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.

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.

Influence of nutritional status, laboratory parameters and dietary patterns upon urinary acid excretion in calcium stone formers / Influência do estado nutricional e dos parâmetros laboratoriais e dietéticos sobre a excreção urinária ácida em pacientes portadores de litíase cálcica

ABSTRACT Introduction: Obesity and Metabolic Syndrome (MS) are associated with low urinary pH and represent risk factors for nephrolithiasis, especially composed by uric acid. Acidogenic diets may also contribute to a reduction of urinary pH. Propensity for calcium oxalate precipitation has been shown to be higher with increasing features of the MS. Objective: A retrospective evaluation of anthropometric and body composition parameters, MS criteria and the dietary patterns of overweight and obese calcium stone formers and their impact upon urinary pH and other lithogenic parameters was performed. Methods: Data regarding anthropometry, body composition, serum and urinary parameters and 3-days dietary records were obtained from medical records of 102(34M/68F) calcium stone formers. Results: A negative correlation was found between urinary pH, waist circumference and serum uric acid levels (males). The endogenous production of organic acids (OA) was positively correlated with triglycerides levels and number of features of MS (males), and with glucose, uric acid and triglycerides serum levels, and number of features of MS (females). No significant correlations were detected between Net Acid Excretion (NAE) or Potential Renal Acid Load of the diet with any of the assessed parameters. A multivariate analysis showed a negative association between OA and urinary pH. Conclusion: The endogenous production of OA and not an acidogenic diet were found to be independently predictive factors for lower urinary pH levels in calcium stone formers. Hypercalciuric and/or hyperuricosuric patients presented higher OA levels and lower levels of urinary pH.

RESUMO Introdução: A obesidade e a Síndrome Metabólica (SM) se associam a pH urinário ácido e representam fatores de risco para litíase renal, especialmente a úrica. Dietas acidogênicas também podem contribuir para a redução do pH urinário. Já foi demonstrado maior risco de precipitação de oxalato de cálcio em proporção aos critérios de SM. Objetivo: Avaliar retrospectivamente o impacto de parâmetros antropométricos, composição corporal, critérios de SM e padrão alimentar sobre o pH urinário e outros parâmetros litogênicos em pacientes com sobrepeso e obesos com litíase cálcica. Métodos: Foram coletados dados de antropometria, composição corporal, exames séricos e urinários, e registros alimentares (3 dias) de 102 (34M/68F) pacientes com litíase cálcica. Resultados: O pH urinário se correlacionou negativamente com a circunferência da cintura e ácido úrico sérico (homens). A produção endógena de ácidos orgânicos (AO) se correlacionou positivamente com os triglicérides séricos e o número de critérios de SM (homens), e com glicemia, ácido úrico, triglicérides e número de critérios para SM (mulheres). Não se observaram correlações significantes entre a excreção renal líquida de ácidos (NAE) e o potencial de carga ácida renal (PRAL) da dieta com nenhum dos parâmetros avaliados. Na análise de regressão multivariada, os AO apresentaram associação negativa significante com o pH urinário. Conclusão: A produção endógena de AO, e não um padrão de dieta acidogênica, foi o fator determinante independente para menores níveis de pH urinário em pacientes com litíase cálcica. Pacientes com hipercalciúria e/ou hiperuricosúria apresentaram maiores valores de AO e menores de pH urinário.

The cross-talk between the kidney and the gut: implications for chronic kidney diseaseThe cross-talk between the kidney and the gut: implications for chronic kidney disease

In recent decades, special attention has been given to the potential association between the gut ecosystem and chronic diseases. Several features and complications of chronic kidney disease (CKD) may induce an unbalanced gut environment, leading to unfavorable consequences for a patient's health. The first section of this review is dedicated to a description of some aspects of gut microbiota and intestinal barrier physiology. The following section explores the impact of CKD on the gut ecosystem and intestinal barrier, particularly the association with uremic toxins, inflammation, and immunodeficiency. Finally, the review describes the state of the art of potential therapies with prebiotics, probiotics, and synbiotics employed to modulate the gut environment and to reduce the generation of colon-derived uremic toxins in CKD.

Impacto da sessão de hemodiálise na força de preensão manual / Impact of hemodialysis session on handgrip strength

Resumo Introdução: A força de preensão manual (FPM) é um método simples, confiável e com bom valor preditivo para avaliar a função muscular de pacientes submetidos à hemodiálise (HD). Porém, ainda não existe um consenso a respeito do momento mais apropriado para a aferição da medida, já que o desempenho da FPM pode ser influenciado pelas flutuações hidroeletrolíticas e de pressão arterial que acometem esses pacientes. Objetivo: Investigar o impacto da sessão de diálise sobre a FPM em pacientes submetidos à HD. Métodos: Trata-se de um estudo transversal com 156 pacientes [57,7% homens, idade mediana de 56,5 (42-67) anos, 28,8% diabéticos, IMC médio de 24,75 ± 4,5 kg/m2 e tempo em HD de 38 (19,25-72,75) meses]. Foram realizadas aferições da FPM com um dinamômetro nos minutos iniciais e ao término da sessão de HD. Os valores obtidos foram comparados com um padrão de referência nacional. Dados clínicos, demográficos e laboratoriais foram coletados do prontuário médico. Resultados: Foi observada uma redução significante da FPM após a sessão de HD (28,6 ± 11,4 kg para 27,7 ± 11,7 kg; p < 0,01). A prevalência de pacientes com FPM abaixo do percentil 30 aumentou de 44,9% para 55,1% (p < 0,01). A redução da pressão arterial durante a diálise foi o único fator que se associou com a redução da FPM. Conclusão: Os achados mostram que o processo de HD influencia negativamente a FPM.

