Table 1.
Variable | ERI tertile | P | ||
---|---|---|---|---|
Low | Medium | High | ||
n | 18 | 18 | 17 | |
ERI (IU/kg/wk/gHb) | 1.4 ± 0.3 | 2.3 ± 0.2 | 3.5 ± 0.8 | <0.001 |
ESA dose (IU/kg/wk)a | 153 ± 37 | 233 ± 25 | 362 ± 79 | <0.001 |
Type of ESA | 0.8 | |||
Erythropoietin | 11 (61 %) | 12 (67 %) | 12 (71 %) | |
Darbepoetin | 7 (39 %) | 6 (33 %) | 5 (29 %) | |
Hemoglobin (g/L) | 111 ± 8 | 102 ± 13 | 105 ± 10 | 0.05 |
Men | 10 (56 %) | 8 (44 %) | 6 (35 %) | 0.5 |
Age (years) | 67.7 ± 13 | 58.4 ± 17.6 | 60.5 ± 15.5 | 0.2 |
Ethnicity | 0.4 | |||
Caucasian | 14 (78 %) | 14 (78 %) | 15 (88 %) | |
Aboriginal or Torres Strait Islander | 0 | 1 (6 %) | 0 | |
Maori/Pacific Islander | 0 | 1 (6 %) | 0 | |
Asian | 3 (17 %) | 2 (11 %) | 0 | |
Other | 1 (6 %) | 0 | 2 (12 %) | |
Cause of kidney disease b | 0.9 | |||
Diabetes | 8 (44 %) | 8 (47 %) | 5 (29 %) | |
Glomerulonephritis | 2 (11 %) | 1 (6 %) | 4 (24 %) | |
Analgesic nephropathy | 0 | 1 (6 %) | 0 | |
Polycystic kidney disease | 1 (6 %) | 1 (6 %) | 1 (6 %) | |
Reflux nephropathy | 1 (6 %) | 1 (6 %) | 1 (6 %) | |
Renovascular disease | 0 | 1 (6 %) | 1 (6 %) | |
Others | 6 (33) | 4 (24 %) | 5 (29 %) | |
Type of dialysis b | 0.4 | |||
Hemodialysis | 17 (94 %) | 16 (94 %) | 17 (100 %) | |
Peritoneal dialysis | 1 (6 %) | 0 | 0 | |
Pre-dialysis | 0 | 1 (6 %) | 0 | |
Diabetes mellitusc | 10 (67 %) | 9 (82 %) | 6 (46 %) | 0.2 |
Ischemic heart diseasec | 7 (47 %) | 4 (36 %) | 7 (54 %) | 0.7 |
Congestive heart failurec | 2 (13 %) | 1 (9 %) | 5 (38 %) | 0.1 |
Cerebrovascular diseasec | 1 (7 %) | 0 | 3 (23 %) | 0.2 |
Peripheral vascular diseasec | 2 (13 %) | 4 (36 %) | 4 (31 %) | 0.4 |
Smoking status b | 0.3 | |||
Never | 9 (50 %) | 5 (29 %) | 9 (53 %) | |
Former | 8 (44 %) | 11 (65 %) | 5 (29 %) | |
Current | 1 (6 %) | 1 (6 %) | 3 (18 %) | |
Body mass index (kg/m2) | 28.6 ± 4.8 | 30.4 ± 7.4 | 29.2 ± 7.6 | 0.7 |
Body mass index category | 0.3 | |||
Underweight (<18.5 kg/m2) | 0 | 0 | 0 | |
Healthy weight (18.5 – 24.9 kg/m2) | 5 (28 %) | 4 (22 %) | 6 (35 %) | |
Overweight (25 – 29.9 kg/m2) | 9 (50 %) | 6 (33 %) | 3 (18 %) | |
Obese (>30 kg/m2) | 4 (22 %) | 8 (44 %) | 8 (47 %) | |
Hematocrit (%) | 34 ± 3 | 32 ± 5 | 32 ± 3 | 0.7 |
Mean cellular volume (fL) | 94.4 ± 7.8 | 95.3 ± 6.6 | 94.3 ± 5.9 | 0.9 |
Reticulocyte count (109/L) | 57 ± 21 | 74 ± 38 | 64 ± 31 | 0.3 |
Total white cell count (x 109 per L) | 6.8 ± 2 | 6.4 ± 2.1 | 6.6 ± 1.5 | 0.9 |
Platelet count (x 109 per L)d | 207 [164, 286] | 188 [167, 207] | 197 [164, 274] | 0.8 |
Ferritin (μg/L)d | 413 [241, 958] | 527 [298, 647] | 487 [315, 594] | 0.9 |
Transferrin saturation (%)d | 26 [20, 30] | 22 [17, 30] | 23 [22, 29] | 0.6 |
Serum bicarbonate (mmol/L) | 23.3 ± 4 | 22.6 ± 3 | 23.6 ± 3 | 0.6 |
Albumin (g/L) | 36 ± 4 | 35 ± 4 | 35 ± 5 | 0.7 |
Serum alkaline phosphatase (U/L)d | 89 [64, 121] | 99 [76, 134] | 148 [87, 175] | 0.054 |
Gamma-glutamyltransferase (U/L)d | 23 [16, 40] | 25 [17, 60] | 32 [21, 57] | 0.4 |
Alanine transaminase (U/L)d | 16 [11, 19] | 15 [9, 22] | 10 [8, 19] | 0.2 |
Aspartate transaminase (U/L)d | 18 [13, 22] | 17 [12, 23] | 14 [10, 17] | 0.3 |
Lactate dehydrogenase (U/L) | 224 ± 57 | 224 ± 85 | 265 ± 63 | 0.2 |
Albumin-corrected calcium (mmol/L) | 2.3 ± 0.2 | 2.3 ± 0.1 | 2.2 ± 0.2 | 0.2 |
Phosphate (mmol/L)e | 1.7 ± 0.5 | 1.7 ± 0.5 | 1.7 ± 0.5 | 0.9 |
Parathyroid hormone (pmol/L)d,f | 17 [9, 35] | 33 [17, 42] | 32 [16, 65] | 0.2 |
C-reactive protein (mg/L) | 3 [2, 21] | 12 [4, 28] | 15 [7, 31] | 0.06 |
Oxidative stress substudy | ||||
n | 14 | 13 | 14 | |
Total F2-isoprostanes (pg/mL)d | 133 [87, 213] | 143 [128, 200] | 112 [67, 173] | 0.3 |
Glutathione peroxidise activity (U/L) | 177 (13) | 181 (10) | 174 (14) | 0.4 |
Superoxide dismutase activity (U/mL)d,f | 1.97 [1.41, 2.6] | 2.01 [1.32, 2.44] | 2.22 [1.71, 2.71] | 0.7 |
Protein carbonyls (nmol/mg)d | 0.56 [0.46, 0.6] | 0.55 [0.46, 0.74] | 0.55 [0.51, 0.69] | 0.9 |
aPatients on darbepoetin were converted to an erythropoietin-equivalent dose using a conversion factor of 200:1
b1 missing data from medium ERI tertile
cMissing data- 3, 7 and 4 values missing from low, medium and high ERI tertiles, respectively
dMedian [IQR]
eto convert phosphate level from mmol/L to mg/dL multiply by 3.1
fto convert parathyroid level from pmol/L to pg/mL multiply by 9.4