The influence of apolipoprotein E polymorphism on plasma concentrations of apolipoprotein B and A-I during the first year of life.
Apolipoprotein (apo)E polymorphism has been shown to be associated with different serum levels of cholesterol, apoB, and apoE. In clarifying the degree of influence of the apoE isoforms, investigations in an early stage of life are useful. The aim of the study was to investigate the plasma levels of apoB and apoA-I as structural proteins of low and high density lipoproteins, in relation to apoE phenotypes during the first year of life. Conclusions about the relationship between apoE phenotype and the development of the lipoprotein patterns can be drawn. The concentrations of apoB and apoA-I in capillary plasma as well as the apoE phenotype were estimated in 199 newborns (7 days old) and in follow-up investigations of a subgroup of 45 at 1, 4, 12, 24, and 52 weeks. The phenotype frequencies were as follows: 70% apoE 3/3, 16% apoE 3/4, 10% apoE 2/3, 2.5% apoE 2/2, and 1.5% apoE 4/2. The plasma concentrations of apoB and apoA-I in the newborns (7 days old) averaged 55% of the adult value and increased toward the end of the first year of life up to approximately 85%. The course of the plasma concentrations of apoB and apoA-I in relation to the apoE phenotype showed that, beginning at 24 weeks, the apoB levels were significantly lower for the phenotype E 2/2 and in tendency also for the phenotype E 2/3 in comparison with E 3/3. At the end of the first year of life, the apoB levels in infants with apoE phenotype 2/2 increased only by 50% and yielded 0.59 g/L.(ABSTRACT TRUNCATED AT 250 WORDS)