Table 2.

Biochemistry

NormalAll(n = 125)CKD1(n = 19)CKD2(n = 43)CKD3(n = 63)P
Ca, mg/dl8.4 to 10.39.2 ± 0.49.0 ± 0.4a,b9.3 ± 0.5a9.3 ± 0.3b0.03
Cac, mg/dl8.4 to 10.39.2 ± 0.49.0 ± 0.4a,b9.3 ± 0.4a9.3 ± 0.3b0.02
    Cac <8.4 mg/dl, %1.65.301.60.32
Alb, g/L44.3 ± 3.644.2 ± 4.145.0 ± 4.545.1 ± 2.60.67
Phos, mg/dl2.3 to 4.73.2 ± 0.63.0 ± 0.53.1 ± 0.63.3 ± 0.60.09
    Phos >4.7 mg/dl, %0.80.00.01.60.61
Creat, mg/dl0.51 to 0.951.44 ± 0.540.93 ± 0.231.21 ± 0.321.76 ± 0.53<0.0001
Total bicarbonate25.1 ± 2.725.6 ± 2.325.5 ± 2.424.7 ± 2.80.16
PTH, ng/L≤4017.2 (5.9 to 24.5) 3.8 (1.5 to 20.1)a14.4 (3.4 to 23.2)a20.6 (11.8 to 33.4)a<0.0001
    PTH >40 ng/L, %9.70.02.317.70.01
FGF-23, pg/ml≤5058.5 (43.4 to 79.9)47.1 (38.8 to 54.6)a50.8 (41.0 to 69.0)b70.8 (54.0 to 101.8)a,b0.0001
    FGF-23 >50 pg/ml, %60.836.848.876.20.001
Calcidiol, ng/ml7 to 6026.9 (17.5 to 35.9)26.9 (17.1 to 34.8)21.0 (16.0 to 41.7)27.6 (20.2 to 34.0)0.73
    Suff (≥30)/Insuff (10 to 30)/Def (<10), %36/60/432/63/540/53/735/63/20.61
Calcitriol, pg/ml20 to 8044.5 (35.4 to 53.3)51.2 (39.5 to 64.8)a47.7 (35.4 to 56.2)a38.4 (33.1 to 50.8)a0.02
    Calcitriol <20 pg/ml, %2.40.02.33.20.73
Alkaline phosphatases, IU/L≤270181.2 ± 53.6159.7 ± 37.5168.7 ± 42.8193.3 ± 60.20.07
eGFR, ml/min per 1.73 m256.9 ± 20.891.5 ± 14.2a65.1 ± 9.0a41.0 ± 8.9a<0.0001
Creat clearance, ml/min per 1.73 m260.9 ± 31.197.1 ± 36.8a65.8 ± 23.3a43.0 ± 17.2a<0.0001
Phosphaturia, mg/d≈diet830 ± 318914 ± 332a942 ± 327b731 ± 279a,b0.003
Calciuria, mg/d≈diet73 ± 82138 ± 134a80 ± 73a49 ± 49a0.002
Proteinuria, g/d0.21 (0.11 to 0.60)0.24 (0.09 to 0.89)0.18 (0.11 to 0.54)0.23 (0.12 to 0.68)0.80
nPCR, g/kg per day0.97 ± 0.361.3 ± 0.501.02 ± 0.360.88 ± 0.300.08
24h-FEPhos, %30.9 ± 13.621.2 ± 7.5a,b30.4 ± 14.0a34.1 ± 13.6b0.0006
24h-FECa, %0.83 ± 0.830.96 ± 0.890.79 ± 0.850.83 ± 0.800.64
  • 24h-FECa, 24h-fractional renal excretion of calcium; 24h-FEPhos, 24h-fractional renal excretion of phosphate; Cac, albumin-corrected calcium; CKD, chronic kidney disease; eGFR, estimated GFR; FGF-23, fibroblast growth factor-23; PTH, parathyroid hormone.

  • a,b Parameters with the same suffix differ significantly.