Hyperhomocysteinemia in chronic renal failure

Homocysteine is a sulfur-containing amino acid derived from the metabolism of methionine, whose abnormal accumulation in plasma is a risk factor for vascular disease in the general population and in patients with chronic renal disease. In these patients, the prevalence of individuals with hyperhomocysteinemia is very high, even in the pre-dialysis stage of the disease. The main factor that seems to be implicated on the elevation of homocysteine levels in this population is the renal mass loss, considering that the kidney has an important role in the metabolism of such amino acid. The treatment of hyperhomocysteinemia consists on supplementation of the vitamins that are involved in the homocysteine metabolism (folate, B6 and B12.). However, for chronic renal disease patients, this treatment is not completely effective, because although it promotes reduction of homocysteine levels, the normalization is not reached in the majority of the patients. This study reviews the hyperhomocysteinemia etiology on chronic renal disease, its main determinants, its relationship with vascular diseases, and the modes of treatment.A homocisteína é um aminoácido sulfurado proveniente do metabolismo da metionina, cujo acúmulo anormal no plasma é um fator de risco para doenças vasculares, tanto na população em geral como nos pacientes com insuficiência renal crônica. Nestes, a prevalência de indivíduos com hiperhomocisteinemia é bastante elevada, mesmo na fase não dialítica da doença, em que a função renal está diminuída, mas ainda não é necessário tratamento dialítico. O principal fator que parece estar implicado na elevação dos níveis de homocisteína nestes pacientes com insuficiência renal crônica é a perda da massa renal, já que esta exerce uma importante função no metabolismo desse aminoácido. O tratamento da hiperhomocisteinemia na população em geral consiste na suplementação com as vitaminas envolvidas no seu metabolismo (folato, B6 e B12). Porém, em pacientes com insuficiência renal crônica, este tratamento não é completamente eficaz, pois apesar de promover a redução dos níveis de homocisteína, não alcança a normalização dos mesmos na maioria dos pacientes. Este estudo compreende uma revisão da etiologia da hiperhomocisteinemia na insuficiência renal crônica, sua relação com as doenças vasculares, seus principais determinantes e as formas de tratamento.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP, EPMSciEL

Adductor pollicis muscle thickness as a predictor of handgrip strength in hemodialysis patients

INTRODUCTION: Recently, the adductor pollicis muscle thickness (APMT) has been suggested as a new nutritional marker in several population. OBJECTIVE: In view of the scarce data regarding the use of this marker in CKD patients, we aimed to evaluate APMT and its association with nutritional parameters in patients on hemodialysis. METHODS: We evaluated 73 hemodialysis patients (52.3 ± 17 years, without residual renal function). The APMT was assessed in the non vascular access arm by means of skinfold caliper. Body composition (bioelectrical impedance), handgrip strength (HGS, dynamometer), nutritional status (subjective global assessment), and laboratory parameters (creatinine, total protein and albumin) were also evaluated. RESULTS: Subjects with APMT values above the median were in greater proportion black/ brown, younger and had higher HGS. The APMT correlated positively with HGS, albumin and body cell mass (%), and negatively with age. In the linear regression analysis adjusted for sex, age and length on hemodialysis, APMT was independently associated with HGS. CONCLUSION: APMT was able to predict HGS in hemodialysis patients, suggesting APMT as a promising nutritional marker in this population.INTODUÇÃO: A espessura do músculo adutor do polegar (EMAP) tem sido sugerida como um novo marcador de estado nutricional em diversas populações. OBJETIVO: Diante da escassez de dados sobre o uso desse marcador nos pacientes com doença renal crônica, o objetivo deste estudo foi avaliar a EMAP e sua associação com indicadores nutricionais em pacientes em hemodiálise. MÉTODOS: Foram avaliados 73 pacientes em hemodiálise (52,3 ± 17 anos, sem função renal residual). A EMAP foi aferida no braço sem o acesso vascular com o auxílio de um adipômetro. A composição corporal (bioimpedância elétrica), a força de preensão manual (dinamômetro), o estado nutricional (Avaliação Global Subjetiva) e os exames laboratoriais (creatinina, proteína total e albumina) também foram avaliados. RESULTADOS: Indivíduos com valores de EMAP acima da mediana eram em maior proporção negros/pardos, jovens e possuíam maior força de preensão manual. A EMAP correlacionou-se positivamente com a força de preensão manual, albumina sérica e massa celular (%), e negativamente com a idade. Na análise de regressão linear ajustada para sexo, idade e tempo em hemodiálise, a EMAP esteve independentemente associada com a força de preensão manual. CONCLUSÃO: A EMAP foi capaz de predizer a força de preensão manual nos pacientes em hemodiálise, o que sugere a EMAP como um marcador promissor de estado nutricional nessa população.Universidade Federal de São Paulo (UNIFESP) EPMUNIFESP, EPMSciEL

