Table 1.
Baseline clinical backgrounds of the patients treated with or without phosphate-binders.
| Characteristics | Entire cohort (n = 2926) | |||
|---|---|---|---|---|
| Use of phosphate-binders | P-value | Standardized difference | ||
| No (n = 517) | Yes (n = 2409) | |||
| Demographics and Comorbidities | ||||
| Age, years | 68.7 ± 12.6 | 62.8 ± 12.6 | <0.001 | 0.469 |
| Sex, male, % | 56 | 60 | 0.085 | 0.084 |
| Diabetes mellitus, % | 35 | 28 | 0.002 | 0.148 |
| Comorbidity, % | 51 | 38 | <0.001 | 0.254 |
| Dialysis history, years | 3.4 (0.9–9.1) | 5.7 (2.4–11.6) | <0.001 | 0.214 |
| Dialysis time per session, hours | 4.6 ± 0.6 | 4.7 ± 0.6 | <0.001 | 0.244 |
| Kt/V for urea | 1.58 ± 0.31 | 1.58 ± 0.30 | 0.903 | 0.006 |
| nPCR, g/kg/day | 0.90 ± 0.23 | 0.96 ± 0.19 | <0.001 | 0.307 |
| Body mass index, kg/m2 | 20.2 ± 3.5 | 21.3 ± 3.3 | <0.001 | 0.314 |
| Cardiothoracic ratio, % | 51.3 ± 6.1 | 50.6 ± 5.4 | <0.001 | 0.123 |
| Systolic blood pressure, mmHg | 151 ± 25 | 154 ± 23 | <0.001 | 0.108 |
| Laboratory tests | ||||
| Blood hemoglobin, g/dL | 10.4 ± 1.2 | 10.6 ± 1.1 | <0.001 | 0.159 |
| Blood urea nitrogen, mg/dL | 57.3 ± 16.0 | 67.8 ± 14.3 | <0.001 | 0.690 |
| Serum creatinine, mg/dL | 8.4 ± 2.4 | 10.6 ± 2.6 | <0.001 | 0.873 |
| Serum albumin, g/dL | 3.6 ± 0.5 | 3.8 ± 0.4 | <0.001 | 0.577 |
| Serum total cholesterol, mg/dL | 151 (127–182) | 151 (131–176) | 0.874 | 0.009 |
| Serum C-reactive protein, mg/dL | 0.18 (0.07–0.50) | 0.13 (0.05–0.26) | <0.001 | 0.258 |
| Corrected serum Ca, mg/dL | 9.3 ± 0.8 | 9.4 ± 0.8 | <0.001 | 0.187 |
| Serum phosphate, mg/dL | 4.6 ± 1.2 | 5.0 ± 1.2 | <0.001 | 0.343 |
| Serum alkaline phosphatase, U/L | 304 ± 161 | 258 ± 136 | <0.001 | 0.313 |
| Serum PTH (intact assay), pg/mL | 100 (51–195) | 102 (45–211) | 0.295 | 0.054 |
| Medication | ||||
| Use of ESAs, % | 89 | 83 | 0.003 | 0.148 |
| Use of anti-hypertensives, % | 62 | 65 | 0.189 | 0.064 |
| Use of VDRAs, % | 61 | 73 | <0.001 | 0.249 |
| Use of phosphate-binders | ||||
| Sevelamer hydrochloride, % | 0 | 35 | <0.001 | 1.031 |
| Ca-containing binders, % | 0 | 86 | <0.001 | 3.524 |
| Total daily dose of phosphate-binders, g/day | 0 | 2499 ± 1512 | NA | NA |
Data are expressed as the mean ± standard deviation, median (interquartile range), or percentage, depending on the nature of the variable. Unpaired t-test, chi-square test, or Wilcoxon sign-rank test was used to compare the two groups. Standardized difference was also calculated. A two-tailed P-value less than 0.05 was considered statistically significant. Comorbidity included history of cardiovascular events, bone fracture, and parathyroidectomy. Total daily dose of phosphate-binders was also calculated by adding daily dose of calcium carbonate and sevelamer hydrochloride and expressed as that of calcium carbonate. In the present study, Phosphate binding capacity of 750 mg of sevelamer hydrochloride was regarded equivalent to that of 500 mg of calcium carbonate. Abbreviations: Ca, calcium; ESAs, erythropoiesis-stimulating agents; NA, not applicable; nPCR, normalized protein catabolic rate; PTH, parathyroid hormone; VDRAs, vitamin D receptor activators.