Comparison of Bioelectrical Impedance Vector Analysis (BIVA) to 7-point Subjective Global Assessment for the diagnosis of malnutrition / Comparação da Análise Vetorial de Impedância Bioelétrica (BIVA) com a Avaliação Subjetiva Global de 7 pontos para o diagnóstico de desnutrição

Abstract Introduction: Bioelectrical impedance vector analysis (BIVA) is a non-invasive and low-cost strategy. The methods used to assess malnutrition in patients undergoing HD are still a challenge. The aim of the present study was to compare BIVA to 7-Point Subjective Global Assessment (7-point SGA) to identify malnutrition. We also investigated the sensitivity and specificity of the previously proposed cutoffs point for BIVA parameters. Methods: Patients of both sexes, over 20 years of age, on HD treatment were included. Anthropometric parameters, laboratory data, and bioelectrical impedance analysis (BIA) were evaluated. Values of resistance (R) and reactance (Xc) obtained by mono-frequency BIA were normalized to body height (H) to generate a graph of the bioimpedance vector with the BIVA software. The analysis of the area under the receiver operating curve ROC (AUC) was performed. Results: Among the included 104 patients, the mean age was 51.70 (±15.10) years, and 52% were male. The BIVA had a sensitivity of 35% for diagnosing malnutrition. The specificity of BIVA for identifying the well-nourished patients was 85.7%. The diagnostic accuracy between the BIVA and 7-point SGA was AUC=0.604; 95%CI 0.490-0.726, higher than the previously established cutoff values (AUC=0.514; 95%CI: 0.369-0.631). The 95% confidence ellipses did not overlap (p<0.05). Conclusion: Our study showed low accuracy of BIVA for diagnosing malnutrition using a 7-point SGA as a reference standard. However, it is a complementary method for assessing nutritional status as it provides data on cellularity and hydration, which are important aspects for the HD population.

Resumo Introdução: Análise vetorial de impedância bioelétrica (BIVA) é uma estratégia não invasiva e de baixo custo. Os métodos usados para avaliar desnutrição em pacientes em HD ainda são um desafio. O objetivo do presente estudo foi comparar BIVA com Avaliação Subjetiva Global de 7 pontos (ASG de 7 pontos) para identificar desnutrição. Também investigamos sensibilidade e especificidade do ponto de corte proposto anteriormente para parâmetros de BIVA. Métodos: Foram incluídos pacientes de ambos os sexos, acima de 20 anos, em HD. Foram avaliados parâmetros antropométricos, dados laboratoriais e análise de impedância bioelétrica (BIA). Valores de resistência (R) e reatância (Xc) obtidos por BIA de mono-frequência foram normalizados para altura corporal (H) gerando um gráfico do vetor de bioimpedância com a ajuda do software BIVA. Foi realizada uma análise da área sob a curva ROC (AUC). Resultados: Entre 104 pacientes incluídos, a idade média foi 51,70 (±15,10) anos, e 52% eram homens. BIVA demonstrou sensibilidade de 35% para diagnosticar desnutrição. A especificidade da BIVA para identificar pacientes bem nutridos foi 85,7%. A precisão diagnóstica entre BIVA e ASG de 7 pontos foi AUC=0,604; IC95%: 0,490-0,726, superior aos valores de corte estabelecidos anteriormente (AUC=0,514; IC95%: 0,369-0,631). Elipses de confiança de 95% não se sobrepuseram (p<0,05). Conclusão: Nosso estudo mostrou baixa precisão da BIVA para diagnóstico de desnutrição usando ASG-7 pontos como padrão de referência. Entretanto, é um método complementar para avaliar estado nutricional, pois fornece dados sobre celularidade e hidratação, aspectos importantes para a população em HD.

Comparison of Bioelectrical Impedance Vector Analysis (BIVA) to 7-point Subjective Global Assessment for the diagnosis of malnutrition.

