[24-hour urinary oxalate excretion in healthy children and in children with calcium urolithiasis].Pol Merkur Lekarski. 2008; 24 Suppl 4:76-9.PM
Hyperoxaluria is one of the crucial risk factors for calcium stone formation.
Estimation of own reference range for 24-hour urinary oxalate (OX) excretion and evaluation of incidence of primary and secondary hyperoxaluria in children with calcium urolithiasis.
MATERIALS AND METHODS
The study comprised 128 healthy children aged 4-17,9 years and 137 children aged 3.7-18 years with calcium urolithiasis.
In healthy children, the mean 24-hour urinary OX excretion was 0.305 +/- 0.109 mmol/ 1.73 m2/ 24 h. An upper normal limit for urinary OX excretion was assumed at 0.474 mmol/1, 73 m2 / 24 h (95th percentile). Patients with stones had significantly higher urinary OX excretion (0.381 +/- 0.173 mmol / 1.73 m/ 24 h) in comparison to healthy children. Secondary hyperoxaluria was revealed in 37 (27%) children, whereas primary hyperoxaluria type I was diagnosed in only 1 (0.7%).
Secondary hyperoxaluria occurred in a significant percentage of children with calcium urolithiasis, predominantly in males, whereas primary hyperoxaluria is casuistic.