Apolipoprotein and Lipid Composition of Plasma Lipoproteins in Neonates during the First Month of Life

Abstract

ABSTRACT. In this study the lipid and apoprotein profiles were investigated in newborns at 0, 7, and 30 days of life. The plasma lipoproteins were separated both by ultracentrifugation and gel filtration in order to compare the patterns obtained by the two techniques. At birth, the apo E concentration is comparable to that measured in adults, but its distribution among lipoproteins is significantly different as more than 80% of the plasma apo E belongs to high-density lipoproteins (HDL). At 7 and 30 days the plasma apo E concentrations are close to the values at birth, but a significant redistribution occurs from HDL to very low-density lipoproteins. By analogy with apo B, the plasma apo CIII concentration is low at birth and increases between 0 and 7 days by a factor of about two. Plasma triglycerides increase significantly during the first week of life so that the apo CIII increase is most pronounced in very low-density lipoproteins. These lipoproteins therefore become enriched in apo E, apo CIII and triglycerides between 0 and 7 days. At birth, a distinct HDL fraction, enriched in apo E, apo A11 and cholesterol (HDLE), could be detected. To compensate for the low LDL levels, this HDLE fraction might function as an additional source for cholesterol delivery to peripheral tissues via the apo (B, E) receptor. At later age, low-density lipoprotein synthesis is enhanced, apo E is transferred to very low-density lipoproteins, and cholesterol delivery via the HDL, becomes less important. These data demonstrate that significant differences occur in the plasma concentration and distribution of the apo CIII and E proteins during the initial period of life, and that these apoproteins fulfill an important metabolic role. (Pediatr Res 20: 324-328, 1986) Abbreviations HDL, high-density lipoproteins VLDL, very low-density lipoproteins LDL, low-density lipoproteins During the perinatal period, major shifts in nutritional supply cause changes in substrate utilization by the fetus and newborn. Unimpeded substrate flow from placenta to fetus is required to meet the energy requirements for growth and for fuel storage, primarily of glycogen and fat. During the intra-and postpartum periods, this constant flow is interrupted so that glycogen is required to maintain serum glucose levels. Glycogen stores are then depleted and active glycogenesis starts. In the perinatal period, fatty acid and ketone body oxidation become important energy sources, and during this period an adaptation to a high fat milk diet becomes therefore necessary.These adaptations are controlled by changes in substrate flow and hormonal milieu of the fetus and newborn. Such changes n substrate result in rapid shifts in the synthesis and metabolism of lipid transporting particles, whose composition then changes from that before birth.In newborns, plasma lipid and lipoprotein patterns also are significantly different from those observed in adults, both in their concentration and distribution. Newborn plasma lipoproteins consist mostly of HDL, while VLDL and LDL are...

Childhood consumption of dietary polyunsaturated fat lowers risk for coronary artery atherosclerosis in African green monkeys.

“…Females in both dietary fat groups were observed to have generally lower TPC, HDL cholesterol, and apoA-I concentrations in plasma than males, with the difference in the latter two end points beginning after about 2 years of life. Overall, these young primates showed a pattern of age-related changes in lipids and apolipoproteins quite similar to that reported for human infants 39 " 42 and children. 43 ' 44 By early adulthood, the juvenile monkeys had attained plasma concentrations similar to those reported for adults of this species fed the same diets.…”

Effect of Early Enteral Feeding on Apolipoprotein AI Levels and High-Density Lipoprotein Heterogeneity in Preterm Infants

“…It is of importance that in contrast to our previous study on entirely parenterally fed preterm infants [10], the preterm infants in the present study who received parenteral nutrition along with a small amount of enteral nutrition for gut priming had postnatal apo AI levels comparable to those of term infants and displayed the same rise in apo AI as exclusively enterally fed preterm infants. The postnatal increase of apo AI happens predominantly in the HDL 3b+3c region [28]. Since significant amounts of apo AI are secreted by the intestine [13], the early enteral nutrition in the TPN group facilitated the previously not reported postnatal rise in apo AI in this group.…”

The Effect of Nutritional Habits on Maternal-Neonatal Lipid and Lipoprotein Serum Levels in Three Different Ethnic Groups

“…In view of these compositional differences between newborn and adult lipoproteins, it can be assumed that specifi c pathways are involved in the metabolism of newborn lipoproteins. Whether these differences refl ect the adaptability of the infants to specifi c dietary regimes consisting mostly of fat or might represent steps in the slow evolution from the patterns in newborns toward the adult profi le is not yet clear [24] .…”

“…In newborns, serum lipid and lipoprotein patterns are signifi cantly different from those observed in adults. Their serum lipoproteins consist mostly of HDL-C, while VLDL-C and LDL-C are present with low concentrations only [24] . In view of these compositional differences between newborn and adult lipoproteins, it can be assumed that specifi c pathways are involved in the metabolism of newborn lipoproteins.…”