Hipouricemia con hipercalciuria. Estudio longitudinal y revisión del tema / Hypouricemia with hypercalciuria: Longitudinal study and review of the topic

Antecedentes y objetivo: La asociación de hipouricemia e hipercalciuria es poco frecuente. En 1974 se describió un nuevo síndrome nominado Hipouricemia con hipercalciuria y reducción de la densidad ósea. Posteriormente, se publicaron algunos casos con esa asociación en los que la excreción fraccional de urato era superior a 20/100ml FGR. Hemos analizado una serie de niños que fueron diagnosticados de hipouricemia e hipercalciuria y que fueron controlados evolutivamente. El objetivo del trabajo es intentar conocer si nuestros pacientes podrían estar afectos del síndrome antes mencionado o ser portadores de una variante de hipercalciuria idiopática. Pacientes y métodos: Estudio retrospectivo longitudinal en el que se estudiaron las historias clínicas de 8 pacientes (5V y 3M) diagnosticados de hipouricemia e hipercalciuria en la infancia. Se anotaron la clínica al diagnóstico, los hallazgos ecográficos y densitométricos, y determinadas variables bioquímicas, con especial hincapié en el manejo tubular renal del urato. Los resultados se compararon con los de 36 niños afectos de hipercalciuria idiopática sin hipouricemia (14V y 22M). Resultados: En el grupo con hipouricemia los niveles iniciales de uricemia fueron 1,9 (0,3) mg/dl (rango: 1,5-2) y los del cociente calcio/creatinina en primera orina del día, 0,27 (0,05) mg/mg (rango: 0,23-0,31). En todos los casos la excreción fraccional de urato fue inferior a 20ml/100ml FGR. Los valores de z-DMO fueron menores de −1 en 4/8 casos. En el último control, solo en 3 casos persistía el cociente calcio/creatinina elevado, y en todos la uricemia era superior a 2mg/dl. El valor de z-DMO había mejorado en 5 casos y empeorado en otros 3... (AU)

Background and objective: The association of hypouricemia and hypercalciuria is rare. In 1974 a new syndrome named Hypouricemia with hypercalciuria and decreased bone density was described. Afterwards, some cases with such association were published in which the fractional excretion of urate was higher than 20/100ml FGR. We have analyzed a series of children who were diagnosed with hypouricemia and hypercalciuria and who were monitored. The aim of this study was to determine whether our patients could be affected by the aforementioned syndrome or be carriers of a variant of idiopathic hypercalciuria. Patients and methods: Retrospective longitudinal study in which the medical records of eight patients (5V and 3M) diagnosed with hypouricemia and hypercalciuria in childhood. Clinical features at diagnosis, ultrasound and densitometric findings and selected biochemical variables were noted, with special emphasis on renal tubular handling of urate. Results were compared with 36 children with idiopathic hypercalciuria without hypouricemia (14V and 22M). Results: In the hypouricemia group baseline urate levels were 1.9 (0.3)mg/dl (range: 1.5-2) and first day urine calcium/creatinine ratio 0.27 (0.05)mg/mg (range: 0.23-0.31). In all cases fractional urate excretion was less than 20/100ml FGR. The z-DMO values were less than −1 in 4/8 cases. At the last follow-up only three cases still had an elevated calcium/creatinine ratio and in all of them the urates levels was greater than 2mg/dl. The z-DMO value had improved in five cases and worsened in three others. In relation to the group without hypouricemia, no differences were observed between the various parameters studied including the z-DMO value, with the exception of fractional excretion and tubular urate reabsorption although plasmatic uric acid levels were still significantly lower... (AU)

Hypouricemia with hypercalciuria: Longitudinal study and review of the topic.

BACKGROUND AND OBJECTIVE: The association of hypouricemia and hypercalciuria is rare. In 1974 a new syndrome named Hypouricemia with hypercalciuria and decreased bone density was described. Afterwards, some cases with such association were published in which the fractional excretion of urate was higher than 20ml/100ml FGR. We have analyzed a series of children who were diagnosed with hypouricemia and hypercalciuria and who were monitored. The aim of this study was to determine whether our patients could be affected by the aforementioned syndrome or be carriers of a variant of idiopathic hypercalciuria. PATIENTS AND METHODS: Retrospective longitudinal study in which the medical records of eight patients (5V, 3M) diagnosed with hypouricemia and hypercalciuria in childhood. Clinical features at diagnosis, ultrasound and densitometric findings and selected biochemical variables were noted, with special emphasis on renal tubular handling of urate. Results were compared with 36 children with idiopathic hypercalciuria without hypouricemia (14V, 22M). RESULTS: In the hypouricemia group baseline urate levels were 1.9 (0.3) mg/dl (range: 1.5-2) and first day urine calcium/creatinine ratio 0.27 (0.05) mg/mg (range: 0.23-0.31). In all cases fractional urate excretion was less than 20ml/100ml FGR. The z-DMO values were less than -1 in 4/8 cases. At the last follow-up only three cases still had an elevated calcium/creatinine ratio and in all of them the urates levels was greater than 2mg/dl. The z-DMO value had improved in five cases and worsened in three others. In relation to the group without hypouricemia, no differences were observed between the various parameters studied including the z-DMO value, with the exception of fractional excretion and tubular urate reabsorption although plasmatic uric acid levels were still significantly lower. CONCLUSION: Our patients with hypercalciuria and hypouricemia would be affected by a variant of idiopathic hypercalciuria in which, due to an unknown cause, the proximal tubular reabsorption of urate is modestly reduced and improves over time. Hypouricemia with hypercalciuria and decreased bone density may not be a specific entity.

