Table 3.

Cystatin C, creatinine, eGFR, and CKD Stage, 1999–2002 vs. 1988–1994, multivariate analysisa

VariablesAdjusted Prevalence Ratios for 1999–2002 (vs. 1998–1994)P
eGFRcystatin C (ml/min/1.73 m2)Ratio (95% CI)
    ≥ 901.31 (1.02–1.67)0.03
    60–890.81 (0.67–1.00)0.05
    45–590.95 (0.74–1.22)0.69
    30–440.77 (0.53–1.13)0.18
    < 301.10 (0.70–1.74)0.66
CKD stage, eGFRcystatin C, ACR
    normal1.16 (0.94–1.41)0.16
    stage 11.09 (0.73–1.64)0.66
    stage 20.70 (0.53–0.93)0.02
    stage 3a0.96 (0.75–1.23)0.76
    stage 3b0.78 (0.54–1.14)0.20
    stage 4/51.12 (0.71–1.76)0.62
Standard creatinine in 1988–1994 and 1999–2004
eGFRcreatinine(ml/min/1.73 m2)
    ≥ 900.59 (0.45–0.76)<0.001
    60–891.44 (1.18–1.76)<0.001
    45–591.49 (1.20–1.84)<0.001
    30–441.24 (0.99–1.56)0.06
    < 301.88 (1.22–2.90)<0.01
CKD stage, eGFRcreatinine, ACR
    normal0.95 (0.81–1.13)0.57
    stage 10.93 (0.64–1.34)0.69
    stage 20.73 (0.54–0.99)0.04
    stage 3a1.50 (1.21–1.87)<0.001
    stage 3b1.26 (1.00–1.58)0.05
    stage 4/51.90 (1.23–2.94)<0.01
Standard creatinine in 1988–1994, minus 0.06 in 1999–2004b
eGFRcreatinine(ml/min/1.73 m2)
    ≥ 901.21 (0.95–1.55)0.12
    60–890.87 (0.70–1.07)0.18
    45–590.86 (0.69–1.08)0.19
    30–441.03 (0.81–1.30)0.82
    < 301.76 (1.11–2.77)0.02
CKD stage, eGFRcreatinine, ACR
    Normal1.16 (0.97–1.38)0.10
    stage 11.22 (0.86–1.73)0.27
    stage 20.57 (0.42–0.79)<0.001
    stage 3a0.87 (0.70–1.09)0.23
    stage 3b1.04 (0.82–1.31)0.74
    stage 4/51.77 (1.12–2.81)0.02
ACR, mg/g
    < 301.17 (0.95–1.44)0.14
    30–2991.04 (0.80–1.35)0.77
    ≥ 3000.45 (0.31–0.67)<0.001
  • ACR, urinary albumin-creatinine ratio; CKD, chronic kidney disease; CI, confidence interval; eGFR, estimated glomerular filtration rate. CKD stages: stage 1, eGFR ≥ 90 ml/min/1.73 m2, ACR ≥ 30; stage 2, eGFR 60–89 ml/min/1.73 m2, ACR ≥ 30; stage 3a, eGFR 45–59 ml/min/1.73 m2; stage 3b, eGFR 30–44 ml/min/1.73 m2; stage 4 eGFR 15–30 ml/min/1.73 m2; stage 5 eGFR < 15 ml/min/1.73 m2.

  • a The analysis was adjusted for the sampling weights used in the study design. Logistic regression was used was used to calculate prevalence ratios. For kidney function outcomes, participants in each kidney function category were compared with all other participants. For example, for eGFRcystatin C45–59 ml/min/1.73 m2, participants with this characteristic were compared with participants with eGFRcystatin C ≥ 60 or < 45 ml/min/1.73 m2. Adjustment was made for age, sex, race, body mass index, and self-reported diabetes, hypertension, and smoking.

  • b When reference populations (aged 20 to 39 yr without diabetes or hypertension) were compared, serum creatinine values were 0.06 mg higher in the 1999–2002 than the 1988–1994 population.