ABSTRACT
OBJETIVO: Estudar as relações entre a excreção urinária de cálcio, sódio e potássio e a associação sódio/potássio urinários em crianças com hipercalciúria idiopática em dieta habitual, antes e depois da administração de citrato de potássio na dose de 1mEq/kg/dia. MÉTODOS: Foram estudadas prospectivamente 26 crianças: 19 (73 por cento) meninos e sete (27 por cento) meninas com idade entre dois e 13 anos, portadores de hipercalciúria idiopática recém-diagnosticada por dosagem de cálcio em urina de 24 horas >4mg/kg/dia. O citrato de potássio foi administrado na dose de 1mEq/kg/dia. Foram realizadas dosagens séricas e em urina de 24 horas de cálcio (Ca), potássio(K), sódio (Na) e creatinina (Cr), antes e 15 dias depois da administração diária do citrato de potássio. Para comparar os resultados de cálcio/creatinina (Ca/Cr), potássio/creatinina (K/Cr) e sódio/potássio (Na/K) urinários nos dois momentos, aplicou-se o teste não-paramétrico de Wilcoxon. Para a análise das associações entre Ca/Cr e K/Cr e entre Ca/Cr e Na/Cr foi utilizado o coeficiente de correlação de Pearson. Considerou-se significante p<0,05. RESULTADOS: Após o uso de citrato de potássio, ocorreu significativa redução da calciúria e da relação Na/K urinários, bem como elevação na caliúria. Não houve modificação da excreção urinária de sódio. CONCLUSÕES: Em dieta habitual, o citrato de potássio eleva a caliúria e diminui a calciúria em criança hipercalciúricas, sendo um eficaz recurso terapêutico.
OBJECTIVE: Evaluate the relationships among the urinary excretion of calcium (UCa), potassium (UK), sodium (UNa) and the ratio between UNa/UK in children with idiopathic hypercalciuria and a regular diet, before and after 1mEq/kg/day potassium citrate administration. METHODS: 26 children with idiopathic hypercalciuria (UCa>4mg/kg/day) were prospectively studied: 19 (73 percent) boys and seven (27 percent) girls between two and 13 years old. Potassium citrate was administered: 1mEq/Kg/day twice a day for 15 days. Blood and 24-hour urinary determinations of calcium, potassium, sodium and creatinine were done in two periods: before and after the 15-day administration of potassium citrate. The following urinary ratios were analyzed before and after potassium citrate use by Wilcoxon test: calcium/creatinine (UCa/UCr), potassium/creatinine (UK/UCr) and sodium/creatinine (UNa/UCr). The association between UCa/UCr, UK/UCr and Ca/Cr, UCa/UCr and UNa/UK were analyzed by Pearson's correlation. Significance was considered for p<0.05. RESULTS: After potassium citrate use, there were significant reductions of UCa and UNa/UK ratios, as well as a significant increase of UK. The UNa did not change. CONCLUSIONS: Children with idiopathic hypercalciuria and regular diet treated with daily potassium citrate increased their potassium urinary excretion and decreased their calciuria.
Subject(s)
Humans , Male , Female , Child, Preschool , Child , Adolescent , Potassium Citrate/administration & dosage , Calcium , Hypercalciuria/diet therapy , Hypercalciuria/drug therapy , Potassium , SodiumABSTRACT
BACKGROUND: Distal renal tubular acidosis (RTA) is a common cause of intractable calcium nephrolithiasis. In adults, the use of potassium citrate (PC) in distal RTA effectively decreases metabolic acidosis and the risk of calcium oxalate stone but it cannot decrease the risk of calcium phosphate stone. However, there is no report for the optimal dose of PC and the risk of calcium stone in distal RTA in children. OBJECTIVE: To evaluate the optimal dose of PC that minimizes the risk of calcium nephrolithiasis in children with distal RTA. METHOD: Prospective study PATIENTS: Children who have distal RTA and were followed-up for 4 months. Patients were studied in a control phase, 1 month of PC 2 mEq/kg/day, 2 months of PC 3 mEq/kg/day and 1 month of PC 4 mEq/kg/day. The urine specimens of 41 normal children were measured for the reference value of the parameters determining the risk of calcium stone. RESULTS: Eight children (mean age of 10 +/- 3.7 years, female : male = 6: 2) with distal RTA were studied during the control phase and after receiving PC 2 mEq/kg/day for I month. Treatment with PC 2 mEq/kg/day was not able to normalize serum bicarbonate and caused no significant change in the urine citrate/creatinine ratio, and activity production of calcium phosphate stone but it caused a significant decrease in the urine calcium/citrate ratio. Although PC 3 mEq/kg/day for I month normalized plasma bicarbonate, only this dose given for 2 months caused a significant increase in the urine citrate/creatinine ratio and urine calcium/ citrate ratio to values that were not different from normal children, while the activity production of calcium phosphate stone did not decrease to normal level. The effect of PC 4 mEq/kg/day was similar to that of 3 mEq/kg/day. CONCLUSION: Potassium citrate 3 mEq/kg/day for 2 months effectively normalized serum bicarbonate and decreased the risk of calcium oxalate stone but this treatment was theoretically unable to reduce the risk of calcium phosphate stone in children with distal RTA.