Composición de las urolitiasis y trastornos metabólicos renales en adultos cubanos

Introducción: La litiasis urinaria es una enfermedad común, cuya prevalencia se incrementa a escala nacional y planetaria. Objetivos: Conocer la composición de las urolitiasis en pacientes adultos cubanos y su relación con los trastornos metabólicos renales. Métodos: Estudio descriptivo, transversal. Universo constituido por los pacientes cubanos de 19 años y más de edad, que se realizaron estudio de composición de urolitiasis en el Instituto de Nefrología "Dr. Abelardo Buch", de La Habana, Cuba, en el período comprendido de 2011-2020. De ellos 443 se habían realizado estudio metabólico renal. Los datos fueron recogidos de los informes de resultados, de composición de litiasis y de estudio metabólico. Se utilizó análisis de distribución de frecuencias, y para identificar las relaciones, el test independencia. Resultados: En cuanto a la composición química, predominaron las litiasis de oxalato de calcio. Los trastornos metabólicos más frecuentes fueron excreción de sodio aumentada (46,7 %) y volumen urinario bajo (29,3 %). La frecuencia de pacientes con litiasis cálcicas, fue superior en los que tuvieron excreción de sodio aumentada (78,3 %), y en los que presentaron hipercalciuria (83,3 %), en contraste con las frecuencias de este tipo de litiasis, en los que no presentaron dichos trastornos (p=0,03 en ambos casos). Conclusiones: Las urolitiasis más comunes en adultos cubanos son las cálcicas, especialmente las de oxalato de calcio. Los trastornos metabólicos más frecuentes son: excreción urinaria aumentada de sodio, volumen urinario bajo y pH urinario ácido. La presencia de litiasis cálcicas se relaciona con excreción urinaria aumentada de sodio y con hipercalciuria.

Introduction: Urinary lithiasis is a common disease, whose prevalence is increasing on a national and planetary scale. Objectives: To know the composition of urolithiasis in Cuban adult patients and its relationship with renal metabolic disorders. Methods: Descriptive, cross-sectional study. Universe constituted by Cuban patients aged 19 and over, who underwent a composition study of urolithiasis at the "Dr. Abelardo Buch" Institute of Nephrology, in Havana, Cuba, in the period 2011-2020. In 443 of them, a renal metabolic study had also been carried out. The data were collected from the results reports of stone composition and metabolic study. Frequency distribution analysis was used, and the independence test was used to identify relationships. Results: Regarding chemical composition, calcium oxalate stones predominated. The most frequent metabolic disorders were increased sodium excretion (46.7%) and low urine volume (29.3%). The frequency of patients with calcium stones was higher in those with increased sodium excretion (78.3%) and in those with hypercalciuria (83.3%), in contrast with the frequencies of this type of lithiasis, in those who did not present these disorders (p=0.03 in both cases). Conclusions: The most common urolithiasis in Cuban adults are calcium ones, especially those of calcium oxalate. The most common metabolic disorders are: increased urinary sodium excretion, low urinary volume and acid urinary pH. The presence of calcium lithiasis is related to increased urinary sodium excretion and hypercalciuria.

Principais distúrbios metabólicos em adolescentes portadores de nefrolitíase / Main metabolic disorders in adolescents with nephrolithiasis

Introdução: Os cálculos renais compreendem uma das mais comuns patologias do trato urinário e têm apresentado maior incidência em adolescentes nos últimos anos. Objetivos: Identificar os distúrbios metabólicos causadores de cálculo renal mais prevalentes em adolescentes. Métodos: Foram analisados os prontuários de 135 indivíduos portadores de nefrolitíase, com idade entre 12 e 18 anos, de ambos os sexos. Na análise laboratorial, incluiu-se: duas amostras de urina de 24 horas, contendo cálcio, citrato, oxalato e ácido úrico; uma amostra sanguínea, contendo creatinina, paratormônio, ácido úrico e cálcio; pH urinário após 12 horas de restrição hídrica e jejum; urocultura e cistinúria qualitativa. Resultados: 88 pacientes apresentaram hipercaIciúria (65,2%), 42 apresentaram hipocitratúria (31,1%) e 29 hiperuricosúria (21,5%). As demais alterações observadas foram: volume urinário reduzido (14,8%), infecções do trato urinário (9,6%), hiperoxalúria (5,2%), hiperparatireoidismo (1,5%) e acidose tubular renal (1,5%). Os distúrbios metabólicos mais frequentemente observados nos adolescentes portadores de cálculo renal foram hipercalciúria, hipocitratúria e hiperuricosúria

Introduction: Kidney stones are one of the most common pathologies of the urinary tract and have had a higher incidence in adolescents in recent years. Objectives: To identify the most prevalent metabolic disorders that cause kidney stones in adolescents. Methods: The medical records of 135 individuals with nephrolithiasis, aged between 12 and 18 years, of both sexes, were analyzed. The laboratory analysis included: two 24-hour urine samples containing calcium, citrate, oxalate and uric acid; a blood sample, containing creatinine, parathyroid hormone, uric acid, and calcium; urinary pH after 12 hours of fluid restriction and fasting; uroculture and qualitative cystinuria. Results: 88 patients had hyperuricosuria (65.2%), 42 had hypocitraturia (31.1%) and 29 had hyperuricosuria (21.5%). The other changes observed were: reduced urinary volume (14.8%), urinary tract infections (9.6%), hyperoxaluria (5.2%), hyperparathyroidism (1.5%) and renal tubular acidosis (1.5 %). Conclusions: The metabolic disorders most frequently observed in adolescents with kidney stones were hypercalciuria, hypocitraturia and hyperuricosuria.

Trastornos metabólicos urinarios en pacientes urolitiásicos con enfermedad renal poliquística y sin ella / Urinary metabolic disorders in urolithiasis patients with and without polycystic kidney disease

Introducción: La urolitiasis se ha incrementado en las últimas décadas. La enfermedad renal poliquística autosómica dominante (ERPAD), enfermedad renal hereditaria más frecuente, ocupa un lugar preponderante. Objetivos: Identificar la frecuencia de presentación de los trastornos metabólicos urinarios en pacientes litiásicos cubanos con ERPAD y sin ella Métodos: Estudio descriptivo, transversal. Fueron estudiados 579 pacientes adultos sin ERPAD, seleccionados por muestreo simple aleatorio y los 21 pacientes con ERPAD, del total de pacientes con litiasis urinaria que se realizó estudio metabólico renal en el Laboratorio de Fisiopatología Renal del Instituto de Nefrología, en el periodo 2010-2015. Los datos fueron tomados de la historia clínica y del informe de estudio metabólico renal. La información se procesó de forma automatizada (SPSS 22.0). Se utilizó el promedio, desviación estándar, análisis de distribución de frecuencias y el test de homogeneidad. Resultados: En los pacientes con ERPAD predominó el sexo femenino (57,1 por ciento), mientras que en los pacientes sin ERPAD, el masculino (63,4 por ciento). Los trastornos más frecuentes en la población no poliquística fueron hipercalciuria (45,3 por ciento) e hipofosfatemia (17,1 por ciento). En los poliquísticos, aclaramiento aumentado de ácido úrico (38,1 por ciento) e hipercalciuria (23,8 por ciento). Se encontraron diferencias estadísticamente significativas para aumento del aclaramiento de ácido úrico (p = 0,01) e hiperfosfatemia (p = 0,04). Conclusiones: Los principales trastornos metabólicos de los pacientes litiásicos, tanto poliquísticos como no poliquísticos, son el aclaramiento de ácido úrico aumentado, hipercalciuria, hiperuricosuria e hipofosfatemia, aunque el orden de presentación es diferente. El aclaramiento de ácido úrico aumentado y la hiperfosfatemia se presentan con mayor frecuencia en los pacientes litiásicos poliquísticos(AU)

