Underreporting of energy intake in peritoneal dialysis patients.

OBJECTIVES: This study aimed to assess the prevalence of underreporting among patients treated by peritoneal dialysis (PD), and to investigate whether the reported energy intake is influenced by overweight status in this population. DESIGN: This was a prospective, observational study. SETTING: This study took place at the Dialysis Unit of the Nephrology Division, Federal University of São Paulo-Oswaldo Ramos Foundation, São Paulo, Brazil. PATIENTS: Forty adult patients were recruited: 24 men and 16 women; age, 53.4+/-16.5 years; body mass index (BMI), 25.1+/-3.8 kg/m(2) (x+/-SD); median duration of dialysis, 19 months (range, 3 to 101 months). Only patients on PD >3 months, free of peritonitis for at least 3 months, without catabolic conditions and with normal thyroid function, were included. METHODS: Energy intake was evaluated using a 3-day food record. Resting energy expenditure (REE) was measured by indirect calorimetry. Body composition was assessed using dual-energy x-ray absorptiometry. The total energy (TE) offered was considered the sum of energy intake plus energy provided by glucose absorption. All measurements were collected at baseline and after 6 months. Underreporting of energy intake was considered to have occurred when the TE/REE ratio was <1.40. RESULTS: The TE/REE ratio was 1.35+/-0.31. Twenty-one patients (52.5%) had a TE/REE ratio <1.40. The TE/REE ratio correlated negatively with BMI (r=-0.52, P < .01), and positively with duration of dialysis (r=0.44, P < .01). No correlation was found between TE/REE ratio and any other variables. Patients were divided into two groups according to BMI <25 kg/m(2) and BMI > or =25 kg/m(2). The majority of patients (83.3%) in the higher BMI group had a TE/REE ratio <1.40. In a logistic regression analysis, using TE/REE ratio <1.40 or > or =1.40 as the dependent variable, BMI> or =25 kg/m2 was the only determinant of energy underreporting. After 6 months of follow-up, no change in either body weight or BMI was evident. CONCLUSIONS: This study showed that a significant number of PD patients underreported the energy intake evaluated by 3-day food diaries. This finding was evidenced particularly in overweight patients.

Factors associated with body-fat changes in prevalent peritoneal dialysis patients.

BACKGROUND: Changes in body fat (BF) were shown to occur over time in peritoneal dialysis (PD) patients. However, the factors associated with BF changes have not been fully investigated in this population. METHODS: We studied 45 patients (25 were male; age, 53, SD +/- 15 years; 21 continuous ambulatory peritoneal dialysis/24 automated peritoneal dialysis; PD vintage, 14 ([range, 3 to 104] months; 40% were diabetic; 31% were previously treated by hemodialysis). Body composition was assessed by dual-energy X-ray absorptiometry and bioelectric impedance analysis, nutritional status was assessed by subjective global assessment, energy intake was assessed by 3-day food records, and resting energy expenditure (REE) was assessed by indirect calorimetry. Glucose absorption, serum bicarbonate, and C-reactive protein were also evaluated. All measurements were performed at baseline and after 12 months. RESULTS: Large variability in BF changes was observed among patients: 53% gained BF (+3.0 +/- 2.8), whereas 47% lost BF (-2.3, SD +/- 1.4). At baseline, groups were similar regarding sex, age, percent diabetics, DP modality, characteristics of peritoneal transport, residual renal function, energy intake, glucose absorption, and REE. However, patients who gained BF had lower BF (16.3, SD +/- 6.9 kg, versus 20.9, SD +/- 6.5 kg; P = .03), had a higher ratio of total energy offered (intake plus absorbed glucose) to REE (1.45, SD +/- 0.39, versus 1.26, SD +/- 0.24; P = .04), and were on PD for a shorter time (10 [range, 3 to 104] versus 20 [range, 4 to 76] months; P = .03). This group also had a higher proportion of malnourished patients (50% versus 19%; P = .03) and of patients previously treated by hemodialysis (46% versus 14%; P = .03). After 12 months, a reduction in the frequency of malnutrition (50% to 25%; P = .02) was observed in the group of patients with increased BF. Patients who lost BF reduced their body cell mass (from 21.7 [SD +/- 5.1 kg] to 20.7 [SD +/- 5.0 kg]; P < .01) and level of serum bicarbonate (from 22.7 [SD +/- 3.7 mmol/L] to 20.9 [SD +/- 3.1 mmol/L]; P < .01). Moreover, this group had an increase in frequency of malnutrition (from 19% to 38%; P = .02), a reduction in the proportion of patients with residual renal function (from 62% to 43%; P = .03), and a higher number of hospitalizations (from 25% to 4%; P = .02) during follow-up. Glucose absorption and C-reactive protein were not associated with BF changes. A regression analysis showed that baseline body mass index was independently associated with a gain of BF (-0.19, SE = 0.09, P = .04), and that hospitalization during follow-up was associated with a loss of BF (2.35, SE = 1.19, P = .04). CONCLUSIONS: Prevalent PD patients exhibited a large variability in BF changes. Baseline body mass index and hospitalizations during follow-up were the most important factors associated with these changes.

