Magnesio e indicadores bioquímicos óseo-minerales según tasa de filtración glomerular en estudiantes sin enfermedad renal / Magnesium and osseous-mineral biochemical indicators according to glomerular filtration rate testing in students without kidney disease

Introducción: La variación del magnesio y de indicadores bioquímicos del metabolismo óseo-mineral según la tasa de filtración glomerular en jóvenes sin enfermedad renal es poco conocida por lo que es necesario considerarla para delimitar lo no atribuible a enfermedad renal crónica. El papel que desempeña el magnesio está en estudio. En la enfermedad renal crónica hay una alteración progresiva del metabolismo óseo-mineral que comienza tempranamente. Objetivos: Evaluar valores séricos de magnesio, calcio, fósforo, fosfatasa alcalina y parathormona, excreciones urinarias de 24 h y excreción fraccional de estos electrolitos según categoría G de tasa de filtración glomerular estimada por clearance de creatinina: G1 (normal a alta) y G2 (levemente disminuida) en estudiantes sin enfermedad renal crónica. Material y métodos: Estudio analítico y corte transversal con una muestra de 55 estudiantes voluntarios sin enfermedad renal en el periodo 2018 a 2019. Los analitos se determinaron en suero y algunos en orina de 24 h. Resultados: Solamente magnesio sérico y excreción fraccional de magnesio excreción fraccional de magnesio mostraron diferencias significativas según la categoría G (p < 0,05). Los valores de magnesio sérico magnesio sérico estuvieron dentro de los valores de referencia para el método. En G2, magnesio sérico, descendido respecto a G1 y excreción fraccional de magnesio aumentada, inversamente relacionados. El magnesio sérico disminuyó en promedio 0,26 mg/dL por unidad de aumento de excreción fraccional de magnesio (p = 0,0502). Conclusiones: Se observaron diferencias en magnesio sérico y excreción fraccional de magnesio al comparar los resultados en G1 y G2. Los demás indicadores bioquímicos estudiados no mostraron diferencias por categoría G. Diseños de corte longitudinal en muestras mayores pueden confirmar o no estos hallazgos. Tales estudios pueden aportar a la comprensión de cambios bioquímicos del metabolismo óseo-mineral en etapas iniciales de disminución de la tasa de filtración glomerular(AU)

Introduction: Not much is known about the variation in magnesium and biochemical indicators of the osseous-mineral metabolism according to glomerular filtration rate testing in young people without kidney disease. This variation should therefore be considered to delimit whatever is not attributable to chronic kidney disease. The role played by magnesium is currently under study. In chronic kidney disease a progressive alteration of the osseous-mineral metabolism starts early. Objectives: Evaluate serum values of magnesium, calcium, phosphorus, alkaline phosphatase and parathormone, 24-hour urinary excretion and fractional excretion of these electrolytes according to category G of the glomerular filtration rate estimated by creatinine clearance: G1 (normal to high) and G2 (slightly reduced) in students without chronic kidney disease. Methods: An analytical cross-sectional study was conducted of a sample of 55 student volunteers without kidney disease in the period 2018-2019. The analytes were determined in serum and some in 24-hour urine. Results: Only serum magnesium and magnesium fractional excretion displayed significant differences according to category G (p < 0.05). Serum magnesium values were within the reference values for the method. In G2, serum magnesium was lower than in G1, whereas magnesium fractional excretion was higher, i.e. an inverse relation is observed. Serum magnesium reduction averaged 0.26 mg/dl per unit of magnesium fractional excretion increase (p = 0.0502). Conclusions: Comparison of G1 and G2 results revealed differences in serum magnesium and magnesium fractional excretion. The remaining biochemical indicators studied did not show any differences in category G. Longitudinal studies with larger samples may or may not confirm these findings, thus contributing to a better understanding of the biochemical changes in osseous-mineral metabolism occurring in the initial stages of glomerular filtration rate reduction(AU)

Un modelo de estudio de la función tubular renal que no depende de la colección de orina de 24 horas / A model of study of renal tubular function that does not depend on the 24-hour urine collection