Introduction: Urolithiasis has increased in recent decades. Autosomal dominant polycystic kidney disease (ADPKD), the most common of all hereditary kidney diseases, occupies a predominant position in terms of incidence. Objectives: Identify the frequency of occurrence of urinary metabolic disorders in Cuban urolithiasis patients with and without ADPKD. Methods: A descriptive cross-sectional study was conducted of 579 adult patients without ADPKD selected by simple random sampling, and 21 patients with ADPKD, from the total urolithiasis patients undergoing renal metabolic evaluation at the Renal Physiopathology Laboratory of the Institute of Nephrology in the period 2010-2015. Data were obtained from medical records and reports of renal metabolic studies. Information was processed with the statistical software SPSS version 22.0. Average and standard deviation were estimated and use was made of frequency distribution analysis and homogeneity testing. Results: A predominance was found of female sex among patients with ADPKD (57.1 percent) and male sex among patients without ADPKD (63.4 percent). The most common disorders were hypercalciuria (45.3 percent) and hypophosphatemia (17.1 percent) in the non-polycystic population, and increased uric acid clearance (38.1 percent) and hypercalciuria (23.8 percent) in polycystic patients. Statistically significant differences were found in uric acid clearance increase (p = 0.01) and hyperphosphatemia (p = 0.04). Conclusions: The main metabolic disorders of lithiasis patients, polycystic as well as non-polycystic, are increased uric acid clearance, hypercalciuria, hyperuricosuria and hypophosphatemia, with a varying order of presentation. Increased uric acid clearance and hyperphosphatemia are more common in polycystic lithiasis patients(AU)

Hipercalciuria idiopática: diagnóstico, clasificación y tratamiento / Idiopathic hypercalciuria: diagnosis, classification, and treatment

Resumen Introducción: La hipercalciuria idiopática se define como la excreción de calcio superior a 220 y 300 mg/día en mujeres y hombres respectivamente o bien mayor a 4 mg/kg peso bajo dieta habitual. Objetivo: Revisar el diagnóstico, clasificación y tratamiento del paciente hipercalciúrico con litiasis renal. Material y métodos: Se incluyeron 250 pacientes con litiasis renal e hipercalciuria idiopática y 80 individuos sanos como controles. Todos realizaron un estudio bioquímico para litiasis renal. Resultados: Si bien el estándar de oro es la medición de la calciuria en 24 h, en el presente estudio sugerimos considerar también la relación Ca/Kg >4 mg/Kg o bien el índice de calciuria >140 mg/gr de creatinina urinaria. Con respecto a los tipos de hipercalciuria, luego de someterlos a una dieta restringida, los dividimos en hipercalciuria dieta dependiente y dieta independiente del calcio. Con respecto al tratamiento sugerimos una diuresis entre 2 y 2 ½ litros/d. En casos de hipercalciuria dieta dependiente aconsejamos una dieta de 600-800 mg de calcio y moderada restricción de proteínas animales y sal. En caso de no respuesta y en aquellos con hipercalciuria dieta independiente, el agregado de tiazidas, clortalidona, indapamida y ocasionalmente bisfosfonatos pueden controlar la hipercalciuria con menor riesgo de recurrencia de litiasis renal y un mejor estado óseo. Conclusiones: Consideramos importante no solo tener en cuenta las distintas formas de diagnóstico de hipercalciuria sino también la clasificación de esta, que permita un tratamiento más específico.

Abstract Introduction: Idiopathic hypercalciuria is defined as urine calcium excretion greater than 220 mg/day in women and 300 mg/day in men, or greater than 4 mg/kg under regular dietary conditions. Objective: The aim of this study is to review the diagnosis, classification, and treatment of hypercalciuric patients with renal lithiasis. Methods: We enrolled 250 patients suffering from renal lithiasis and idiopathic hypercalciuria and 80 healthy subjects as control group. Lab tests were performed to diagnose renal lithiasis. Results: Although the 24-hour urine test is the gold standard to determine calciuria, in this study we propose considering the Ca/Kg >4 mg/Kg ratio or an index of >140 mg of Ca per gram urine creatinine. Regarding the different types of hypercalciuria, after following a strict diet, subjects were divided into two groups: diet-dependent and diet-independent hypercalciuria. Concerning the treatment, we suggest diuretic therapy to achieve a urine output of 2-2.5 liters per day. In the case of subjects with diet-dependent hypercalciuria, we advise an intake of 600-800 mg of calcium and a moderate reduction in animal protein and salt intake. In cases of non-response to treatment in subjects with diet-dependent hypercalciuria, thiazides, chlorthalidone, indapamide and, in some cases, bisphosphonates may help control hypercalciuria with a lower risk of lithiasis recurrence and healthier bones. Conclusions: We believe it is important to consider not only the methods to diagnose hypercalciuria but also its classification to provide a better treatment.

[Renal tubular distal acidosis: nephrocalcinosis as initial diagnosis.] / Nefrocalcinosis como manifestación de la acidosis tubular renal distal.

We present a case of a woman affected by Systemic Lupus Erythematosus (SLE) and distal renal tubular acidosis (DRTA) that during pregnancy presented an exacerbation of SLE together with a renal colic with spontaneous stone passage. Radiological exam revealed diffuse calcifications in both kidneys which suggests, in a context of DRTA, a nephrocalcinosis. With the stabilization of SLE and medical treatment directed to correct metabolic alterations we achieved radiological and clinical stability of lithiasic disease.

