Table 2.
Biochemical profile of patients with normal eGFR, with and without urine concentration defect
| NRF (n = 67) | iUCD (n = 8) | P-value | |
|---|---|---|---|
| Age, median (IQR), years | 5 (3–13) | 5 (3–7) | 0.45 |
| Serum Na, mean ± SD, mEq/L | 140.0 ± 2.5 | 139.9 ± 1.9 | 0.88 |
| Serum K, mean ± SD, mEq/L | 4.4 ± 0.5 | 4.1 ± 0.6 | 0.21 |
| Serum Cl, mean ± SD, mEq/L | 104.3 ± 3.0 | 103.1 ± 1.4 | 0.08 |
| Serum Ca, median (IQR), mg/dL | 9.6 (9.1–10.0) | 9.4 (9.4–9.7) | 0.78 |
| Serum P, mean ± SD, mg/dL | 4.9 ± 0.8 | 5.1 ± 1.0 | 0.55 |
| Serum Mg, mean ± SD, mg/dL | 2.2 ± 0.2 | 2.1 ± 0.3 | 0.48 |
| Serum UA, mean ± SD, mg/dL | 4.1 ± 1.2 | 4.4 ± 1.2 | 0.44 |
| FeNa, median (IQR), % | 0.5 (0.3–0.7) | 0.8 (0.5–2.1) | 0.13 |
| FeUA, mean ± SD, % | 9.4 ± 4.1 | 8.8 ± 4.5 | 0.73 |
| Ca/Cr, mean ± SD, mg/mg | 0.14 ± 0.12 | 0.09 ± 0.09 | 0.36 |
| Mg/Cr, mean ± SD, mg/mg | 0.15 ± 0.08 | 0.22 ± 0.08 | 0.04* |
| TRP, median (IQR), % | 91.0 (88.0–93.0) | 90.0 (88.0–92.0) | 0.68 |
| TmP/eGFR, mean ± SD, mg/dL | 4.3 ± 1.1 | 4.6 ± 1.1 | 0.51 |
| CrCl, mean ± SD, mL/min/1.73 m2 | 122.1 ± 30.6 | 107.7 ± 20.5 | 0.24 |
Italics are used for not-normally distributed variables. *P-value ≤0.05. Ca/Cr, urinary calcium/creatinine ratio; CrCl, creatinine clearance; FeNa, fractional excretion of sodium; FeUA, fractional excretion of uric acid; iUCD, isolated urine concentration defect; Mg/Cr, urinary magnesium/creatinine ratio; NRF, normal renal function; TmP/eGFR, maximum reabsorption of phosphates per unit volume of glomerular filtration rate; TRP, tubular reabsorption of phosphates.