Introducción: El ensayo de muestras matutinas de orina pudiera mejorar el estudio de la función tubular en niños y adolescentes. Objetivo: Describir las tubulopatías diagnosticadas en niños y adolescentes después del ensayo de muestras matutinas de orina. Métodos: Se completó un estudio retrospectivo y analítico en el Laboratorio de Estudio de la Función Renal, Servicio de Laboratorio Clínico, Hospital Pediátrico Docente "Juan Manuel Márquez", con 70 informes de la función tubular hechos en muestras matutinas de orina de 56 probandos (varones: 50,0 por ciento; edad promedio: 4,3 ± 5,5 años; edades < 12 meses: 41,1 por ciento) atendidos entre 2015-2019 (ambos inclusive) que contenían los valores del filtrado glomerular, la excreción urinaria absoluta y fraccional de las sustancias de interés, la brecha aniónica, la presión parcial de los gases, y la acidez titulable, el pH, la densidad y la osmolaridad de los fluidos pertinentes. Los resultados obtenidos se integraron dentro de las construcciones de caso de varias tubulopatías. Resultados: La función tubular estaba conservada en el 41,1 por ciento de los probandos. La inmadurez tubular explicó los hallazgos en otros dos niños. La hipercalciuria idiopática (16,0 por ciento), la diabetes insípida de causa nefrogénica (8,9 por ciento) y la insuficiencia renal aguda (5,3 por ciento) fueron los hallazgos más frecuentes. En 14 de los probandos se diagnosticaron 10 tubulopatías que recorrieron el raquitismo carencial, la hipofosfatasia, la enfermedad de Leigh, el síndrome de Bartter, la enfermedad de Dent y la acidosis tubular I, II y IV. Conclusiones: El estudio tubular en muestras matutinas de orina permite el diagnóstico de importantes tubulopatías en las edades pediátricas(AU)

Introduction: The morning urine sample assay may improve the study of tubular function in children and adolescents. Objective: Describe the tubulopathies diagnosed in children and adolescents after the trial of morning urine samples. Methods: A retrospective and analytical study was completed at the Renal Function´s Study Laboratory, in the Clinical Laboratory Service at "Juan Manuel Marquez" Teaching Pediatric Hospital, with 70 reports of tubular function made in morning urine samples of 56 testees (males: 50.0 percent; average age: 4.3 ± to 5.5 years; ages< 12 months: 41.1 percent) attended from 2015 to 2019 (both inclusive) containing glomerular filtration values, absolute and fractional urinary excretion of substances of interest, anionic gap, partial gas pressure, and titrable acidity, pH, density and osmolarity of relevant fluids. The results obtained were integrated into the case constructions of various tubulopathies. Results: Tubular function was preserved in 41.1 percent of the testees. Tubular immaturity explained the findings in two other children. Idiopathic hypercalciuria (16.0 percent), nephrogenic diabetes insipidus (8.9 percent) and acute renal failure (5.3 percent) were the most frequent findings. In 14 of the testees, 10 tubulopathies were diagnosed were through deficiency rickets, hypophosphatasia, Leigh's disease, Bartter syndrome, Dent disease and tubular acidosis I, II and IV.. Conclusions: The tubular study with morning urine samples allows the diagnosis of important tubulopathies in the pediatric ages(AU)

Excreção fracionada urinária de sódio, potássio e cloreto em cordeiros suplementados com cloreto de amônio para prevenção de urolitíase / Urinary fractional excretion of sodium, potassium and chloride in lambs supplemented with ammonium chloride to prevent urolithiasis