Se presenta el caso de una mujer afecta de Lupus Eritematoso Sistémico (LES) y acidosis tubular renal distal (ATRD) que en el embarazo presenta una exacerbacióndel LES junto con un cuadro de cólico nefrítico con expulsión espontánea de cálculos. Las pruebas radiológicas muestran calcificaciones difusas en ambos parénquimas renales lo cual sugiere, en el contexto de una ATRD, una nefrocalcinosis. Junto con la estabilización del LES y un tratamiento médico dirigido a corregir las alteraciones metabólicas se alcanza una estabilidad radiológica y clínica de la enfermedad litiásica.

Thiazide and thiazide-like diuretics in nephrolithiasis / Diuréticos tiazídicos e tiazídicos-like na nefrolitíase

Abstract Thiazide and thiazide-like diuretics are widely used for the management of hypercalciuria among stone-forming patients. Although the effects of different thiazides should be relatively similar in terms of prevention of stone recurrence, their potency and side effects may differ. However, there is scarce data concerning the metabolic and bone effects of these agents among recurrent nephrolithiasis patients with hypercalciuria. The aim of this update article was to compare our experience in the use of thiazide and thiazide- like diuretics with that of the current literature, concerning their anticalciuric properties and consequent reduction of recurrent stone formation. Their impact on bone mass and potential side effects were also discussed.

Resumo Diuréticos tiazídicos e tiazídicos-like são amplamente usados para o tratamento da hipercalciúria em pacientes com formação de cálculos. Embora os efeitos dos diferentes tiazídicos devam ser relativamente semelhantes em termos de prevenção da recorrência do cálculo, sua potência e efeitos colaterais podem ser diferentes. No entanto, há poucos dados sobre os efeitos metabólicos e ósseos desses agentes em pacientes com nefrolitíase recorrente com hipercalciúria. O objetivo deste artigo de atualização foi comparar nossa experiência quanto ao uso de tiazídicos e tiazídicos-like com a publicada na literatura atual, no que diz respeito às suas propriedades anticalciúricas e consequente redução da formação de cálculos recorrentes. Discutimos também seu impacto na massa óssea e potenciais efeitos colaterais.

Litiasis renal en niños / Renal lithiasis in children

Resumen Justificación y objetivo: La litiasis renal se debe a la precipitación de cristales por un desequilibrio en la orina entre sustancias promotoras y las sustancias inhibitorias. Es una patología con una prevalencia entre 2-10% en la población pediátrica, con una incidencia que ha aumentado en los últimos 25 años; razón por la cual este estudio pretende conocer la prevalencia, las manifestaciones clínicas y metabólicas de la litiasis renal en la población pediátrica del Hospital Nacional de Niños de Costa Rica. Métodos: Es un estudio retrospectivo, descriptivo y observacional, mediante la revisión de expedientes de pacientes menores a 18 años con el diagnóstico de litiasis renal, atendidos en el Hospital Nacional de Niños, en el periodo comprendido entre enero del año 2000 al 2018. Resultados: Se incluyeron un total de 106 pacientes. El 57,5% hombres, la edad promedio al diagnóstico de 6,6 ± 3,8 años; la frecuencia de casos se ha incrementado en 5,5 veces en los últimos 5 años. Factores de riesgo detectados: anormalidades del tracto urinario 22,6% y antecedentes familiares de litiasis 17,9%. El análisis metabólico mostró un gasto urinario bajo en el 74,3%, hiperfosfaturia en un 43,2%, hipomagnesuria 39,2% e hipercalciuria 37,8%. Etiologías determinadas: metabólica 54,7%, malformaciones de las vías urinarias 16% e idiopática en un 30,9%. La litotricia intracorpórea se aplicó en un 61,2%. La recidiva se observó en el 28,5% de los casos, se encontró relación entre la incidencia de recidiva con el tamaño del lito (p = 0,001) y el tratamiento quirúrgico. (p = 0,010). Conclusiones: Existe un aumento en la frecuencia de casos de litiasis pediátrica con una etiología multifactorial en el Hospital Nacional de Niños de Costa Rica.

Abstract Background and aim: Renal lithiasis is due to the precipitation of crystals due to an imbalance in the urine between promoter substances and inhibitory substances. It is a pathology with a prevalence between 2-10% in the pediatric population, with an incidence that is increasing in the last 25 years, because of that, this study pretend to know the prevalence, the clinical and metabolic, manifestation of the renal lithiasis in the pediatric population. Methods: It is a retrospective, descriptive and observational study, by reviewing records of patients under 18 years of age with a diagnosis of renal lithiasis, treated at the Hospital Nacional de Niños, in the period of 2000 to 2018. Results: A total of 106 patients were included, 57,5% men, the average age at diagnosis of 6,6+- 3,8 years, the frequency of cases has increased 5,5 times in the last 5 years. Risk factors detected: urinary trac abnormalities 22,6% and family history of nephrolithiasis 17,9%. The metabolic analysis showed a low urinary flow rate in 74,3%, hyperphosphaturia in 43,2%, hypomagnesuria 39,2% and hypercalciuria 37,8%. Etiologies determined: metabolic 54,7%, malformations of the urinary trac 16% and idiopathic in 30,9%. Intracorporeal lithotripsy was applied in 61,2%. Recurrence was observe in 28,5 % of cases, a relationship was found between the incidence of recurrence with the size of litho (p= 0.001) and surgical treatment (p= 0.01). Conclusions: There is a significant increase in the incidence of pediatric lithiasis cases with a multifactorial etiology.

[Metabolic diagnosis.] / Diagnóstico metabólico.

Kidney stones is a prevalent condition with a rising incidence in the last few decades. Diseasere lapse is an especially important issue, that requires further investigations in order to prevent new episodes. Adequate work up must be suited to patients´ characteristics such as age and the presence of risk factors forrecurrence. An initial approach should focus on a thorough clinical history, with special attention to dietary habits, analysis of the stone composition when available, and basic blood and urine exams to guide further investigations. In this article, we aim to explain proper metabolic evaluation in kidney stone formers, explaining its indications, how to perform it and how to interpret it, in order to stablish an adequate treatment. Special attention will be given to: hypercalciuria, yperoxaluria, hyperuricosuria, hypocitraturia, hypomagnesuria, hyperparathyroidism and the most frequent disturbances in urine analysis.