Waist circumference and visceral fat in CKD: a cross-sectional study.

BACKGROUND: In the general population, waist circumference was noted to be a reliable predictor of visceral fat. In addition, increased waist circumference was strongly associated with risk factors for cardiovascular disease. In patients with chronic kidney disease (CKD), the association of waist circumference with visceral fat was never tested. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: 122 patients with CKD not yet on dialysis therapy (75 men; diabetes mellitus, 30%; age, 55.3 +/- 11.3 years; body mass index, 27.1 +/- 5.2 kg/m(2); estimated glomerular filtration rate, 35.4 +/- 15.2 mL/min/1.73 m(2)) were studied. PREDICTOR: Waist circumference. OUTCOMES & MEASUREMENTS: Anthropometry, abdominal visceral fat measured by means of computed tomography, and cardiovascular disease risk factors. RESULTS: Waist circumference strongly correlated with visceral fat (r = 0.75 for men, r = 0.81 for women; P < 0.01). kappa Statistic was 0.56, indicating relatively good agreement between methods. Body mass index showed a lower correlation coefficient (r = 0.68 for men, r = 0.76 for women; P < 0.01) and poor agreement (0.36) with visceral fat in comparison to waist circumference. In men, waist circumference and visceral fat similarly correlated with high-density lipoprotein cholesterol level, triacylglycerol level, and Homeostasis Model Assessment Index (P < 0.05). In women, waist circumference correlated with age, C-reactive protein level, and Homeostasis Model Assessment Index, whereas visceral fat also correlated with low-density lipoprotein cholesterol and triacylglycerol levels (P < 0.05). LIMITATIONS: Findings are restricted to patients with CKD not yet on dialysis therapy from a single center. CONCLUSIONS: Waist circumference was strongly associated with visceral fat in patients with CKD. Associations between waist circumference and cardiovascular disease risk factors were similar to those observed for visceral fat, particularly in men. These findings suggest that waist circumference may be a simple and inexpensive tool to be used in epidemiological studies.

Estimativa de ingestão protéica de pacientes em hemodiálise comparação entre registro alimentar e equivalente protéico deaparecimento de nitrogênio (pna) / Estimation of protein intake of hemodialysis patients comparison between food record and protein equivalent ofnitrogen appearance (pna)

Introdução: A avaliação do consumo alimentar, particularmente da ingestão de proteínas, constitui uma ferramenta importante na prevenção, tratamento emonitoramento da desnutrição nos pacientes em hemodiálise. Para tanto, os métodos mais comumente utilizados na prática clínica são o registro alimentar eo equivalente protéico do aparecimento de nitrogênio (PNA). Objetivo: Avaliar a concordância entre o registro alimentar e o PNA para a estimativa da ingestãoprotéica nos pacientes em hemodiálise. Casuística e Métodos: Foram estudados 39 pacientes (67% homens, 46,8±14,7anos, IMC 23,5±4,6kg/m2) emtratamento hemodialítico. Os critérios de exclusão foram presença de doenças catabólicas, função renal residual e uso de glucocorticóides. O registro alimentarfoi preenchido durante três dias e o PNA foi calculado conforme recomendado pelo NKF-DOQI. Resultados: A ingestão protéica obtida pelo registro alimentarfoi menor que aquela obtida pelo PNA (56,3±23,4 vs 67,9±23,9g/dia, respectivamente; P≤0,001). Os métodos apresentaram uma boa correlação (r=0,54;P<0,001), porém uma grande variabilidade individual foi observada (-51,7 a +28,5g/dia). A ingestão protéica obtida por ambos os métodos correlacionou-sepositivamente com o IMC (registro alimentar: r=0,41 e PNA r=0,80; P<0,05). A diferença entre os métodos (registro alimentar - PNA) correlacionou-senegativamente com o IMC (r=-0,49; P<0,01). A análise por subgrupos de IMC mostrou que o registro alimentar subestimava a ingestão protéica em relação aoPNA apenas nos pacientes com IMC≥25kg/m2. A regressão linear múltipla apontou o IMC≥25kg/m2 como único fator independentemente associado àsvariações entre os métodos. [β =-16,9 (-31,1 a -2,8); P=0,02] Conclusão: O método do registro alimentar exibiu valores menores de proteínas em relação aométodo do PNA nos pacientes em hemodiálise, sendo a condição de sobrepeso/obesidade um importante determinante destas variações.

