843 HIGHER SERUM CARNITINE LEVELS AND KETOGENESIS IN BREAST FED AS COMPARED TO FORMULA FED INFANTS

Abstract

The normal newborn infant undergoes a marked metabolic transition in the first days of life. A major feature of this postnatal metabolic adaptation is development of the capacity to utilize fatty acids and ketone bodies as energy substrates. Because of the essential role of carnitine in fatty acid oxidation and ketogenesis, we have investigated relationships between serum carnitine concentrations and serum levels of ketone bodies in breast fed as compared to formula fed newborns. The mean carnitine concentrations in cord blood of normal fullterm newborns was 34 nmoles/ml. At 42 hours of age, breast fed newborns demonstrated higher carnitine levels (56 nmoles/ml) as compared with canitine levels of formula fed infants (32 nmoles/ml). Correspondingly, by 42 hours of age, serum ketone body concentrations (β-hydroxybutyrate plus aceto-acetate) were higher in breast fed (5.9 nmoles/ml) as compared with formula fed infants (3.0 nmoles/ml). The mean glucose concentrations in both groups of infants showed no significant differences. Carnitine concentrations of isolated samples of human breast milk ranged between 50-100 nmoles/ml and were similar to that of formula (40-80 nmoles/ml) suggesting that the carnitine in breast milk may be better absorbed than carnitine in commercial formulas. The data further suggests a relationship between serum carnitine concentration and ketogenesis in newborn infants.