A urolitíase é uma doença importante de cordeiros confinados. A acidificação da urina, pela ingestão de cloreto de amônio, é o método preventivo mais frequentemente empregado. Devido à falta de informação específica em ovinos, este estudo foi realizado para avaliar as alterações que ocorrem nos eletrólitos urinários de cordeiros, que receberam cloreto de amônio na dieta. Foram utilizados 100 cordeiros, com 3 meses de idade, que foram mantidos em confinamento durante 56 dias, e distribuídos em 3 grupos: G1 (n=40) que receberam 400mg/kg de peso vivo (PV) de cloreto de amônio/dia, durante 21 dias; G2 (n=40) que receberam 400mg/kg de PV de cloreto de amônio/dia durante 42 dias; e G3 (n=20) que não receberam cloreto de amônio. Os cordeiros foram examinados e as amostras de sangue e urina foram colhidas a cada 7 dias: 0 (antes do início da ingestão de cloreto de amônio), 7, 14, 21, 28, 35, e 42 dias. As concentrações séricas e urinárias de sódio (Na+), potássio (K+), cloreto (Cl-), e de creatinina foram mensuradas em todos os momentos de colheita. A excreção fracionada urinária (EFu) de eletrólitos e a diferença de íons fortes (SID) na urina [(Na+ + K+) - Cl] foram calculadas. A EFu de Na+, K+ e Cl- não variou ao longo do tempo em G3, provando que a dieta de confinamento, por si só, não influenciou a excreção urinária destes eletrólitos. A ingestão de cloreto de amônio, pelo grupo G1 e G2, influenciou a EFu sobre o tempo de confinamento. A SID urinária foi mais precisa do que a EFu de Cl- para demonstrar que a concentração de Cl- aumentou na urina, o que destacou a relevância desta variável.(AU)

Urolithiasis is an important disease of lambs confined. The urine acidification, by ammonium chloride intake, is the preventive method most frequently employed. Due to the lack of specific information in sheep, this study was performed to evaluate the electrolyte changes that occur in the urine of lambs receiving ammonium chloride in the diet. One hundred male lambs, 3 months old, were kept in a feedlot during 56 days, and distributed in 3 groups: G1 (n=40) receiving 400mg/kg BW of ammonium chloride/day during 21 days; G2 (n=40) receiving 400mg/kg BW of ammonium chloride/day during 42 days; and G3 (n=20) that did not receive ammonium chloride. The lambs were examined and blood and urine samples were collected every 7 days: 0 (the beginning of ammonium chloride intake), 7, 14, 21, 28, 35, and 42 days. Serum and urine sodium (Na+), potassium (K+), chloride (Cl-), and creatinine concentrations were measured. The urinary fractional excretion (FE) of electrolytes and the urine strong ion difference [(Na+ + K+) - Cl-] were calculated. FEs of Na+, K+, and Cl- did not vary over time in G3, proving that the feedlot diet, by itself, did not influence the urinary excretion of these electrolytes. The ingestion of ammonium chloride, instead, influenced FEs over the time of feedlot. The urinary SID was more accurate than the FE of Cl- to demonstrate that the concentration of Cl- increased in the urine. It highlights the relevance of this variable.(AU)

Clinical characteristics and renal uric acid excretion in early-onset gout patients / 中华内科杂志

Objective To investigate clinical characteristics and renal uric acid excretion in early-onset gout patients.Methods Consecutive inpatients with primary gout were recruited between 2013 and 2017.The patients with gout onset younger than 30 were defined as early-onset group while the others were enrolled as control group.Clinical characteristics and uric acid (UA) indicators were compared between two groups.Results Among 202 recruited patients,the early-onset group included 36 patients (17.8％).Compared with control group,the early-onset group presented more patients with obesity [13 patients (36.1％) vs.22 patients (13.3％),P＜0.05],significantly higher serum UA level [(634± 124)μmol/L vs.(527± 169).μmol/L] and glomerular load of UA[(7.2±2.8)mg· min-1 · 1.73m-2 vs.(4.4±2.2)mg· min-1 · 1.73m-2] and estimated glomerular filtration rate (GFR) [(83±21)ml· min-1 · 1.73m-2 vs.(67±21)ml· min-1 · 1.73m-2] (all P＜ 0.05),lower fractional excretion of UA [4.4％ (3.4％,6.1％) vs.7.2％ (5.2％,9.6％),P＜0.05],whereas 24h urinary UA excretion was comparable [(2 788±882)l,μmol/1.73m2 vs.(2 645±1 140)μmol/1.73m2,P=0.274].Subgroup analysis of patients without chronic kidney disease showed significantly lower fractional excretion of UA in the early-onset group [4.5％(3.3％,6.1％) vs.6.7％ (5.1％,8.7％),P＜0.05].Logistic regression analysis showed that obesity (OR=3.25) and fractional excretion of UA less than 7％ (OR=9.01,all P＜0.05) were risk factors of gout early onset.Conclusion The gout patients with early-onset younger than 30 present high serum and glomerular load of uric acid which might be due to obesity and relative under-excretion of renal uric acid.

