Table 2.

BP and laboratory variables compared by categories of GFR and race and ethnicitya

VariableRacial/Ethnic GroupP
AllWhiteBlackHispanicOtherRace/EthnicityRace/Ethnicity × GFR
SBP (mmHg)
    all122.20 (0.40)122.40 (0.50)124.28 (0.40)119.77 (0.39)119.00 (0.99)<0.00010.0014
    GFR <60140.52 (1.02)139.65 (1.16)147.51 (1.75)146.03 (2.72)143.20 (2.81)0.0026
    GFR ≥60121.14 (0.37)b121.28 (0.46)123.33 (0.40)119.34 (0.38)118.13 (0.92)<0.0001
DBP (mmHg)
    all74.19 (0.18)74.08 (0.21)75.58 (0.29)73.14 (0.40)74.05 (0.55)<0.00010.0016
    GFR <6075.15 (0.53)74.44 (0.57)79.82 (1.20)76.21 (1.49)80.17 (2.54)0.0017
    GFR ≥6074.13 (0.18)74.06 (0.21)75.41 (0.30)73.09 (0.40)73.83 (0.53)<0.0001
Potassium (mmol/L)
    all4.06 (0.01)4.07 (0.01)4.00 (0.01)4.01 (0.02)4.02 (0.03)<0.00010.0937
    GFR <604.20 (0.02)4.21 (0.02)4.12 (0.06)4.20 (0.04)4.30 (0.06)0.1503
    GFR ≥604.05 (0.01)b4.07 (0.01)4.00 (0.01)4.01 (0.02)4.01 (0.02)<0.0001
Hemoglobin (g/L)
    all141.52 (0.32)142.56 (0.36)133.84 (0.33)142.82 (0.38)140.66 (0.77)<0.00010.8854
    GFR <60136.18 (0.52)137.14 (0.56)124.36 (1.25)133.93 (2.37)138.21 (3.56)<0.0001
    GFR ≥60141.84 (0.32)b142.93 (0.36)134.25 (0.35)142.97 (0.38)140.75 (0.76)<0.0001
Bicarbonate (mmol/L)
    all28.12 (0.23)28.21 (0.25)27.76 (0.24)27.61 (0.30)28.03 (0.37)0.13680.0539
    GFR <6028.05 (0.31)28.16 (0.33)27.65 (0.41)26.75 (0.53)27.09 (0.45)0.0213
    GFR ≥6028.12 (0.23)28.21 (0.25)27.76 (0.25)27.63 (0.30)28.06 (0.37)0.1387
Calcium (mmol/L)
    all2.32 (0.01)2.32 (0.01)2.31 (<0.01)2.31 (0.01)2.31 (0.01)0.09980.5715
    GFR <602.34 (0.01)2.34 (0.01)2.34 (0.01)2.28 (0.02)2.32 (0.02)0.0110
    GFR ≥602.31 (0.01)b2.32 (0.01)2.32 (0.00)2.31 (0.01)2.30 (0.01)0.1373
Phosphorus (mmol/L)
    all1.11 (<0.01)1.11 (<0.01)1.13 (<0.01)1.13 (<0.01)1.12 (<0.01)0.00020.8931
    GFR <601.13 (0.01)1.13 (0.01)1.16 (0.02)1.19 (0.02)1.14 (0.05)0.0765
    GFR ≥601.11 (<0.01)c1.11 (<0.01)1.12 (<0.01)1.13 (<0.01)1.12 (<0.01)0.0001
Uric acid (mmol/L)
    all317.03 (1.27)316.56 (1.53)321.85 (2.38)312.78 (2.38)317.99 (3.74)0.03940.0012
    GFR <60389.60 (4.41)384.58 (4.77)432.39 (7.70)399.72 (11.87)411.43 (8.17)<0.0001
    GFR ≥60312.57 (1.22)b311.83 (1.48)317.08 (2.15)311.32 (2.16)314.57 (3.91)0.1812
  • a Data are means (SE). ANOVA was used for between-group comparisons. GFR values are given as ml/min per 1.73 m2.

  • b P < 0.0001 for comparison of GFR categories.

  • c P < 0.001 for comparison of GFR categories.