INTRODUCTION: Bioelectrical impedance vector analysis (BIVA) is a non-invasive and low-cost strategy. The methods used to assess malnutrition in patients undergoing HD are still a challenge. The aim of the present study was to compare BIVA to 7-Point Subjective Global Assessment (7-point SGA) to identify malnutrition. We also investigated the sensitivity and specificity of the previously proposed cutoffs point for BIVA parameters. METHODS: Patients of both sexes, over 20 years of age, on HD treatment were included. Anthropometric parameters, laboratory data, and bioelectrical impedance analysis (BIA) were evaluated. Values of resistance (R) and reactance (Xc) obtained by mono-frequency BIA were normalized to body height (H) to generate a graph of the bioimpedance vector with the BIVA software. The analysis of the area under the receiver operating curve ROC (AUC) was performed. RESULTS: Among the included 104 patients, the mean age was 51.70 (±15.10) years, and 52% were male. The BIVA had a sensitivity of 35% for diagnosing malnutrition. The specificity of BIVA for identifying the well-nourished patients was 85.7%. The diagnostic accuracy between the BIVA and 7-point SGA was AUC=0.604; 95%CI 0.490-0.726, higher than the previously established cutoff values (AUC=0.514; 95%CI: 0.369-0.631). The 95% confidence ellipses did not overlap (p<0.05). CONCLUSION: Our study showed low accuracy of BIVA for diagnosing malnutrition using a 7-point SGA as a reference standard. However, it is a complementary method for assessing nutritional status as it provides data on cellularity and hydration, which are important aspects for the HD population.

The relationship between grip strength with health-related quality of life and mortality in hemodialysis patients.

Purpose: Hemodialysis (HD) is a therapeutic modality that enables the highest survival for individuals with chronic kidney disease (CKD). In contrast, HD contributes to the pro-inflammatory state and may negatively affect the muscle strength and quality of life (QoL) of these individuals. To date, few studies have evaluated the association between decrease in strength and QoL in HD patients. Thus, our objective was to assess whether diminished muscle strength is associated with worse health related QoL and mortality. Methods: We included patients aged ≥ 18 years on HD. Clinical and demographic data were collected from patients' medical records. Clinical data, nutritional status (laboratory, anthropometry, bioimpedance analysis) and health-related QoL (World Health Organization's quality of life questionnaire, WHOQOL-Bref) were analyzed at baseline. Mortality was recorded for 32 months. Results: Among the 105 patients evaluated, the median age was 52 (43-64) years, and males were predominant (n = 73; 70%). The general median of QoL was 66.8 ± 11.9. Approximately 30% of patients were considered to have a worse QoL and 12,4% to have low muscle strength. This was not associated with QoL and mortality. HD vintage greater then to 5 years was associated with higher dissatisfaction in the perception of the environmental domain and overall QoL. Conclusion: Our data suggest that low muscle strength was not associated with health-related QoL using the WHOQOL-Bref instrument and mortality.

Short-Term Creatine Supplementation May Alleviate the Malnutrition-Inflammation Score and Lean Body Mass Loss in Hemodialysis Patients: A Pilot Randomized Placebo-Controlled Trial.