Serum albumin as nutritional marker of hemodialysis patients

The prevalence of protein-energy malnutrition is high in patients with chronic renal failure on long-term hemodialysis therapy. Among several parameters available for the assessment of nutritional status, albumin has been the most commonly used given its strong association with morbidity and mortality in those patients. However, many factors such as age, comorbidities, hypervolemia and body losses, can affect the serum albumin concentration. Furthermore, the albumin metabolism can be altered in the presence of inflammation, a common condition in this group of patients. Thus, this communication aimed to address the general aspects of albumin and discuss its usefulness for assessing nutritional status in chronic renal failure patients undergoing hemodialysis.A prevalência de desnutrição protéico-energético em pacientes com insuficiência renal crônica submetidos à terapia de hemodiálise é elevada. Dentre os diversos parâmetros disponíveis para a avaliação do estado nutricional, a albumina tem sido o mais comumente utilizado para este fim visto a sua estreita associação com a morbidade e mortalidade nesta população. No entanto, vários fatores como idade, comorbidades, hipervolemia e perdas corpóreas podem influenciar as concentrações séricas de albumina. Além disso, na vigência de inflamação, condição comumente presente neste grupo de pacientes, o metabolismo da albumina pode encontrar-se alterado, influenciando os seus níveis plasmáticos. Sendo assim, esta comunicação tem como objetivo abordar os aspectos gerais da albumina e discutir a sua utilização na avaliação do estado nutricional de pacientes com insuficiência renal crônica submetidos à hemodiálise.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de MedicinaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP, EPM, Depto. de MedicinaUNIFESP, EPMSciEL

Demographic and occupational profile of dietitians working in dialysis centers in Brazil

ABSTRACT Introduction: In 2004, the Ministry of Health stipulated that dialysis centers were required to have at least one dietitian on their staff. However, the regulation did not include recommendations regarding the number of dietitians or the workload based on the number of patients assisted. Objective: To describe the demographic and occupational profiles of dietitians working in dialysis centers in Brazil. Methodology: An electronic questionnaire was disseminated in social media and messaging apps with questions about the demographic and occupational profile of dietitians working in dialysis centers and matters related to patient care. Results: A total of 207 questionnaires were answered, covering 24% of the dialysis centers in Brazil. More than half of the dietitians (58%) had worked for more than five years in dialysis centers, and 83% reported additional training in Nephrology. The median (interquartile range) number of patients per monthly working hour was 1.6 (1.0-2.3). Considering all dialysis centers, 64% of the patients were seen at least once a month. Differences in demographic/occupational profiles and patient care were associated with workload, the main source of dialysis funding, and Brazilian geographical region. Conclusion: Most dietitians were experienced and trained in Nephrology. Substantial variability was found in the number of patients per dietitian workload, and proportion of patients receiving monthly nutritional care. Further studies are needed to discuss the demands of dietitians, dialysis centers, and patients

Short-term effects of a very-low-protein diet supplemented with ketoacids in nondialyzed chronic kidney disease patients

