Apolipoprotein E polymorphism in ischemic cerebrovascular diseases and vascular dementia patients in Taiwan

This study aims to clarify the association between apolipoprotein E gene (ApoE) polymorphism, ischemic cerebrovascular diseases (ICVD) and vascular dementia (VaD) in Taiwan Chinese. 277 patients with ICVD, 49 patients with probable VaD and 112 controls were recruited for this study. Distributions of ApoE epsilon4 carriers and allele frequencies were 28.5 and 14.5% for patients with ICVD, 20.4 and 10.2% for patients with VaD, whereas these values were 22.9 and 11.6% for controls. Distributions of ApoE epsilon2 carriers and allele frequencies were 10.1 and 5.2% for ICVD patients, 6.1 and 3.1% for VaD patients, but 12.5 and 8.0% for controls. There were no differences between ICVD patients and controls, or VaD patients and controls in their epsilon4 carriers. Those patients aged 65 and under, carrying the epsilon2 allele, had a lower risk of developing ICVD and VaD than did their counterparts. These findings suggest that ApoE epsilon4 plays no significant role in the development of ICVD and VaD, but that ApoE epsilon2 has a protective effect with regard to the development of ICVD and VaD for Taiwan Chinese below the age of 65.