Table 1.
Baseline characteristics of the patients
| Characteristic | Total (n=479) | High Hemoglobin (n=239) | Low Hemoglobin (n=240) | |
|---|---|---|---|---|
| Male sex | n (%) | 285 (60) | 142 (59) | 143 (60) |
| Age, yr | 70±11 | 71±11 | 70±12 | |
| Body mass index, kg/m2 | 22±3 | 22±3 | 22±3 | |
| Smoking | ||||
| Current/ever | n (%) | 70 (14) | 31 (13) | 39 (16) |
| Never | n (%) | 367 (77) | 185 (77) | 182 (76) |
| Unknown | n (%) | 42 (9) | 23 (10) | 19 (8) |
| Cause | ||||
| Chronic GN | n (%) | 149 (31) | 71 (30) | 78 (32) |
| Hypertensive nephrosclerosis | n (%) | 245 (51) | 128 (54) | 117 (49) |
| Polycystic kidney disease | n (%) | 38 (8) | 22 (9) | 16 (7) |
| Other | n (%) | 47 (10) | 18 (7) | 29 (12) |
| Past history of cardiovascular disease | ||||
| Myocardial infarction | n (%) | 25 (5) | 14 (6) | 11 (5) |
| Heart failure | n (%) | 52 (11) | 33 (14) | 19 (8) |
| Stroke | n (%) | 47 (10) | 23 (10) | 24 (10) |
| Peripheral artery disease | n (%) | 13 (3) | 6 (3) | 7 (3) |
| Darbepoetin alfa naïve | n (%) | 336 (70) | 167 (70) | 169 (70) |
| Systolic BP, mm Hg | 133±16 | 132±17 | 133±15 | |
| Diastolic BP, mm Hg | 72±11 | 72±12 | 73±11 | |
| eGFR, ml/min per 1.73 m2 | 14±3 | 14±3 | 14±3 | |
| CKD | ||||
| Stage 4 | n (%) | 165 (34) | 85 (36) | 80 (33) |
| Stage 5 | n (%) | 314 (66) | 154 (64) | 160 (67) |
| Hemoglobin, g/dl | 9.3±0.6 | 9.4±0.6 | 9.3±0.6 | |
| Ferritin, ng/ml | 148 (95–234) | 142 (91–225) | 152 (100–256) | |
| TSAT, % | 33±12 | 33±12 | 33±11 | |
| Uric acid, mg/dl | 7.2±1.8 | 7.2±1.9 | 7.2±1.7 | |
| Albumin, g/dl | 3.8±0.4 | 3.8±0.4 | 3.8±0.4 | |
| Urinary protein-to-creatinine ratio, g/g | 1.16 (0.47–2.29) | 1.13 (0.45–2.29) | 1.25 (0.48–2.28) | |
| C-reactive protein, mg/dl | 0.09 (0.03–0.20) | 0.08 (0.03–0.20) | 0.10 (0.03–0.20) | |
| Iron supplementation | n (%) | 137 (29) | 73 (31) | 64 (27) |
| Antihypertensive medication | n (%) | 399 (83) | 200 (84) | 199 (83) |
| ACEI | n (%) | 53 (11) | 25 (11) | 28 (12) |
| ARB | n (%) | 306 (64) | 165 (69) | 141 (59) |
| Lipid-lowering agents | n (%) | 179 (37) | 95 (40) | 84 (35) |
| Spherical carbonaceous adsorbent | n (%) | 99 (21) | 49 (21) | 50 (21) |
Data are expressed as number (frequency), mean±SD, or median (interquartile range), as appropriate. TSAT, transferrin saturation; ACEI, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker.