Table 1.

Clinical characteristics of the study population by presence or absence of edemaa

Clinical CharacteristicOverallEdemaNo EdemaP
n14634 (23)112 (77)
Age (yr)55.2 ± 13.462.9 ± 12.652.9 ± 12.8<0.001
Men93 (64)16 (47)77 (69)0.02
Race0.60
    white13 (9)4 (12)9 (8)
    black131 (90)30 (88)101 (90)
    other2 (1)0 (0)2 (2)
Predialysis weight (kg)81.9 ± 19.692.9 ± 20.078.6 ± 18.3<0.001
Postdialysis weight (kg)79.3 ± 19.090.1 ± 19.276.0 ± 17.8<0.001
BMI (kg/m2)27.2 ± 6.332.5 ± 5.525.6 ± 5.6<0.001
Years of ESRD4.2 ± 3.83.7 ± 3.24.3 ± 4.00.43
Never smokers45 (31)12 (35)33 (29)0.52
Current smokers56 (38)5 (15)51 (46)0.001
Cause of ESRD0.27
    diabetes50 (34)14 (41)36 (32)
    hypertension76 (52)18 (53)58 (52)
    other20 (14)2 (6)18 (16)
Past cardiovascular disease
    coronary artery disease44 (30)13 (38)31 (28)0.24
    cerebrovascular disease25 (17)8 (24)17 (15)0.26
    peripheral vascular disease21 (14)5 (15)16 (14)0.95
Antihypertensive medications
    direct vasodilators18 (12)3 (9)15 (13)0.48
    dihydropyridine calcium-channel blockers52 (36)12 (35)40 (36)0.96
Mean home BP (mmHg)
    systolic139.6 ± 22.3146.6 ± 24.0137.4 ± 21.40.04
    diastolic80.6 ± 13.377.7 ± 14.081.5 ± 13.00.15
    pulse pressure59.0 ± 16.468.9 ± 17.155.9 ± 14.9<0.001
Mean predialysis unit BP (mmHg)
    systolic147.0 ± 21.4150 ± 25.4146 ± 20.10.35
    diastolic80.3 ± 13.176.8 ± 12.481.3 ± 13.20.08
    pulse pressure66.7 ± 13.973.2 ± 16.864.7 ± 12.4<0.01
Clinical laboratory tests
    Kt/V1.6 ± 0.391.65 ± 0.461.60 ± 0.360.41
    albumin (g/dl)3.8 ± 0.363.8 ± 0.293.8 ± 0.380.91
    hemoglobin (g/dl)12.5 ± 1.512.3 ± 1.412.5 ± 1.50.41
    creatinine (mg/dl)10.3 ± 2.79.6 ± 2.610.5 ± 2.70.09
    ferritin (ng/ml)676 ± 490679 ± 361675 ± 5250.97
    calcium (mg/dl)9.2 ± 0.749.2 ± 0.839.2 ± 0.720.72
    phosphorus (mg/dl)5.4 ± 1.85.5 ± 1.95.4 ± 1.70.65
    Ca × P48.9 ± 16.249.8 ± 16.048.7 ± 16.30.72
Echocardiographic markers
    LVM/height2.7 (g/m2.7)59.0 ± 16.669.9 ± 19.955.6 ± 14.0<0.001
    ejection fraction (%)0.37 ± 0.080.38 ± 0.080.37 ± 0.080.51
    IVC diameter (mm/m2)8.7 ± 3.78.5 ± 3.38.7 ± 3.80.8
    IVC collapsibility index (%)31.5 ± 17.927.2 ± 15.932.8 ± 18.30.13
    right atrial pressure (mmHg)6.1 ± 2.26.2 ± 3.16.1 ± 1.90.89
    left atrial diameter (cm)4.31 ± 0.674.35 ± 0.614.30 ± 0.690.75
    pulmonary artery SBP (mmHg)43.9 ± 9.447.2 ± 1.643.0 ± 9.60.04
    elevated pulmonary artery SBP9 (8)2 (8)7 (8)0.96
Circulating volume markers
    NT-proBNP (pg/ml)6165 ± 79074830 ± 64646570 ± 82790.25
    renin predialysis (ng/ml per h)2.24 ± 4.782.86 ± 4.772.05 ± 4.790.17
    renin postdialysis (ng/ml per h)2.53 ± 4.973.25 ± 5.482.32 ± 4.810.24
    aldosterone predialysis (ng/ml)17.2 ± 21.423.3 ± 30.115.4 ± 17.80.07
    aldosterone postdialysis (ng/ml)15.2 ± 25.716.2 ± 22.614.9 ± 26.70.22
    inflammation markers
    CRP (mg/dl)0.98 ± 1.481.22 ± 1.610.90 ± 1.430.03
    IL-6 (pg/ml)4.0 ± 6.83.9 ± 3.64.0 ± 7.50.12
Blood volume monitoring markers
    RBV index (slope %/h)−2.35 ± 1.48−2.27 ± 1.40−2.37 ± 1.500.73
    volume index (slope %/h per ml/kg per h UFR index)−0.28 ± 0.18−0.31 ± 0.23−0.27 ± 0.160.18
    UFR index (ml/kg per h)8.4 ± 3.87.4 ± 3.18.7 ± 4.00.09
  • a Data are mean ± SD or n (%). Continuous variables P values computed through two-group t test except for circulating volume and inflammation markers, for which Kruskal-Wallis rank sum test was used. Categorical variables P values computed through Pearson χ 2. BMI, body mass index; CRP, C-reactive protein; IVC, inferior vena cava; LVM, left ventricular mass; RBV, relative blood volume; SBP, systolic BP; UFR, ultrafiltration rate.