Prevalence of chronic kidney disease in a population in southern Brazil (Pro-Renal Study) / Prevalência da doença renal crônica em uma população do Sul do Brasil (estudo Pro-Renal)

Abstract Introduction: Chronic kidney disease (CKD) affects 10-12% of the adult population in many countries. In Brazil, there is no reliable information about the actual prevalence of CKD. Objective: To determine the prevalence of CKD by estimated glomerular filtration rate (eGFR) and proteinuria/albuminuria in an urban population randomly selected in Southern Brazil. Patients and Methods: 5,216 individuals were randomly selected out of a pool of 10,000 individuals identified from the database of a local energy company. The screening consisted of collection of demographic data, history of diabetes mellitus, hypertension, kidney/cardiovascular disease in the family and obesity through the body mass index - BMI (CKD risk factors). Blood samples were collected for determination of serum creatinine and subsequent eGFR estimation by the MDRD formula and urine samples for determination of albuminuria by dipstick. Albuminuria was further evaluated by HemoCue© in a selected CKD risk group. Results: The population was predominantly Caucasians (93%), 64% were females and the mean age of participants was 45 years old (18-87). BMI (kg/m2) was 27±5. Albuminuria was found in 5.25% of individuals. 88.6% of this population had no CKD (eGFR > 60 ml/min/1.73m2 & normoalbuminuria) and 11.4% were identified as having CKD, with majority on stages 3A (7.2%) and 3B (1.1%). Hypertension, diabetes, older age and obesity was associated with a higher prevalence of CKD (p < 0.001). Conclusions: The prevalence of CKD in an urban population in southern Brazil mirrors other developed countries and indicates that kidney disease is an important public health problem in Brazil.

Resumo Introdução: A doença renal crônica (DRC) afeta 10-12% da população adulta em muitos países. No Brasil, não há informações confiáveis sobre a prevalência real de DRC. Objetivo: Determinar a prevalência de DRC pela taxa de filtração glomerular estimada (eGFR) e albuminúria em uma população urbana selecionada aleatoriamente no sul do Brasil. Pacientes e Métodos: 5216 indivíduos foram selecionados aleatoriamente de um grupo de 10 mil indivíduos identificados a partir do banco de dados de uma empresa de energia local. O rastreio consistiu na coleta de dados demográficos, história de diabetes mellitus, hipertensão, doença renal/cardiovascular na família e obesidade pelo índice de massa corporal -IMC (fatores de risco da DRC). Foram coletadas amostras de sangue para determinação da creatinina sérica e subsequente estimativa de eGFR pela fórmula MDRD e amostras de urina para determinação da albuminúria por fita. Albuminúria foi confirmada por HemoCue© em um grupo de risco de CKD selecionado. Resultados: A população era predominantemente de caucasianos (93%), 64% eram do sexo feminino e a idade média dos participantes de 45 anos (18-87). O IMC (kg/m2) foi de 27 ± 5. Albuminúria foi encontrada em 5,25 % dos indivíduos. 88,6% dessa população não apresentou CKD (eGFR > 60 ml/min/1,73 m2 e normoalbuminúria) e 11,4% foram identificados como portadores de DRC, com maioria nos estádios 3A (7,2%) e 3B (1,1%). Hipertensão arterial, diabetes, idade avançada e obesidade foram associados a maior prevalência de DRC (p < 0,001). Conclusões: A prevalência de DRC em uma população urbana no sul do Brasil reflete outros países desenvolvidos e indica que a doença renal é um importante problema de saúde pública no Brasil.

