Table 1 Baseline characteristics of study participants by quartile of ESA resistance index
| Â | ESA resistance index quartile | Â | ||||
|---|---|---|---|---|---|---|
Characteristic | Total (n = 165) | <5.49 (n = 41) | 5.49–< 9.67 (n =41) | 9.67–< 19.2 (n =41) | > = 19.2 (n =42) | P-valuea |
Age (yr) | 58 ± 12 | 58 ± 11 | 61 ± 11 | 58 ± 13 | 59 ± 13 | 0.43 |
Male Sex, n (%) | 95 (58) | 22 (54) | 29 (71) | 23 (56) | 21 (50) | 0.24 |
Body mass index (kg/m2) | 33 ± 8 | 35 ± 7 | 31 ± 7 | 34 (9) | 32 (11) | 0.12 |
Maintenance hemodialysis duration (mo) | 35 (21, 66) | 30 (21, 60) | 29 (18, 49) | 36 (22, 58) | 48 (28, 87) | 0.30 |
Ever smoker, n (%) | 94 (57) | 20 (49) | 29 (71) | 24 (59) | 21 (50) | 0.14 |
Pre-dialysis systolic blood pressure (mmHg) | 152 ± 24 | 150 ± 23 | 151 ± 22 | 154 ± 24 | 154 ± 27 | 0.77 |
Randomized to PATH study treatment, n (%) | 78 (47) | 20 (49) | 20 (49) | 18 (44) | 20 (48) | 0.97 |
Race, n (%) | Â | Â | Â | Â | Â | 0.18 |
 White | 59 (36) | 15 (37) | 19 (46) | 16 (39) | 9 (21) | - |
 African American | 102 (62) | 25 (61) | 22 (54) | 23 (56) | 32 (76) | - |
 Asian | 1 (1) | 1 (2) | 0 (0) | 2 (5) | 0 (0) | - |
 Other | 3 (2) | 0 (0) | 0 (0) | 0 (0) | 1 (2) | - |
Type of vascular access, n (%) | Â | Â | Â | Â | Â | 0.74 |
 Fistula | 106 (64) | 27 (66) | 28 (68) | 28 (68) | 23 (55) | - |
 Graft | 50 (30) | 12 (29) | 11 (27) | 11 (27) | 16 (38) | - |
 Catheter | 9 (6) | 2 (5) | 2 (5) | 2 (5) | 3 (7) | - |
Cause of ESRD, n (%) | Â | Â | Â | Â | Â | 0.83 |
 Diabetes | 69 (42) | 17 (41) | 14 (34) | 22 (54) | 16 (38) | - |
 Hypertension | 66 (40) | 16 (39) | 17 (41) | 14 (34) | 19 (45) | - |
 Glomerulonephritis | 11 (7) | 4 (10) | 3 (7) | 2 (5) | 2 (5) | - |
 Polycystic kidney disease | 7 (4) | 1 (2) | 3 (7) | 2 (5) | 1 (2) | - |
 Other | 12 (7) | 3 (7) | 4 (10) | 1 (2) | 4 (10) | - |
Comorbid disease, n (%) | Â | Â | Â | Â | Â | Â |
 Diabetes | 96 (58) | 24 (58) | 22 (54) | 27 (66) | 23 (55) | 0.67 |
 History of cardiovascular disease | 83 (50) | 16 (39) | 22 (54) | 20 (49) | 25 (59) | 0.29 |
Medication use | Â | Â | Â | Â | Â | Â |
 ESA dose (units/kg/week) | 117 (66, 217) | 41 (25, 53) | 88 (72, 100) | 157 (132, 182) | 298 (242, 389) | <0.001 |
 IV iron dose (mg/week) | 50 (25, 62.5) | 50 (25, 62.5) | 50 (0, 75) | 62.5 (25, 62.5) | 62.5 (25, 100) | 0.12 |
Blood laboratory results at enrollment | Â | Â | Â | Â | Â | Â |
 spKt/V | 1.4 ± 0.4 | 1.4 ± 0.5 | 1.4 ± 0.2 | 1.4 ± 0.6 | 1.4 ± 0.3 | 0.91 |
 Albumin (mg/dl) | 3.9 ± 0.3 | 4.0 ± 0.3 | 4.1 ± 0.2 | 4.0 ± 0.3 | 3.9 ± 0.3 | 0.01 |
 Hemoglobin (mg/dl) | 11.6 ± 1.1 | 11.9 ± 0.8 | 11.7 ± 0.9 | 11.8 ± 1.1 | 11.1 ± 1.3 | 0.02 |
 Parathyroid hormone (pg/dl) | 331 (192, 520) | 410 (234, 613) | 326 (196, 430) | 264 (185, 457) | 388 (189, 649) | 0.28 |
 Iron (ug/dl) | 69.7 ± 21.5 | 64.8 ± 22.8 | 67.2 ± 20.7 | 55.9 ± 20.9 | 50.7 ± 17.7 | <0.001 |
 Transferrin saturation (%) | 24 ± 8.7 | 25 ± 10 | 28 ± 8.8 | 24 ± 7.0 | 23 ± 7.0 | 0.002 |
 Ferritin (ng/dl) | 512 (375, 767) | 512 (420, 835) | 608 (353, 778) | 464 (345, 652) | 604 (358, 759) | 0.25 |