Fracción de excreción de magnesio y estado del túbulo-intersticio en pacientes nefróticos / Fractional excretion of magnesium and status of tubulointerstitium in nephrotic patients

INTRODUCCIÓN: la fracción de excreción de los electrólitos puede constituir un marcador temprano de daño renal en las glomerulopatías. OBJETIVO: identificar la posible relación existente entre variables clínicas, fracción de excreción de magnesio y estado del túbulo-intersticio, en pacientes con proteinuria nefrótica a los que se les realizó biopsia renal en el Instituto de Nefrología entre abril de 2012 y junio de 2013. MÉTODOS: se realizó un estudio observacional analítico, transversal, en el que se excluyeron los pacientes con factores que modificaran la fracción de excreción de magnesio. A los 40 pacientes incluidos en el estudio se les recogieron datos antropométricos, demográficos y clínicos, se les midió la fracción de excreción de magnesio, se les practicó biopsia renal y se les cuantificó el porcentaje de fibrosis con el programa Image J. La información fue procesada mediante el paquete estadístico SPSS 15.0. Se utilizó la técnica estadística de análisis de distribución de frecuencias, en las variables cuantitativas se calcularon estadígrafos descriptivos. Fueron empleados los tests de Wilcoxon, de Kruskal Wallis y el coeficiente de correlación de Spearman's-rho, en las pruebas de hipótesis. RESULTADOS: se encontró correlación estadísticamente significativa de la fibrosis intersticial con la fracción de excreción de magnesio (rsp= 0,37, p= 0,02) y con la tasa de filtración glomerular (rsp= -0,56, p= 0,00). No fue encontrada asociación de la fracción de excreción de magnesio con el empleo de medicamentos, ni con el antecedente de hipertensión arterial. CONCLUSIÓN: la fibrosis intersticial se relaciona con la fracción de excreción de magnesio y con la tasa de filtración glomerular en pacientes con proteinuria nefrótica.

INTRODUCTION: fractional excretion of electrolytes can be used as an early marker of renal damage in glomerulopathies. OBJECTIVE: to identify the possible relationship between some clinical variables, the fractional excretion of magnesium and the tubulointerstitial status in patients with nephrotic proteinuria assisted at The National Institute of Nephrology from April 2012 to June 2013. METHODS: an observational analytical study was conducted. Patients with conditions that modify the fractional excretion of magnesium were excluded. 40 patients were included in this study at the Institute of Nephrology from April 2012 until June 2013, and their demographic, anthropometric and clinical data were collected; the fractional excretion of magnesium was measured as well. Renal biopsies were practiced to all patients and the percent of fibrosis was measured with the aid of image J program. Data were processed with Statistical package for Social Science (SPSS) version 15.0. The statistical technique of frequency distribution analysis was used; quantitative variables descriptive statistics were calculated. Wilcoxon tests, Kruskal Wallis and correlation coefficient Spearman's- rho were used in hypothesis tests. RESULTS: the percent of interstitial fibrosis was related to fractional excretion of magnesium (rsp= 0,37, p= 0,02) and glomerular filtration rate (rsp= -0,56, p= 0,00). No association of the fractional excretion of magnesium with the use of drugs or with history of hypertension was found. CONCLUSIONS: tubulointerstitial fibrosis is related to the fractional excretion of magnesium and glomerular filtration rate in patients with nephrotic proteinuria.

Correlation study between fractional excretion of uric acid and primary gout / 中国医师进修杂志

