Table 1. Patient characteristics by serum phosphorus categorya
| <3 mg/dl (n = 895) | 3–4 mg/dl (n = 3860) | 4–5 mg/dl (n = 8723) | 5–6 mg/dl (n = 10,421) | 6–7 mg/dl (n = 8367) | 7–8 mg/dl (n = 4547) | 8–9 mg/dl (n = 2219) | ≥9 mg/dl (n = 1506) | P Value | |
|---|---|---|---|---|---|---|---|---|---|
| a Values are means; medians presented for vintage and ferritin. P values for proportions and means are age-adjusted. BUN, blood urea nitrogen; URR, urea reduction ratio. | |||||||||
| Age (years) | 67.3 | 66.4 | 64.6 | 61.9 | 58.6 | 55.3 | 52.1 | 48.7 | <0.0001 |
| Gender (% female) | 53% | 48% | 50% | 50% | 48% | 48% | 46% | 42% | <0.0001 |
| Race/ethnicity (%) | <0.0001 | ||||||||
| white | 27% | 37% | 39% | 39% | 35% | 35% | 37% | 44% | |
| black | 56% | 45% | 42% | 41% | 44% | 44% | 43% | 36% | |
| Hispanic | 14% | 15% | 15% | 16% | 17% | 18% | 17% | 16% | |
| other | 3% | 3% | 4% | 3% | 4% | 4% | 4% | 3% | |
| Diabetes (%) | 46% | 48% | 50% | 49% | 46% | 43% | 40% | 35% | <0.0001 |
| Vintage (years) | 1.50 | 1.46 | 1.51 | 1.59 | 1.82 | 1.95 | 2.12 | 2.07 | <0.0001 |
| Weight (kg) | 65.5 | 68.8 | 70.6 | 72.1 | 73.9 | 74.9 | 75.3 | 74.8 | <0.0001 |
| Quetèlet’s (body mass) index (kg/m2) | 25.1 | 25.7 | 26.2 | 26.7 | 27.2 | 27.4 | 27.8 | 27.0 | <0.0001 |
| Bicarbonate (mEq/L) | 23.3 | 22.6 | 21.9 | 21.2 | 20.6 | 19.9 | 19.2 | 18.1 | <0.0001 |
| BUN (mg/dl) | 47 | 51 | 55 | 58 | 62 | 65 | 68 | 72 | <0.0001 |
| Creatinine (mg/dl) | 7.7 | 8.0 | 8.5 | 9.3 | 10.3 | 11.0 | 11.6 | 12.2 | <0.0001 |
| Albumin (g/dl) | 3.60 | 3.74 | 3.82 | 3.86 | 3.90 | 3.91 | 3.92 | 3.93 | <0.0001 |
| Cholesterol (mg/dl) | 163 | 170 | 172 | 173 | 172 | 170 | 167 | 165 | 0.05 |
| Hemoglobin (g/dl) | 10.1 | 10.3 | 10.5 | 10.5 | 10.5 | 10.4 | 10.4 | 10.3 | 0.002 |
| Ferritin (μg/L) | 476 | 433 | 431 | 411 | 418 | 408 | 383 | 342 | <0.0001 |
| URR (%) | 69.8% | 69.5% | 69.4% | 68.9% | 68.4% | 67.7% | 67.1% | 65.9% | <0.0001 |