Métodos de avaliação da composição corporal em pacientes submetidos à hemodiálise

Comparison of Body Mass Index, Skinfold Thickness, and Bioelectrical Impedance Analysis With Dual-Energy X-Ray Absorptiometry in Hemodialysis Patients

BACKGROUND

Malnutrition is a consistent finding in hemodialysis (HD) patients and is associated with high mortality. The aim was to compare nutrition status indicators using dual-energy x-ray absorptiometry (DXA) as reference in HD patients.

METHODS

Observational cross-sectional study with 42 patients, 55.8 years (±14.6) old, 60% male, HD 2-3 times per week for ≥3 months. HD ranged from 3 months to 28 years (median, 17.3; interquartile range, 8.73-39.0). We used body mass index (BMI) and fat mass (FM) by skinfold thickness (SFT), bioelectrical impedance analysis (BIA), and DXA. Statistical analyses used Bland-Altman plots, Lin's concordance correlation coefficient, the paired t-test, and Pearson or Spearman correlation. P < .05 was significant.

RESULTS

SFT and DXA presented the lowest prevalence of malnutrition (2.4%) and BMI the highest (28.6%). BMI, BIA FM, and SFT FM presented strong positive correlations with DXA FM (r = 0.915; r = 0.976; r = 0.910, P < .001, respectively). BIA FM and fat-free mass (FFM) demonstrated substantial agreement with DXA values (ρ = 0.974 and 0.960, P < .001). Thus, the measurement procedures used, SFT and BIA, underestimated %FM (-4.65% and -2.13%) and overestimated FFM (3.12 kg and 1.0 kg) according to DXA. No differences were found between mean values of BIA FM and DXA (P = .178).

CONCLUSIONS

Compared with DXA, BIA was the most appropriate nutrition indicator for measuring body composition.

Nutrition Support in Critically Ill Patients with AKI

How to cite this article: Ramakrishnan N, Shankar B. Nutrition Support in Critically Ill Patients with AKI. Indian J Crit Care Med 2020;24(Suppl 3):S135-S139.

Association of body fat with inflammation in peritoneal dialysis

Peritoneal dialysis (PD) frequently leads to body weight gain, which appears to be a potential cause of the chronic inflammation frequently present in these patients. The consequences of this inflammation are impaired nutritional status, accelerated atherosclerosis, and increased mortality. To assess the association between inflammation and body fat in female patients treated with PD. Nineteen female patients on PD for at least 6 months with no infectious complications or malignant or acute inflammatory diseases. Nutritional status was determined by measuring weight, height, body mass index (BMI), waist (WC), and mid-arm circumferences (MAC), mid-arm muscle area, and tricipital fold (TCF). Bioelectrical impedance (BIA) was used to determine body composition. Biochemical evaluation included the determination of serum albumin, urea, creatinine, and C-reactive protein (CRP). The glucose absorbed from the dialysis solution was quantitated. According to BMI, two patients were classified as malnourished and ten as overweight/obese. Sixteen individuals had high WC measurements and 12 had excess body fat (BF) as measured by BIA. High CRP levels were observed in 12 patients, who had higher WC, MAC, BMI, TCF, and BF measurements compared to non-inflamed patients. Positive associations were detected between CRP and BMI, MAC, WC, and TCF. Associations between BF and CRP suggest that adiposity may be a potent exacerbating factor of inflammation in this population, especially visceral fat. Thus, obesity may be considered to be one more factor responsible for the early atherosclerosis and high cardiovascular mortality observed in these patients.

