Table 6. Characteristics of the population included according to phosphate tertiles.
| Variable | T1 (n = 49) <3.98 mg/dl | T2 (n = 52) 3.99–4.99 mg/dl | T3 (n = 49) >5 mg/dl | P |
|---|---|---|---|---|
| Age (years; mean, s.d.) | 72.3 ± 15.7 | 66.2 ± 14.3 | 67.3 ± 14.5 | 0.09 |
| BMI (Mean, SEM) a | 26.4 ± 6.4 | 26.1 ± 6.2 | 27.0 ± 4.8 | 0.73 |
| Gender (male; n, %) | 26 (53.1) | 31 (59.6) | 28 (57.1) | 0.79 |
| Comorbidities | ||||
| Hypertension (%) | 43 (87.8) | 42 (80.8) | 40 (81.6) | 0.59 |
| Diabetes (%) | 15 (30.6) | 15 (28.8) | 14 (28.6) | 0.97 |
| Coronary artery disease (%) | 13 (26.5) | 10 (19.2) | 9 (18.4) | 0.55 |
| Cerebrovascular disease (%) | 4 (8.2) | 8 (15.4) | 7 (14.3) | 0.50 |
| Charlson comorbidity index | 4.0(2.0–5.0) | 4.0 (2.0–5.0) | 4.0 (2.0–5.0) | 0.93 |
| Vascular Access | ||||
| AV Fistula, n (%) | 38 (77.6) | 30 (57.7) | 33 (67.3) | 0.10 |
| Catheters, n (%) | 10 (20.4) | 17 (32.7) | 14 (28.6) | 0.37 |
| Grafts, n (%) | 1 (2.0) | 5 (9.6) | 2 (4.1) | 0.21 |
| Dialysate Calcium 3 mEq/L (n, %) | 44 (89.8) | 44 (84.6) | 43 (87.8) | 0.73 |
|
Dialysis technique HF-HD (n, %) OL-HDF (n, %) |
28 (44.9) 27 (55.1) |
21 (40.4) 31 (59.6) |
26 (53.1) 23 (46.9) |
0.43 |
| Dialysis vintage (months) b, § | 54.8 (16.9–84.5) |
49.2 (16.4–76.8) |
47.3 (18.6–86.5) |
0.96 |
| Albumin (g/L) ¶ | 3.6 ± 0.3 | 3.7 ± 0.3 | 3.7 ± 0.4 | 0.58 |
| Hb (g/L) c,¶ | 11.3 ± 1.2 | 11.1 ± 1.2 | 11.1 ± 1.4 | 0.58 |
| TSAT (%)d,¶ | 28.7 ± 15.0 | 26.9 ± 9.90 | 28.8 ± 12.3 | 0.68 |
| Ferritin (ng/L) § | 436.0 (343.0–714.5) |
504.0 (331.5–742.7) |
472.0 (287.5–849.5) |
0.59 |
| hs-CRP (mg/L) e,§ | 5.2 (2.6–8.2) | 7.3 (4.2–10.9) | 8.8 (5.8–12.4) | 0.01 |
| Ca (mg/dL) e,¶ | 8.86 ± 0.47 | 8.81 ± 0.64 | 8.55 ± 0.77 | 0.03 |
| iCa (mEq/L) g,¶ | 2.21 ± 0.11 | 2.20 ± 0.16 | 2.13 ± 0.19 | 0.03 |
| P (mg/dl) h,§ | 3.4 (2.9–3.7) | 4.3 (4.1–4.8) | 5.7 (5.3–6.2) | <0.001 |
| Alkaline phosphatase (U/L) § | 91.0 (74.5–115.0) |
90.0 (69.0–121.7) |
90.0 (71.0–124.0) |
0.76 |
| iPTH (pg/ml) i,§ | 162.0 (104.0–268.9) |
327.5 (167.0–429.7) |
392.0 (204.5–672.5) |
<0.001 |
| 25(OH)D (ng/ml) j,¶ | 10.7 ± 6.4 | 9.9 ± 5.0 | 9.0 ± 3.7 | 0.29 |
| 1,25 (OH)2 D (pg/ml) k,¶ | 9.7 ± 6.2 | 10.5 ± 6.7 | 12.6 ± 6.7 | 0.08 |
| iFGF23 (pg/ml) l,§ | 158.0 (77.5–438.0) |
502.5 (218.5–1167.7) |
1030.0 (539.5–1754.0) |
<0.01 |
| cFGF23 (RU/ml) m,§ | 471.0 (191.5–874.0) |
959.5 (419.0–2049.7) |
1561.0 (879.0–2652.5) |
<0.001 |
¶ Mean ± Standard deviation (SD)
§ Median and Interquartile Range (IQR)
a BMI, Body Mass Index
b Dialysis Vintage, Time since the initiation of dialysis
c Hb, Hemoglobin serum levels
d TSAT, Transferrin Saturation
e hs-CRP, C-Reactive Protein
f Ca, total serum calcium
g Ca, Ionized Serum Calcium
h P, Serum Phosphate
i iPTH, Intact Parathyroid Hormone
j 25 (OH)D, 25 hydroxy vitamin D (calcidiol)
k 1,25 (OH)2 D, 1,25 dihydroxy vitamin D (calcitriol)
l iFGF23, Intact Fibroblast Growth Factor 23
m cFGF23, C-Terminal Fibroblast Growth Factor 23.
- To convert iCa in mEq/L to mmol/L, multiply by 0.5.
- One-way ANOVA with Bonferroni corrections for multiple comparisons