Table 1.
Baseline Characteristics by FGF23 Quartile
| Total N = 3,502 | Total FGF23 N = 3,502 1.4-14,318.9 RU/mL |
FGF23 Q1 n = 876 1.4-93.5 RU/mL |
FGF23 Q2 n = 875 93.6-138.7 RU/mL |
FGF23 Q3 n = 876 138.8-224.3 RU/mL |
FGF23 Q4 n = 875 224.5-14,318.9 RU/mL |
|---|---|---|---|---|---|
| Age, y | 57.4 ± 11.2 | 55.9 ± 11.3 | 58.1 ± 10.9 | 58.1 ± 11.1 | 57.4 ± 11.2 |
| Male, n (%) | 1,925 (55.0) | 558 (63.7) | 526 (60.1) | 470 (53.7) | 371 (42.4) |
| Black, n (%) | 1,406 (40.2) | 355 (40.5) | 336 (38.4) | 333 (38.0) | 382 (43.7) |
| Hispanic, n (%) | 459 (13.1) | 64 (7.3) | 119 (13.6) | 138 (15.8) | 138 (15.8) |
| Current smoking, n (%) | 456 (13.0) | 70 (8.0) | 85 (9.7) | 120 (13.7) | 181 (20.7) |
| Body mass index, kg/m2 | 31.9 ± 7.6 | 30.4 ± 6.5 | 31.2 ± 6.9 | 32.2 ± 7.7 | 33.7 ± 8.9 |
| Systolic blood pressure, mm Hg | 128.5 ± 22.0 | 123.5 ± 19.4 | 126.8 ± 21.6 | 131.6 ± 22.7 | 132.3 ± 23.2 |
| Hypertension, n (%) | 2,997 (85.6) | 655 (74.8) | 748 (85.5) | 787 (89.8) | 807 (92.2) |
| Diabetes, n (%) | 1,618 (46.2) | 256 (29.2) | 373 (42.6) | 479 (54.7) | 510 (58.3) |
| Stroke, n (%) | 314 (9.0) | 68 (7.8) | 65 (7.4) | 84 (9.6) | 97 (11.1) |
| Cardiovascular disease, n (%) | 921 (26.3) | 166 (19.0) | 220 (25.1) | 244 (27.9) | 291 (33.3) |
| # of hypertension medications | 2.4 ± 1.3 | 1.9 ± 1.3 | 2.3 ± 1.2 | 2.5 ± 1.2 | 2.8 ± 1.1 |
| ACE/ARB use, n (%) | 2,357 (67.8) | 514 (59.2) | 611 (70.5) | 632 (72.8) | 600 (68.7) |
| eGFR, mL/min/1.73m2 | 45.0 ± 15.4 | 55.0 ± 14.4 | 48.0 ± 13.6 | 41.5 ± 12.4 | 35.5 ± 13.6 |
| 24 H Urine protein (g/24 H) | 0.18 (0.07-0.90) | 0.10 (0.06-0.32) | 0.12 (0.06-0.57) | 0.26 (0.08-1.25) | 0.46 (0.11-2.03) |
| Total cholesterol, mg/dL | 184.9 ± 45.3 | 184.0 ± 39.4 | 182.0 ± 40.5 | 186.8 ± 47.5 | 186.8 ± 52.6 |
| Statin, n (%) | 1,851 (53.3) | 385 (44.4) | 463 (53.4) | 513 (59.1) | 490 (56.1) |
| Calcium, mg/dL | 9.2 ± 0.5 | 9.2 ± 0.4 | 9.2 ± 0.5 | 9.2 ± 0.5 | 9.1 ± 0.6 |
| Phosphate, mg/dL | 3.7 ± 0.7 | 3.4 ± 0.5 | 3.6 ± 0.6 | 3.8 ± 0.6 | 4.0 ± 0.8 |
| PTH, pg/mL | 52.0 (34.0-84.7) | 39.5 (28.7-57.2) | 46.8 (32.0-72.5) | 58.8 (38.0-92.9) | 77.0 (45.9-136.3) |
| CRP, mg/L | 2.5 (1.0-6.3) | 1.8 (0.9-4.5) | 2.1 (1.0-4.9) | 2.6 (1.1-6.3) | 3.9 (1.4-8.6) |
| TSAT | 23.4 ± 8.8 | 26.0 ± 8.4 | 24.1 ± 8.1 | 23.1 ± 9.1 | 20.2 ± 8.6 |
| Ferritin, ng/mL | 155.3 (82.3-281.1) | 180.8 (100.4-325.4) | 178.8 (100.0-294.4) | 147.2 (81.6-269.7) | 119.0 (59.6-229.0) |
Note: Results are reported as mean ± standard deviation for normally distributed variables and median with interquartile range for nonnormally distributed variables.
Abbreviations: ACE/ARBs, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers; CRP, C-reactive protein; eGFR, estimated glomerular filtration rate; FGF23, fibroblast growth factor 23; N, number; PTH, parathyroid hormone; Q, quartile; TSAT, transferrin saturation.