Table 1.

Baseline characteristics by level of kidney function using the CKD-Epi equation

CharacteristicsTotaleGFREPI (ml/min per 1.73 m2)Pa
>6030 to 59<30
n102850147750
Age85.5 (3.5)85.2 (3.4)85.7 (3.6)86.2 (3.7)<0.01
Women63.862.766.550.00.89
White race85.983.288.588.00.03
Body mass index (kg/m2)26.8 (4.7)26.6 (4.6)26.8 (4.7)27.8 (5.0)0.22
Ever smoked49.250.248.248.00.54
Diabetes14.413.113.932.00.02
Hypertension65.66069.584.0<0.01
Systolic blood pressure (mmHg)132.7 (21.1)133.7 (20.8)131.4 (20.9)135.7 (25.9)0.19
HDL cholesterol (mg/dl)54.3 (15.3)55.7 (15.2)53.7 (15.3)44.9 (12.3)<0.01
LDL cholesterol (mg/dl)101.3 (31.5)104.0 (32.0)99.0 (30.5)96.0 (33.7)<0.01
Vitamin D25 (ng/ml)25.9 (10.4)24.8 (9.1)27.2 (11.5)25.1 (11.3)<0.01
C-reactive protein (mg/L)b2.0 (1.0, 4.5)1.8 (0.9, 4.1)2.1 (1.0, 5.0)3.0 (1.8, 7.8)<0.01
Creatinine (mg/dl)1.1 (0.5)0.8 (0.1)1.2 (0.2)2.7 (1.4)<0.01
Cystatin C (mg/L)1.2 (0.5)1.0 (0.2)1.3 (0.3)2.4 (1.0)<0.01
MDRD eGFR61.8 (19.1)77.0 (12.9)49.8 (8.2)23.7 (7.4)<0.01
CKD-Epi eGFR58.8 (17.0)72.9 (8.5)47.7 (8.1)21.9 (7.1)<0.01
Cystatin C eGFR using one- variable equation69.8 (21.7)82.6 (17.7)60.3 (15.9)31.2 (10.6)<0.01
Cystatin C eGFR using three- variable equation61.9 (19.2)73.4 (15.9)53.4 (13.7)28.3 (9.5)<0.01
  • The data are presented either as means (SD) or percentages. Represent P = 0.0000 as P < 0.01.

  • a Trend P values.

  • b Median [IQR] with Kruskal-Wallis test.