Table 1.
Demography and biomarkers of 225 study participants according to the stage of CKD.
| CKD I | CKD II | CKD IIIa | CKD IIIb | CKD IV | CKD V | |
|---|---|---|---|---|---|---|
| n | 21 | 26 | 26 | 42 | 80 | 30 |
| Sex (M/F) | 14/7 | 11/15 | 15/11 | 33/9 | 48/32 | 23/7 |
| Age (years) | 35 (13.4) | 49 (16.4) | 61 (11.3) | 63 (12.7) | 62 (13.5) | 57 (15.2) |
| BMI (kg/m2) | 27 (4.9) | 27 (5.9) | 28 (6.5) | 28 (4.8) | 27 (5.6) | 27 (5.9) |
| Erythrocytes (T/L) | 4.9 (0.6) | 4.7 (0.4) | 4.4 (0.6) | 4.4 (0.5) | 4.1 (0.5) | 3.7 (0.6) |
| Hemoglobin (g/dL) | 15 (1.8) | 14 (1.6) | 13 (1.6) | 13 (1.6) | 12 (1.5) | 11 (1.6) |
| Hematocrit (%) | 42.6 (4.9) | 40.8 (4.3) | 38.7 (4.5) | 38.8 (4.2) | 35.8 (4.3) | 32.2 (5.1) |
| MCV (fl) | 87 (4.1) | 88 (5.5) | 89 (4.4) | 89 (5.9) | 88 (6.3) | 87 (4.8) |
| MCH (pg) | 30 (1.6) | 29 (2.1) | 30 (1.6) | 29 (1.9) | 29 (2.2) | 29 (1.6) |
| MCHC (g/dL) | 34 (0.9) | 34 (1.2) | 33 (0.9) | 33 (1.1) | 33 (1.1) | 33 (1.3) |
| RDW (%) | 13 (0.8) | 14 (2.4) | 14 (1.4) | 14 (1.2) | 14 (1.7) | 15 (1.5) |
| Total calcium (mmol/L) | 2.4 (0.2) | 2.5 (0.1) | 2.4 (0.2) | 2.4 (0.1) | 2.3 (0.2) | 2.3 (0.2) |
| Alb-corr calcium (mmol/L) | 2.3 (0.1) | 2.4 (0.1) | 2.4 (0.1) | 2.3 (0.1) | 2.3 (0.2) | 2.3 (0.3) |
| Phosphate (mmol/L) | 1.0 (0.9–1.1) | 1.0 (1.0–1.1) | 1.1 (0.9–1.2) | 1.1 (1.0–1.2) | 1.2 (1.1–1.3) | 1.6 (1.–1.8) |
| Creatinine (mg/dl) | 0.86 (0.79–0.98) | 0.99 (0.86–1.17) | 1.34 (1.19–1.5) | 1.88 (1.69–2.04) | 2.66 (2.27–3.07) | 5.05 (4.2–6.04) |
| Protein (g/L) | 70.1 (9.2) | 70.6 (7.1) | 70.7 (7.1) | 70.6 (6.5) | 68.2 (6.3) | 69.3 (7.3) |
| Albumin (g/L) | 44 (6.6) | 43 (4.6) | 41 (3.9) | 42 (4.1) | 41 (4.1) | 41 (4.2) |
| PTH (pg/mL) | 22 (20–28) | 35 (29–57) | 45 (36–73) | 64 (48–86) | 107 (80–164) | 191 (10–323) |
| eGFR (ml/min/1.73m²) | 101 (95–107) | 74 (69–78) | 51 (47–56) | 35 (32–38) | 23 (18–26) | 11 (1–13) |
| cFGF23 (RU/mL) | 71 (66–127) | 107 (78–161) | 126 (105–187) | 221 (158–382) | 299 (195–450) | 820 (54–1837) |
| iFGF23 (pg/mL) | 58 (55–68) | 68 (51–79) | 95 (81–110) | 119 (100–153) | 172 (132–264) | 924 (40–4676) |
| Klotho (pg/mL) | 627 (385–1408) | 660 (614–699) | 644 (497–826) | 649 (552–803) | 522 (415–622) | 480 (413–549) |
| CRP (mg/dL) | 0.2 (0.1–0.3) | 0.1 (0.1–0.6) | 0.4 (0.2–0.6) | 0.4 (0.2–0.9) | 0.3 (0.1–0.8) | 0.8 (0.4–1.8) |
| IL-6 (pg/mL) | 1.5 (1.5–2.4) | 2.2 (1.5–5.8) | 4.3 (3–6.1) | 6.0 (4.5–10.8) | 6.4 (3.5–12.9) | 9.8 (6.6–16.5) |