Nutritional aspects in acute kidney injury

Nutritional assessment is an indispensable tool for the evaluation and clinical monitoring of patients with acute kidney injury (AKI). Acute loss of renal function interferes with the metabolism of all macronutrients, responsible for proinflammatory, pro-oxidative and hypercatabolic situations. The major nutritional disorders in AKI patients are hypercatabolism, hyperglycemia, and hypertriglyceridemia. Those added to the contributions of the underlying disease, complications, and the need for renal replacement therapy can interfere in the nutritional depletion of those patients. Malnutrition in AKI patients is associated with increased incidence of complications, longer hospitalization, and higher hospital mortality. However, there are few studies evaluating the nutritional status of AKI patients. Anthropometric parameters, such as body mass index, arm circumference, and thickness of skin folds, are difficult to interpret due to changes in hydration status in those patients. Biochemical parameters commonly used in clinical practice are also influenced by non-nutritional factors like loss of liver function and inflammatory status. Although there are no prospective data about the behavior of nutritional markers, some authors demonstrated associations of some parameters with clinical outcomes. The use of markers like albumin, cholesterol, prealbumin, IGF-1, subjective global assessment, and calculation of the nitrogen balance seem to be useful as screening parameters for worse prognosis and higher mortality in AKI patients. In patients with AKI on renal replacement therapy, a caloric intake of 25 to 30 kcal/kg and a minimum amount of 1.5 g/kg/day of protein is recommended to minimize protein catabolism and prevent metabolic complications.

Nutritional evaluation of stage 5 chronic kidney disease patients on dialysis

CONTEXT AND OBJECTIVE

Patients with chronic kidney failure undergoing dialysis have high prevalence of protein-energy malnutrition. There is still no uniform method for assessing these patients' nutritional status. It is recommended that a set of subjective and objective methods should be applied so that an adequate nutritional diagnosis can be reached. The aim of this study was to evaluate the nutritional profile of patients undergoing hemodialysis.

DESIGN AND SETTING

Cross-sectional study conducted in the Dialysis Treatment Unit, Araraquara, São Paulo, Brazil, in 2008.

METHODS

Anthropometric and biochemical indicators were characterized for 48 patients who also gave responses to the modified Subjective Global Assessment questionnaire (SGAm), and possible correlations between these indicators were investigated.

RESULTS

The frequency of moderate or severe malnutrition ranged from 22% to 54%, according to the parameter used. Regarding the patients' conformity with the ideal weight, 29% of them weighed less than 75% of the ideal, and thus were classified as having moderate or severe malnutrition. The most significant correlations were observed between body mass index (BMI) and the idealness of triceps skinfold (TSF), upper arm circumference (UAC) and upper arm muscle circumference (UAMC); and between SGAm and the idealness of UAC and UAMC.

CONCLUSION

The frequency of malnutrition showed great variability among the patients, according to the evaluation criterion chosen. Routine nutritional monitoring and validation of methods for assessing body composition among such patients are extremely important for diagnosing malnutrition early on, thus preventing complications and reducing the morbidity and mortality rates in this population.

Bioimpedância elétrica e sua aplicação em avaliação nutricional

A busca por métodos de estimativa da composição corporal é uma preocupação constante da comunidade científica, com vistas à obtenção de um acurado diagnóstico do estado nutricional de indivíduos e populações. A bioimpedância elétrica tem sido uma alternativa atraente na avaliação da composição corporal, pela possibilidade de se trabalhar com equipamento não invasivo, portátil, de fácil manuseio, boa reprodutibilidade e, portanto, viável para a prática clínica e para estudos epidemiológicos. Sua utilização, que tem como finalidade determinar o fracionamento da composição corporal, tem sido apontada como uma técnica capaz de superar alguns desafios encontrados em outros métodos para avaliar o estado nutricional. Entre os componentes da bioimpedância elétrica, o ângulo de fase consiste em uma ferramenta cada vez mais utilizada na prática clínica, sendo estudado como indicador prognóstico e de estado nutricional. Esse ângulo indica alterações na composição corporal e na função da membrana celular, portanto, no estado de saúde de indivíduos. Dada a carência de estudos brasileiros sobre determinadas aplicações da bioimpedância elétrica, a proposta deste estudo, buscando contribuir com a literatura, é traçar um panorama sobre o emprego dessa técnica e, ainda, apresentar trabalhos que a comparam com outros métodos de avaliação nutricional e composição corporal.

