Idiopathic hypercalciuria and bone injury in children

Abstract

Introduction: Idiopathic hypercalciuria is a benign pathology associated with hemathuria and urolithiasis, being one of the most common pediatric disturbances in calcium/phosphorus metabolism. Observations made in the last years point out its relation with bone demineralization in infants and adults. 

Objective: Determine the influence of idiopathic hypercalciuria in bone mineral content in chilean pediatric patients. 

Method: Transversal study evaluating 11 patients with idiopathic hypercalciuria. Measurements of 24-hours urine and isolated urine calcium, plasmatic levels of calcium/phosphorus, plasmatic electrolytes, plasmatic parathormone and lumbar/femur bone densitometry (DEXA) were performed. In order to define the relationship between calciuria and other variables, a simple correlative analysis for continuos variables was used. P < 0,05 was statistically significant. 

Results: 11 children were studied, 6 males of 8,2 ± 2,7 years. The 24-hours urine calcium average was 9,1 ± 1,37 mg/kg/day, parathormone plasmatic level = 40 ± 15 pg/ml and Z score lumbar spine DEXA = 2,1 ± 0,29. The analysis showed a negative correlation between 24-hours calciuria and lumbar spine bone mineral density (p < 0,05, r = -0,65) and between hypercalciuria with parathormone levels (p < 0,05, r = -0,58). 

Conclusion: Idiopathic hypercalciuria in children represents a risk factor for bone injury that must be considered every time a patient is evaluated.