Evaluation of the total energy expenditure and its components in patients with chronic kidney disease

Abstract

The recommendation of energy intake is based on the total energy expenditure, which has resting energy expenditure (60-75%) and physical activity (15-30%) as the major components. Studies show that in chronic kidney disease patients the resting energy expenditure is reduced or similar to that of healthy individuals. Moreover, there are evidences of the important role of the comorbidities such as hyperparathyroidism, diabetes, and inflammation increasing the resting energy expenditure in this population. Although advances have occurred in the investigations concerning resting energy expenditure in chronic kidney disease patients, the physical activity has been scarcely explored in this population. The proportion in which each one of the components contributes for the total energy expenditure could influence the energy recommendations for this population. Since there is a lack of studies that analyzed the total energy expenditure in patients with chronic kidney disease, the aim of the present study is to evaluate the total energy expenditure and its components in patients undergoing hemodialysis. It will be included 40 patients on hemodialysis at the Dialysis Unit of the Federal University of São Paulo. The exclusion criteria are age <18 years, length on dialysis <3 months, hospitalization in the month prior to the study, amputation, severe cardiopulmonary diseases, neurological diseases and malignance. A control group of healthy individuals, pair-matched by gender and age, with sedentary or light active lifestyles will be formed. The total energy expenditure will be assessed by a biaxial accelerometer, which also provides data of energy expenditure from physical activity. The questionnaires Physical Activity Scale for the Elderly and Stanford 7-day Physical Activity Recall will be applied for evaluating the level of physical activity. The resting energy expenditure will be evaluated by indirect calorimetry. Body composition will be assessed by dual energy X-ray absorptiometry and bioelectrical impedance. It will include measurements of anthropometry (body mass index, arm and abdominal circumferences, and triceps skinfold thickness), subjective global assessment, muscle strength evaluation by dynamometer, and laboratorial parameters (creatinine, urea, hematocrit, hemoglobin, albumin, glucose, glycated hemoglobin, insulin, parathyroid hormone, thyroid stimulating hormone, serum bicarbonate, C-reactive protein, and interleukin-6). (AU)