Low birthweight @entity1 and total parenteral nutrition immediately after birth. III. Randomised study of energy substrate utilisation, XXXX balance, and @entity544 production.

@entity1 @entity1568 @entity26 @entity1735 @entity544 @entity413
This study aimed to investigate energy substrate utilisation and @entity1568 balance in low birthweight @entity1 receiving total parenteral nutrition during the first days of life, and in particular, to determine the effect of two different @entity413 intakes on @entity544 production. Twenty @entity1 (mean (SE) birthweight 1314 (65) g, mean (SE) gestation 30.9 (0.4) weeks) were recruited to the study. Immediately after birth they were randomised to a @entity1735 intake of 8 g/kg/day (5.5 mg/kg/minute) or 12 g/kg/day (8.3 mg/kg/minute). After 24 hours they were changed to the alternative regimen which was continued for a further 24 hours. Fat and protein intakes were kept constant throughout the study. Indirect calorimetry was performed during each of the regimens, urine was collected for urinary @entity1568 , and substrate utilisation calculated for 12 @entity1 . The @entity1735 utilisation rate was increased during the higher @entity1735 intake. Lipid utilisation rates were significantly different, with net lipid synthesis occurring during high @entity1735 intake. Protein utilisation rates were not influenced by the different @entity1735 intakes. The mean plasma @entity413 concentration was higher during the high @entity1735 intake but the mean highest and lowest values were not significantly different during the two study periods. A plasma @entity413 below 2.6 mmol/l was recorded more frequently during the low @entity413 intake (9/20 v 5/20). Capillary PCO2 values measured during high and low @entity413 intakes were similar (5.9 (0.2) v 6.2 (0.3) kPa. @entity544 production rates were increased during the higher @entity1735 intake but the differences were not significant. Similarly, there was no significant difference in the respiratory quotients (RQ), @entity26 consumption, or energy expenditure during the two study periods.
