RESUMO
The aim of this study was to determine the prevalence of idiopathic hypercalciuria [IH] in school children in Ahvaz, a city with different ethnic groups located in the Southwest of Iran. In a descriptive cross sectional study from October to December 2006, we determined urinary calcium [UCa] and urinary creatinine [UCr] in the morning urine samples of 500 primary school children. The levels of 24-hour UCa and UCr were measured in these children. Level of 24-hour UCa exceeding 4 mg/kg/day was considered as hypercalciuria, and UCa/UCr ratio exceeding 0.21 [mg/kg] was considered abnormal. Children who had hypercalciuria with a normal concentration of serum Ca were categorized as idiopathic hypercalciuric. Of 500 children aged 6-12 years, 231 were males and 269 females. In the first screening, 64 [12.8%] children [45 males, 19 females] had an abnormal UCa/UCr ratio. But in the end only 15 had the criteria of IH, i.e. the prevalence of IH was 3% [1.8-4.8%, confidence interval of 95%]. The prevalence in females and males was 0.74% and 5.6%, respectively [P= 0.003]. Of these children 10 had hematuria [including 2 cases of gross hematuria], 8 children gave a history of recurrent abdominal pain, 5 children suffered from dysuria and 3 persons had a history of personal or familial urolithiasis The study showed that 3% of primary school children in Ahvaz had IH predisposing to short-term and long-term complications of the disease. IH was significantly more common in boys than in girls