La patología litiásica es una afección frecuente en nuestra sociedad que está aumentando su prevalencia en las últimas décadas. Especialmente preocupante es su alta probabilidad de recidiva tras un primer episodio. Este hecho, obliga a profundizar en la búsqueda de la causa que origina la litiasis, para intentar evitar en la medida de lo posible los nuevos eventos litiásicos en el futuro. La profundidad del estudio dependerá de varios factores como la edad del paciente y de las características del mismo que le conviertan en más vulnerable a la recidiva litiásica. La etiopatogenia de la litiasis es un proceso multicausal, por lo que en nuestra evaluación debemos realizar una exhaustiva historia clínica del paciente con especial atención a los aspectos dietéticos, un correcto estudio cristalográfico del cálculo y radiológico del paciente y por último un estudio analítico de sangre y orina que nos oriente sobre qué tipo de litiasis y cuál es su posible origen. En este artículo, procederemos a desmenuzar el diagnóstico metabólico y a intentar aclarar su significado, aportando una orientación terapéutica para cada caso. Comentaremos en especial los estados de hipercalciuria, hiperoxaluria, hiperuricosuria, hipocitraturia e hipomagnesuriaen orina de 24h, el diagnóstico diferencial del hiperparatiroidismo y las alteraciones más frecuentes del sistemático de orina.

[Interpretation of the metabolic study in renal lithiasis and its treatment]. / Interpretación del estudio metabólico en la litiasis renal y su tratamiento.

Urolithiasis is a common disease, and is an important health problem that is associated with a great economic burden. The nature of stone disease varies according by dietary and lifestyle factors, including, among others, climate variations. The majority of patients will suffer a new lithiasic episode at some point in their life, unless preventive measures, such as changing lifestyles and dietary habits, are put in place to avoid it. The risk factors involved in lithogenesis should be evaluated in order to reduce recurrences. In the majority of these patients, metabolic changes are observed in the urine that predispose lithogenesis. The kind of evaluation depends on stone composition and on the clinical presentation. A diagnosis of systemic and renal diseases of lithogenic nature can be diagnosed with these studies, and they also enable the adoption of precise prophylactic measures that achieve control of recurrence in a great number of patients.

Association between dietary pattern and metabolic disorders in children and adolescents with urolithiasis / Associação entre o padrão alimentar e distúrbios metabólicos em crianças e adolescentes com urolitíase

Abstract Objective: To describe the dietary patterns and occurrence of metabolic disorders in children and adolescents with urolithiasis treatment at a referral hospital in southern Brazil in order to learn the features of urolithiasis in this population to better develop preventive actions. Methods: Descriptive study conducted between 2016 and 2017 in a tertiary care referral hospital. Fourty patients aged 2-19 years old with urolithiasis proven by imaging were included. Clinical and dietary data were obtained through interviews and medical records. For statistical analyses, the chi-squared test was performed. Results: 40 individuals were analyzed. Mean age at diagnosis was 7.2 ± 4 years. 25% were overweight or obese. 95% had metabolic disorders, hypocitraturia being the predominant type. Protein intake was adequate in all participants and carbohydrate intake, in 70% of them; 37.5% had lipid intake above recommended and 65% had low fiber intake. The mean daily sodium intake was 2.64 g (±1.74), with 55% of participants ingesting more than the recommended amount. A total of 52.5% had low potassium intake, with a mean of 4.79 g/day (±2.49). Calcium intake was adequate in 27.5%. No significant differences were identified in relation to mean daily consumption among participants with or without the various metabolic disorders. Conclusion: Pediatric urolithiasis is often accompanied by metabolic disorders; therefore, metabolic evaluation should be part of the diagnostic process and subsequent analysis of these patients' dietary patterns, helping to optimize treatment and prevent recurrences and complications.

Resumo Objetivo: Descrever o padrão alimentar e a ocorrência de distúrbios metabólicos em crianças e adolescentes portadoras de urolitíase acompanhadas em hospital de referências no sul do Brasil a fim de conhecer as particularidades da urolitíase nessa população para melhor desenvolver ações de prevenção. Métodos: Estudo observacional descritivo realizado entre 2016 e 2017 em centro de referência em atenção terciária. Foram selecionados 40 pacientes de dois a 19 anos com urolitíase comprovada por exame de imagem. Dados clínicos e alimentares foram obtidos através de prontuário e entrevista. Para análise estatística, utilizou-se o teste qui-quadrado. Resultados: Foram analisados 40 indivíduos, 55% masculinos. Idade média ao diagnóstico 7,2 ± 4 anos; 25% tinham sobrepeso ou obesidade; 95% tinham distúrbios metabólicos, predominou a hipocitratúria. O consumo proteico e de carboidratos foi adequado em 100% e 70% dos participantes, respectivamente, 37,5% apresentaram ingestão de lipídeos acima do recomendado e 65% apresentaram ingestão de fibras alimentares abaixo do recomendado. O consumo diário médio de sódio foi de 2,64 g (± 1,74), com 55% acima do recomendado; 52,5% apresentaram baixa ingestão de potássio com média de 4,79 g/dia (± 2,49). O consumo de cálcio foi adequado em 27,5%. Não foram identificadas diferenças significativas em relação ao consumo médio diário dos nutrientes entre os participantes com ou sem os diversos distúrbios metabólicos. Conclusões: A urolitíase pediátrica é frequentemente acompanhada de distúrbios metabólicos, o que confirma a necessidade de avaliação metabólica adequada ao diagnóstico e análise do padrão alimentar a fim de identificar erros alimentares, aprimorar o tratamento desses distúrbios e prevenir recorrências e complicações.

Aspectos clínicos, epidemiológicos y terapéuticos en niños y adolescentes con hipercalciuria idiopática / Clinical, epidemiological and therapeutic aspects in children and adolescents with idiopathic hypercalciuria

Introducción: La hipercalciuria idiopática es un trastorno metabólico frecuente y poco reconocido, cuyo curso clínico depende en gran medida de cambios en los hábitos dietéticos desde la infancia. Objetivo: Caracterizar a niños y adolescentes con hipercalciuria idiopática según variables clínicas, epidemiológicas y terapéuticas. Métodos: Se realizó una investigación observacional, longitudinal y prospectiva de 44 pacientes con hipercalciuria idiopática, atendidos en el Servicio de Miscelánea del Hospital Pediátrico Docente Sur Antonio María Béguez César de Santiago de Cuba, desde enero de 2014 hasta diciembre de 2015. Resultados: Las formas sintomáticas de la enfermedad resultaron ser las más frecuentes (68,2 %); asimismo, predominó el sexo masculino (72,7 %) y el promedio de edad fue de 7,2 ± 4 años. Existió asociación estadística entre las edades preescolar y escolar en cuanto al diagnóstico de hipercalciuria idiopática. La hematuria macroscópica recurrente fue el síntoma más usual en la mayoría de los casos (59,1 %); en tanto, 25,0 % de los pacientes presentó litiasis renal y el tratamiento no farmacológico a base de líquidos y dieta se relacionó con una evolución satisfactoria en 68,2 % de los afectados, a pesar de que el restante 31,8 % necesitó tratamiento medicamentoso. Conclusiones: Las características clínicas y epidemiológicas de los pacientes con hipercalciuria idiopática de esta casuística no difirieron de las registradas a nivel mundial, considerando que este trastorno metabólico es relativamente frecuente en los servicios de pediatría.

