Determination and comparison of mean random urine calcium between children with vesicoureteral reflux and those with improved vesicoureteral reflux.

Urinary reflux can cause irreversible complications such as reflux nephropathy and ESRD. Diagnostic imaging such as voiding cystourethrogram (VCUG) is invasive and causes irradiation. Several studies have shown that markers such as urine IL-8 or serum Procalcitonin might be useful for the diagnosis of vesico-ureteral reflux (VUR) as a substitution for invasive methods. The aim of this study was to determine and compare the mean urine Ca/Cr ratio and hypercalciuria between two groups of children aged 2-10 years affected by VUR. This is a cross-sectional study in which 32 children having the following entrance criteria were included: children 2-10 years old not affected by urinary tract infection during the last three months and their reflux or recovery having been diagnosed by VCUG or direct radionuclide cystography, divided into two groups of affected by reflux and recovered from reflux. Then, the point urine specimens were collected with permission of their parents in a single laboratory and urine Ca and Cr for each specimen were measured. The Ca/Cr ratio was calculated for each child to evaluate Ca excretion from the urine, which was possible without collecting the 24-hours urine. The Ca/Cr ratio mean and the hypercalciuria were compared between the groups. To analyze our data, the Mann-Whiney test and the Chi-square test were used, using SPSS V.15. Thirty-two children, including 18 children recovered from reflux and 14 affected by reflux, were entered in our study. The Ca/Cr ratio mean was 0.692 ± 1.874 for the affected and 0.118 ± 0.187 for the recovered group. The Ca/Cr ratio mean for the affected male and female groups was 0.012 ± 0.008 and 0.805 ± 1.0913, respectively. This amount was 0.0175 ± 0.01767 for the recovered male and 0.131 ± 0.195 for the recovered female group. There was no significant statistical difference between the groups with respect to the Ca/Cr ratio mean, but there was a significant statistical difference between the two groups of females (P-value = 0.026). Also, there was no significant statistical difference between the two groups of males relative frequency of hypercalciuria was significantly higher in the group affected by reflux than in the recovered from reflux group (P-value = 0.017). Urine Ca excretion is elevated in children with reflux, and may be more useful as an appropriate marker for the diagnosis of VUR than other invasive methods.