V. Melichar

Changes in the blood levels of lipid metabolites and glucose following a fatty meal in infants.

Fat appears to be of particular importance for infant mammals as is indicated by the fact that milk contains usually more fat than the solid food consumed by adults (Table 1). I n agreement with this, the RQ of newborn infants during the third to fifth postnatal’days indicates a preponderant utilization of fat for energy purposes [33] (80-90% of the nutrients utilized). This was demonstrated for infant rats [9, 10, 111, in which fat utilization during starvation is much higher than in adults of the same species. It seems, however, that fa t is also metabolized in a qualitatively different way by infant mammals than by adults. This was the conclusion from previous experiments [I , 10, 11, 17, 18, 36, 371, in which fat absorption from the intestine and fat utilization were studied in infant rats. In the work presented here similar differences were looked for in human infants. Blood levels of lipids and glucose were studied during fat absorption. These are a fairly good indicator of processes occurring during absorption [ 5 ] . Although changes in blood lipid levels have been studied repeatedly in infants [3, 4, 14, 29,

Free Fatty Acid and Glucose in the Blood of Various Groups of Newborns. Preliminary Report

Immediately after birth, changes in the RQ indicate a preferential utilization of lipids [l, 61. Va,n Duyne & Have1 [ 2 ] and Nov&k et al. [4] showed that immediately after birth the blood-glucose level falls, while the free fatty acid (FFA) content of the blood increases. The intravenous administration of glucose prevents this rise in FFA content [4]. It has been also shown [3] that the relationship between FFA and glucose contents in the blood is different in the newborn than later in life. In the present paper this relationship has been studied in more detail. The blood Ievels of FFA and glucose were determined about 12 hours after birth in several groups of newborn infants (Table 1). Fig. 1 shows that in full-term normal infants there is a negative correlation between these two indicators. In hypotrophic infants (born a t term but