IJCS | Volume 32, Nº2, May/June 2019

258 Rosário et al. Adductor pollicis muscle in heart failure Int J Cardiovasc Sci. 2019;32(3)253-260 Original Article of APM thickness with BMI, AMC, AMA, and lean mass obtained by EBI, especially in women. Although the present study has observed a correlation betweenAPM thickness and BMI, over half of the patients were classified as having excess weight according to the BMI, and approximately 70% were considered malnourished according to APM thickness. This can be explained by the fact that the BMI is unable to differentiate body compartments, in addition to the fact that increased BMI is associated with a chronic proinflammatory status able to lead to protein depletion. 6 The APM thickness was also associated with the SPA. The SPA corresponds to the PA adjusted for gender and age from reference values for the Brazilian population. 22 Thus, the SPA can be used to compare studies from different populations with different age and gender distributions. The cutoff value of -1.65 represents the 5th percentile and can be considered as the lowest acceptable limit for a healthy population. 25 Still, no studies have defined cutoff values for SPA specific to the HF population. The use of EBI in patients with HF is considered valid by several authors. 37-39 However, there is still debate about its use in these patients. According to the Brazilian Medical Association, 10 the use of EBI is not appropriate in situations of ionic or fluid imbalance, such as edema and ascites, conditions frequently observed in patients with HF and which promote water retention and increase in extracellular compartment and, therefore, overestimate the fat-free mass, 36 a situation highlighted as one of the main sources of error in the application of the method. Martinez et al. 40 claim that due to the variation in tissue hydration in patients with HF, it would be more appropriate to use “raw measures” generated by EBI, such as reactance, resistance, and PA, since these do not depend on regression equations or the patient’s weight. In the present study, the standardization of assessment using widely known protocols, 10,21 in addition to the exclusion of patients not using diuretics, maintaining a homogeneous group, and those with clinical evidence of edema and ascites, were essential for better reliability of the EBI results. When the HF functional classification was assessed, the APM thickness values were observed to be significantly higher in NYHA I patients when compared withNYHA II ones. TheNYHA functional classification 11 is an instrument with established validity and reliability, used to evaluate the symptomatic effect of cardiac disease, allowing to stratify the degree of limitation imposed by the disease on daily activities. 41 HF is related to a low tolerance to exercises with pronounced metabolic and respiratory responses capable of leading to inactivity, causing muscle atrophy, which is ultimately associated with fatigue and decreasedmuscle strength. 42,43 This way, it is reasonable to propose that the greater the physical limitation, the higher the NYHA functional class 11 and, consequently, the lower the somatic protein mass. Therefore, it is possible that the reduction in APM thickness is related to a reduction in daily activities and is independent from the catabolism and the disease itself. 43 Although the present study has been a pioneer in evaluating APM thickness as an indicator of nutritional status in patients with HF, it has some limitations. Due to financial and infrastructure limitations, methods that are more accurate in assessing body composition, such as dual- energy X-ray absorptiometry, could not be carried out. Therefore, the sensitivity and specificity of APMthickness comparedwith themethods considered the gold standard for the evaluation of the somatic nutritional protein status could not be measured. Additionally, the intraobserver and interobserver variability of APM measurements were not evaluated. However, in order to standardize the protocols of assessment and minimize the variability in APMmeasurements, the nutritionists responsible for the nutritional assessment were previously trained to perform anthropometric assessment and EBI. Conclusions The present study showed an increased frequency of malnutrition when APM thickness was used as a diagnostic indicator of nutritional status. Traditional indicators used to categorize the nutritional status were also directly associatedwith APM thickness. In addition, APM thickness values were directly associated with PA and SPA, recognized prognostic markers in different clinical situations. Additional prospective studies should be conducted in order to evaluate alterations in APM thickness in relation to disease duration and severity, as well as the presence of clinical complications and survival of patients with HF. Author contributions Conception and design of the research: Rosário FS, Giannini DT, Leal VO, Mourilhe-Rocha R. Acquisition