Table 2.

Univariate associations of renal function measures in US adolescents aged 12 to 17 yearsa

CharacteristicsRenal Function Measures
CreatinineeGFRSchwartzeGFRCKiDCystatin CLog (ACR)b
n557555754054055504
Age, per 1.5 years0.07 (<0.01)−7.13 (0.42)−2.87 (0.63)−0.02 (0.01)−0.05 (0.02)
    P<0.0001<0.00010.00040.0080.004
    r20.270.080.080.04<0.01
Female gender (vs. male)−0.10 (0.01)−17.85 (1.01)−0.86 (1.21)−0.08 (0.01)0.36 (0.04)
    P<0.0001<0.00010.5<0.0001<0.0001
    r20.100.10<0.010.120.03
Race/ethnicity
    African American (vs. Caucasian)0.03 (0.01)−5.38 (1.18)2.28 (2.16)−0.05 (0.02)−0.10 (0.05)
        P<0.0001<0.00010.30.010.06
    Hispanic/Mexican (vs. Caucasian)−0.05 (0.01)8.23 (1.71)5.18 (2.01)−0.04 (0.01)0.07 (0.05)
        P<0.0001<0.00010.020.0070.2
    Other race (vs. Caucasian)−0.03 (0.01)4.29 (3.88)−1.39 (2.24)−0.04 (0.0)−0.13 (0.10)
        P0.040.30.50.0030.2
        r20.020.020.040.04<0.01
Body mass index, per 3.1 kg/m20.01 (<0.01)−1.30 (0.38)−0.78 (0.28)0.01 (<0.01)−0.11 (0.01)
    P<0.00010.0010.020.06<0.0001
    r20.020.010.010.030.03
Systolic BP, per 6.9 mmHg0.02 (<0.01)0.47 (0.35)−0.80 (0.64)0.01 (<0.01)−0.03 (0.01)
    P<0.00010.20.20.050.02
    r20.05<0.010.010.05<0.01
Diastolic BP, per 7.0 mmHg0.01 (<0.01)−1.92 (0.38)−0.36 (0.47)>−0.01 (<0.01)0.03 (0.01)
    P0.004<0.00010.50.60.02
    r2<0.010.01<0.01<0.01<0.01
  • ACR, albumin-creatinine ratio; eGFRCKiD, estimated GFR calculated with the revised Schwartz formula; eGFRSchwartz, estimated GFR calculated with the original Schwartz formula.

  • Units: serum creatinine, mg/dl; GFRSchwartz, ml/min/1.73 m2; GFRCKiD, ml/min/1.73 m2; cystatin C, ACR, mg/g.

  • a Separate linear regression models for serum creatinine, GFRSchwartz, GFRCKiD, cystatin C, and log-transformed ACR as dependent variables and age, gender, race/ethnicity, body mass index, systolic BP and diastolic BP as separate candidate explanatory variables. ACR was log-transformed because of non-Gaussian distribution characteristics. Parameter estimates are presented as beta coefficients (standard error). Intervals for continuous variables represent half the interquartile range.

  • b The exponents of the parameter estimates are as follows: −0.05 to 0.95, 0.36 to 1.43, −0.10 to 0.90, 0.07 to 1.07, −0.13 to 0.88, −0.11 to 0.90, −0.03 to 0.97, 0.03 to 1.03.