Introduction: The assessment of food consumption, particularly of protein intake, constitutes an important tool in the prevention, treatment, and monitoringof malnutrition in hemodialysis patients. Food record and protein equivalent of nitrogen appearance (PNA) are the most commonly used methods for suchpurpose in the clinical practice. Aim: To evaluate the agreement between food record and PNA for the assessment of protein intake in hemodialysis patients.Subjects and Methods: Thirty-nine hemodialysis patients (67% male, 46.8 ± 14.7 years old, BMI 23.5 ± 4.6 kg/m2) were studied. The exclusion criteriawere catabolic illnesses, residual renal function and use of glucocorticoids. Food intake was recorded 3 days and PNA was calculated as proposed by theNKF-DOQI. Results: The protein intake assessed by food record was lower than that obtained by PNA (56.3 ± 23.4 vs 67.9 ± 23.9 g/day, respectively;P≤0.001). The methods were well correlated (r=0.54; P<0.001), however, a large individual variability was observed (-51.7 to +28.5 g/day). The protein intakeobtained by both methods correlated positively with BMI (food record: r=0.41 and PNA: r=0.80; P<0.05). The difference between the methods (food record,PNA) correlated negatively with BMI (r=-0.49; P<0.001). The analysis by subgroups of BMI showed that the food record method underestimated proteinintake in relation to PNA only in patients with BMI ≥25kg/m2. The multiple linear regression analysis pointed to BMI ≥25kg/m2 as a factor independentlyassociated with variations between the methods. Conclusion: The food record method showed lower values of protein in comparison with the PNA methodin hemodialysis patients, and overweight/obesity status was an important determinant of these variations.

Impacto de um programa de educação nutricional no controle da hiperfosfatemia de pacientes em hemodiálise / The impact of a nutrition educational program on the control of the hyperphosphatemia in hemodialysis patients

Introdução: O controle do fósforo sérico é um desafio no tratamento de pacientes em hemodiálise. O emprego de estratégias educativas poderia contribuirpara melhorar a adesão destes pacientes ao tratamento. Assim, o objetivo deste estudo foi avaliar o impacto de um programa de educação nutricional sobreo conhecimento a respeito do fósforo e sobre a fosfatemia de pacientes em hemodiálise. Métodos: Foram incluídos 147 pacientes [85homens/62mulheres,idade= 50,5±15,7 anos, tempo em diálise = 32 (1-205) meses] que estavam no programa de hemodiálise durante o período de agosto a dezembro de 2006.O material educacional incluiu um questionário de avaliação de conhecimentos, uma palestra, jogos e livretos educativos. Foram medidas as concentraçõesséricas de fósforo e uréia, e a eficiência da diálise foi avaliada por meio do Kt/V. Resultados: Após a aplicação do programa educacional, houve umaumento da pontuação do questionário de conhecimentos (5,7±1,1 para 6,6±0,7;P<0,01) e uma redução do fósforo sérico (5,5±1,6 para 5,2±1,6mg/dl;P<0,01). A uréia sérica se manteve e o Kt/V aumentou (1,34±0,28 para 1,43±0,31;P<0,01). Quando os pacientes foram divididos de acordo com aconcentração sérica de fósforo do início do programa, foi observado que, no grupo normofosfatêmico (fósforo sérico ³5,5mg/dl, n=81), não houve alteraçõesno fósforo sérico após a aplicação do programa (4,4±0,7 para 4,6±1,6 mg/dl;P=0,12). Já no grupo hiperfosfatêmico (fósforo sérico ³5,5mg/dl, n=66),observou-se uma redução da concentração sérica de fósforo (6,9±1,2 para 5,8±1,6mg/dl;P<0,01), uréia (173±33 para 167±36mg/dl;P=0,02) e um aumentodo Kt/V (1,26±0,28 para 1,38±0,22;P<0,01). A variação do fósforo sérico neste grupo correlacionou-se positivamente com a variação da uréia sérica(r=0,29; P=0,02), mas não com a variação do Kt/V. A redução da concentração sérica de fósforo para valores inferiores a 5,5mg/dl ocorreu em 39,4.