Formula to detect high sodium excretion from spot urine in chronic kidney disease patients / Fórmula para detectar elevada excreção de sódio a partir de amostra isolada de urina de pacientes com doença renal crônica pré-dialítica

Abstract Introduction: Excessive sodium intake is related to adverse renal and cardiovascular outcomes in patients with chronic kidney disease (CKD) and assessment of sodium intake is complex and not evaluated very often in clinical practice. Objective: To develop a new formula to estimate 24h sodium excretion from urine sample (second void) of patients with CKD. Methods: We included 51 participants with CKD who provided 24-hour urine collection and a sample of the second urine of the day to determine the sodium excretion. A formula to estimate the 24-hour sodium excretion was developed from a multivariate regression equation coefficients. The accuracy of the formula was tested by calculating the P30 (proportion of estimates within 30% of measured sodium exection) and the ability of the formula to discriminate sodium intake higher than 3.6 g/day was evaluated by ROC curve. Results: Correlation test between measured and estimated sodium was significant (r = 0.57; p < 0.001), but P30 test identified a low accuracy (61%) of the formula. Different cutoff points were tested by performance tests and a ROC curve was generated with the cutoff that showed better performance (3.6 g/day). An area under the curve of 0.69 with a sensitivity of 0.91 and specificity of 0.53 was obtained. Conclusion: A simple formula with high sensitivity in detecting patients with sodium consumption higher than 3.6 g/day from isolated urine sample was developed. Studies with a higher number of participants and with different populations are necessary to test formula´s validity.

Resumo Introdução: O consumo excessivo de sódio está relacionado a piores desfechos renais e cardiovasculares em pacientes com doença renal crônica (DRC), mas a avaliação deste consumo é complexa e mensurada com baixa frequência na prática clínica. Objetivo: Desenvolver uma nova fórmula para estimar a excreção de sódio de 24h a partir da concentração de sódio em amostra isolada da segunda urina do dia em pacientes com DRC pré-dialítica. Métodos: 51 participantes com DRC forneceram coleta de urina de 24h e uma amostra da segunda urina do dia para determinação da excreção de sódio. Uma fórmula para estimar a excreção de sódio de 24h foi desenvolvida a partir dos coeficientes da equação de regressão. A acurácia da fórmula foi testada por meio do cálculo do P30. A habilidade da fórmula em discriminar consumo de sódio superior a 3,6 g/dia foi avaliada pela curva ROC. Resultados: O teste de correlação entre sódio mensurado e estimado pela fórmula foi r = 0,57; p < 0,001, porém o resultado do P30 identificou baixa acurácia (61%). Diferentes pontos de corte foram testados por meio de testes de performance e uma curva ROC foi gerada com o ponto de corte de melhor performance (3,6 g/dia). Foi obtida uma área sob a curva de 0,69 com sensibilidade 0,91 e especificidade 0,53. Conclusão: Foi desenvolvida uma fórmula simples com elevada sensibilidade em detectar pacientes com consumo de sódio superior a 3,6 g/dia a partir de amostra de urina isolada. Estudos que testem a fórmula com um maior número de participantes e com outras populações são necessários.

Performance of urinary kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, and N-acetyl-beta-D-glucosaminidase to predict chronic kidney disease progression and adverse outcomes

Urinary biomarkers can predict the progression of chronic kidney disease (CKD). In this study, kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and N-acetyl-β-D-glucosaminidase (NAG) were correlated with the stages of CKD, and the association of these biomarkers with CKD progression and adverse outcomes was determined. A total of 250 patients, including 111 on hemodialysis, were studied. Urinary KIM-1, NGAL, and NAG were measured at baseline. Patients not on dialysis at baseline who progressed to a worse CKD stage were compared with those who did not progress. The association of each biomarker and selected covariates with progression to more advanced stages of CKD, end-stage kidney disease, or death was evaluated by Poisson regression. NGAL was moderately correlated (rs=0.467, P<0.001) with the five stages of CKD; KIM-1 and NAG were also correlated, but weakly. Sixty-four patients (46%) progressed to a more advanced stage of CKD. Compared to non-progressors, those patients exhibited a trend to higher levels of KIM-1 (P=0.064) and NGAL (P=0.065). In patients not on dialysis at baseline, NGAL was independently associated with progression of CKD, ESKD, or death (RR=1.022 for 300 ng/mL intervals; CI=1.007-1.037, P=0.004). In patients on dialysis, for each 300-ng/mL increase in urinary NGAL, there was a 1.3% increase in the risk of death (P=0.039). In conclusion, urinary NGAL was associated with adverse renal outcomes and increased risk of death in this cohort. If baseline urinary KIM-1 and NGAL predict progression to worse stages of CKD is something yet to be explored.

