Relation of Apolipoprotein E Polymorphism to Serum Lipid Profiles in Obese Children

Obesity is a risk factor for future atherosclerosis in children. Apolipoprotein B (apoB) is the principal apolipoprotein of low-density lipoprotein, which is one of causative factors of atherosclerosis, and apolipoprotein E ε4 allele (apoE4) allele has been considered to be a risk factor for coronary artery diseases. We investigated the influence of apoE polymorphism on lipid and apolipoprotein levels in obese children. Thirtyseven Japanese obese children with a mean age of 10.1 years and 134 normal children were included in the study. Serum lipids and apolipoproteins were measured by an autoanalyzer, and apoE phenotyping was performed by isoelectric focusing of delipidated serum samples on polyacrylamide gel followed by immunoblotting. The Stat-View statistical computer package was used for data processing. Obese children with at least one apoE4 allele had significantly higher apoB levels and apoB/apoA-I ratios than E3 homozygotes (p=0.0080 and p=0.0104,respectively). Frequencies of apoE phenotypes and alleles in the obese children were not different from those in normal children. Obese children with at least one apoE4 allele had higher apoB levels and apoB/apoA-I ratios. It is suggested that obese children with at least one apoE4 allele are at a higher risk for future atherosclerosis than those without it. ApoE phenotyping may be a useful clinical test for identifying obese children who require more careful management.