Hypercalciuria in children

Background: The term nephrotic syndrome is applicable to any condition with heavy proteinuria (> 40 mg/m2/hour or protein/creatinine ratio > 2), hypoproteinemia (plasma albumin < 2.5 gm/dl), edema and hyperlipidemia.Objectives: The aim of this study is assessing the value of urinary calcium/creatinine ratio in a random voided urine sample in assessing the degree of calcium excretion in nephrotic children as an index for hypercalciuria as well as the abdominal ultrasonography in assessing the degree of nephrocalcinosis.Patients and methods: The study was conducted on 70 patients; 35males and 35 females and 30 healthy controls; 15 males and 15 females who were subjected to complete blood count, serum albumin and cholesterol level, serum calcium, phosphorus and alkaline phosphatase, assessment of calcium and creatinine in a spot urine sample obtained randomly and abdominal ultrasonography. Subjects were subdivided into 3 main groups: Group A: 30 patients steroid resistant; 12 males and 18 females. Group B: 40 patients steroid sensitive 24 males and 16 females. Group C: 30 healthy controls; 15 males and 15 females.Results: In our study, we exclude patients who receive immunosuppressive drugs. Also, we exclude patients with other systemic diseases as musculoskeletal disease, liver disease and chornic renal failure.Conclusion: From our study, we can conclude that hypercalciuria in nephrotic children is mainly due to long duration of furosemide and steroid therapy and it is transient process which may disappear with discontinuation of diuretic and steroid therapy and calcium/creatinine ratio returned to normal value again. The long term prognosis of furosemide-associated nephrocalcinosis in nephrotic children is still unclear although discontinuation of the diuretic often results in radiological resolution of calcification. One should be aware of nephrocalcinosis as a side effect of prolonged diuretic therapy and periodically monitor urine for hypercalciuria in children on such therapy and serial ultrasonography is recommended to follow up and to detect nephrocalcinosis.