TABLE 1.
Demography, non-medical, and medical variables classified by phosphorus quartiles.
| Total | Q1 (< 3.6 mg/dL) |
Q2 (3.6–4.2 mg/dL) |
Q3 (4.3–5.1 mg/dL) |
Q4 (>5.2 mg/dL) |
p | |
| n (%) | 654 (100) | 185 (28.29) | 146 (22.32) | 169 (25.84) | 154 (23.55) | |
| Age (year) | 48.32 ± 15.1 | 54.12 ± 12.5a | 51.68 ± 13.8b | 47.29 ± 15.2 | 39.30 ± 14.7c | 0.001 |
| Gender, n (%) | 0.035 | |||||
| Male | 267 (40.8) | 91 (34.1) | 59 (22.1) | 64 (24.0) | 53 (19.9) | |
| Female | 387 (59.2) | 94 (24.3)b | 87 (22.1) | 105 (24.0) | 101 (26.1) | |
| Economic income, n (%) | 0.190 | |||||
| Low | 373 | 107 (23.4) | 87 (19) | 102 (2.3) | 77 (16.8) | |
| Medium-high | 84 | 32 (7) | 19 (4) | 23 (5) | 10 (2.2) | |
| Education, n (%) | 0.001 | |||||
| Low | 199 | 80 (17.5)a | 49 (10.7) | 46 (10.1) | 24 (5.2)d | |
| Intermediate | 173 | 38 (8.3) | 47 (10.3) | 49 (10.7) | 39 (8.5) | |
| High | 85 | 21 (4.6) | 10 (2.2) | 30 (6.6) | 24 (5.2) | |
| Activity, n (%) | 0.001 | |||||
| Non or home | 155 | 38 (8.3) | 37 (8.1) | 45 (9.8) | 35 (7.7) | |
| Employee | 274 | 101 (22.1)a | 66 (14.4) | 68 (14.7) | 39 (8.5)d | |
| Professional | 28 | 0 | 30 (0.7) | 12 (2.6) | 13 (2.6) | |
| Diabetes mellitus | 0.001 | |||||
| Yes n (%) | 357 | 125 (28.7) | 93 (21.4) | 99 (22.7) | 59 (13.6) | |
| Weight (k) | 65.53 ± 13.43 | 64.85 ± 11.87 | 66.16 ± 13.35 | 64.70 ± 13.76 | 66.56 ± 14.83 | 0.474 |
| Height (cm) | 160.21 ± 10.20 | 158.49 ± 8.91b | 160.33 ± 10.95 | 160.34 ± 11.77 | 162.03 ± 8.70 | 0.016 |
| BMI (k/m2) | 25.68 ± 7.23 | 25.79 ± 4.09 | 26.06 ± 9.05 | 25.57 ± 9.60 | 25.29 ± 4.87 | 0.818 |
| SBP (mmHg) | 131.83 ± 22.95 | 134.17 ± 23.14 | 132.15 ± 22.77 | 129.88 ± 21.64 | 130.86 ± 24.24 | 0.330 |
| DBP (mmHg) | 80.82 ± 14.08 | 79.18 ± 14.00b | 81.40 ± 13.37 | 79.91 ± 14.32 | 83.25 ± 14.33d | 0.045 |
| sGlucose (mg/dL) | 130.19 ± 81.51 | 145.85 ± 100.25a | 143.93 ± 93.75 | 120.99 ± 65.61 | 108.46 ± 46.69 | 0.001 |
| Urea (mg/dL) | 102.91 ± 39.11 | 84.44 ± 33.81a | 92.99 ± 30.39b | 106.10 ± 35.33 | 130.99 ± 39.97c | 0.001 |
| Creatinine (mg/dL) | 7.74 ± 3.42 | 6.14 ± 2.82a | 6.47 ± 2.74 | 7.72 ± 2.76 | 10.87 ± 3.25 | 0.001 |
| Cholesterol (mg/dL) | 179.45 ± 42.62 | 175.21 ± 44.87 | 179.11 ± 41.61 | 181.54 ± 41.57 | 182.53 ± 41.93 | 0.386 |
| HDL Cholesterol (mg/dL) | 38.53 ± 20.27 | 39.81 ± 20.07 | 37.35 ± 15.37 | 40.35 ± 26.97 | 35.32 ± 13.29 | 0.254 |
| Triglycerides (mg/dL) | 177.53 ± 101.97 | 197.32 ± 142.05e | 176.05 ± 87.99 | 165.00 ± 78.59 | 168.94 ± 72.72 | 0.014 |
| sAlbumin (g/dL) | 3.23 ± 0.56 | 3.02 ± 0.54a | 3.20 ± 0.56b | 3.23 ± 0.52c | 3.50 ± 0.53d | 0.001 |
| CRP (mg/L) | 5.23 ± 9.06 | 6.11 ± 10.00 | 5.48 ± 8.31 | 4.39 ± 8.6 | 4.9 ± 8.2 | <0.315 |
| Phosphorus (mg/dL) | 4.43 ± 1.32 | 3.03 ± 0.52a | 3.93 ± 0.17b | 4.66 ± 0.26e | 6.31 ± 0.92c | 0.001 |
| tCa (mg/dL) | 8.71 ± 1.33 | 8.19 ± 1.62a | 8.86 ± 1.14 | 8.84 ± 0.96 | 9.05 ± 1.29d | 0.001 |
| cCaAlb (mg/dL) | 9.33 ± 1.24 | 8.97 ± 1.53a | 9.50 ± 1.08 | 9.45 ± 0.91 | 9.45 ± 1.25d | 0.001 |
| PTH (pg/mL) | 34.63 ± 66.98 | 27.06 ± 51.70 | 20.27 ± 34.04 | 40.31 ± 71.74 | 53.98 ± 96.84 | 0.004 |
| RR F (mL/min) | 2.85 ± 2.0 | 3.28 ± 2.42 | 3.33 ± 2.35b | 2.76 ± 2–12c | 1.77 ± 1.33d | 0.001 |
| Ultrafiltration (mL/24 h) | 837.82 ± 445.73 | 798.24 ± 449.43 | 861.11 ± 430.94 | 913.22 ± 483.49 | 763.90 ± 385.45 | 0.061 |
| Follow-up (months) | 17.72 ± 7.79 | 16.63 ± 8.07 | 17.43 ± 6.88 | 18.48 ± 8.16 | 18.46 ± 7.73 | 0.078 |
| Deaths, all-cause (n) | 93 | 36 | 14 | 21 | 22 | 0.066 |
| Death rate (events/100 pts/year) | 9.7 | 3.9 | 1.5 | 2.1 | 2.2 | |
| Deaths, cardiovascular (n) | 54 | 17 | 7 | 15 | 16 | 0.383 |
| Death rate, cardiovascular (events/100 pts/year) | 5.6 | 1.9 | 0.7 | 1.5 | 1.6 |
Data are expressed as mean ± SD, or in frequency (%). SBP, systolic blood pressure; DBP, diastolic blood pressure; CRP, C–reactive protein; cCa, albumin-corrected calcium; PTH, parathyroid hormone; RRF, residual renal function = the mean creatinine and urea clearance. One-way ANOVA test with the significance of p < 0.005, p < 0.05, test post-hoc: aQ1 vs. Q3, Q4. bQ2 vs. Q3, Q4. cQ4 vs. Q3. dQ1 vs. Q4. eQ1 vs. Q3.