Table 4.

Laboratory characteristics of 586 pediatric patients with CKD

VariableaNHANES Estimates Adjusted to CKiDCKiD OverallCKiD GFR Categories, ml/min per 1.73 m2Pb
≥50 (n = 211)≥40 to <50 (n = 131)≥30 to <40 (n = 137)<30 (n = 107)
Sodium, mEq/L141.2139.0140.0140.0139.0139.00.28
Potassium, mEq/L4.14.54.44.54.54.8<0.01
Chloride, mEq/L104.3106.0105.0106.0106.0107.0<0.01
CO2, mEq/Lc26.722.024.022.022.021.0<0.01
Glucose, mg/dl87.392.093.090.091.093.00.73
Calcium, mg/dl9.59.79.79.79.69.60.01
Phosphate, mg/dl4.24.54.44.44.65.0<0.01
Albumin, g/dl4.44.34.34.34.34.2<0.01
BUN, mg/dl10.927.020.028.033.044.0<0.01
Creatinine, mg/dl0.91.30.91.21.62.0<0.01
Cystatin C, mg/L0.91.81.41.72.02.6<0.01
Urine protein:creatinine0.50.20.40.71.0<0.01
Hemoglobin, g/dl13.312.513.112.712.211.6<0.01
Hematocrit, %39.436.838.537.435.233.7<0.01
RCDW, M/mm312.513.213.013.113.313.5<0.01
White blood cell, k/mm37.06.56.56.86.46.30.92
Platelet, k/mm33042802832812832700.32
Ferritin, ng/dld3548444865580.02
Serum iron, μg/dld8676817475760.64
Transferrin saturation, % leveld2425252426260.20
  • Median values are presented. CKD, chronic kidney disease; NHANES, National Health and Nutrition Examination Survey; CKiD, Chronic Kidney Disease in Children study; CO2, carbon dioxide; BUN, blood urea nitrogen. RCDW, red cell distribution width.

  • a Missing data: n = 5 missing sodium; n = 15 missing potassium; n = 5 missing chloride; n = 5 missing CO2; n = 5 missing glucose; n = 5 missing calcium; n = 14 missing phosphate; n = 5 missing albumin; n = 2 missing serum creatinine; n = 152 missing cystatin C; n = 11 missing hemoglobin; n = 12 missing hematocrit; n = 38 missing RCDW; n = 15 missing white blood cell; n = 12 missing platelet; n = 87 missing ferritin; n = 89 missing serum iron; n = 91 missing transferrin saturation.

  • b P values for trend determined using nonparametric Cuzick test for continuous variables.

  • c On the basis of locally measured values of CO2.

  • d Baseline data defined as first available.