BACKGROUND: Creatine supplementation has been proposed to alleviate muscle loss in various populations, but has not been investigated in hemodialysis (HD) patients. Thus, our objective was to evaluate whether creatine supplementation could attenuate the loss of lean body mass (LBM) and malnutrition-inflammation score (MIS) in HD patients. METHODS: A randomized, placebo-controlled, double blind, parallel-design study included HD patients, of both sexes, aged 18-59 years. The patients were allocated to a Placebo Group (PG; n = 15; received maltodextrin, 1st week: 40 g/day and 2nd-4th weeks: 10 g/day) and a Creatine Group (CG; n = 15; received creatine plus maltodextrin, 1st week: 20 g/day of creatine plus 20 g/day of maltodextrin and 2nd-4th weeks: 5 g/day of creatine plus 5 g/day of maltodextrin). Pre and post the intervention, patients were evaluated for food intake, MIS, body composition and biochemical parameters. RESULTS: CG group attenuated the MIS (Pre: 5.57 ± 0.72 vs. Post: 3.85 ± 0.47 score, P = 0.003) compared with PG (Pre: 5.71 ± 0.97 vs. Post: 5.36 ± 0.95 score, P = 0.317) (supplement × time P = 0.017, effect size: 0.964). The change of LBM was greater in CG than in PG (CG: Δ0.95 vs PG: Δ0.13 kg). At post-intervention, 28.6% of PG patients presented LBM loss and 71.4% remain stable. In contrast, 14.4% of CG patients had LBM loss, 42.8% remain stable and 42.8% gained. Food intake and quality of life did not change. CG increased the BMI and gait speed in post-compared to pre-moment, but no difference among the groups. CONCLUSION: In HD patients, four weeks of creatine supplementation may alleviate the MIS as well as attenuate the LBM loss compared to placebo.

Total protein or leucine intakes are not associated with handgrip strength in hemodialysis patients: A pilot study.

BACKGROUND & AIMS: Inadequate protein intake is associated with lean body mass (LBM) loss. However, it is unclear whether high protein diet and leucine intake are associated with handgrip strength (HGS), a validated marker of muscle function. This study aims to: i) assess the prevalence of patients with low HGS; and ii) verify if HGS is correlated with high protein diet and leucine consumption in hemodialysis patients. METHODS: This cross-sectional study analysed patients at two center hemodialysis (HD) clinic and sixty-two patients aged ∼39 years with length of time on HD ∼60 months undergoing HD was carried out. Body weight (kg), LBM (kg) and body fat mass (%) assessments were performed by dual-energy X-ray absorptiometry and height (m) through portable stadiometer. Body mass index (BMI) (kg/m2) was calculated using the body weight and height. HGS (kg) was measured using a hydraulic dynamometer. Fisher's exact test, Chi-square, Pearson's correlation, and logistic regression were done to test the hypothesis. RESULTS: Out of 62 patients, 47 (75.8%) presented low HGS. In addition, no correlation was found between protein intake (if in percentage or g/kg/d) and HGS (r = 0.07, p = 0.58; r = -0.04, p = 0.70, respectively). Although there is a low correlation among leucine intake (g/d) and HGS (r = 0.39, p = 0.01), low HGS was not associated with leucine intake in the crude model (OR: 0.86 95%CI(0.60-1.24) p = 0.441), nor after adjustment for age, sex and BMI (OR: 0.84 95%CI(0.56-1.26), p = 0.422). CONCLUSIONS: Approximately 75% of patients undergoing hemodialysis presented low HGS. Additionally, neither a high protein diet nor leucine intake was associated with the HGS values.

Pre-sarcopenia in patients undergoing hemodialysis: Prevalence and association with biochemical parameters.

BACKGROUND & AIMS: Albumin and C reactive protein (CRP) concentrations are associated with the loss of lean body mass in the elderly. However, it remains to be ascertained whether these parameters are associated with pre-sarcopenia of chronic renal failure adult's patients undergoing replacement therapy. Therefore, we aimed to investigate the prevalence of pre-sarcopenia and it association with serum albumin and CRP concentrations in adult patients. METHODS: A cross-sectional study was conducted enrolling hemodialysis patients. Body weight, body mass index (BMI), and arm, thigh and calf circumferences were assessed using the inelastic tape; handgrip strength using a dynamometer; and body fat mass and appendicular lean mass (ALM) using the DXA. The classification of pre-sarcopenia was obtained by ALM values. RESULTS: From sixty-two patients, 35.5% were diagnosed with pre-sarcopenia. Logistic regression analysis revealed no show association between pre-sarcopenia (absence or presence) with serum CRP or albumin concentrations in both models, crude or adjusted by body fat mass. CONCLUSIONS: Approximately one-third of patients undergoing replacement therapy presented pre-sarcopenia, but no association with serum albumin and CRP concentrations were found.