The association of hypercalciuria and hyperuricosuria with vesicoureteral reflux in children

Evaluation of renal function and scars in children with primary vesicoureteral reflux

OBJECTIVE

To evaluate growth, glomerular and tubular function, renal damage, scars in children affected by primary VUR.

METHOD

We retrospectively evaluated the clinical records of our Unit from January 2006 to September 2020. For each patient we evaluated growth, laboratoristic and scintigraphic glomerular and tubular function, renal damage and collective system urodynamics at baseline and at the last visit.

RESULT

We enrolled 41 patients affected by primary VUR and treated with continuous antibiotic prophylaxis. Glomerular function and urodynamics did not change over time. EFNa directly correlated with weight (r 0.44 p 0.004) and TRP inversely correlated with severity of reflux (r -0.32, p 0.04). Female sex was associated to nephrolithiasis (OR 17.0, p 0.02) and proteinuria (at T0 OR 5.8 p 0.03 at T1 OR 5.8, p 0.03). Daily proteinuria increased with age (r 0.66, p <0.0001 at T0 and r 0.44 p 0.004 at T1) while protein-to-creatinine ratio decreased. Renal scars at T0 inversely correlated with glomerular and tubular function at T1 but they did not correlate with severity or laterality of reflux.

CONCLUSION

Even if renal function remains stable through years, it is critical to identify the subjects with significant congenital renal damage.

An Important Risk Factor Affecting Hypercalciuria in Children: Vesicoureteral Reflux

INTRODUCTION

 A large number of genes and environmental factors, like dietary habits, play a role in the development of hypercalciuria in children. In this study, we aimed to determine the effects of the presence and grade of vesicoureteral reflux (VUR) on hypercalciuria status in children.

MATERIALS AND METHODS

 Data for 165 patients who admitted to the Pediatric Urology Department were retrospectively analyzed. The patients were composed of following four different groups: (1) urinary stone patients, (2) VUR patients under follow-up, (3) corrected VUR patients, and (4) control. The demographic features, clinical data, and laboratory tests for the groups were compared.

RESULTS

 The mean age of the patients was 100.6 ± 54.69 months and the female/male ratio was 79:86. The mean urinary calcium/creatinine (UCa/Cr) excretion and the frequency of high UCa/Cr ratios in the corrected VUR group were similar to those in the control group (p = 0.375 and 0.965, respectively). In contrast, the mean UCa/Cr excretion and frequency of high UCa/Cr ratios in the urinary stone and follow-up VUR groups were significantly higher than those in the corrected VUR group (p < 0.001, < 0.001, 0.003, and 0.029, respectively). The mean UCa/Cr excretion and frequency of high UCa/Cr ratios in the follow-up VUR group were similar to those in the urinary stone group (p = 0.323 and 0.425, respectively). In the follow-up VUR group, although reflux laterality had no effect on the UCa/Cr ratios (p = 0.180 and 0.108, respectively), the mean and frequency of high UCa/Cr ratios were higher in high-grade reflux cases (p < 0.001 and p = 0.042, respectively).

CONCLUSION

 Both the mean UCa/Cr ratio and the rate of hypercalciuria in the corrected reflux group were significantly lower than the corresponding values in the follow-up VUR and urinary stone groups. Further, the follow-up VUR patients had similar urinary calcium excretion levels as the stone patients. VUR treatment is associated with a decrease in urinary calcium excretion to the normal population level. A positive correlation between reflux degree and calcium excretion was observed.