Objective To study the correlation between fractional excretion of uric acid (FEUA) and blood uric acid,body mass index (BMI),blood pressure,blood glucose,blood lipid and other metabolic factors in patients with primary gout.Methods Sixty-two patients with primary gout (gout group) and 32 healthy people (control group) were selected in this study.Gout group was divided into uric acid excretion decreasing group (FEUA ＜ 7％,29 cases),mixed group (7％ ≤FEUA ≤ 12％,25 cases) and uric acid production increasing group (FEUA ＞ 12％,8 cases) according to the level of FEUA.The fasting blood glucose (FPG),2-hour postprandial blood glucose (2 h PBG),blood lipid,serum creatinine,blood uric acid,glycosylated hemoglobin were tested.24 hours urine was collected and urinary uric acid and urinary creatinine was measured,FEUA was calculated and analyzed.Results BMI,mean arterial pressure,blood uric acid,glycosylated hemoglobin,total cholesterol,2 h PBG in gout group was higher than that in control group,and high density lipoprotein cholesterol,FEUA was lower than that in control group,and there was significant difference (P ＜ 0.05).There was no significant difference in age,FPG,low density lipoprotein cholesterol,triacylglycerol between two groups (P＞ 0.05).There was no significant difference in age,blood uric acid,FPG,2 h PBG,glycosylated hemoglobin,total cholesterol,low density lipoprotein cholesterol,high density hpoprotein cholesterol among uric acid excretion decreasing group,mixed group and uric acid production increasing group (P ＞ 0.05),and there was significant difference in BMI,mean arterial pressure,triacylglycerol,FEUA among three groups(P＜ 0.05).FEUA was negatively correlated with blood uric acid in control group and gout group (r =-3.900,-0.476,P ＜0.05).FEUA was positively correlated with 24 h urinary uric acid in gout group (r =0.465,P =0.001),and nagatively correlated with triacylglycerol (r =-0.304,P ＜ 0.05).Pearson analysis showed that FEUA was negatively correlated with blood uric acid in uric acid excretion decreasing group (FEUA ＜ 7％) (r =-0.392,P ＜ 0.05),FEUA was positively correlated with blood uric acid in non uric acid excretion decreasing group (FEUA ≥7％)(r =0.437,P ＜ 0.05),but 24 h urinary uric acid was not correlated with blood uric acid(P ＞ 0.05).Multi-stepwise regression analysis showed that blood uric acid,glycosylated hemoglobin,FEUA was significantly correlated with the onset of the gout (P ＜ 0.05).Conclusions Besides blood uric acid level,there are significant changes in primary gout in blood pressure,serum glucose and lipid levels.FEUA could be used to estimate the ability of renal excrete the uric acid.Mean arterial pressure,glycosylated hemoglobin and FEUA are the risk factors for gout.

Toxicidade do dimetilsulfóxido em cães hígidos e doentes renais crônicos / Toxicity of dimethyl sulfoxide in healthy dogs and with chronic kidney disease

O objetivo do presente trabalho foi avaliar os efeitos do tratamento com dimetilsulfóxido (DMSO) sobre aspectos pertinentes à função renal, perfil bioquímico sérico, parâmetros hematológicos e condição clínica de cães sadios e de cães com doença renal crônica (DRC). As avaliações foram feitas antes, durante e após a administração de DMSO a 10% na dose de 0,5g kg-1, cada 24h, por três dias. O DMSO resultou em alguns efeitos adversos nos cães sadios e também nos cães com DRC, nos quais os efeitos foram mais frequentes e mais graves. Apesar desses efeitos adversos, tanto em cães sadios quanto para cães com DRC 2-3, não há contraindicações para o uso do fármaco quando em curto espaço de tempo. A gravidade dos efeitos adversos relacionados ao tratamento com DMSO e possível associação com o óbito em cães com DRC em estádio 4, constituem fatores para contraindicação do fármaco nesse grupo de pacientes.

The objective of this study was to evaluate the effects of dimethyl sulfoxide (DMSO) treatment on aspects of renal function, serum profile, total blood count parameters and clinical condition of health or chronic kidney disease (CKD) dogs. The evaluations were done before, during and after the administration of DMSO 10% at a dose of 0.5g kg-1, each 24h, for three days. DMSO resulted in some adverse effects in both healthy and CKD dogs, however the effects were more frequent and worse in CKD dogs. Despite these adverse effects, both groups don't have contraindications to use the drug in a short time. The severity of adverse effects related to the DMSO and its possible association with death in stage 4 CKD dogs, are contraindications for the drug in this group of patients.