The urine albumin-to-creatinine ratio is a reliable indicator for evaluating complications of chronic kidney disease and progression in IgA nephropathy in China

OBJECTIVE: This study investigated the correlation between the albumin-to-creatinine ratio in the urine and 24-hour urine proteinuria and whether the ratio can predict chronic kidney disease progression even more reliably than 24-hour proteinuria can, particularly in primary IgA nephropathy. METHODS: A total of 182 patients with primary IgA nephropathy were evaluated. Their mean urine albumin-to-creatinine ratio and 24-hour proteinuria were determined during hospitalization. Blood samples were also analyzed. Follow-up data were recorded for 44 patients. A cross-sectional study was then conducted to test the correlation between these parameters and their associations with chronic kidney disease complications. Subsequently, a canonical correlation analysis was employed to assess the correlation between baseline proteinuria and parameters of the Oxford classification. Finally, a prospective observational study was performed to evaluate the association between proteinuria and clinical outcomes. Our study is registered in the Chinese Clinical Trial Registry, and the registration number is ChiCTR-OCH-14005137. RESULTS: A strong correlation (r=0.81, p<0.001) was found between the ratio and 24-hour proteinuria except in chronic kidney disease stage 5. First-morning urine albumin-to-creatinine ratios of ≥125.15, 154.44 and 760.31 mg/g reliably predicted equivalent 24-hour proteinuria ‘thresholds’ of ≥0.15, 0.3 and 1.0 g/24 h, respectively. In continuous analyses, the albumin-to-creatinine ratio was significantly associated with anemia, acidosis, hypoalbuminemia, hyperphosphatemia, hyperkalemia, hypercholesterolemia and higher serum cystatin C. However, higher 24-hour proteinuria was only associated with hypoalbuminemia and hypercholesterolemia. Higher tubular atrophy and interstitial fibrosis scores were also associated with a greater albumin-to-creatinine ratio, as observed in the canonical correlation analysis. Finally, the albumin-to-creatinine ratio and 24-hour proteinuria were associated with renal outcomes in univariate analyses. CONCLUSION: This study supports the recommendation of using the albumin-to-creatinine ratio, rather than 24-hour proteinuria, to monitor proteinuria and prognosis in primary IgA nephropathy.

Documento de Consenso: Implicancia de la Proteinuria en el Diagnóstico y Seguimiento de la Enfermedad Renal Crónica / Consensus Document: Implication of Proteinuria in the Diagnosis and Follow-up of Chronic Kidney Disease