Evolução da massa corporal magra após 12 meses da cirurgia bariátrica

OBJETIVO: O objetivo da pesquisa foi determinar a perda de massa corporal magra em pacientes após cirurgia bariátrica. MÉTODOS: O estudo retrospectivo foi conduzido com 17 prontuários de mulheres obesas submetidas à Derivação Gástrica em Y de Roux com anel de contenção gástrica, incluindo dados obtidos no período pré-operatório imediato e no 1º, 3º, 6º e 12º meses após a cirurgia. Os dados obtidos no prontuário incluíram a idade, medidas de peso, de altura e massa corporal magra e gorda, calculados pela impedância bioelétrica. RESULTADOS: A média de idade das pacientes foi de 43,1, DP=7,7 anos e durante o seguimento houve diminuição significativa do índice de massa corporal [51,2 (40,2-74,1) para 33,7 (24,8-53,4)kg/m²] e da massa corporal gorda [67,5 (51,2-67,4) para 32,1 (16,4-61,9)kg] em 12 meses de seguimento. No primeiro mês após a cirurgia, houve diminuição da massa corporal magra (M=65,3, DP=7,6 para M=59,7, DP=8,1kg), que representou 8,5% em relação aos valores iniciais, sendo que a partir daí, os dados mantiveram-se constantes. CONCLUSÃO: A perda de massa corporal magra pode refletir uma alteração no metabolismo proteico durante o pós-operatório imediato da cirurgia bariátrica, que pode implicar em evolução clínica e nutricional desfavoráveis.

Association between body mass index and body fat in chronic kidney disease stages 3 to 5, hemodialysis, and peritoneal dialysis patients

OBJECTIVE

Chronic kidney disease (CKD) patients may present with altered body composition. Body mass index (BMI) is a simple method for evaluating body fat mass (FM) in the general population. In CKD patients, there are few reports demonstrating the association between BMI and body composition. Our objective was to investigate the reliability of BMI as an indicator of FM in patients with CKD stages 3 to 5.

METHODS

Seventy-eight nondiabetic CKD patients (aged 48, SD +/- 12 years; 45% male) and 30 healthy control subjects (aged 46, SD +/- 12 years; 40% male), matched for age and sex, were evaluated. Chronic kidney disease patients were divided, according to K/DOQI guidelines, into 27 subjects at stages 3 to 4 (mean glomerular filtration rate of 43 +/- 12 mL/minute; age, 52 +/- 10 years), and 51 at stage 5: 25 in hemodialysis (HD) (aged 45, SD +/- 12 years; 44% male), and 26 in peritoneal dialysis (PD) (aged 49, SD +/- 13 years; 42% male). Body mass index was calculated as weight/height(2), and body composition was evaluated through dual-energy x-ray absorptiometry.

RESULTS

There was no difference in median BMI (kg/m(2)) among healthy control subjects (24.8; range, 19.2-34.1), CKD stages 3 to 4 (26.4; range, 20.4-37.6), HD patients (24.5; range, 19.4-35.7), and PD patients (24.5; range, 20.2-37.7; P > .05). Likewise, no significant difference was verified in median body FM (kg) among control subjects (18.8; range, 9.2-36.5), CKD stages 3 to 4 (21.2; range, 11.6-37.9), HD patients (17.1; range, 4.8-38.9), and PD patients (20.1; range, 6.5-41.5; P > .05). Moreover, a positive and significant correlation was found between BMI and FM (kg) in CKD stages 3 to 4 (Rho = 0.67, P = .0002), in HD patients (Rho = 0.67, P = .0002), in PD patients (Rho = 0.79, P < .0001), and in control subjects (Rho = 0.79, P < .0001). Although BMI and lean body mass (in kg) was significantly correlated in CKD stages 3 to 4 (Rho = 0.58, P = .001) and healthy control subjects (Rho = 0.30, P = .007), no significant correlation was found in HD patients (Rho = 0.19, P = .34) and in PD patients (Rho = 0.17, P = .38).

CONCLUSIONS

Body composition did not differ in patients with CKD stages 3 to 5, and between dialysis modalities. Although BMI was strongly and significantly correlated with body FM in CKD patients at stages 3 to 5, lean body mass was not. These findings suggest that BMI is a reliable indicator of body FM in this CKD population.