Rol de la excreción fraccional de ácido úrico en el estudio de hiponatremia / Role of the fractional excretion of uric acid in the study of hyponatremia

Introducción: La hiponatremia es el trastorno hidroelectrolítico más común entre pacientes internados. Conocer de manera precoz el estado del líquido extracelular (LEC) para el estudio de las causas de hiponatremia y su posterior tratamiento es de suma importancia. Se ha planteado la posibilidad de utilizar la excreción fraccional de ácido úrico (EFAU) como herramienta complemetaria para discernir LEC normal de LEC disminuído, incluso en pacientes bajo tratamiento diurético. Métodos: Se evaluaron en 45 pacientes seleccionados en forma prospectiva, parámetros clínicos y de laboratorio habituales al momento del diagnóstico de hiponatremia, para definir el estado del LEC. Una vez definido éste, se calculó la EFAU. Resultados: Se observó que en los 21 pacientes que conformaron el grupo de LEC disminuido, la tensión arterial, la natriuria, la excreción fraccional de sodio, la excreción fraccional de urea y la EFAU fueron significativamente menores (p < 0.05) que en los 24 pacientes del grupo LEC normal. Dentro de estas variables, la EFAU fue la de mayor sensibilidad y especificidad para predecir LEC disminuido, con un valor de corte < 10.9 %. Dentro del subgrupo de 15 pacientes que recibían diuréticos, la EFAU < 10.9 % tuvo una sensibilidad de 100% y una especificidad de 100% para predecir LEC disminuido. Conclusión: Así, la EFAU debería instaurarse dentro del protocolo de estudio de un paciente con hiponatremia, dado que, realizada con muestra aislada de sangre y orina, es un método sencillo y eficaz para efectuar en la urgencia, sobre todo en pacientes con diuréticos.

Introduction: Hyponatremia is the most common hydroelectrolitic disorder in hospitalized patients. It is essential to acquire an early understanding of the extracellular liquid (ECL) status for the study of the causes of hyponatremia and its subsequent treatment. The possibility of using the fractional excretion of uric acid (FEUA) as a supplementary tool to distinguish normal ECL from reduced ECL has been considered, including patients undergoing diuretic treatment. Methods: The typical clinical and laboratory parameters were examined at the time of the diagnosis of hyponatremia in 45 patients prospectively selected, to define the status of ECL. Once defined, the FEUA was estimated. Results: For the 21 patients within the reduced ECL group, blood pressure, natriuria, fractional excretion of sodium, fractional excretion of urea and FEUA were significantly lower (p < 0.05) than for the 24 patients within the normal ECL group. Among these variables, the FEUA was the one which showed more sensitivity and specificity to predict a reduced ECL, with a cutoff value < 10.9 %. Within the of 15 patients on diuretic treatment, FEUA < 10.9 % had a 100% sensitivity and a 100% specificity to predict a reduced ECL. Conclusion: Therefore, the FEUA should be included in the study protocol of a patient with hyponatremia,since when performed in an isolated sample of blood andurine, it constitutes a simple and efficient method to be implemented under emergency situations, especially in patients receiving diuretics.

Obesidad y excreción urinaria de sodio en niños y adolescentes / Obesity and urinary sodium excretion in children and adolescents

Background: Qbesity is a disease characterized by an abnormal accumulation body fat that results in neuroen-docrine changes that alter the homeostasis of sodium, producing an increased risk of hypertension in adulthood. objective: To evaluate the effect of obesity on urinary sodium excretion in children and adolescents. subjects and Methods: 266 male and female children in the age group of 5-15 years were studied: 154 obese (OB) with > 95th percentile of BMI, and 112 normal-weight patients (C) with percentile 5-85 of BMI, from the outpatient service of the Children Hospital, Posadas, Misiones, Argentina during the years 2008 -2009. The determinations of serum sodium (Na s) and 24-hour urine (Na ur) were performed using Ion Selective Electrode. The fractional excretion of sodium (FENa percent) was calculated. results: Na ur values (mEq/kg/day) and FENa percent reported significantly lower differences in the obese group compared to controls: OB Na ur 2.23 vs C Na ur 3.40 (p < 0.0001); OB FENa percent 0.59 vs C FENa percent 0.71 (p = 0.001). Conclusion: Results obtained in the present study showed that obese children have a significantly decreased urinary sodium excretion compared to normal weight children. This difference could be caused by renal retention of this ion.

