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.

Association Between Serum Myostatin Levels, Hospital Mortality, and Muscle Mass and Strength Following ST-Elevation Myocardial Infarction.

AIM: This study aimed to evaluate the association between serum myostatin levels, hospital mortality, and muscle mass and strength following ST-segment elevation myocardial infarction (STEMI). METHODS: This was a prospective observational study. Within 48 hours of admission, bioelectrical impedance and handgrip strength were assessed and blood samples collected for myostatin evaluation. Hospital mortality was recorded. A multiple logistic regression model was also constructed, adjusted by parameters that exhibited significant differences in the univariate analysis, to evaluate the association between myostatin levels and hospital mortality. RESULTS: One hundred and two (102) patients were included: mean age was 60.5±10.6 years, 67.6% were male, and 6.9% died during hospital stay. Univariate analysis showed that patients with lower myostatin levels had higher mortality rates. Serum myostatin levels positively correlated with handgrip strength (r=0.355; p<0.001) and appendicular skeletal muscle mass index (r=0.268; p=0.007). Receiver operating characteristic (ROC) curve analysis revealed that lower myostatin levels were associated with hospital mortality at the <2.20 ng/mL cut-off. Multiple logistic regression showed that higher serum myostatin levels were associated with reduced hospital mortality when adjusted by ß blocker use (OR, 0.228; 95% CI, 0.054-0.974; p=0.046). CONCLUSIONS: Serum myostatin concentrations positively correlated with muscle mass and strength in STEMI patients. Further assessment of serum myostatin association with mortality should be conducted using a larger sample and assessing the additive value to the Global Registry of Acute Coronary Events (GRACE) or thrombolysis in myocardial infarction (TIMI) risk scores.

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.

Role of Thiamin in Health and Disease.

Thiamin is a hydrosoluble vitamin that plays a role in several biological processes, mainly in glucose metabolism. There are several risk factors for developing thiamin deficiency, such as malnutrition, refeeding syndrome, gastrointestinal surgery, and alcoholism. Recently, the role of thiamin in critically ill patients has gained prominence, and the prevalence of thiamin deficiency was found to be increased in patients with severe burns, major surgery, septic shock, end-stage renal disease, and heart failure. In adults, thiamin deficiency presents as encephalopathy, dry beriberi (with neurological signs and symptoms), or wet beriberi (with cardiovascular signs and symptoms). Thiamin deficiency can be diagnosed clinically, and all clinicians should be aware of this disease, especially in patients with risk factors for thiamin deficiency. Thiamin supplementation should be started as early as possible in patients suspected to have thiamin deficiency. Treatment is safe, inexpensive, simple, and life-saving. Diagnosis is confirmed on a positive response to treatment.

Pamidronate attenuates diastolic dysfunction induced by myocardial infarction associated with changes in geometric patterning.

BACKGROUND/AIMS: The aim of this study was to evaluate the influence of pamidronate on ventricular remodeling after myocardial infarction. METHODS: Male Wistar rats were assigned to four groups: a sham group, in which animals were submitted to simulated surgery and received weekly subcutaneous injection of saline (S group; n=14); a group in which animals received weekly subcutaneous injection of pamidronate (3 mg/kg of body weight) and were submitted to simulated surgery (SP group, n=14); a myocardial infarction group, in which animals were submitted to coronary artery ligation and received weekly subcutaneous injection of saline (MI group, n=13); and a myocardial infarction group with pamidronate treatment (MIP group, n=14). The rats were observed for three months. RESULTS: Animals submitted to MI had left chamber enlargement and worse diastolic and systolic function compared with SHAM groups. E/A ratio, LV posterior and relative wall thickness were lower in the MIP compared with the MI group. There was no interaction between pamidronate administration and MI on systolic function, myocyte hypertrophy, collagen content, and calcium handling proteins. CONCLUSION: Pamidronate attenuates diastolic dysfunction following MI.