Measuring resting energy expenditure in pediatrics

Abstract

We read with interest the study by Kaplan et al.1Kaplan AS Zemel BS Neiswender KM Stallings VA Resting energy expenditure in clinical pediatrics: measured versus predicted equations.J Pediatr. 1995; 127: 200-205Abstract Full Text Full Text PDF PubMed Scopus (83) Google Scholar and particularly the editorial by Pencharz and Azcue2Penchard PB Azcue MP Measuring resting energy expenditure in clinical practice [Editorial].J Pediatr. 1995; 127: 269-271Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar on the measurement of resting energy expenditure (REE) in clinical practice.1Kaplan AS Zemel BS Neiswender KM Stallings VA Resting energy expenditure in clinical pediatrics: measured versus predicted equations.J Pediatr. 1995; 127: 200-205Abstract Full Text Full Text PDF PubMed Scopus (83) Google Scholar, 2Penchard PB Azcue MP Measuring resting energy expenditure in clinical practice [Editorial].J Pediatr. 1995; 127: 269-271Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar We agree that REE measurements in children are frequently necessary to provide a good clinical “energy diagnosis” and treatment in patients with failure to thrive, protein-energy malnutrition, or obesity. Although REE is 65% to 75% of total daily energy expenditure, the assessment of this compartment is invaluable in these cases because disease causes an increase in the energy expenditure variability.3Abdulrazzaq YM Brooke OG Respiratory metabolism in preterm infants: the measurement of oxygen consumption during prolonged periods.Pediatr Res. 1984; 18: 928-931PubMed Google Scholar The editorial suggests that REE does not change significantly with the time of day that the evaluation is performed. However, several investigators have shown that REE has a high intraday variability that can be reduced if the measurement conditions are standarized, as occur with other biologic variables as blood pressure. We currently measure REE at the same time of day, after adequate time for nutrient absorption, and after 30 minutes of rest. After performing more than 1000 calorimetric measurements in our laboratory, we have observed that the measurement of REE is nearly impossible in healthy children who weigh less than 8 kg, because we cannot expect them to remain at rest or in fasting conditions before and during the test. In those cases, we should measure energy expenditure for a period long enough to obtain a representative value of the total daily energy expenditure (3 hours or more for a newborn infant), or we must use the published equations to predict energy expenditure. Because REE is closely related to body cell mass, it is logical that Kaplan et al.1Kaplan AS Zemel BS Neiswender KM Stallings VA Resting energy expenditure in clinical pediatrics: measured versus predicted equations.J Pediatr. 1995; 127: 200-205Abstract Full Text Full Text PDF PubMed Scopus (83) Google Scholar observe that it is better to predict REE from height and weight than from weight only. In effect, as previously published,4Salas JS Moukarzel E Dozio E Goulet OJ Putet G Ricour C Estimating resting energy expenditure by simple lean-body-mass indicators in children on total parenteral nutrition.Am J Clin Nutr. 1990; 51: 958-962PubMed Google Scholar 89%, 91%, or 96% of the variance in REE can be explained by weight, weight and height, or lean body mass, respectively, in a very large hospitalized pediatric population. In our study, we developed REE prediction equations with the measured lean body mass because this is the variable that accounts for the greater variability of REE. 9/35/71614