| 25(OH)D (nmol/L) | 57 (43–70) | 51 (26–81) | 58 (35–79) | 59 (43–80) | 43 (26–72) | 36 (25–53) |
| 1,25(OH)2D (pmol/L) | 60 (41–74) | 52 (38–63) | 36 (30–46) | 34 (24–42) | 26 (19–34) | 22 (16–32) |
| EPO (mU/mL) | 6.3 (4.4–9.9) | 8.5 (6.9–14.7) | 9.7 (7.4–16.7) | 13.0 (8.8–20.5) | 9.5 (7–14.7) | 10.8 (7–15.2) |
| Hepcidin (pg/mL) | 17353 (7789–28894) | 24374 (9501–43820) | 29067 (18155–41327) | 27956 (19053–38164) | 31306 (16513–56586) | 48667 (32297–91577) |
| Ferritin (µg/L) | 98 (46–147) | 111 (37–191) | 116 (70–216) | 103 (55–190) | 104 (50–174) | 119 (73–242) |
| Transferrin (mg/dL) | 263.8 (40.1) | 273.7 (53.4) | 249.5 (48.5) | 252.2 (50.4) | 240.2 (39.5) | 217.3 (30.2) |
| TSAT (%) | 28.9 (11.7) | 22.5 (8.8) | 25.1 (9.3) | 20.5 (7.5) | 22.2 (9.0) | 21.5 (6.9) |
| Serum iron (µg/dL) | 112.0 (67–132) | 84.5 (72–105) | 86.0 (58–109) | 69.0 (52–79) | 69.0 (51–90) | 61.0 (53–72) |
| sTFR (mg/L) | 1.2 (1–1.5) | 1.3 (1.1–1.9) | 1.3 (1.2–1.6) | 1.5 (1.3–1.8) | 1.4 (1.1–1.7) | 1.4 (1.1–1.8) |
| PK (mg/g) | 137.0 (52–547) | 214.0 (84–1225) | 256.0 (82–1201) | 318.0 (129–1233) | 748.5 (229–1758) | 1717.0 (1073–2354) |
BMI: body mass index; MCV: mean corpuscular volume; MCH: mean corpuscular hemoglobin; MCHC: mean corpuscular hemoglobin concentration; RDW: red cell distribution width; alb-corr calcium: albumin-corrected calcium; BUN: blood urea nitrogen; PTH: parathyroid hormone; eGFR: estimated glomerular filtration rate (CKD-EPI formula); cFGF23: c-terminal Fibroblast Growth Factor 23; iFGF23: intact Fibroblast Growth Factor 23; CRP: C-reactive protein; IL-6: Interleukin 6; 25(OH): 25-hydroxy-Vitamin D3; 1,25(OH)2D: 1, 25-dihydroxy-Vitamin D3; EPO: erythropoietin; SD: standard deviations; TSAT: transferrin saturation; sTFR: soluble transferrin receptor; PK: protein creatinine ratio; shown are mean and standard deviation (SD) for normally distributed variables or median and quartiles (Q1–Q3) for variables with skewed distribution. Reference ranges: total calcium: 2.2–2.65 mmol/l; phosphate: 0.91–1.45 mmol/l; magnesium: 0.66–1.07 mmol/l; creatinine men: 0.70–1.20 mg/dl, women: 0.50–0.90 mg/dl; protein: 64–83 g/L; albumin: 35–52 g/L; cFGF23: 0.8 pmol/L (median); iFGF23: 23.2–95.4 pg/mL; PTH: 15–65 pg/mL; 25(OH)D: 75-250 nmol/L; 1,25(OH)2D: 19.9–79.3 pg/mL; RDW: 11–16%; TSAT: 16–45 %; CRP: < 0.5 mg/dl; IL-6: < 7 pg/mL; serum iron (>18 yrs): 33–193 g/dl; sTFR (>18 years): 0.76-1.76 (mg/L); PK: < 150 mg/g.