Table 1.
Baseline characteristics of study population by hemoglobin phenotype
| Normal hemoglobin (HbAA; n=121) | Any variant hemoglobina (n=33) | Sickle cell trait (HbAS; n=24) | Hemoglobin C trait (HbAC; n=9) | |
|---|---|---|---|---|
| Age (years) | 59.5 (13.9) | 59.6 (13.8) | 59.4 (12.9) | 60.1 (16.8) |
| Sex | ||||
| Male | 61 (50.4%) | 17 (51.5%) | 13 (54.2%) | 4 (44.4%) |
| Female | 60 (49.6%) | 16 (48.5%) | 11 (45.8%) | 5 (55.6%) |
| Body mass index (kg/m2)b | 27.7 (23.4, 33.2) | 27.1 (23.3, 31.8) | 26.1 (23.1, 30.7) | 28.9 (24.0, 33.2) |
| Hemoglobin (mg/dl) | 11.8 (0.9) | 12.0 (1.0) | 12.0 (0.9) | 12.2 (1.4) |
| Erythropoietin dose/treatment (units)b | 3684.2 (1955, 6756.4) | 4897.4 (2425, 8230.8) | 4475.6 (2232.5, 8092) | 7092.1 (2980, 8230.8) |
| Intravenous iron dose/treatment (mg)b | 12.5 (0, 19.1) | 12.8 (0, 16.0) | 12.5 (0, 15.9) | 12.9 (12.1,17.5) |
| Interdialytic weight gain (kg)b | 2.60 (1.90, 3.20) | 2.80 (2.30, 3.70) | 2.55 (2.30, 3.45) | 3.50 (2.40, 4.40) |
| Number of treatmentsb | 39 (37, 40) | 39 (38, 40) | 39 (38, 40) | 38 (32, 40) |
| Missed treatments (% of prescribed)b | 0 (0, 5.3) | 0 (0, 2.6) | 0 (0, 2.5) | 0 (0, 5) |
| Days hospitalized/weekc | 0.17 (0.35) | 0.05 (0.17) | 0.05 (0.18) | 0.08 (0.16) |
| Dialysis vintage (years)b | 3.3 (1.7, 6.0) | 6.1 (2.5, 8.7) | 6.2 (2.9, 9.3) | 5.8 (2.1, 6.8) |
| Kt/V | 1.52 (0.33) | 1.51 (0.27) | 1.47 (0.16) | 1.64 (0.43) |
| Albumin (mg/dl) | 3.90 (0.32) | 3.96 (0.34) | 3.96 (0.34) | 3.94 (0.36) |
| Ferritin (ng/ml) | 723.5 (273.3) | 787.6 (277.3) | 834.1 (298.3) | 663.3 (167.0) |
| Iron saturation (%) | 32.1 (7.6) | 31.8 (8.2) | 31.2 (8.9) | 33.2 (6.1) |
| Phosphorus (mg/dl) | 5.40 (1.34) | 5.36 (1.63) | 5.40 (1.62) | 5.23 (1.74) |
| iPTH (pg/ml)b | 340 (240.8, 547.7) | 393.3 (250.8, 622.7) | 451.6 (269.3, 714.2) | 342.8 (169.0, 475.9) |
| Vascular access | ||||
| Arteriovenous fistula | 48 (39.7%) | 20 (60.6%) | 14 (58.3%) | 6 (66.7%) |
| Arteriovenous graft | 44 (36.4%) | 8 (24.2%) | 5 (20.8%) | 3 (33.3%) |
| Indwelling catheter | 39 (24.0%) | 5 (15.2%) | 5 (20.8%) | 0 |
| Diabetes | 74 (61.2%) | 22 (66.7%) | 16 (66.7%) | 6 (66.7%) |
| History of smoking | 19 (15.7%) | 5 (15.2%) | 2 (8.3%) | 3 (33.3%) |
| History of alcohol abuse | 11 (9.1%) | 2 (6.1%) | 2 (8.3%) | 0 |
| History of GI bleed | 14 (11.6%) | 3 (9.1%) | 1 (4.2%) | 2 (22.2%) |
Abbreviations: GI bleed, gastrointestinal bleeding; iPTH, intact parathyroid hormone.
a
Includes HbAS and HbAC.
b
Median (IQR).
c
Week defined as three dialysis treatments (all patients assigned to thrice weekly dialysis).