Abstract Introduction: Handgrip strength (HGS) is a simple and reliable method with a good predictive clinical value for assessing muscle function of patients undergoing hemodialysis (HD). However, there is no consensus regarding the appropriate moment for performing the HGS measurement since the performance of the HGS can be influenced by fluid, electrolyte and blood pressure changes that affect patients on HD. Objective: To investigate the impact of the dialysis session on the HGS in patients undergoing HD. Methods: This is a cross-sectional study with 156 patients [57.7% male, median age of 56.5 (42-67) years old, 28.8% diabetes, mean BMI of 24.75 ± 4.5 kg/m2 and HD vintage of 38 (19.25 to 72.75) months]. Measures of HGS were performed with a dynamometer during the initial minutes of the HD session and at the end of the session. The values obtained were compared with a national standard reference. Clinical, demographic and laboratory data were collected from medical records. Results: A significant reduction of HGS was observed after the HD session (28.6 ± 11.4 kg to 27.7 ± 11.7 kg; p < 0.01). The prevalence of patients with HGS below the 30th percentile increased from 44.9% to 55.1% (p < 0.01). The decrease in blood pressure during dialysis was the only factor associated with the reduction of HGS. Conclusion: These findings show that the HD procedure affects negatively the HGS.

The short-term effects of olive oil and flaxseed oil for the treatment of constipation in hemodialysis patients.

OBJECTIVES: To evaluate the effects of olive oil and flaxseed oil compared with mineral oil for the treatment of constipation in patients undergoing hemodialysis. METHODS: A 4-week, double-blind, randomized, and controlled trial was conducted. Fifty constipated patients (29% male, 51 ± 12 years) diagnosed by the Rome III criteria were randomly assigned to receive mineral oil (control group; n = 17), olive oil (n = 16), or flaxseed oil (n = 17). The initial oil dose was 4 mL/day, and adjustments during the follow-up could be made as needed. The impact of the intervention was assessed by the Rome III criteria scores. RESULTS: The most frequent symptoms of constipation evaluated by the Roma III criteria at baseline were comparable among the groups and included "incomplete evacuation" (92%), "lumpy or hard stools," (72%) and "anorectal obstruction" (70%). The Rome III score improved significantly in patients receiving mineral oil (10.5 ± 5.0 to 4.1 ± 4.0; P < .01), olive oil (10.3 ± 4.2 to 3.2 ± 3.8; P = .01), and flaxseed oil (9.6 ± 4.2 to 6.0 ± 5.1; P < .01), with no significant group-by-time interaction (P = .15). The scores of 5 from 6 constipation symptoms reduced similarly in the mineral oil and olive oil groups, whereas only the frequency of evacuation and the consistency of stools improved in the flaxseed oil group. CONCLUSIONS: We demonstrated that the daily use of olive oil or flaxseed oil was as effective as mineral oil in the treatment of constipation in patients undergoing hemodialysis.

Subjective global assessment for the diagnosis of protein-energy wasting in nondialysis-dependent chronic kidney disease patients.

OBJECTIVES: Subjective global assessment (SGA) has been demonstrated to be a reliable method for protein-energy wasting (PEW) evaluation in chronic kidney disease (CKD) patients on dialysis. Few data are available on PEW evaluation in nondialysis stages of CKD, and the validity of SGA has been scarcely investigated in this population. Herein, we aimed to evaluate in nondialysis-dependent CKD patients (NDD-CKD): (1) the prevalence of PEW by SGA; (2) the most common abnormalities of the SGA components; and (3) the agreement of SGA with the traditional anthropometric parameters. DESIGN AND SUBJECTS: This is a retrospective cross-sectional study including 922 NDD-CKD patients referred to the renal dietitians in the period of 2001 to 2012. Nutritional status was assessed by 7-point SGA. Body mass index (BMI), midarm circumference, midarm muscle circumference, and triceps skinfold thickness were available from 494 patients. RESULTS: From the 922 patients, 58.6% were men, mean age was 63.8 ± 13.6 years, BMI was 27.7 ± 5.3 kg/m(2). The majority of the patients were in CKD Stages 3 (48.9%) or 4 (40.3%). PEW (SGA ≤5) was present in 11% of the patients and 32% had signs of PEW (SGA 6). In the logistic regression analysis, the presence of comorbidities and worse renal function were independently associated with PEW. Among the SGA components, the most frequent abnormality in patients with PEW was muscle and fat wasting (88.6%). BMI, midarm circumference, midarm muscle circumference, and triceps skinfold thickness were lower across the worse SGA scores, and a moderate to good level of agreement was found between the anthropometric parameters and presence of PEW evaluated by SGA. CONCLUSIONS: The prevalence of PEW was 11% in our unselected cohort of NDD-CKD patients. The physical examination component (muscle/fat wasting) was the most frequent alteration found in those patients. When compared with anthropometric parameters, 7-point SGA has shown to be a valid tool to assess PEW in NDD-CKD population.