Metabolic assessment in patients with urinary lithiasis

INTRODUCTION: Metabolic investigation in patients with urinary lithiasis is very important for preventing recurrence of disease. The objective of this work was to diagnose and to determine the prevalence of metabolic disorders, to assess the quality of the water consumed and volume of diuresis as potential risk factors for this pathology. PATIENTS AND METHODS: We studied 182 patients older than 12 years. We included patients with history and/or imaging tests confirming at least 2 stones, with creatinine clearance > 60 mL/min and negative urine culture. The protocol consisted in the collection of 2, 24-hour urine samples, for dosing Ca, P, uric acid, Na, K, Mg, Ox and Ci, glycemia and serum levels of Ca, P, Uric acid, Na, K, Cl, Mg, U and Cr, urinary pH and urinary acidification test. RESULTS: 158 patients fulfilled the inclusion criteria. Among these, 151 (95.5 percent) presented metabolic changes, with 94 (62.2 percent) presenting isolated metabolic change and 57 (37.8 percent) had mixed changes. The main disorders detected were hypercalciuria (74 percent), hypocitraturia (37.3 percent), hyperoxaluria (24.1 percent), hypomagnesuria (21 percent), hyperuricosuria (20.2 percent), primary hyperparathyroidism (1.8 percent) secondary hyperparathyroidism (0.6 percent) and renal tubular acidosis (0.6). CONCLUSION: Metabolic change was diagnosed in 95.5 percent of patients. These results warrant the metabolic study and follow-up in patients with recurrent lithiasis in order to decrease the recurrence rate through specific treatments, modification in alimentary and behavioral habits.

Litiasis urinaria en pediatría / Paediatric urolithiasis

Existe escasa información sobre litiasis urinaria pediátrica en Chile. Objetivo: Conocer las características epidemiológicas, clínicas y de la boratorio de esta patología. Pacientes y Métodos: Se diseñó un estudio prospectivo que incluyó ingresos hospitalarios y consultas externas por litiasis en el Hospital de la Pontificia Universidad Católica. Se elaboró una ficha que consignó identificación, antecedentes familiares, caracterización clínica, laboratorio y tratamiento. Resultados: Entre enero de 1997 y diciembre del 2000, 52 niños ingresaron al protocolo, (26 mujeres), con edad promedio de 8 años (rango 2 meses a 16 años 5 meses). El 50 por ciento tenía antecedentes familiares de urolitiasis. Los síntomas y signos al momento de la consulta fueron: dolor abdominal en 23 (44 por ciento), hematuria en 21 (40 por ciento), fiebre en 13 (25 por ciento), eliminación de cálculo en 11 (21 por ciento), vómito en 11 (21 por ciento), e infección urinaria en 9 (17 por ciento). En 9 (17 por ciento) fue un hallazgo. Se hospitalizaron 26 niños, correspondiendo a 1,6 niños con litiasis por cada 1000 ingresos en dicho período. En el estudio, 12 (23 por ciento) pacientes, tenían malformaciones urinarias, siendo las más frecuentes: doble sistema pielocalicilar (4), estenosis pielouretral (2) y reflujo vesicouretral (2). Catorce (37 pot ciento) pacientes presentaban alteraciones metabólicas al estudio, de los cuales 11 (79 por ciento) resultaron ser hipercalciuria idiopática. En cuatro (8 por ciento) la litiasis ocurrió durante períodos de inmovilización prolongada. Trece pacientes (25 por ciento) tuvieron estudio bioquímico del cálculo: todos incluían oxalato de calcio puro o en su forma mixta. Diez (20 por ciento) pacientes requirieron tratamiento urológico. Conclusiones: Los síntomas de consulta más frecuente fueron dolor abdominal, hematuria y fiebre. La mitad tenían antecedentes familiares de litiasis urinaria. El 23 por ciento tenían malformaciones urinarias y el 37 por ciento presentaban alteraciones metabólicas. El estudio bioquímico del cálculo indicó en todos la presencia de oxalato de calcio puro o mixto.

