450 - Is There an Association of the Ratio of Non-Protein Calories to Grams of Amino Acids with Amino Acid and Acyl Carnitine Blood Levels in Very Low birth Weight Infants Receiving Parenteral Nutrition?

Poster Number: 450
Publication Number: 450.1801

Background: Studies evaluating the optimal intake of amino acids for very low birth weight (VLBW) infants have often not considered the non-protein calorie to grams of amino acids ratio (NPKcal/g AA) in parenteral nutrition solutions.

Objective: The objectives of this study were to document the ratio in a group of VLBW infants and explore any associations of the ratio to AA and acyl carnitine levels.

Design/Methods: This was a secondary analysis of a retrospective study of the influence of gestational age and chronological age on AA and acyl carnitine profiles. Acyl carnitine and AA levels on day of life 7of three study groups, based upon terciles of the NPKcal/g AA, who were receiving minimal enteral feedings and an enterally fed control group were compared. Growth velocities and changes in z-scores were evaluated.

Results: Data was available for 556 subjects (Table 1). NPKcal/g AA terciles were: 6.3-17.6 (Low, N=153), 17.7-21.2 (Mid, N=150), and 21.3-36.2 (High, N=159). Higher levels of ornithine, citrulline, blood urea nitrogen, isovalerylcarnitine+methylbutyrylcarnitine, and octenoylcarnitine were found in the Low versus the High group (Table 2). From day 1-42 of life the Low group had a lower head circumference (HC) growth velocity and the Low and Mid groups had more negative HC changes in z-scores versus the control group. Linear regression analysis found that both gestational age and NPKcal/g AA were independent factors that influenced differences in these values.

Conclusion(s): This study suggests that VLBW often receive parenteral nutrition solutions containing inadequate energy to prevent oxidation of administered AA. The impact of inadequate caloric intake needs to be considered when evaluating growth and outcomes in nutritional studies of VLBW infants.