Table 1.

Characteristics of study participants by eGFR categorya

CharacteristiceGFR (ml/min per 1.73 m2)Total(n = 4849)P
≥60 (n = 4818)<60 (n = 31)
Age (yr)36 (27 to 45)51 (42 to 56)36 (27 to 45)<0.001
Male gender49.446.249.00.82
Black race11.14.311.6<0.001
BMI (kg/m2)26.2 (22.9 to 30.3)28.3 (24.5 to 32.1)26.2 (22.8 to 30.3)0.03
Diabetes4.713.94.80.33
SBP (mmHg)117 (109 to 126)134 (119 to 153)117 (109 to 126)<0.001
DBP (mmHg)74 (67 to 81)82 (77 to 88)74 (67 to 81)<0.01
Hypertensive (≥140/90)13.356.313.7<0.01
Current smoker32.231.832.10.97
Physical activity (active)81.679.981.40.64
Total METS/mo50.5 (10.0 to 141.5)45.0 (10.5 to 111.0)50.5 (10.0 to 142.0)0.79
<200% FPL30.225.230.50.65
≥1 alcoholic drink/wk40.520.439.80.01
Health statusb0.08
    excellent52.915.652.4
    very good25.643.625.5
    good17.818.418.2
    fair3.322.43.5
    poor0.400.4
History of MI1.70.071.70.21
History of stroke0.060.040.50.78
History of CHD2.211.32.30.31
Education >12 yr45.938.745.60.57
CRP (mg/dl)0.21 (0.21 to 0.40)0.33 (0.21 to 0.77)0.21 (0.21 to 0.40)0.01
Serum creatinine (mg/dl)0.77 (0.67 to 0.87)1.37 (1.17 to 1.67)0.77 (0.67 to 0.87)<0.001
Cholesterol (mg/dl)194 (169 to 222)220 (189 to 258)194 (169 to 223)<0.001
HDL (mg/dl)49 (40 to 59)42 (35 to 55)49 (40 to 59)0.02
LDL (mg/dl)c121 (98 to 144)124 (112 to 152)121 (97 to 144)0.31
BUN (mg/dl)12 (10 to 15)20 (18 to 28)12 (10 to 15)<0.001
Hematocrit (%)41.5 (38.5 to 44.6)40.0 (37.9 to 42.3)41.5 (38.5 to 44.6)0.12
Microalbuminuriad8.838.58.40.03
eGFR (ml/min per 1.73 m2)108.3 (95.6 to 125.4)55.0 (45.3 to 57.9)107.9 (95.0 to 125.4)<0.001
  • a Represents participants in the study sample who had valid test results on at least one of three cognitive tests. Continuous variables are median (interquartile range) with P values calculated by Wilcoxon rank-sum test between the chronic kidney disease (CKD) categories and do not take into account the complex sampling design of the Third National Health and Nutrition Examination Survey (NHANES III). Categorical variables are percentages with P values calculated by χ2 and take into account the complex sampling design of NHANES III. BMI, body mass index; BUN, blood urea nitrogen; CHD, coronary heart disease; CRP, C-reactive protein; DBP, diastolic BP; eGFR, estimated GFR; FPL, federal poverty level; METS, metabolic equivalents; MI, myocardial infarction; SBP, systolic BP.

  • b P for difference between excellent/good health versus fair/poor health between eGFR groups. Proportions may not total 100% because of rounding.

  • c LDL missing on 55% of cohort because of nonadherence to fasting laboratory requirements.

  • d Microalbuminuria defined by gender-specific cut points: ≥17 μg/mg for men and ≥25 μg/mg for women.