The role of residual renal function on potassium intake and excretion in patients on peritoneal dialysis.

BACKGROUND: Patients on chronic dialysis are at increased risk of developing disorders in potassium balance. The preservation of residual renal function (RRF), frequently observed in patients on peritoneal dialysis (PD), may contribute to better control of serum potassium. This study aimed to investigate the role residual renal function on potassium intake and excretion in PD patients. METHODS: In this cross-sectional study, dietary potassium was evaluated by the 3-day food record. Potassium concentration was determined in serum, 24 h dialysate, stool ample, and 24 h urine of patients with diuresis > 200 mL/day, who were considered non-anuric. RESULTS: Fifty-two patients, 50% men, 52.6 ± 14.0 years, and PD vintage 19.5 [7.0-44.2] months, were enrolled. Compared to the anuric group (n = 17, 33%), the non-anuric group (n = 35, 67%) had lower dialysate potassium excretion (24.8 ± 5.3 vs 30.9 ± 5.9 mEq/d; p = 0.001), higher total potassium intake (44.5 ± 16.7 vs 35.1 ± 8.1 mEq/d; p = 0.009) and potassium intake from fruit (6.2 [2.4-14.7] vs 2.9 [0.0-6.0]mEq/d; p = 0.018), and no difference in serum potassium (4.8 ± 0.6 vs 4.8 ± 0.9 mEq/L; p = 0.799) and fecal potassium (2.2 ± 0.5 vs 2.1 ± 0.7 mEq/L; p = 0.712). In non-anuric patients, potassium intake correlated directly with urinary potassium (r = 0.40; p = 0.017), but not with serum, dialysate, or fecal potassium. In the anuric group, potassium intake tended to correlate positively with serum potassium (r = 0.48; p = 0.051) and there was no correlation with dialysate or fecal potassium. CONCLUSION: The presence of residual renal function constitutes an important factor in the excretion of potassium, which may allow the adoption of a less-restrictive diet.

Development and Validation of a Food Frequency Questionnaire to Assess Potassium Intake of Patients on Hemodialysis.

OBJECTIVE: To develop and to validate a food frequency questionnaire (FFQ) to assess potassium intake of patients on hemodialysis. METHODS: This is a cross-sectional study that included 41 patients in the FFQ development step and 53 patients in the FFQ validation step. In the FFQ development step, the patients completed a 3-day food record (used as a reference method). Total potassium intake and potassium from each food item were calculated. Food items that contributed up to 90% of the total potassium intake were considered to be included in the FFQ food list. Then the FFQ was applied in person through the google-forms platform. The result of potassium intake obtained by the FFQ was compared with that obtained by the 3-day food record. RESULTS: A total of 94 patients were included: 53.2% women; age 55.7 ± 15.0 years; 47.9% had diabetes; body mass index 25.0 ± 4.5 kg/m2; and dialysis vintage 34.5 (17.0-68.2) months. Demographic, clinical, and laboratory parameters did not differ between the development and validation groups. From the 255 registered food items, 85 comprised the FFQ. The standardized Cronbach's alpha obtained was 0.71. No difference was found between the potassium intake obtained by the FFQ and by the 3-day food record (1,438.5 ± 659.4 mg/d vs. 1,464.8 ± 529.4 mg/d; P = .753, respectively) with an intraclass correlation coefficient of 0.66 (P = .001). No systematic bias or proportionality bias between the methods was observed in the Bland-Altman graphical analysis. CONCLUSION: The quantitative FFQ presented strong relative validity and may constitute a practical tool in the analysis of potassium intake of patients on hemodialysis.

Avaliação do risco cardiovascular em pacientes renais crônicos em fase não dialítica por indicadores antropométricos / Cardiovascular risk evaluation in chronic renal patients in non-dialysis by anthropometric indicators

Introdução: Estudos que adotaram os indicadores antropométricos de risco cardiovascular na avaliação de pacientes com doença renal crônica (DRC) em fase não dialítica são escassos. Objetivo: Avaliar o risco cardiovascular por indicadores antropométricos em pacientes com DRC em fase não dialítica e fatores associados. Métodos: Estudo transversal com 106 pacientes atendidos em hospital universitário, em São Luís-MA. Aplicou-se formulário estruturado com informações sociodemográficas, estilo de vida, morbidades e estadiamento da doença renal. Para avaliação antropométrica e identificação do risco cardiovascular, adotaram-se os indicadores: índice de massa corporal, circunferência da cintura, circunferência do pescoço, diâmetro abdominal sagital, relação cintura-estatura e índice de conicidade. Os testes do Qui-quadrado de Person e Exato de Fischer avaliaram a associação entre as variáveis e adotou-se o nível de significância p<0,05. Resultados: Pela circunferência da cintura, houve risco cardiovascular muito elevado nas mulheres (75,4%), e pelo índice de conicidade, todas estavam em risco (p<0,001). Nos pacientes com ≥60 anos de idade, houve risco cardiovascular pelos indicadores diâmetro abdominal sagital (77,5%), razão cintura-estatura (92,6%) e índice de conicidade (98,2%) (p<0,005). A circunferência do pescoço apontou risco elevado nos fumantes (100,0%) e etilistas (88,9%) (p=0,001). Pela circunferência do pescoço (73,5%) e razão cintura-estatura (91,7%), os renais crônicos diabéticos apresentaram risco cardiovascular elevado (p<0,05). Conclusão: O risco cardiovascular evidenciado por diferentes indicadores antropométricos aponta que ações de promoção da saúde devem ser implementadas, de modo a melhorar o estilo de vida e contribuir para o melhor prognóstico desses pacientes.

