The phase angle and mass body cell as markers of nutritional status in hemodialysis patients.

OBJECTIVE: Bioelectrical impedance analysis (BIA) is a fast, noninvasive method for assessing body composition, and its role in the evaluation of nutritional status in haemodialysis (HD) has been studied. This study aimed to compare BIA parameters to clinical, biochemical, and anthropometric markers of nutrition in HD patients, such as subjective global assessment modified for renal disease (SGA-1), serum albumin, body mass index (BMI), percent of standard body weight (%SBW), deviation of triceps skinfold thickness (TSF), mid-arm circumference (MAC), mid-arm muscle circumference (MAMC) from the standard value (50th percentile), anthropometry-derived fat (FM-A), and fat-free mass (FFM-A). METHODS: BIA was performed 30 minutes after a HD session and the reactance (Xc), resistance (R), phase angle (PA), body cell mass (BCM), fat mass (FM-BIA), and fat-free mass (FFM-BIA) values were recorded. The prevalence of malnutrition was estimated according to PA and percent of BCM. The correlation between methods was assessed through Pearson's correlation coefficient and Bland and Altman analysis. RESULTS: A total of 58 patients were studied (30 women and 28 men; mean age of 49.2 +/- 14.8 years). The mean PA was 6.19 +/- 1.33 degrees and the mean percent of BCM was 33.75 +/- 5.91%. The prevalence of malnutrition was 17.5% and 43.9% according to the PA and percent of BCM, respectively. PA had a negative correlation with age and SGA-1 score and a positive correlation with percent SBW, MAC, MAMC, FFM-A, and albumin. Percent of BCM had a negative correlation with age, MAC, MAMC and FM-A and a positive correlation with FFM-A and albumin. A significant correlation between FFM-A and FFM-BIA was observed, as well as between FM-A and FM-BIA. CONCLUSIONS: BIA indexes reflected nutritional state. PA and BCM seem to be less influenced by changes in volume and can be used for nutritional assessments of dialysis patients.

Desnutrição na insuficiência renal crônica: qual o melhor método diagnóstico na prática clínica? / Malnutrition in chronic renal failure: what is the best diagnostic method to assess?

Introdução: A desnutrição protéico-calórica, o processo inflamatório sistêmico e os distúrbios mestabólicos são frequentes em pacientes com insuficiência renal crônica em terapia dialítica, contribuindo para sua morbimortalidade. Material e Métodos: No presente estudo, a prevalência de desnutrição em pacientes renais crônicos em hemodiálise em um único centro do Nordeste do Brasil foi avaliada segundo três diferentes técnicas de avaliação subjetiva global (ASG), o índice de massa corporal (IMC), o percentual de peso atual em relação ao ideal, a adequação a o percentil 50 da prega cutânea triciptal (PCT), da circunferência do braço (CB), da circunferência muscular do braço (CMB), a albumina pré-diálise, o ângulo de fase e o percentual de massa celular corporal (MCC). A correlação do diagnóstico nutricional realizado através da ASG com as medidas antropométricas, bioquímicas e bioimpedância elétrica foi pesquisada. Resultados: Foram avaliados 58 pacientes, sendo 30 do sexo feminino (51,7%), com idade média de 49 anos. A prevalência de desnutrição segundo os diferentes métodos variou entre 12,1% a 94,8%. A ASG clássica teve uma concordância moderada no diagnóstico nutricional com a ASG gerada pelo paciente, IMC com ponto de corte em 22,0 kg/m² e CMB; regular com o IMC com ponto de corte em 18,5 kg/m², adequação do peso atual em relação ao ideal, CB e ângulo de fase ruim com a ASG adaptada ao renal, PCT e percentual de MCC. Conclusões: Os métodos de avaliação nutricional comumente utilizados na pr´tica clínica têm restrições na população em diálise, tendo em vista os diferentes percentuais obtidos com os diferentes métodos. Estudos longitudinais, prospectivos, pesquisando a associação dos marcadores nutricionais com eventos adversos como hospitalização e mortilidade, devem continuar sendo realizados para maior esclarecimento do problema.

Introduction: Protein-energy malnutrition, the systemic inflammatory process mestabólicos and disturbances are common in patients with chronic renal failure undergoing dialysis therapy, contributing to morbidity and mortality. Methods: In this study, the prevalence of malnutrition in patients on hemodialysis in a single center in northeastern Brazil was assessed by three different techniques of subjective global assessment (SGA), body mass index (BMI), the percentage of current weight in relation to the ideal, the suitability to the 50th percentile of triceps skinfold thickness (TSF), arm circumference (AC), arm muscle circumference (MAMC), albumin pre-dialysis, the phase angle and percentage of body cell mass (CCM). The correlation of nutritional diagnosis achieved by the ASG to the anthropometric measurements, biochemical and bioelectrical impedance was investigated. Results: We studied 58 patients, 30 females (51.7%), mean age 49 years. The prevalence of malnutrition according to the different methods ranged from 12.1% to 94.8%. The ASG had a classic moderate agreement in the nutritional diagnosis with ASG generated by the patient, with BMI cutoff of 22.0 kg / m² and CMB; regular with BMI cutoff of 18.5 kg / m², adequacy of current weight in relation to the ideal, CB and phase angle with bad ASG adapted to renal PCT and percentage of MCC. Conclusions: The nutritional assessment methods commonly used in clinical pr'tica have restrictions on the population on dialysis, in view of the different percentages obtained with different methods. Longitudinal, prospective, researching the association of nutritional markers with adverse events such as hospitalization and mortilidade should continue being carried out to further clarify the problem.

[Malnutrition in chronic kidney failure: what is the best diagnostic method to assess?].

INTRODUCTION: Protein-energy malnutrition, systemic inflammation, and metabolic disorders are frequent among patients with chronic kidney failure undergoing dialysis, contributing to their morbidity and mortality. MATERIAL AND METHODS: In the present study, the prevalence of malnutrition in chronic renal patients undergoing hemodialysis in one single center in the Northeastern region of Brazil was assessed according to the following: three different methods of subjective global assessment (SGA); body mass index (BMI); percent of standard body weight; adequacy to the 50th percentile of triceps skinfold (TSF) and arm muscle circumference (AMC) thicknesses; pre-dialysis albumin; phase angle; and percentage of body cell mass (%BCM). Agreement of the nutritional status diagnosis performed through SGA with anthropometric, biochemical, and bioelectrical impedance measures was assessed. RESULTS: The study assessed 58 patients [females, 30 (51.7%); mean age = 49 years]. The prevalence of malnutrition according to the different methods ranged from 12.1% to 94.8%. Conventional SGA showed a moderate agreement with patient-generated SGA (PG-SGA), BMI (cutoff point, 22.0 kg/m²), and AMC; a fair agreement with BMI (cutoff point, 18.5 kg/m²), percent of standard body weight, AC, and phase angle; and a poor agreement with SGA adapted to the renal patient, TSF, and %BCM. CONCLUSIONS: The nutritional assessment methods commonly used in clinical practice are subject to restrictions when applied to the dialysis population, considering the different percentages obtained with the different methods. Longitudinal, prospective studies on the association of nutritional markers with adverse events, such as hospitalization and mortality, should be carried out to clarify remaining issues.