Introduction: The idiopathic hypercalciuria is a frequent and not very recognized metabolic disorder which clinical course depends in great extent on changes in the dietary habits from the childhood. Objective: To characterize children and adolescents with idiopathic hypercalciuria according to the clinical, epidemiological and therapeutic variables. Methods: An observational, longitudinal and prospective investigation was carried out in 44 patients with idiopathic hypercalciuria, assisted in the Miscellaneous Service of Antonio María Béguez Cesar Southern Teaching Children Hospital in Santiago de Cuba, from January, 2014 to December, 2015. Results: The symptomatic forms of the disease were the most frequent (68.2 %); also, the male sex prevailed (72.7 %) and the average age was 7.2 ± 4 years. Statistical association existed among the preschool and school ages as for the diagnosis of idiopathic hypercalciuria. The recurrent macroscopic hematuria was the most usual symptom in the majority of cases (59.1 %); as long as, the 25.0 % of patients presented renal lithiasis and the diet and liquids-based non pharmacological treatment was associated with a satisfactory evolution in 68.2 % of the affected patients, although the remaining 31.8 % needed drugs treatment. Conclusions: The clinical and epidemiological characteristics of patients with idiopathic hypercalciuria of this case material didn't differ from the ones registered worldwide, taking into account that this metabolic disorder is relatively frequent in pediatric services.

Association between dietary pattern and metabolic disorders in children and adolescents with urolithiasis.

OBJECTIVE: To describe the dietary patterns and occurrence of metabolic disorders in children and adolescents with urolithiasis treatment at a referral hospital in southern Brazil in order to learn the features of urolithiasis in this population to better develop preventive actions. METHODS: Descriptive study conducted between 2016 and 2017 in a tertiary care referral hospital. Fourty patients aged 2-19 years old with urolithiasis proven by imaging were included. Clinical and dietary data were obtained through interviews and medical records. For statistical analyses, the chi-squared test was performed. RESULTS: 40 individuals were analyzed. Mean age at diagnosis was 7.2±4 years. 25% were overweight or obese. 95% had metabolic disorders, hypocitraturia being the predominant type. Protein intake was adequate in all participants and carbohydrate intake, in 70% of them; 37.5% had lipid intake above recommended and 65% had low fiber intake. The mean daily sodium intake was 2.64g (±1.74), with 55% of participants ingesting more than the recommended amount. A total of 52.5% had low potassium intake, with a mean of 4.79g/day (±2.49). Calcium intake was adequate in 27.5%. No significant differences were identified in relation to mean daily consumption among participants with or without the various metabolic disorders. CONCLUSION: Pediatric urolithiasis is often accompanied by metabolic disorders; therefore, metabolic evaluation should be part of the diagnostic process and subsequent analysis of these patients' dietary patterns, helping to optimize treatment and prevent recurrences and complications.

Hipercalciuria idiopática ¿se pueden evitar los diuróticos? / Idiopathic hypercalciuria: can the diuretics be avoided?

La hipercalciuria idiopática se define como la excreció;n de calcio superior a 220 y 300 mg/día en mujeres y hombres respectivamente o bien mayor a 4 mg/kg peso. En mujeres con osteoporosis se observa en el 19% de los casos, mientras que en litiasis renal varía entre el 50 y 70%. Seleccionamos 206 pacientes hipercalció;ºricos, de nuestra base de datos, con y sin litiasis renal, a los que se les había indicado una dieta restringida. Luego los dividimos, de acuerdo a la respuesta, en dieta dependiente y dieta independiente. De estos solo consideramos 122 pacientes con diagnó;sticos de hipercalciuria dieta-dependiente (105 mujeres y 17 hombres), que fueron seguidos con control dietario (800 mg de calcio, alrededor de 1 g de proteínas animales y < 100 mEq de sodio diarios). No se consideró; la aparició;n de cálculos, o la recurrencia de los mismos, como tampoco el compromiso ó;seo. Luego de una media de 17 meses todos tenían controlada la calciuria e incluso hubo 16 (13%) que luego de 42 meses de seguimiento persistían normocalció;ºricos solo con dieta. Concluimos que es fundamental la divisió;n de las hipercalciurias, segó;ºn su respuesta a una dieta restringida, con el fin de evitar o postergar el uso de diuró;©ticos y sus efectos adversos, con una administració;n adecuada de la dieta.

Idiopathic hypercalciuria is defined as calcium excretion greater than 220 and 300 mg / day in women and men respectively, or greater than 4 mg / kg body weight. In women with osteoporosis it is observed in 19% of cases, while in kidney stones cases varies between 50 and 70%. We selected 206 hypercalciuric patients from our database, with and without renal lithiasis, to whom a restricted diet had been indicated. We divided them, according to the response, into a dependent diet and an independent diet. We considered 122 patients with diagnosis of hypercalciuria diet dependent (105 women and 17 men), which were followed with dietary control (800 mg of calcium, around 1 g of animal proteins and < 100 mEq sodium a day). The appearance of stones, or the recurrence of stones, was not considered, nor was bone involvement. After an average of 17 months, everyone had their calciuria controlled and there were even 16 (13%) who, after 42 months of follow-up, continued to be normocalciuric only on a diet. We conclude that the division of the hypercalciurias is fundamental, according to their response to a restricted diet, in order to avoid or postpone the use of diuretics and its adverse effects, with an adequate management of the diet.