Estudio metabólico de la enfermedad urolitiasica de calcio: realidad en nuestra población / Metabolic study of the calcium urolithiasis disease: reality in our population

Se llevó a cabo un protocolo de investigación tanto Radiográfia como de laboratorio en 75 pacientes portadores de enfermedad urolitiásica de calcio con actividad metabólica moderada o mayor, o con evidencia radiográfica de 2 o más litiasis al momento del diagnóstico. La hiperoxaluria y la hipocitraturia son las alteraciones más frecuentemente pesquizadas, solas o en combinación con otras alteraciones. Se logró pesquizar alguna anomalía en 80 por ciento de los pacientes investigados

Oxalate binding to rat kidney mitochondria: induction by oxidized glutathione.

Increased oxalate binding with negative correlation with reduced glutathione content was observed during lipid peroxidation in rat kidney mitochondria. In presence of oxidized glutathione (GSSG), peroxidized mitochondria lost 48% of protein-SH with concomitant 3-fold increase in oxalate binding activity while control mitochondria lost only 20% protein-SH with only 0.8 fold increase in oxalate binding activity. The GSSG-induced oxalate binding was apparently due to two-fold increased affinity of oxalate to the protein. Reduced glutathione (GSH) inhibited oxalate binding competitively with Ki, 1.4 x 10(-3) M. Urolithic rat kidney mitochondria showed 30-50% increase in oxalate binding activity along with depletion of GSH and protein-SH. These studies suggest that oxalate binding is regulated by thiol status of mitochondria.

Importancia del déficit de inhibidores de la cristalización en la etiopatogenia de la urolitiasis / Importance of crystallization inhibitors deficit in the etiopathogenic of urolithiasis

Background: five percent of consultations at the emergency room of Catholic University Hospital are due to nephrolithiasis. The causes of this high frequency remain unknown. Aim: to know the main metabolic and anatomic factors involved in the genesis of nephrolithiasis. Patients and methods: 41 patients (31 male) were studied presenting with a renal colic were studied as soon as the acute episode subsided and without diet modifications. Fasting blood calcium and creatinine and 24 h urine calcium, uric acid, citrate, magnesium and pH were measured and an intravenous pyelogram was performed. 21 subjects without a history of nephrolithiasis were used as controls. Results: Patients with nephrolithiasis did not differ from controls in urinary calcium (159 ñ 67 and 172 ñ 67 mg/24 h respectively), uricosuria (417 ñ 171 and 431 ñ 121 mg/24 h respectively) or urinary magnesium (55 ñ 19 and 62 ñ 21 mg/24 h respectively, whereas urinary citrate was lower (219 ñ 172 vs 319 ñ 179 mg/24 h in controls p <0.05). All patients had a normal renal functions, urinary acidification and intravenous pyelogram. Seven percent of patients with nephrolithiasis had hypercalciuria, 2.4 percent had hyperuricosuria, 68.3 percent had a low urinary citrate and 44.4 percent had low urinary magnesium. Conclusions: in this sample, there is a strong association of nephrolithiasis with low levels of crystallization inhibitors in special with urinary citrate, a crystallization inhibitor

Restoration of antioxidants in liver by methionine feeding in experimental rat urolithiasis.

The effect of methionine or citrate on antioxidant defense system has been studied in urolithic rat. Liver weight and its protein concentration did not change in the rats fed with calculi producing diet (CPD) when compared to normal diet fed rats. Feeding rats along with citrate (c-CPD) or methionine (m-CPD) improved their body weight gain. Liver microsomes and mitochondria fractions of CPD and c-CPD fed groups showed increased susceptibility for lipid peroxidation in presence of ascorbate and t-butyl hydroperoxide when compared to either control or m-CPD fed groups. Increased superoxide dismutase and xanthine oxidase activities, decreased catalase, glutathione peroxidase and glucose-6-phosphate dehydrogenase activities, decreased concentrations of reduced glutathione, total thiols, ascorbic acid and vitamin-E and increased formation of hydroxyl radical, hydroperoxides and diene conjugates were observed in the liver of both CPD fed group as well as c-CPD fed group. Except SOD and xanthine oxidase, all other parameters were normalized in m-CPD fed group. This suggested that feeding methionine reduced the susceptibility for lipid peroxidation by restoration of the level of free radical scavengers.

