Polymorphisms of apolipoprotein E and methylenetetrahydrofolate reductase in the Japanese population

Aim: The aim of this study is to analyze the effect of apolipoprotein E (apo E) and methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms on serum lipid and homocysteine levels in the general Japanese population. Methods: We analyzed the polymorphisms in individuals randomly selected from among participants of Serum Lipid Survey 2000. Results: The frequency of the epsilon 2, epsilon 3, and epsilon 4 alleles of APOE was 4.2, 85.3, and 10.5%, respectively. Individuals with the genotype epsilon 4/epsilon 4 had the highest total and low-density lipoprotein (LDL) cholesterol levels while those with epsilon 2/epsilon 2 had the lowest. Individuals with the epsilon 2/epsilon 2 and epsilon 2/epsilon 4 genotypes had higher remnant-like particles (RLP)-cholesterol levels than those with epsilon 2 epsilon 3, epsilon 3 epsilon 3, and epsilon 3 epsilon 4. There was a trend for individuals with the epsilon 2/epsilon 4 and epsilon 2/epsilon 2 genotypes to have higher triglyceride levels, although the difference was not significant. The presence of the T allele in a MTHFR polymorphism (C667T) was associated with higher homocysteine levels, which is more prominent in men than in women. Conclusion: Thus in our large-scale analysis we have shown that RLP-cholesterol is better associated with APOE genotype than triglyceride and the effect of the T allele on MTHFR polymorphism (C667T) homocysteine levels is more prominent in men than in women among Japanese.