Table 1.
Characteristics of stone-forming patients with associated hypocitraturia and healthy controls
| Characteristics | Stone-formers with hypocitraturia | Healthy controls | p |
|---|---|---|---|
| N | 123 (♂ 66, ♀ 57) | 424 (♂ 212, ♀ 212) | |
| Age (years) | 15.12 (7.16–17.91) | 14.58 (5.50–17.16) | 0.02 |
| Weight (kg) | 54.0 (23.9–83.0) | 53.5 (21.5–81.6) | 0.08 |
| Body mass index (kg/m2) | 19.83 (14.79–26.81) | 19.74 (14.64–27.23) | 0.58 |
| Urine volume (ml/kg/24 h) | 20.92 (9.02–55.25) | 20.16 (8.38–42.85) | 0.32 |
| Urine pH | 6.31 (5.63–7.08) | 6.33 (5.68–7.10) | 0.30 |
| Oxaluria (mmol/1.73 m2/24 h) | 0.43 (0.14–0.89) | 0.33 (0.08–0.44) | <0.001 |
| Citraturia | |||
| (mg/g creatinine/24 h) | 283.38 (45.66–385.13) | 587.04 (422.73–1186.38) | <0.001 |
| (mmol/l) | 1.20 (0,14–3,27) | 2.91 (1.37–8.37) | |
| Calciuria | |||
| (mg/kg/24 h) | 1.99 (0.58–4.51) | 1.90 (0.56–3.50) | 0.23 |
| (mmol/l) | 2.39 (0.53–6.64) | 2.13 (0.58–6.30) | |
| Ca2+ (mmol/l) | 0.40 (0.12–1.20) | 0.32 (0.14–0.69) | <0.001 |
| Ca2+/Catotal (mmol/mmol) | 0.20 (0.06–0.52) | 0.14 (0.05–0.43) | 0.15 |
| Ca2+/citrate (mmol/mmol) | 0.39 (0.07–3,57) | 0.10 (0.03–0.32) | <0.001 |
| Catotal/citrate (mmol/mmol) | 1.91 (0.52–14.39) | 0.71 (0.22–1.70) | <0.001 |
| Ox2- (mmol) | 0.48 (0.16–2.70) | 0.70 (0.32–2.70) | <0.001 |
| BRI (l–1) | 1.02 (0.04–5.61) | 0.46 (0.05–1.53) | <0.001 |
Values are presented as the median, with the range (5–95 %) given in parenthesis
BRI, Bonn Risk Index; Ca2+, urinary ionized calcium concentration; Catotal, calciuria (total calcium); Ox2-, amount of titrated oxalate needed for the onset of spontaneous crystallization in 200 ml of the 24-h urine sample