Urinary Tract Infection in Children Associated with Idiopathic Hypercalciuria

OBJECTIVE: The aim of this study was to evaluate the association of symptomatic non-calculous idiopathic hypercalciuria (IH) with urinary tract infection (UTI) in children. MATERIAL AND METHODS: This was a retrospective case review of children who had urinary calcium excretion greater than 2 mg/kg/day or random urine calcium-creatinine ratio (UCa/UCr) greater than 0.18 mg/mg. RESULTS: One hundred and twenty-four consecutive children with clinical complaints and elevated urine calcium excretion were reviewed. Fifty children (40%) had UTI of which 39 (78%) had recurrent UTI. There was no difference in age between children with UTI and those without UTI. Twenty-four-hour urine calcium and random UCa/UCr were also not different. Only 4 children (8%) had renal stones whereas hematuria, abdominal pain and urine incontinence were frequent associated findings. Six of the children with recurrent UTI (15%) had an anatomical urinary tract abnormality. Therapy in all children consisted of increased fluid intake and reduction in diet sodium and oxalate; however, 14 of the 39 children with recurrent UTI (36%) required therapy with a thiazide diuretic. Recurrent UTI was abolished in 24 children, one child had a single recurrence and 4 children had no response to treatment. CONCLUSIONS: We propose that non-calculous IH may be an important contributing factor to recurrent UTI in children.