Hipercalciuria hidiopática como factor predisponente de infección urinaria / Idiopathic hypercalciuria as predisposing factor of urinary infection

Introducción: La hipercalciuria idiopática es una alteración metabólica relativamente frecuente y existen escasas publicaciones de su relación con la infección del tracto urinario. Objetivos: Precisar si existe asociación entre la infección urinaria e hipercalciuria idiopática para determinar si esta alteración metabólica constituye un factor de riesgo de infección urinaria. Métodos: Estudio descriptivo longitudinal prospectivo en pacientes de edad pediátrica con diagnóstico de infección urinaria atendidos en el Hospital Pediátrico Universitario William Soler entre 1ro. enero de 2016 y 31 de diciembre de 2017. Dos semanas después de controlada la infección se recogió muestra de orina de la primera micción del día para determinación de índice calcio/creatinina y precisar la excreción de calcio en 24 horas. Si esta prueba arroja resultados positivos, entre dos y cuatro semanas posteriores, se repite la muestra y si ambas son positivas y el calcio en sangre es normal se diagnostica hipercalciuria idiopática. Resultados: Se incluyeron en el estudio 130 pacientes. En 43,8 por ciento se encontró hipercalciuria idiopática. En su primer episodio infeccioso se estudiaron 52,3 por ciento y los restantes con antecedentes de infección o recurrencia. En 86,2 por ciento la infección fue catalogada como pielonefrítica. La distribución por sexo de la hipercalciuria no mostró diferencia y el síntoma hematuria con dolor abdominal recurrente resultó sugestivo de infección asociada a hipercalciuria (p < 0,05). El germen infectante no contribuye a pensar en hipercalciuria. Conclusión: La hipercalciuria idiopática constituye un factor predisponente de infección del tracto urinario(AU)

Introduction: Idiopathic hypercalciuria is a relatively frequent metabolic alteration and there are scarce publications on its relation with the urinary tract´s infection. Objective: To specify if there is a relation between urinary infection and idiopathic hypercalciuria, in order to determine if this last one constitutes a risk factor of urinary infection. Methods: Prospective, descriptive and longitudinal study in pediatric age's patients with a diagnosis of urinary infection that were attended in William Soler University Pediatric Hospital from January 1st, 2016 to December 31st, 2017. After two weeks of the infection being controlled, a urine sample from the first micturition of the day was collected to determine calcium/creatinine index and to specify calcium excretion in 24 hours. If this test shows positive results, after two to four weeks the sample is repeated, and if both are positive and calcium level in blood is normal, so idiopathic hypercalciuria is diagnosed. Results: 130 patients were included in the study. In 43.8 percent idiopathic hypercalciuria was found. 52.3 percent were studied during the first infectious episode, and there is presented a history of infection or recurrence. In 86.2 percent of the patients, the infection was catalogued as pyelonephritis. Hypercalciuria´s gender distribution didn't show any differences, and the symptom called hematuria with recurrent abdominal pain was suggestive to an infection related to hypercalciuria (p < 0.05). The infectious germ does not induce to think in hypercalciuria. Conclusions: Idiopathic hypercalciuria constitutes a predisposing factor of urinary tract's infection(AU)

The idiopathic hypercalciuria reviewed. Metabolic abnormality or disease? / La hipercalciuria idiopática revisada. ¿Anomalía metabólica o enfermedad?

Idiopathic hypercalciuria (IH) is defined as that clinical situation in which an increase in urinary calcium excretion is observed, in the absence of hypercalcemia and other known causes of hypercalciuria. In recent years, its diagnosis in pediatric age has been more frequent because it has been known that it can debut with very different symptoms, in the absence of kidney stone formation. The discovery of genetic hypercalciuric stone-forming rats has allowed us to glimpse the pathophysiological mechanism of IH since they show many data in common with humans with IH as normal levels of blood calcium, intestinal calcium hyperabsorption, increased bone resorption and a defect in the renal tubular calcium reabsorption. In 1993, it was shown that in these animals there is an increase in the number of vitamin D receptors (VDR) in the intestine, which favors an increase in the functional capacity of calcitriol-VDR complexes that explains the increase in intestinal transport of calcium. The same happens at the bone level producing a greater resorption. In our opinion, IH is a 'metabolic anomaly' or, better, an inheritable constitutive metabolic characteristic. In this sense, what patients with IH would inherit is the availability of having a greater number of VDRs in their cells than those with normal urinary calcium excretion. IH cannot be considered a sensu stricto disease, so pharmacological treatment must be individualized.

Etiología de la hematuria monosintomática en pediatría / Etiology of monosymptomatic hematuria in Pediatrics

Introducción: La hematuria es el hallazgo clínico más frecuente entre las enfermedades genitourinarias, después de las infecciones del tracto urinario a cualquier edad. Objetivo: Identificar las características generales y etiología de la hematuria monosintomática en pacientes pediátricos. Métodos: Investigación descriptiva longitudinal y prospectiva con los pacientes atendidos con hematuria monosintomática en el Servicio de Nefrología del Hospital Pediátrico Docente William Soler entre el primero de enero de 2014 y 31 de diciembre de 2015. Resultados: Se reclutaron 45 pacientes. Predominó en escolares (40 por ciento) y adolescentes (40 por ciento), sexo masculino (55,5 por ciento). Se recogió el antecedente personal o familiar de hematuria en 44,5 por ciento y 55,5 por ciento, respectivamente. La urolitiasis familiar estuvo presente en 37,7 por ciento. El tipo de hematuria más frecuente fue la macroscópica (75,8 por ciento), no glomerular (71,2 por ciento), sin proteinuria (77,8 por ciento), y hematíes eumórficos (62,2 por ciento). La causa más frecuente fue la hipercalciuria idiopática (51,1 por ciento) y el 80 por ciento de todos los pacientes solo recibió tratamiento higieno-dietético. En 20 por ciento de los pacientes no se pudo precisar la causa etiológica. Conclusiones: La causa más frecuente de hematuria fue no glomerular (hipercalciuria idiopática) y en aquellos con hematuria cuya causa etiológica no se pudo precisar, es obligado mantener un seguimiento prolongado(AU)