Dosagem de citrato urinario em individuos adultos normais e em pacientes com calculose urinaria recidivante / Urinary citrate dosage in normal adult persons and in patients with recurrent urinary calculi

A presenca de acido citrico na urina e sua habilidade em ligar ions calcio formando complexos soluveis esta bem reconhecida. Tem sido sugerido que, por este mecanismo, o citrato possa desempenhar papel importante na prevencao de calculos urinarios. No presente trabalho os autores discutem a utilidade da dosagem de citrato urinario em pacientes portadores de nefrolitiase, no sentido de identificar sua deficiencia. Apresentam ainda, revisao das atuais recomendacoes para a suplementacao de citrato para os pacientes hipocitraturicos, com o objetivo de prevenir a formacao de novos calculos. Foram analisadas urinas de 48 individuos adultos normais e de 46 pacientes calculosos. O citrato foi dosado em urina de 24 horas, utilizando-se um metodo enzimatico especifico. Os resultados sao expressos em concentracao (mg) e em relacao a excrecao de creatinina (mg/g). Dos pacientes analisados, 18 (39,1 por cento) se mostraram hipocitraturicos quando cotejados com os resultados obtidos no grupo controle de individuos do mesmo sexo. Em seis pacientes (13 por cento) a hipocitraturia foi a unica anormalidade metabolica detectada.

Abordagem médica dos cálculos urinários / Medical approach of urinary calculi

The authors are trying to emphasize the reviewed and newer medical aspects about the modern way of boarding the urinary lithiasis. Particulary in this study, it is put in relief the metabolic aspects of the urinary calculi.

Metabolic factors for urolithiasis in acromegalic patients

Acromegaly is associated with metabolic disturbances of calcium and phosphorus which can also contribute to renal lithogenesis. In order to characterize these disturbances more precisely, an oral calcium load test was performed on 14 active acromegalic patients. Serum and urinary levels of calcium, phosphorus, uric acid, creatinine and urinary cyclic AMP were determined. Of the 14 patients, 5 (36%) presented hypercalciuria, 5 (36%) presented intestinal calciumhyperabsorption and 6 (43%) had uric acid hyperexcretion. Two patients (14%) presented nephrolithiasis. The medical records of 32 additional acromegalic patients with or without active disease were reviewed for a history of previous stones, which was observed in three cases (9.5%). The present data suggest that nephrolithiasis occurs more frequently among acromegalic patients because of the underlying metabolic disturbances of calcium presented by this population

Estudo metabolico dos pacientes com nefrolitiase em Uberlandia, MG / Metabolic study in patients with nephrolithiasis in Uberlandia, MG

Os autores estudaram 170 adultos e 29 criancas com nefrolitiase e encontraram respectivamente em 62,8 por cento e 72,8 por cento dos pacientes alteracoes metabolicas relacionadas a etiopatogenese dos calculos renais. Concluem que estas avaliacoes devem ser feitas rotineiramente e que os fatores responsaveis pela litiase renal encontrados em nosso meio assemelham-se aqueles detectados em outras regioes

Lipids changes in rat tissues in experimental urolithiasis.

Total lipids, free and ester cholesterol, triglyceride and phospholipids were determined in plasma, liver, kidney and intestine in control and calculi producing diet (CPD) fed rats. Cholesterol, phospholipids and triglycerides were increased in plasma while they were decreased in all the three tissues of CPD fed rats, compared to that of control. Distribution studies of phospholipids in the tissues of treated rats showed marked decrease in the concentration of the major lipids, i.e., PC, PE, PI and SPH. However, significant increase in absolute concentration as well as percent distribution of phosphatidic acid in kidney of treated rats was observed.