Introduction: Studies that have adopted anthropometric indicators for the evaluation of cardiovascular risk in patients with chronic kidney disease (CKD) in the non-dialysis phase are scarce. Objective: To assess cardiovascular risk, with anthropometric indicators, in patients with CKD in the non-dialysis phase and their associated factors. Methods: Cross-sectional study with 106 patients treated at a university hospital in São Luís-MA. A structured form was applied to collect information on sociodemographics, lifestyle, morbidities, and stage of kidney disease. For anthropometric evaluation and identification of cardiovascular risk, the following indicators were adopted: body mass index, waist circumference, neck circumference, sagittal abdominal diameter, waist-to- height ratio, and conicity index. Person's chi-square test and Fischer's exact test evaluated the association between the variables and adopted the significance level p<0.05. Results: According to waist circumference, there was very high cardiovascular risk in women (75.4%); and according to the conicity index, all were at risk (p<0.001). In patients with ≥60 years of age, there was cardiovascular risk according to the indicators of sagittal abdominal diameter (77.5%), waist-to-height ratio (92.6%), and conicity index (98.2%) (p<0.005). Neck circumference showed high risk in smokers (100.0%) and alcohol users (88.9%) (p=0.001). According to neck circumference (73.5%) and waist-to-height ratio (91.7%), diabetic chronic renal patients presented high cardiovascular risk (p<0.05). Conclusion: The cardiovascular risk, evidenced by different anthropometric indicators, shows that actions promoting a healthy lifestyle should be implemented, thus contributing to the better prognosis of these patients.

Diet in Chronic Kidney Disease: an integrated approach to nutritional therapy.

A healthy diet is an essential requirement to promote and preserve health, even in the presence of diseases, such as chronic kidney disease (CKD). In this review, nutritional therapy for CKD will be addressed considering not only the main nutrients such as protein, phosphorus, potassium, and sodium, which require adjustments as a result of changes that accompany the reduction of renal functions, but also the benefits of adopting dietary patterns associated with better outcomes for both preventing and treating CKD. We will also emphasize that these aspects should also be combined with a process of giving new meaning to a healthy diet so that it can be promoted. Finally, we will present the perspective of an integrated approach to the individual with CKD, exploring the importance of considering biological, psychological, social, cultural, and economic aspects. This approach has the potential to contribute to better adherence to treatment, thus improving the patient's quality of life.

Diet in Chronic Kidney Disease: an integrated approach to nutritional therapy

SUMMARY A healthy diet is an essential requirement to promote and preserve health, even in the presence of diseases, such as chronic kidney disease (CKD). In this review, nutritional therapy for CKD will be addressed considering not only the main nutrients such as protein, phosphorus, potassium, and sodium, which require adjustments as a result of changes that accompany the reduction of renal functions, but also the benefits of adopting dietary patterns associated with better outcomes for both preventing and treating CKD. We will also emphasize that these aspects should also be combined with a process of giving new meaning to a healthy diet so that it can be promoted. Finally, we will present the perspective of an integrated approach to the individual with CKD, exploring the importance of considering biological, psychological, social, cultural, and economic aspects. This approach has the potential to contribute to better adherence to treatment, thus improving the patient's quality of life.

RESUMO Uma dieta saudável é essencial para promover e preservar a saúde, mesmo na presença de doenças como a Doença Renal Crônica (DRC). Nesta revisão, a terapia nutricional para pacientes de DRC será abordada levando em conta não só os principais nutrientes que precisam ser ajustados devido às alterações que acompanham a redução das funções renais, tais como proteínas, fósforo, potássio e sódio. Abordaremos também os benefícios da adoção de padrões alimentares associados a desfechos melhores tanto para a prevenção quanto para o tratamento da DRC. Também enfatizaremos que esses aspectos devem ser aliados a um processo de ressignificação do conceito de dieta saudável para que seja possível a sua promoção. Por último, apresentaremos a perspectiva de uma abordagem integrada para o indivíduo com DRC, explorando a importância de considerar aspectos biológicos, psicológicos, sociais, culturais e econômicos. Essa abordagem tem o potencial de contribuir para uma melhor adesão ao tratamento, melhorando assim a qualidade de vida do paciente.