Objective: To evaluate the effects on the nutritional and metabolic parameters of a very-low-protein diet supplemented with ketoacids (VLPD+KA) in comparison with a conventional low-protein diet (LPD) in chronic kidney disease (CKD) patients.Design: Prospective, randomized, controlled clinical study.Setting: Outpatient Clinic of the Nephrology Division of Federal University of São Paulo, Brazil.Subjects: the study involved 24 patients with advanced CKD ( creatinine clearance <25 ml/min) that were randomly assigned to either a VLPD+KA (VLPD+KA group, 12 patients) or to a conventional LPD with 0.6 g/kg/day ( LPD group, 12 patients). the patients were followed for 4 months.Results: Nutritional status was adequately maintained with both diets for the studied period. Protein intake and serum urea nitrogen decreased significantly only in the VLPD+KA group ( from 0.68 +/- 0.17 to 0.43 +/- 0.12 g/kg/day, P<0.05; from 61.4 +/- 12.8 to 43.6 +/- 14.9 mg/dl, P<0.001; respectively). Ionized calcium did not change in the VLPD+KA group but tended to decrease in the LPD group. Serum phosphorus tended to decrease in the VLPD+KA group probably as a result of a significant reduction in dietary phosphorus (529 +/- 109 to 373 +/- 125 mg/day, P<0.05) associated to the phosphorus-binding effect of the ketoacids. No change in these parameters was found in the LPD group. Serum parathormone increased significantly only in the LPD group (from 241 +/- 138 to 494 +/- 390 pg/ ml, P<0.01). the change in PTH concentration was negatively correlated with changes in ionized calcium concentration ( r = - 0.75, P = 0.02) and positively correlated with changes in serum phosphorus ( r = 0.71, P = 0.03) only in the LPD group.Conclusion: This study indicates that a VLPD+KA can maintain the nutritional status of the patients similarly to a conventional LPD. Besides, an improvement in calcium and phosphorus metabolism and a reduction in serum urea nitrogen were attained only with the VLPD+KA. Thus, VLPD+KA can constitute another efficient therapeutic alternative in the treatment of CKD patients.Sponsorship: This study was supported by CAPES, Oswaldo Ramos Foundation and Fresenius Kabi, Ltda.Universidade Federal de São Paulo, Nutr Program, São Paulo, BrazilUniversidade Federal de São Paulo, Div Nephrol, São Paulo, BrazilUniversidade Federal de São Paulo, Nutr Program, São Paulo, BrazilUniversidade Federal de São Paulo, Div Nephrol, São Paulo, BrazilWeb of Scienc

Resting energy expenditure and its determinants in hemodialysis patients

Objective: Chronic kidney disease is associated with several metabolic disturbances that can affect energy metabolism. As resting energy expenditure (REE) is scarcely investigated in patients on hemodialysis (HD) therapy, we aimed to evaluate the REE and its determinants in HD patients.Design: Cross-sectional study.Setting: Dialysis Unit of the Nephrology Division, Federal University of São Paulo, Brazil.Subjects: the study included 55 patients ( 28 male, 41.4 +/- 12.6 years old) undergoing HD therapy thrice weekly for at least 2 months, and 55 healthy individuals pair matched for age and gender. Subjects underwent fasting blood tests, as well as nutritional assessment, and the REE was assessed by indirect calorimetry.Results: REE of HD patients was similar to that of pair-matched controls (1379 +/- 7272 and 1440 +/- 7259 kcal/day, respectively), even when adjusted for fat-free mass (P = 0.24). REE of HD patients correlated positively with fat-free mass (r = 0.74; P < 0.001) and body mass index (r = 0.37; P < 0.01), and negatively with dialysis adequacy (r = -0.46; P < 0.001). No significant univariate correlation was found between REE and age, dialysis vintage, serum creatinine, urea, albumin, bicarbonate, parathyroid hormone (PTH) or high-sensitivity C-reactive protein (CRP). in the multiple linear regression analysis, using REE as dependent variable, the final model showed that besides the well-recognized determinants of REE such as fat-free mass and age, PTH and CRP were the independent determinants of REE in HD patients (R-2 = 0.64).Conclusions: in this study, the REE of HD patients was similar to that of healthy individuals, even with the positive effect of secondary hyperparathyroidism and inflammation on REE of these patients.Universidade Federal de São Paulo, Div Nephrol, BR-04039000 São Paulo, BrazilUniversidade Federal de São Paulo, Nutr Program, São Paulo, BrazilUniversidade Federal de São Paulo, Div Nephrol, BR-04039000 São Paulo, BrazilUniversidade Federal de São Paulo, Nutr Program, São Paulo, BrazilWeb of Scienc

Exercício aeróbico baseado no primeiro limiar ventilatório em pacientes com excesso de peso e doença renal crônica: impacto sobre a capacidade cardiorrespiratória e funcional