Introducción: La obesidad es una enfermedad caracterizada por el aumento de grasa corporal, que genera modificaciones neuroendocrinas involucrando alteraciones en la homeostasis del sodio, que podrían generar hipertensión arterial en la adultez. Objetivo: Evaluar el efecto de la obesidad sobre la excreción urinaria de sodio en niños y adolescentes. Pacientes y Método: Se estudiaron 266 niños de ambos sexos, entre 5 y 15 años: 154 obesos (OB) definidos como IMC percentil > 95, y 112 normopeso (C), IMC percentil 5-85, provenientes del Servicio de Consultorio Externo del Hospital de Pediatría-Posadas, Misiones, Argentina, durante los años 2008-2009. Las determinaciones de sodio en suero (Na s) y orina de 24 h (Na ur) se realizaron con electrodo ion selectivo. Se calculó la excreción fraccional de sodio (EFNa por ciento). Resultados: Los valores de Naur (mEq/ kg/día) y la EFNa por ciento significativamente menores en el grupo de obesos con respecto a los controles: Na ur QB 2,23 vs Na ur C 3,40 (p < 0,0001); EFNa por ciento OB 0,59 vs EFNa por ciento C 0,71 (p = 0,001). Conclusión: En el presente estudio los resultados mostraron que los niños y adolescentes obesos presentan una disminución significativa de la excreción urinaria de sodio respecto de los niños normopeso. Dicha diferencia podría estar generada por la retención renal de dicho ion.

Participação da excreção renal de cálcio, fósforo, sódio e potássio na homeostase em cães sadios e cães com doença renal crônica / Participation of renal excretion of calcium, phosphorus, sodium and potassium on the homeostasis in healthy dogs and in dogs with chronic kidney disease

In chronic kidney disease (CKD), the first problem to be solved by the organism is to maintain water and sodium homeostasis and, with the worsening of the renal injuries, other severe problems related to the calcium and phosphorus homeostasis emerge. The present study has the purpose to evaluate the renal excretion and serum profile of calcium, phosphorus, sodium and potassium in healthy dogs and in dogs with naturally acquired CKD. Three groups of adult male and female dogs of varied breeds were evaluated. Normal dogs were in the control group (G1) and the CKD dogs were distributed into two groups in accordance with the stage of renal function impairment (G2 e G3, respectively, stages 1-2 and stages 3-4, proposed by IRIS 2006 staging CKD). The G3 dogs showed increased serum levels of ionized calcium and phosphorus, in addition to the reduction of sodium levels. Regarding the renal excretion of the analyzed electrolytes, the G1 and G2 groups showed a decrease of filtered load and increase of fractional excretion, yet there were no significant variations on the urinary excretions. The results suggest that the kidneys of the CKD dogs can maintain similar values of electrolytes urinary excretion as the kidneys of normal dogs. The mechanism involves an increase of fractional excretion while glomerular filtration decreases. This compensation process, however, can lose its efficiency in the later stages of the disease, in relation to the maintenance of phosphorus and sodium serum levels.

Na doença renal crônica (DRC) a manutenção da homeostase de água e sódio é o primeiro problema a ser contornado pelo organismo e com o agravamento das lesões renais surgem outros problemas graves relacionados à homeostase de cálcio e fósforo. O presente estudo tem por escopo avaliar a excreção renal de cálcio, fósforo, sódio e potássio, e o perfil sérico destes eletrólitos em cães normais e em cães com DRC naturalmente adquirida. Foram avaliados três grupos de cães adultos, machos ou fêmeas, de raças variadas. Animais normais compuseram o grupo controle (G1) e os cães com DRC foram distribuídos em dois grupos de acordo com os estágios de comprometimento da função renal (G2 e G3, respectivamente, estágios 1-2 e estágios 3-4, descritos pela IRIS 2006 staging CKD). Os cães do G3 apresentaram aumento das concentrações séricas de cálcio ionizado e fósforo, além de diminuição da concentração sérica de sódio. Quanto à excreção renal dos eletrólitos analisados, os animais dos grupos G1 e G2 apresentaram diminuição de carga filtrada e aumento de excreção fracionada, mas as excreções urinárias não variaram significativamente. Os resultados são indicativos de que os rins de cães com DRC podem manter a excreção urinária dos eletrólitos em valores se melhantes aos dos normais. O mecanismo envolve aumento da excreção fracionada na medida em que haja diminuição da filtração glomerular. Esse processo de compensação, entretanto, pode perder a eficiência nos estágios mais avançados da enfermidade no que se refere à manutenção das concentrações séricas de fósforo e sódio.

