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Lysine kinetics in preterm infants: the importance of enteral feeding
S R D van der Schoor1, P J Reeds, F Stellaard
1Erasmus MC-Sophia Children's Hospital, Department of Paediatrics, Dr Molewaterplein 60, 3015 GJ, Rotterdam, The Netherlands.
Insights
First pass lysine metabolism in preterm infants is higher with partial enteral feeding. Full enteral feeding improves lysine balance and protein deposition compared to parenteral administration.
Area of Science:
- Biochemistry
- Neonatal Nutrition
- Pediatric Gastroenterology
Background:
- Lysine is an essential amino acid crucial for newborn development.
- Intestinal first-pass metabolism significantly impacts systemic lysine availability.
- Understanding lysine metabolism in preterm infants is vital, especially with varying enteral intake levels.
Purpose of the Study:
- To investigate the extent of intestinal first-pass lysine metabolism in preterm infants.
- To compare lysine kinetics under partial versus full enteral feeding conditions.
- To determine the impact of feeding method on lysine utilization and balance in preterm neonates.
Main Methods:
- Study involved six preterm infants with low birth weight.
- Dual stable isotope tracer techniques were employed to measure lysine kinetics.
- Infants were assessed during two feeding periods: 40% enteral/60% parenteral and 100% enteral feeding.
Main Results:
- Fractional intestinal lysine uptake was significantly higher during partial enteral feeding (32% vs. 18%).
- Absolute lysine uptake did not differ significantly between feeding groups.
- Whole body lysine oxidation decreased, and lysine balance improved with full enteral feeding.
Conclusions:
- Preterm infants exhibit higher fractional intestinal lysine uptake during partial enteral feeding.
- Full enteral feeding enhances lysine utilization, reducing oxidation and improving net balance.
- Dietary lysine is more effective than parenteral lysine in promoting protein deposition in preterm infants.
Introduction:
Lysine is the first limiting essential amino acid in the diet of newborns. First pass metabolism by the intestine of dietary lysine has a direct effect on systemic availability. We investigated whether first pass lysine metabolism in the intestine is high in preterm infants, particularly at a low enteral intake.
Patients And Methods:
Six preterm infants (birth weight 0.9 (0.1) kg) were studied during two different periods: period A (n = 6): 40% of intake administered enterally, 60% parenterally; lysine intake 92 (6) micromol/(kg x h); and period B (n = 4): 100% enteral feeding; lysine intake 100 (3) micromol/(kg x h). Dual stable isotope tracer techniques were used to assess splanchnic and whole body lysine kinetics.
Results:
Fractional first pass lysine uptake by the intestine was significantly higher during partial enteral feeding (period A 32 (10)% v period B 18 (7)%; p<0.05). Absolute uptake was not significantly different. Whole body lysine oxidation was significantly decreased during full enteral feeding (period A 44 (9) v period B 17 (3) micromol/(kg x h); p<0.05) so that whole body lysine balance was significantly higher during full enteral feeding (period A 52 (25) v period B 83 (3) micromol/(kg x h); p<0.05).
Conclusions:
Fractional first pass lysine uptake was much higher during partial enteral feeding. Preterm infants receiving full enteral feeding have lower whole body lysine oxidation, resulting in a higher net lysine balance, compared with preterm infants receiving partial enteral feeding. Hence parenterally administered lysine is not as effective as dietary lysine in promoting protein deposition in preterm infants.
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