Energy expenditure and substrate utilization in the course of renutrition of malnourished children.

Energy expenditure (EE) and substrate utilization in the course of renutrition of malnourished children is not well understood in children receiving total parenteral nutrition (TPN). The aim of this study was to evaluate, during protein-glucose renutrition, EE and substrate utilization and the relationship between EE and growth and/or protein metabolism. Seven malnourished children were studied during the first 3 weeks of TPN. Weight-for-height = 81.4 +/- 8.0%, with an initial weight of 4.5 +/- 3.3 kg. Caloric support was progressively increased according to a preestablished protocol. Every 7 days the following were determined: (1) EE at 3 different 3-hour intervals per day using an open circuit indirect calorimetric system, (2) anthropometrically defined fat free mass (FFM), and (3) 24-hour urinary 3-methylhistidine (3-M-His) and protein balance. Compared to initial values, EE increased 13% at day 7 and 36% at day 14. A negative relationship was found between the amount of perfused glucose and lipid utilization (r = -0.82; p less than 0.0001). EE per kilogram of total body FFM changes during renutrition were more than EE changes per kilogram of total body weight. There was a relationship between EE and weight gain (r = 0.62; p less than 0.005) and a positive relationship between EE and protein gain (r = 0.48; p = 0.012) and 3-M-His excretion (r = 0.51; p less than 0.026).(ABSTRACT TRUNCATED AT 250 WORDS)

Estimating resting energy expenditure by simple lean-body-mass indicators in children on total parenteral nutrition.

The aim of this study was to determine simple predictive factors of the resting energy expenditure (REE) in children. Two groups, A (n = 14) and B (n = 23), were defined by their weight-for-height index, less than 90% and greater than 90%, respectively. Anthropometrically assessed lean body mass (LBM), 24-h urinary creatinine, and REE were measured. From multiple-regression analysis, the best-fitting equation for calculating REE (REE = 54.4 LBM (kg) + 0.095 creatinine (mmol/kg) + 4.7) was highly significant (r = 0.987, p less than 0.0001). Although the regressions of REE on weight were significantly different between the two groups, the equations using LBM or 24-h urinary creatinine did not discriminate between them. These findings suggest that an equation based on LBM or 24-h urinary creatinine excretion could be a more accurate estimate of REE than are conventional methods based on weight or height, and it may be applicable to diverse nutritional states.