Lehtimäki T, Porkka K, Viikari J, Ehnholm C, Akerblom H K, Nikkari T
Department of Biomedical Sciences, University of Tampere, Finland.
Pediatrics. 1994 Oct;94(4 Pt 1):489-93.
Apolipoprotein E (apoE) phenotype is a genetic determinant of plasma total cholesterol and low density lipoprotein (LDL) cholesterol concentrations, that are classical coronary heart disease risk factors. ApoE appears in three major isoforms E2, E3, and E4, coded by corresponding alleles epsilon 2, epsilon 3, and epsilon 4. These give rise to six different phenotypes.
To study the associations of apoE phenotype with cord serum lipids (during minimal enteral nutrition), and with serum lipids of 3-year-old children.
We determined serum lipid levels and apoE phenotypes in 206 newborns and 259 3-year-old children in connection with a larger follow-up study of atherosclerosis precursors in children and young adults. ApoE phenotyping was done directly from plasma by isoelectric focusing followed by immunoblotting.
The effect of apoE phenotype on serum total and LDL cholesterol was significantly different in newborns and 3-year-old children (two-way ANOVA, interaction between apoE phenotype and age group: P < .001 for both). In 3-year-old children, the concentrations of serum total cholesterol and LDL cholesterol increased with apoE phenotype in the order of E3/2, E3/3, E4/3, and E4/4, in both males and females (P < .0001). On the contrary, in neonates total cholesterol and LDL cholesterol concentrations were low and did not differ significantly between apoE phenotypes (P > .05) either in males or in females. The mean serum levels of triglycerides and high density lipoprotein cholesterol did not differ between apoE phenotypes either in 3-year-old children or newborns.
The results show that the differences in serum total and LDL cholesterol levels between apoE phenotypes are formed after birth by the influence of environmental factors and suggest that both genetic and external factors influence the levels of serum cholesterol concentrations during the first years of life.
载脂蛋白E（apoE）表型是血浆总胆固醇和低密度脂蛋白（LDL）胆固醇浓度的遗传决定因素，而这两种胆固醇是经典的冠心病危险因素。ApoE有三种主要亚型E2、E3和E4，分别由相应的等位基因ε2、ε3和ε4编码。这些等位基因产生六种不同的表型。
研究apoE表型与脐带血清脂质（在微量肠内营养期间）以及3岁儿童血清脂质的关联。
在一项针对儿童和年轻成人动脉粥样硬化前体的更大规模随访研究中，我们测定了206名新生儿和259名3岁儿童的血清脂质水平和apoE表型。通过等电聚焦继以免疫印迹法直接从血浆中进行apoE表型分析。
apoE表型对血清总胆固醇和LDL胆固醇的影响在新生儿和3岁儿童中存在显著差异（双向方差分析，apoE表型与年龄组之间的交互作用：两者均P <.001）。在3岁儿童中，男性和女性的血清总胆固醇和LDL胆固醇浓度均随apoE表型按E3/2、E3/3、E4/3和E4/4的顺序升高（P <.0001）。相反，在新生儿中，总胆固醇和LDL胆固醇浓度较低，且在男性或女性的apoE表型之间无显著差异（P>.05）。在3岁儿童或新生儿中，apoE表型之间的甘油三酯和高密度脂蛋白胆固醇的平均血清水平也无差异。
结果表明，apoE表型之间血清总胆固醇和LDL胆固醇水平的差异是在出生后由环境因素的影响形成的，这表明遗传因素和外部因素在生命的最初几年都影响血清胆固醇浓度水平。