Litíase experimental em ratos: sistematizaçäo do modelo com corpo estranho / Experimental urolithiasis in rats: foreign body model systematization

O modelo de litíase com corpo estranho pode quantificar a formaçäo e o ritmo de crescimento do cálculo urinário. Para tanto, utilizaram-se ratos Wistar, machos, adultos, submetidos a estudo por 42 dias. O protocolo constou de cirurgia com introduçäo do corpo estranho e coletas de urinas de 24h com dosagens bioquímicas (creatinina, ácido úrico, cálcio e fósforo) nos dias 1, 21 e 42. Na última coleta, obteve-se plasma, urocultura, estudo histológico dos rins e bexiga, além da análise petrográfica dos cálculos. Näo houve alteraçäo na evoluçäo do peso corporal, exceto para o grupo em que se utilizou como corpo estranho a traquéia. Aumentou a diurese em todos os animais. Este modelo provoca a formaçäo de cálculos em cerca de 90% dos ratos, com ritmo de crescimento semelhante em todos os grupos, exceto para a traquéia, em que foi mais elevado. A difratometria de raio X mostrou que, independentemente do núcleo e da contaminaçäo bacteriana, o cálculo formado foi de fosfato-amônio-magnesiano (estruvita), indicando que o pH urinário deste animal prevalece sobre o fenômeno de epitaxia. Sugerimos que este modelo pode ser útil para estudar variáveis da fisiopatologia e tratamento da urolitíase

Estudio metabólico en 100 pacientes con urolitiasis con especial énfasis en la diferenciación de las hipercalciurias / Metabolic study in 100 with urolithiasis patients specially in differentiating hypercalciuria

Se reportan los hallazgos de 100 pacientes con urolitiasis estudiados con un protocolo simple factible de realizarse en laboratorios y que permite con un mínimo margen de error diagnóstico las causas más frecuentes de formación de cálculos. La edad promedio de los pacientes fue 39 años predominante el sexo masculino 2 a 1. El 40 por ciento presentaron antecedentes familiares de litiasis. Las determinaciones en sangre mostraron: calcio 9,1 mas menos 0,1 mg por ciento; fósforo 3,6 mas menos 0,1 mg por ciento; ácido úrico en varones 5,0 mas menos 0,2 y en mujeres 3,8 mas menos 0,2 mg por ciento. La diferencia fue estadísticamente significativa (p menor que 0,01). La creatinina sérica fue de 0,9 mas menos 0,03 mg por ciento. En 41 pacientes se detectó hipercalciuria idiopática como único defecto. En 20 pacientes la hipercalciuria se encontró asociada a hiperuricosuria. En 26 pacientes no se detectó defecto alguno y en 8 sólo se encontró hiperuricosuria aislada. La prueba de tolerancia aguda se realizó 50 pacientes con hipercalciuria, encontrándose que el 50 por ciento eran renales, el 28 por ciento absurtivos y el 22 por ciento con ambos defectos; el 49 por ciento de cálculos analizados fueron oxalato de calcio puro, el 20 por ciento oxalato de calcio y fosfato de calcio y el 14 por ciento oxalato de calcio y uratos. El 9 por ciento de cálculos se encontró solamente ácido úrico y en 8 por ciento estruvita. Se detectaron 5 pacientes con hipercalciuria secundaria; dos con hiperparatiroidismo, uno con acidosis tubular distal y 2 con riñones esponjosos. De 78 urocultivos realizados fueron positivos 25 (32 por ciento). La escherichia coli fue el patógeno más comunmente aislado en 80 casos. En la radiografía los cálculos se encontraron con mayor frecuencia en los riñones y/o uréteres en el 80 por ciento de los casos; y solamente en 2,5 por ciento la litiasis se encontró en vejiga. El 12 por ciento se detectó estrechez úteropiélica uni o bilateral, duplicación total o parcial del sistema colector en 5 por ciento, deformaciones calicilares en 10 por ciento, cifra muy superior a la encontrada en la población sana. En 3 por ciento riñón esponjoso medular y en 5 por ciento litiasis coraliforme. Se concluye que en nuestro medio es factible diagnosticar y tipificar el defecto metabólico causal en formadores de cálculo sin tener que recurrir a estudios sofisticados y costosos