La Enfermedad Renal Crónica (ERC) es una entidad clínica secundaria a múltiples etiologías, que se caracteriza por ser silente en etapas tempranas y, en ausencia de tratamiento adecuado, frecuentemente tiene un curso progresivo que conduce al fallo irreversible de la función del órgano y requerimiento de tratamiento sustitutivo (diálisis o trasplante renal). La ERC es un factor de riesgo de enfermedad cardiovascular (CV), siendo ésta la complicación más frecuente, e inclusive la principal causa de fallecimiento de estos pacientes. Las dos causas más prevalentes de ERC son la diabetes mellitus y la hipertensión arterial. La ERC constituye un problema de Salud Pública, no sólo por la necesidad potencial de diálisis y trasplante a largo plazo, sino por la comorbilidad CV que implica desde etapas tempranas. Nuestras Sociedades Científicas y Profesionales Nacionales han recomendado, en un documento previo publicado en el año 2010, que la evaluación de la función del riñón se haga mediante la estimación del índice de filtrado glomerular (IFGe) por fórmula, a partir de la medición de la creatinina plasmática. La fórmula recomendada por nuestras sociedades en los adultos es la MDRD (Modification of Diet in Renal Disease), en la cual el único parámetro medido es la determinación de la creatinina en sangre, más allá de recientes opiniones sobre la potencial superioridad de la fórmula CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration), particularmente cuando la afectación de la función es leve. De todas maneras e independientemente de cuál sea la mejor fórmula para utilizar, la valoración funcional renal es una imagen del estado funcional del riñón de ese momento, y las evidencias acumuladas demuestran que poco nos dice sobre la posibilidad evolutiva de esa situación funcional y clínica. La presencia de concentraciones elevadas de proteína o albúmina en orina de modo persistente es un signo de lesión renal y constituye, junto con el IFGe, la mejor estrategia sobre la que se sustenta el diagnóstico y pronóstico de la ERC. Para determinar la pérdida de proteínas o albúmina en orina se pueden utilizar: tiras reactivas, en muestras de orina al azar, primera orina de la mañana, u orina de 24 horas, dependiendo de cuál sea la situación o momento clínico en el que estemos actuando, siendo diferente si estamos realizando una pesquisa poblacional, una confirmación diagnóstica especializada, en el seguimiento de un tratamiento clásico, o bien evaluando una nueva estrategia antiproteinúrica. Cabe destacar que el uso de tiras reactivas para la determinación de proteínas totales en orina ha sido evaluado por distintos estudios, los cuales han comparado la exactitud diagnóstica de la tira reactiva frente a la medida de proteína en orina de 24 horas en poblaciones con alta prevalencia de proteinuria (reacciones positivas a partir de 1+). Sin embargo, los resultados muestran una sensibilidad y especificidad variable. Por ello, la mayoría de las guías de práctica clínica aconsejan la confirmación de un resultado positivo mediante una medida cuantitativa. Por otra parte, la medida semicuantitativa de albúmina a partir de tiras reactivas la cual se basa en métodos inmunológicos o no inmunológicos, es capaz de detectar pequeñas concentraciones de albúmina (límite de detección promedio 20 mg/L). Además, el valor predictivo positivo y negativo es variable dependiendo de la concentración utilizada para definir albuminuria. Teniendo en cuenta los conceptos mencionados, en los casos que se considere necesario valorar pequeñas cantidades de pérdida proteica por orina, debe medirse Albúmina urinaria y el cociente Albúmina/Creatinina, preferentemente en la primera orina de la mañana. Cada situación clínica requiere conductas y metodologías preferenciales. Cuando pretendemos realizar la confirmación diagnóstica o el seguimiento de una enfermedad renal ya conocida, actualmente se recomienda el uso del cociente Albúmina/Creatinina o del cociente Proteína/Creatinina en la primera orina de la mañana en adultos y niños pequeños, y la orina de 24 h en niños con adecuado control de esfínteres. La concentración de proteína o albúmina en orina se recomienda que sea referida a la concentración de creatinina urinaria para minimizar los errores dependientes del volumen, y del estado de hidratación del paciente. La expresión de resultados será mg/g o bien mg/mmol, en función del tipo de unidades utilizadas por cada laboratorio. Los resultados se deberán expresar sin decimales (mg/g) o con un decimal (mg/mmol). Si las muestras no son procesadas el mismo día de la obtención, deben almacenarse a temperaturas entre 2 y 8 ºC hasta 7 días. Se recomienda abandonar el uso de los términos microalbuminuria y macroalbuminuria y sustituirse por el de albuminuria ya que la pérdida urinaria de albúmina constituye una variable continua de riesgo renal y cardiovascular. Este documento proporciona una visión general y actualizada sobre el rol de la proteinuria en eldiagnóstico y seguimiento de la ERC.