Therapeutic strategy towards renal restoration in chronic kidney disease.

Background: The population with end-stage renal disease is increasing. This continued growth is related to: i) diagnostic failure in screening for early chronic kidney disease (CKD) associated with tubulointerstitial fibrosis (TIF), ii) failure in preventing renal disease progression due to lack of understanding of the precise determinants that induce TIF, and iii) delayed treatment which simply slows renal disease progression, but is unable to restore renal function. Objective: To review therapeutic strategy to restore renal function in CKD stressing fractional excretion of magnesium (FE Mg) as a sensitive biomarker for screening early CKD associated with TIF. Results: There is much evidence to support the crucial role of renal microvascular disease as the determinant of TIF and disease progression. A unique pattern of hemodynamic maladjustment is characterized by a preferential constriction of the efferent arteriole that induces peritubular capillary flow reduction in CKDs. Conclusion: The present information leads to a therapeutic strategy to restore renal function in early CKD patients.

The Role of Aldosterone on the Development of Renal Tubular Reabsorption in Low Birth Weight Infants

PURPOSE: To determine the postnatal changes in aldosterone action on the renal tubular reabsorption in low birth weight(LBW) infants, we assessed the relation of the aldosterone concentrations to renal parameters during the first 10 days of life. METHODS: Twenty LBW infants were evaluated and their gestational ages ranged from 32.4 to 39.3 weeks and their birth weights ranged from 1,440 to 2,500 g. Estimated glomerular filtration rate, fractional excretion of sodium(FENa) and potassium(FEK), and plasma aldosterone concentrations were analyzed according to the postnatal age and the conceptional age(CA). RESULTS: Glomerular functions were improved after birth and were correlated with CA. FENa and FEK decreased after birth and correlated with CA. Plasma aldosterone concentrations increased to 318.6 +/- 147.2 ng/dL at 48 hours and then decreased to 162.0 +/- 72.2 ng/dL at 10 days after birth. Plasma aldosterone concentrations of infants less than 38th week of CA were higher than that of infants more than 38th week. There was a significant negative correlation coefficient between plasma aldosterone concentrations and FENa in infants more than 34th week of CA, but not in that of less than 34th week. CONCLUSIONS: LBW infants have higher plasma aldosterone concentrations, but a poor correlation between plasma aldosterone concentration and urinary sodium excretion for the first few days of life and in lower chronologic aged infants. These results show that the renal tubule reabsorption of sodium is less responsive to plasma aldosterone in these infants and, therefore, the careful management of fluid and electrolyte balance is mandatory.

Diagnostic Significance of Fractional Excretion of Unmeasured Anion(FEua)in Metabolic Acidosis / 대한신장학회잡지

Alcohol can cause rhabdomyolysis by either direct toxicity or associated metabolic abnormality such as hypophosphatemia and hypokalemia. It can also predispose to or cause trauma, seizures, or coma- induced ischemic pressure necrosis. In order to investigate the clinical features of acute renal failure caused by alcohol induced rhabdomyolysis, we reviewed the medical records of the 12 patients. All patients had been drinking much amounts of alcohol for several years. All patients showed elevation of muscle enzyme such as creatine phosphokinase, lactic dehydrogenase, aspartate transaminase and blood urea nitrogen and serum creatinine. Predisposing factors of rhabdomyolysis were ischemic compression due to unconsciousness and dehydration(2 cases), and hypophosphatemia and dehydration(1 case), seizure and dehydration(1 case), and only severe dehydration(3 cases). Initial symptoms were painful swelling at lesion site(5 cases), abdominal pain(2 cases), general ache(2 cases), leg pain without swelling(1 case), dyspnea(1case), and lethargy(1 case). Seven patients developed delirium tremens during recovery stage. Eight patients showed oliguric acute renal failure and 8 patients were treated with hemodialysis. Complications were disseminated intravascular coagulation(DIC)(3 cases), compartment syndrome(2 cases), capillary leak syndrome and DIC(1 case). One of 12 patients died of disseminated intravascular coagulation and other patients showed complete recovery of renal function.