Table 2. Laboratory Results and Use or Nonuse of Phosphorus Binders, According to Quartiles of cFGF-23 Level.*.
| Variable | cFGF-23 Quartile 1 (<1090 RU/ml) |
cFGF-23 Quartile 2 (1090–1750 RU/ml) |
cFGF-23 Quartile 3 (1751–4010 RU/ml) |
cFGF-23 Quartile 4 (>4010 RU/ml) |
P Value |
|---|---|---|---|---|---|
| Albumin (g/dl) | 3.4±0.5 | 3.3±0.5 | 3.3±0.6 | 3.3±0.5 | 0.13 |
| Creatinine (mg/dl) | 5.3±2.2 | 5.4±2.2 | 6.3±2.2 | 6.6±2.9 | <0.001 |
| Phosphate (mg/dl) | 3.9±1.2 | 4.1±1.3 | 4.5±1.6 | 5.2±2.1 | <0.001 |
| Calcium (mg/dl) | 8.8±0.8 | 8.9±0.7 | 8.8±0.8 | 9.0±0.8 | 0.15 |
| Parathyroid hormone (pg/ml) | 180 (99–313) | 137 (95–273) | 253 (119–377) | 234 (145–435) | 0.22 |
| Alkaline phosphatase (U/liter) | 82 (64–103) | 89 (67–114) | 91 (69–114) | 100 (77–131) | <0.001 |
| 1,25-Dihydroxyvitamin D (pg/ml)† | 9.1±5.2 | 6.9±6.0 | 8.4±5.0 | 7.5±5.8 | 0.45 |
| Phosphorus binders (% of patients) | 12 | 8 | 9 | 6 | 0.18 |
*
Plus–minus values are means ±SD. P values are for linear trend. To convert the values for creatinine to micromoles per liter, multiply by 88.4. To convert the values for phosphate to millimoles per liter, multiply by 0.3229. To convert the values for calcium to millimoles per liter, multiply by 0.250. cFGF-23 denotes C-terminal fibroblast growth factor 23, and RU reference units.
†
Data on 1,25-dihydroxyvitamin D levels were available for 121 patients.