Introduction: Hematuria is the most frequent clinical finding among genitourinary diseases afterwards urinary tract infection at any age. Objective: To identify general characteristics and etiology of monosymptomatic hematuria in in pediatrics patients. Methods: Descriptive, longitudinal and prospective research of the patients by monosymptomatic hematuria attended at the Nephrology service in William Soler Teaching Pediatric Hospital from January 1, 2014 to December 31, 2015. Results: 45 patients were recruited. Schoolchildren (40 percent) were predominant and adolescents (40 percent), and males (55.5 percent). It was collected personal or familial records of hematuria in 44.5 percent and 55.5 percent, respectively. Familial urolithiasis was present in 37.7 percent. The most common type of hematuria was the macroscopic (75.8 percent), non-glomerular (71.2 percent), without proteinuria (77.8 percent) and with eumorphic hematies (62.2 percent). The most frequent etiological cause was idiopathic hypercalciuria (51.1 percent), and 80 percent of all patients only received hygiene-dietetic treatment. In the 20 percent of the patients was not possible to determine the etiological cause. Conclusions: The most frequent cause of hematuria was non-glomerular (idiopathic hypercalciuria); and in those patients with hematuria of non-precised etiological cause, it is mandatory to keep long-term follow-up(AU)

A comparison of induced effects on urinary calcium by thiazides and different dietary salt doses: Implications in clinical practice. / Comparación de los efectos inducidos sobre la calciuria por tiazidas y diferentes dosis de sal en la dieta: implicaciones en la práctica clínica.

INTRODUCTION: Both dietary restriction of sodium chloride (NaCl) and treatment with thiazides have been used in hypercalciuric patients. OBJECTIVES: To calculate regular salt intake and investigate the correlation between natriuresis and urinary calcium with usual diet (B) and after changing the amount of NaCl intake and administration of thiazides. MATERIAL AND METHODS: Nineteen healthy young individuals had their diet replaced by 2l of Nutrison® Low Sodium (500mg sodium/day) daily for two days. Then, 5g of NaCl were added every two days («5¼, «10¼ and «15¼), administering 50mg (H50) and 100mg (H100) of Higroton® on the last two days. Blood sodium, plasma renin activity (PRA) and aldosterone were determined in venous blood samples, as were urinary sodium and calcium. STATISTICAL ANALYSIS: Wilcoxon t-test and the Pearson linear correlation were calculated. RESULTS: Urinary Na (mEq/24h): 210.3±87.6 («B¼); 42.7±20.4 («5¼); 135.5±50.6 («10¼); 225.5±56.7 («15¼). Urinary calcium (mg/24h): 207.8±93.6 («B¼); 172.8±63.1 («5¼); 206.2±87.7 («10¼); 227.4±84.1 («15¼). A positive correlation was observed between natriuresis and urinary calcium in «10¼ (r=0.47) and «15¼ (r=0.67). After Higroton®, natriuresis: 232.3±50.7; 377±4 (H50); 341.1±68.4 (H100); Ca in urine: 209.8±57.4; 213.2±67.6 (H50); 159.1±52.2 (H100). CONCLUSIONS: Salt intake in the population studied was estimated to be 14.9±4.9g/day with a positive correlation found between sodium and calcium urine output with daily intakes of 11.25 and 16.25g of salt. With the usual intake, for each gram of salt, urinary calcium increased by 5.46 mg/24 h and with 100mg of Higroton® it decreased by 50.7mg/24h. These data could be useful for the management of patients with excretory hypercalciuria or hypoparathyroidism.

Calcium-creatinine ratio in a morning urine sample for the estimation of hypercalciuria associated with non-glomerular hematuria observed in children and adolescents. / Índice calcio-creatinina en una muestra matutina de orina para la estimación de hipercalciuria asociada con hematuria no glomerular observada en las edades infanto-juveniles

Background: Hypercalciuria might be revealed during the differential diagnosis of hematuria accompanying renal lithiasis (RL). In spite of this, diagnostic accuracy of calcium urinary excretion might be affected by incomplete 24-hour urine collections. In the present study, the diagnostic utility of calcium/creatinine (ICaCre) index for determining hypercalciuria associated with non-glomerular hematuria (NGH) and RL was assessed. Method: ICaCre (mg/mg) index was calculated from calcium (mmol/l) and creatinine (µmol/l) concentrations in an aliquot from a 24-hour urine collection in 169 children and adolescents with NGH or RL. Calciuria values > 4.0 mg/kg in 24 hours were distributed according to the presence of NGH or RL. Results: Mean ICaCre index was 0.2 ± 0.1 mg/mg. Calciuria values estimated from ICaCre were statistically higher to those from 24-hour urine collection (p < 0.05). The frequency of hypercalciuria was independent from the measurement method (estimated from ICaCre 39.5% vs. 24 h collection 32.1%; p > 0.05). Hypercalciuria distribution was as follows: no NGH + no RL: 59.0%; no NGH + RL: 60.0% (∆ = +1.0%); NGH + no RL: 68.2% (∆ = +9.2%); NGH + RL: 73.3% (∆ = +14.4%). Conclusions: The use of ICaCre index for determining calcium urine excretion might be effective in the study of hypercalciuria associated with NGH and RL.

Introducción: La hipercalciuria suele revelarse durante el diagnóstico diferencial de la hematuria que acompaña a la litiasis renal. La exactitud diagnóstica de la excreción urinaria de calcio puede afectarse por las insuficiencias asociadas con la colección de orina de 24 horas. En este estudio se evaluó la utilidad diagnóstica del índice calcio/creatinina (ICaCre) en la estimación de la hipercalciuria asociada con hematuria y litiasis renal. Método: Se calculó el ICaCre de las concentraciones urinarias de calcio (mmol/l) y creatinina (µmol/l) en una alícuota de colección de 24 horas de orina en 169 niños y adolescentes atendidos por hematuria no glomerular (HNG) o litiasis renal (LR). La calciuria de 24 horas > 4.0 mg/kg en 24 horas se distribuyó según la presencia de HNG o LR. Resultados: El ICaCre promedio fue de 0.2 ± 0.1 mg/mg. La excreción urinaria de calcio estimada del ICaCre fue significativamente superior a la obtenida en colección de orina de 24 horas (p < 0.05). Los métodos de determinación de la calciuria concordaron en la frecuencia de hipercalciuria (ICaCre 39.5% vs. colección de 24 horas 32.1%; p > 0.05). Según la presencia de HNG o LR, la hipercalciuria se distribuyó de la siguiente manera: no HNG + no LR: 59%; no HNG + LR: 60% (diferencia: +1.0%); HNG + no LR: 68.2% (diferencia: +9.2%); HNG + LR: 73.3% (diferencia: +14.4%). Conclusiones: El ICaCre para estimar la excreción urinaria de calcio puede ser efectivo en el estudio de la hipercalciuria asociada con HNG y LR.