Table 2.
General characteristics of subjects in RS-I and RS-II according to quintiles of fasting phosphate levels
| Men | Women | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Phosphate in quintiles | Phosphate in quintiles | |||||||||||
| 1 | 2 | 3 | 4 | 5 | p* | 1 | 2 | 3 | 4 | 5 | p* | |
| (I) RS-I | ||||||||||||
| N (mg/dL) | 315 (2.56) | 315 (2.92) | 316 (3.15) | 315 (3.37) | 316 (3.77) | 431 (3.02) | 431 (3.40) | 431 (3.62) | 431 (3.83) | 430 (4.21) | ||
| Age (year) | 71.6 | 72.4 | 71.4 | 71.9 | 71.8 | 0.968 | 73.0 | 72.3 | 72.8 | 72.4 | 71.9 | 0.049 |
| BMI (kg/m2) | 26.7 | 26.4 | 26.2 | 26.2 | 26.0 | 0.005 | 29.0 | 27.5 | 27.2 | 26.7 | 25.9 | < 0.001 |
| Ever smoke (%) | 90% | 87% | 92% | 92% | 95% | 0.008 | 47% | 47% | 50% | 53% | 51% | 0.091 |
| Calcium (mg/dL) | 9.59 | 9.66 | 9.62 | 9.66 | 9.72 | < 0.001 | 9.77 | 9.80 | 9.76 | 9.79 | 9.84 | 0.026 |
| 25 (OH) D (nmol/L) | 62.8 | 62.6 | 62.7 | 59.1 | 59.9 | 0.034 | 45.4 | 48.9 | 46.8 | 48.6 | 50.1 | 0.035 |
| CRP (mg/L) | 4.57 | 3.62 | 4.15 | 3.79 | 5.12 | 0.340 | 4.92 | 4.06 | 3.79 | 3.60 | 3.23 | < 0.001 |
| Glucose (mmol/L) | 6.09 | 5.96 | 6.04 | 6.04 | 6.15 | 0.529 | 6.18 | 5.79 | 5.87 | 5.77 | 5.77 | < 0.001 |
| Prevalent DM (%) | 14% | 12% | 13% | 14% | 15% | 0.424 | 17% | 10% | 12% | 9% | 9% | 0.001 |
| Creatinine (μmol/L) | 91.4 | 92.7 | 90.2 | 91.3 | 96.2 | 0.167 | 72.4 | 72.7 | 71.5 | 71.9 | 71.9 | 0.652 |
| eGFR (mL/min) | 73.9 | 72.0 | 75.0 | 74.2 | 73.7 | 0.432 | 73.1 | 73.1 | 74.2 | 74.1 | 74.4 | 0.356 |
| Mg (mmol/L) | 0.84 | 0.84 | 0.85 | 0.85 | 0.86 | 0.002 | 0.84 | 0.85 | 0.85 | 0.85 | 0.86 | < 0.001 |
| Chol to HDL ratio | 4.75 | 4.93 | 4.75 | 4.56 | 4.47 | < 0.001 | 4.41 | 4.42 | 4.33 | 4.17 | 4.18 | < 0.001 |
| Prevalent CVD (%) | 7% | 9% | 8% | 7% | 10% | 0.221 | 4% | 2% | 2% | 4% | 3% | 0.712 |
| (II) RS-II | ||||||||||||
| N (mg/dL) | 226 (2.49) | 227 (2.86) | 226 (3.07) | 227 (3.31) | 227 (3.71) | 272 (2.92) | 272 (3.32) | 272 (3.54) | 272 (3.77) | 273 (4.14) | ||
| Age (year) | 63.8 | 64.4 | 65.0 | 64.7 | 63.8 | 0.884 | 65.4 | 66.2 | 64.4 | 65.2 | 63.1 | < 0.001 |
| BMI (kg/m2) | 27.1 | 26.7 | 26.8 | 26.7 | 27.3 | 0.482 | 29.1 | 27.9 | 27.4 | 26.8 | 26.0 | < 0.001 |
| Ever smoke (%) | 86% | 81% | 80% | 87% | 89% | 0.142 | 57% | 62% | 57% | 58% | 63% | 0.642 |
| Calcium (mg/dL) | 9.50 | 9.59 | 9.53 | 9.58 | 9.64 | < 0.001 | 9.64 | 9.66 | 9.70 | 9.68 | 9.75 | 0.001 |
| 25 (OH) D (nmol/L) | 66.6 | 68.0 | 65.1 | 65.7 | 62.8 | 0.103 | 57.1 | 57.2 | 58.3 | 58.9 | 63.2 | 0.071 |
| CRP (mg/L) | 2.41 | 2.22 | 2.42 | 1.88 | 2.93 | 0.479 | 2.82 | 2.54 | 1.92 | 2.34 | 2.01 | 0.037 |
| Glucose (mmol/L) | 6.08 | 5.98 | 6.24 | 6.06 | 6.50 | 0.013 | 6.10 | 5.84 | 5.79 | 5.78 | 5.84 | 0.049 |
| Prevalent DM (%) | 11% | 9% | 15% | 11% | 21% | 0.002 | 12% | 9% | 10% | 9% | 7% | 0.164 |
| Creatinine (μmol/L) | 87.6 | 87.4 | 88.7 | 86.8 | 88.2 | 0.915 | 69.5 | 70.0 | 68.4 | 69.2 | 68.9 | 0.923 |
| eGFR (mL/min) | 80.9 | 81.3 | 79.2 | 81.3 | 81.7 | 0.475 | 79.7 | 79.1 | 81.6 | 80.5 | 81.8 | 0.691 |
| Mg (mmol/L) | 0.83 | 0.83 | 0.83 | 0.83 | 0.84 | 0.290 | 0.82 | 0.83 | 0.83 | 0.83 | 0.84 | < 0.001 |
| Chol to HDL ratio | 4.93 | 4.71 | 4.62 | 4.66 | 4.93 | 0.906 | 4.35 | 4.20 | 4.31 | 4.15 | 4.12 | 0.042 |
| Prevalent CVD (%) | 8% | 11% | 13% | 9% | 13% | 0.351 | 3% | 3% | 3% | 3% | 1% | 0.608 |
Statistically significant p-values (<0.05) are highlighted in bold font
*P values corresponds to age-adjusted significance of trend across quintiles
BMI body mass index, 25(OH)D 25-hydroxyvitamin D levels, CRP C-reactive protein, prevalent DM prevalent diabetes mellitus, eGFR estimated glomerular filtration rate, Mg magnesium, Chol to HDL ratio total cholesterol to HDL cholesterol ratio, prevalent CVD prevalent cardiovascular disease
Conversion to SI Units: to convert 25-hydroxyvitamin D levels to ng/mL multiply by 0.4; to convert glucose to mg/dL multiply by 18.02; to convert creatinine to mg/dL multiply by 0.011; to convert magnesium to mg/dL multiply by 2.43