Table 1 Baseline Characteristics according to Educational attainment
N | Total | Educational attainment | P | P for trend | ||
|---|---|---|---|---|---|---|
College or beyond | Completed High school | Lower than high school | ||||
1361 | 437 | 467 | 457 | |||
Age (year, mean ± SD) | 60.9 ± 6.9 | 60.3 ± 7.1 | 60.0 ± 6.9 | 62.4 ± 6.6 | < 0.001 | < 0.001 |
Male (N, %) | 860 (63.2) | 361 (82.6) | 299 (64.0) | 200 (43.8) | < 0.001 | < 0.001 |
LVH (N, %) | 413 (30.3) | 101 (23.1) | 132 (28.3) | 180 (39.4) | < 0.001 | < 0.001 |
eGFR (mL/min/1.73m2) | 45.5 ± 25.1 | 47.1 ± 23.3 | 46.7 ± 26.6 | 42.7 ± 25.0 | 0.001a | 0.008 |
BMI (kg/m2, mean ± SD) | 24.6 ± 3.1 | 24.6 ± 2.9 | 24.4 ± 3.2 | 24.9 ± 3.2 | 0.049 | 0.155 |
CKD stage (N, %) |  |  |  |  | < 0.001 | < 0.001 |
 Stage G1 | 112 (8.2) | 27 (6.2) | 50 (10.7) | 35 (7.7) |  |  |
 Stage G2 | 226 (16.6) | 89 (20.3) | 72 (15.4) | 65 (14.2) |  |  |
 Stage G3a | 250 (18.4) | 107 (24.5) | 83 (17.8) | 60 (13.1) |  |  |
 Stage G3b | 322 (23.7) | 90 (20.6) | 112 (24.0) | 120 (26.3) |  |  |
 Stage G4 | 352 (25.9) | 101 (23.1) | 114 (24.4) | 137 (30.0) |  |  |
 Stage G5 | 99 (7.3) | 23 (5.3) | 36 (7.7) | 40 (8.8) |  |  |
Underlying renal disease (N, %) | Â | Â | Â | Â | 0.042 | 0.049 |
 Diabetic nephropathy | 429 (31.8) | 130 (29.9) | 142 (30.7) | 157 (34.7) |  |  |
 Hypertensive nephropathy | 327 (24.2) | 109 (25.1) | 105 (22.7) | 113 (25.0) |  |  |
 Glomerulonephritis | 341 (25.3) | 104 (23.9) | 136 (29.4) | 101 (22.3) |  |  |
 Polycystic kidney disease | 140 (10.4) | 60 (13.8) | 42 (9.1) | 38 (8.4) |  |  |
Diabetes mellitus (N, %) | 571 (42.0) | 168 (38.4) | 189 (40.5) | 214 (46.8) | 0.022 | 0.019 |
bHemoglobin A1c (%, mean ± SD) | 6.9 ± 1.4 | 6.7 ± 1.2 | 6.9 ± 1.3 | 7.1 ± 1.5 | 0.005a | 0.001 |
Hypertension (N, %) | 1334 (98.0) | 430 (98.4) | 457 (97.9) | 447 (97.8) | 0.673 | 0.635 |
 Systolic blood pressure (mmHg, mean ± SD) | 128.84 ± 16.7 | 127.8 ± 15.2 | 129.1 ± 17.3 | 129.5 ± 17.5 | 0.539a | 0.138 |
 Diastolic blood pressure (mmHg, mean ± SD) | 75.9 ± 11.2 | 76.3 ± 10.7 | 76.6 ± 10.9 | 74.9 ± 11.8 | 0.071 | 0.068 |
Monthly income (N, %) |  |  |  |  | < 0.001 | < 0.001 |
  > $ 4500 | 269 (19.8) | 163 (37.3) | 73 (15.6) | 33 (7.2) |  |  |
 $ 1500 to 4500 | 701 (51.5) | 214 (49.0) | 279 (59.7) | 208 (45.5) |  |  |
  < $ 1500 | 391 (28.7) | 60 (13.7) | 115 (24.6) | 216 (47.3) |  |  |
Physical activity (N, %) |  |  |  |  | < 0.001 | < 0.001 |
 High | 287 (21.1) | 95 (21.7) | 112 (24.0) | 80 (17.5) |  |  |
 Moderate | 536 (39.4) | 201 (46.0) | 170 (36.4) | 165 (36.1) |  |  |
 Low | 538 (39.5) | 141 (32.3) | 185 (39.6) | 212 (46.4) |  |  |
Anemia (N, %) | 662 (49.1) | 178 (41.2) | 225 (48.8) | 259 (57.0) | < 0.001 | < 0.001 |
ESA (N, %) | 119 (8.7) | 30 (6.9) | 33 (7.1) | 56 (12.3) | 0.005 | 0.006 |
Serum laboratory values | ||||||
 Hemoglobin (g/dL, mean ± SD) | 12.6 ± 2.0 | 13.2 ± 2.0 | 12.6 ± 1.9 | 12.0 ± 1.92 | < 0.001 | < 0.001 |
 Creatinine (mg/dL, mean ± SD) | 1.9 ± 1.1 | 1.9 ± 1.1 | 1.9 ± 1.1 | 1.9 ± 1.1 | 0.986 | 0.869 |
 Albumin (g/dL, mean ± SD) | 4.2 ± 0.4 | 4.2 ± 0.4 | 4.2 ± 0.4 | 4.1 ± 0.4 | 0.014 | 0.003 |
 Calcium (mg/dL, mean ± SD) | 9.1 ± 0.5 | 9.1 ± 0.5 | 9.1 ± 0.5 | 9.1 ± 0.5 | 0.413 | 0.206 |
 Phosphorus (mg/dL, mean ± SD) | 3.7 ± 0.7 | 3.6 ± 0.6 | 3.7 ± 0.7 | 3.9 ± 0.7 | < 0.001 | < 0.001 |
 Total cholesterol (mg/dL, mean ± SD) | 170.7 ± 38.2 | 168.8 ± 36.8 | 170.6 ± 37.4 | 172.7 ± 40.1 | 0.309 | 0.126 |
 LDL (mg/dL, mean ± SD) | 93.1 ± 31.8 | 91.5 ± 30.9 | 93.2 ± 32.4 | 94.4 ± 31.9 | 0.396 | 0.176 |
 cHDL (mg/dL, mean ± SD) | 47.7 ± 14.6 | 47.4 ± 14.3 | 47.7 ± 13.6 | 48.9 ± 15.9 | 0.816 | 0.527 |
 dTriglyceride (mg/dL, mean ± SD) | 159.2 ± 95.7 | 157.0 ± 89.4 | 157.7 ± 85.7 | 162.8 ± 110.3 | 0.607 | 0.361 |
 e25-OH vitamin D (ng/mL, mean ± SD) | 18.5 ± 8.5 | 19.1 ± 9.0 | 18.5 ± 7.3 | 17.9 ± 9.2 | 0.126 | 0.042 |
f24 hour urine sodium (mmol/day, mean ± SD) | 154.8 ± 67.7 | 156.4 ± 64.7 | 155.5 ± 70.2 | 152.7 ± 67.9 | 0.44 | 0.437 |