INTRODUCTION: Chronic kidney disease (CKD) and obesity are both associated with reduced physical capacity. The potential benefit of aerobic training on physical capacity has been recognized. The exercise intensity can be established using different methods mostly subjective or indirect. Ventilatory threshold (VT) is a direct and objective method that allows prescribing exercise intensity according to individual capacity. OBJECTIVES: To evaluate the impact of aerobic training at VT intensity on cardiopulmonary and functional capacities in CKD patients with excess of body weight. METHODS: Ten CKD patients (eight men, 49.7 ± 10.1 years; BMI 30.4 ± 3.5 kg/m², creatinine clearance 39.4 ± 9.8 mL/min/1.73 m²) underwent training on a treadmill three times per week during 12 weeks. Cardiopulmonary capacity (ergoespirometry), functional capacity and clinical parameters were evaluated. RESULTS: At the end of 12 weeks, VO2PEAK increased by 20%, and the speed at VO2PEAK increased by 16%. The training resulted in improvement in functional capacity tests, such as six-minute walk test (9.2%), two-minute step test (20.3%), arm curl test (16.3%), sit and stand test (35.7%), and time up and go test (15.3%). In addition, a decrease in systolic and diastolic blood pressures was observed despite no change in body weight, sodium intake and antihypertensive medication. CONCLUSION: Aerobic exercise performed at VT intensity improved cardipulmonary and functional capacities of overweight CKD patients. Additional benefit on blood pressure was observed. These results suggest that VT can be effectively applied for prescribing exercise intensity in this particular group of patients.INTRODUÇÃO: O excesso de peso e a doença renal crônica (DRC) estão associados à baixa capacidade cardiorrespiratória (CR) e funcional (CF). Já foi observado que o treinamento aeróbico (TA) melhora a CR e CF. Métodos indiretos e subjetivos são comumente empregados para a prescrição da intensidade do TA. O limiar ventilatório (LV) é um método direto e objetivo que permite prescrever a intensidade do TA de acordo com a capacidade física do paciente. OBJETIVOS: Avaliar o impacto do TA com base na intensidade do LV sobre a CR e CF de pacientes com excesso de peso e portadores de DRC na fase não dialítica. MÉTODOS: Dez pacientes (oito homens; 49 ± 10,1 anos, IMC 30,4 ± 3,5 kg/m² , depuração de creatinina 39,4 ± 9,8 mL/min/1,73m²) foram submetidos à TA 3 vezes por semana durante 12 semanas. CR (ergoespirometria), CF e parâmetros clínicos foram avaliados. RESULTADOS: O TA promoveu aumento de 20% no consumo pico de O2 (VO2PICO), 16% na velocidade alcançada no VO2PICO e melhora em 9,2% na caminhada de seis minutos, 20,3% na marcha estacionária, 35,7% no sentar e levantar, 16,3% na resistência muscular de membro superior e 15,3% no tempo de ir e voltar. A pressão arterial diminuiu sem modificação nos anti-hipertensivos, no peso ou no consumo de sódio. CONCLUSÃO: Os resultados indicam que o TA baseado na intensidade do LV melhora a CR, CF e pressão arterial de pacientes portadores de DRC com excesso de peso. Isso sugere que o TA baseado na intensidade LV é eficaz e pode ser empregado com segurança nesses pacientes.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo (UNIFESP)UNIFESP Fundação Oswaldo RamosUNIFESP, Fundação Oswaldo RamosSciEL

Physical activity and energy expenditure in haemodialysis patients: an international survey

Background. The assessment of physical activity and energy expenditure is relevant to the care of maintenance haemodialysis (MHD) patients. In the current study, we aimed to evaluate measurements of physical activity and energy expenditure in MHD patients from different centres and countries and explored the predictors of physical activity in these patients. Methods. In this cross-sectional multicentre study, 134 MHD patients from four countries (France, Switzerland, Sweden and Brazil) were included. The physical activity was evaluated for 5.0 ± 1.4 days (mean ± SD) by a multisensory device (SenseWear Armband) and comprised the assessment of number of steps per day, activity-related energy expenditure (activity-related EE) and physical activity level (PAL). Results. The number of steps per day, activity-related EE and PAL from the MHD patients were compatible with a sedentary lifestyle. In addition, all parameters were significantly lower in dialysis days when compared to non-dialysis days (P < 0.001). The multivariate regression analysis revealed that diabetes and higher body mass index (BMI) predicted a lower PAL and older age and diabetes predicted a reduced number of steps. Conclusions. The physical activity parameters of MHD patients were compatible with a sedentary lifestyle. This inactivity was worsened by aging, diabetes and higher BMI. Our results indicate that MHD patients should be encouraged by the health care team to increase their physical activit