL | 3.84 ± 0.37 | 3.83 ± 0.39 | 3.81 ± 0.42 | 3.75 ± 0.49 | <0.001 |
Serum total cholesterol, mg/dL | 151 (130–176) | 156 (133–180) | 153 (135–180) | 151 (130–179) | 0.42 |
Blood urea nitrogen, mg/dL | 66.2 ± 15.2 | 65.8 ± 15.1 | 66.8 ± 14.8 | 65.5 ± 14.9 | 0.73 |
Serum creatinine, mg/dL | 9.9 ± 2.7 | 10.2 ± 2.6 | 10.4 ± 2.6 | 10.7 ± 2.7 | <0.001 |
Serum C-reactive protein, mg/dL | 0.13 (0.01–0.32) | 0.13 (0.06–0.30) | 0.12 (0.05–0.30) | 0.12 (0.04–0.30) | 0.91 |
Albumin-corrected serum calcium, mg/dL | 8.5 ± 0.4 | 9.2 ± 0.1 | 9.7 ± 0.1 | 10.4 ± 0.5 | <0.001 |
Serum phosphate, mg/dL | 4.9 ± 1.2 | 4.9 ± 1.2 | 5.0 ± 1.1 | 5.1 ± 1.2 | <0.001 |
Serum alkaline phosphatase, U/L | 247 (190–320) | 232 (175–302) | 231 (182–310) | 227 (174–319) | 0.53 |
Serum PTH (intact assay), pg/mL | 126 (68–230) | 99 (54–14) | 89 (38–198) | 95 (30–275) | 0.11 |
Medications | |||||
Use of anti-hypertensive drugs, % | 64 | 63 | 63 | 59 | 0.11 |
Use of phosphate-binders, % | 78 | 83 | 86 | 84 | <0.001 |
Calcium-based phosphate-binders, % | 71 | 76 | 7 | 67 | 0.11 |
Non-calcium-based phosphate-binders, % | 24 | 24 | 32 | 38 | <0.001 |
Use of VDRAs | |||||
Oral administration, % | 61 | 63 | 58 | 46 | <0.001 |
Intravenous administration, % | 7 | 9 | 15 | 29 | <0.001 |
