Association of apolipoprotein E genotype with early onset of coronary heart disease in Greek men

Apolipoprotein (apo) E polymorphism has been associated with coronary heart disease (CHD) although its relation to the age of CHD onset is still not defined. The age of onset of established CHD was obtained from 502 Greek men and compared to 103 healthy men. The age grouping was based on the age of CHID onset (earlier <= 44 years, n = 73, intermediate 45-64 years, n = 32 1, and later >= 65 years, n = 108). Apo E genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and the lipid profile was assessed. No differences in genotype and allele frequencies were found within the CHD groups. The apo epsilon 3/4 genotype and the apo epsilon 4 allele were less frequent in the earlier-onset group than in healthy men (11.0 % vs 22.3%, Pearson Chi-Square p = 0.028 and 6.8% vs 13.6%, Pearson Chi-Square p = 0.023, respectively). The lipid profile was similar in all genotypes of all groups except for high-density lipoprotein cholesterol levels, which were higher in epsilon 2 carriers compared to non-epsilon 2 carriers (in mg/dL [+/- SD]; 44 [9] vs 39 [10], in mmol/L [ SD]; 1.1 [0.2] vs 1.0 [0.3] p = 0.005). There is an association between apo E genotype and early onset of CHD in Greek men. In the earlier CHID onset group, the apo epsilon 3/4 genotype was less frequent compared to healthy men. This supports that the apo epsilon 3/4 genotype is associated with decreased risk of premature CHID. Because the results of similar studies are not consistent, it may be that the relationship between apo E genotype and CHID is related to ethnicity rather than a universal phenomenon.