Chronic kidney disease (CKD) is a clinical entity secondary to multiple etiologies, characterized by being still in its early stages and, without an adequate treatment, it frequently follows a progressive course that leads to an irreversible failure of the organ function and requires a substitute treatment (dialysis or renal transplant). CKD is a risk factor for cardiovascular disease (CV); this is the most frequent complication, representing the principal cause of death for these patients. The two most prevalent causes of CKD are diabetes mellitus and arterial hypertension. CKD constitutes a Public Health problem, not only because of its potential need for dialysis and transplant in the long run, but also for the cardiovascular co-morbidity implicated from its initial stages. Our Scientific and Professional National Societies recommended, in a previous document published in 2010, that evaluation of the renal function be estimated by means of the glomerular filtrate index (GFI) by a formula, taking into account the measure of plasmatic creatinine. For our societies, the recommended formula in adults is MDRD (Modification of Diet in Renal Disease). In this one, the only parameter measured is determination of creatinine in blood; although recent opinions highlight the potential superiority of CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration), particularly when the renal function is slightly affected. However, disregarding which the best formula to be used is, the evaluation of the renal function is an image of the functional condition of the kidney at a specific time, and the accumulated evidences offer little or no possibility of knowing the evolution of the functional and clinical situation. The persistent presence of increased concentrations of protein or albumin in urine is a signal of renal injury and constitutes, together with GFI, the best strategy on which both diagnosis and prediction of CKD rely on. In order to determine the loss of proteins or albumin in urine, test strips in urine samples taken at ramdom or from first morning urine samples or from 24-hours urine samples were used depending on the clinical situation. It depends whether we are performing a population screening, a specialized diagnostic confirmation, the monitoring of a classic treatment or the evaluation of a new antiproteinuric strategy. It should be highlighted that the use of test strips for the screening of total proteins in urine has already been evaluated by different means. These have compared the diagnostic precision of the test strip with the measure of protein in a 24-hour urine in populations with a high prevalence of proteinuria. However, the results show a variable sensitivity and specificity. That is why the majority of the clinical practice guides suggest the confirmation of a positive result by means of a quantitative measure. On the other hand, the semiquantitative measure of albumin by means of test strips based on immunological or non-immunological procedures is capable of detecting small concentrations of albumin (the mean of limit of detection is 20 mg/L). Moreover, the positive and negative predictive value is variable depending on the concentration used to define albuminuria. Taking into account the concepts mentioned above, in those cases that are considered necessary to evaluate small amounts of protein loss in urine, the determination of urinary albumin and of the albumin/creatinine ratio should be requested; preferably in the first morning urine. Each clinical situation requires preferential handlings and methodologies. When trying to perform diagnostic confirmation or monitoring of the already existing kidney disease the use of albumin/creatinine ratio or protein/creatinine ratio in urine is recommended in the first morning urine in adults and little children, and in the 24-hour urine in children with adequate control of sphincters. It is recommended that the concentration of protein or albumin in urine be referred to the concentration of urinary creatinine to minimize the errors depending on the volume and on the hydration status of the patient. The results will be expressed in mg/g, or else mg/mmol, depending on the types of units used by each laboratory. The results should be expressed without decimals (mg/g) or with one decimal (mg/mmol). If the samples are not processed the same day of their collection, they should be stored at temperatures between 2 °C and 8 °C for 7 days. It is also advisable to avoid the use of the terms microalbuminuria and macroalbuminuria, and replace them by albuminuria, as the urinary loss of albumin constitutes a continuous variable of renal and cardiovascular risk. This document provides a general and updated vision of the role of proteinuria in the diagnosis and monitoring of CKD.

Proceso de atención enfermero a persona con insuficiencia renal crónica / Nursing process person with chronic renal failure

El proceso de atención en enfermería (PAE) tiene como finalidad brindar atención integral y especializada a cada agente de cuidado, impulsando y conservando la salud del usuario cuando lo requiera. Este PAE se realizó en el Hospital “Lic. Adolfo Ló- pez Mateos” y se utilizó la teoría del déficit de autocuidado de Dorothea Orem. Se trata de Jesús (nombre ficticio), masculino de 66 años con un padecimiento de insuficiencia renal crónica y peritonitis bacteriana; HAS (hipertensión arterial sistémica), DM T2 (diabetes mellitus tipo 2) descontroladas debido a una falta de adhesión al plan terapéutico.

The completion of the Nursing Care Process is designed to provide comprehensive care to each agent specialized care by developing and maintaining the health of the user when required. The Nursing Care Process (SAP) at the Hospital “Lic. Adolfo López Mateos”, was applied using Dorothea Orem’s theory in conjunction with his theory of self-care deficit. This is Jesus, 66 years old male with chronic renal disease, bacterial peritonitis, HAS (hypertension), T2 DM (diabetes mellitus type 2) uncontrolled due to a lack of adherence to therapeutic plan.