Table 2. Mineral metabolites according to cut points of eGFR.
| eGFR <20 N=87 |
eGFR 20-29 N=671 |
eGFR 30-39 N=955 |
eGFR 40-49 N=1024 |
eGFR 50-59 N=742 |
eGFR 60-69 N=287 |
eGFR ≥70 N=113 |
|
|---|---|---|---|---|---|---|---|
| eGFR, ml/min/1.73m2 | 18 ± 2 | 26 ± 3 | 35 ± 3 | 45 ± 3 | 54 ± 3 | 64 ± 2 | 77 ± 7 |
| Serum phosphate, mg/dl | 4.7 ± 1.0❋ | 4.1 ± 0.7❋ | 3.8 ± 0.6❋ | 3.6 ± 0.6❋ | 3.5 ± 0.6 | 3.4 ± 0.5 | 3.5 ± 0.6 |
| Serum calcium, mg/dl | 8.8 ± 0.7❋ | 9.1 ± 0.6 | 9.2 ± 0.5 | 9.2 ± 0.5 | 9.2 ± 0.5 | 9.2 ± 0.4 | 9.1 ± 0.4 |
| FGF23, RU/ml | 348❋ (234 – 486) |
247❋ (169 – 378) |
173❋ (118 – 270) |
135❋ (94 – 188) |
102❋ (77 – 152) |
94 (67 – 121) |
82 (62 – 114) |
| PTH, pg/ml | 175❋ (101 – 234) |
103❋ (63 – 163) |
64❋ (41 – 99) |
48❋ (32 – 73) |
41❋ (30 – 59) |
36 (28 – 51) |
33 (25 – 48) |
| 1,25D, ng/ml* | 23 ± 5 | 23 ± 8❋ | 25 ± 11❋ | 28 ± 11 | 29 ± 10 | 30 ± 11 | 33 ± 17 |
| 25D, ng/ml* | 11 ± 3 | 17 ± 12 | 18 ± 10 | 21 ± 12 | 22 ± 11 | 23 ± 12❋ | 17 ± 8 |
| FEPi, % | 41❋ (32 – 50) |
35❋ (26 – 46) |
28❋ (21 – 36) |
24❋ (18 – 32) |
22❋ (17–28) |
20❋ (14 – 24) |
17 (13 – 22) |
| 24-hr urinary phosphate, mg/day† | 589❋ (409 – 793) |
632❋ (465 – 845) |
680❋ (492 – 895) |
723❋ (530 – 952) |
799 (568 – 1049) |
812 (598 – 1103) |
836 (566 – 1106) |
| Dietary phosphorus intake, mg/day‡ | 1250 (827 – 1574) |
1002❋ (702 – 1387) |
1006❋ (690 – 1346) |
1050 (762 – 1432) |
1083 (776 – 1471) |
1085 (786 – 1409) |
1131 (841 – 1544) |
| 24-hr urinary phosphate/dietary phosphorus intake§ | 0.53❋ (0.34 – 0.86) |
0.65 (0.44 – 0.94) |
0.69 (0.45 – 0.99) |
0.70 (0.48 – 0.99) |
0.72 (0.52 – 1.0) |
0.74 (0.54 – 1.04) |
0.72 (0.52 – 0.96) |
| Total caloric intake, kcal/day‡ | 1942 (1382 – 2715) |
1530❋ (1163 – 2210) |
1592❋ (1126 – 2198) |
1636 (1244 – 2273) |
1704 (1243 – 2310) |
1644 (1297 – 2363) |
1852 (1388 – 2348) |
Values are means ± standard deviation, medians (interquartile range).
❋
P <0.05 compared with eGFR >70 ml/min/1.73m2. eGFR was not tested.
*
25-hydroxyvitamin D and 1,25-hydroxyvitamin D levels were available in 333 and 332 participants, respectively.
†
Twenty four-hour urinary data were available for 3,659 participants.
‡
Dietary data were available for 2,797 participants.
§
24-hr urinary phosphate/dietary phosphorus intake was available for 2702 participants.
The CRIC central laboratory's reference ranges were 2.4 – 4.7 mg/dl for serum phosphate, 8.9 – 10.3 mg/dl for serum calcium, and 14 – 66 pg/ml for PTH.