Apolipoprotein E among Korean Alzheimer's disease patients in community-dwelling and hospitalized elderly samples

This study evaluated the association of the apolipoprotein E epsilon4 allele (epsilon4) with Alzheimer's disease (AD) and investigated the relationships of epsilon4 with clinical characteristics of AD in both community-dwelling and hospitalized Korean elderly populations. The apolipoprotein E genotypes were compared between a group of 52 community-dwelling patients with AD (C-AD), a group of 52 hospitalized patients with AD (H-AD) and a group of 52 healthy controls matched to C-AD. Clinical characteristics and scores on several assessment scales were compared between C-AD and H-AD as well as between two subgroups within each AD group: those with epsilon4 and those without epsilon4. For H-AD, the assessment scales were administered again 6 months later, and the temporal course of AD was compared between the subgroups. The frequency of epsilon4 was significantly higher in both AD groups than in controls. Between C-AD and H-AD, no differences were found in epsilon4 frequency, while symptoms of dementia were significantly severer in H-AD than in C-AD. Within each AD group, no differences were observed in terms of clinical characteristics and scores on the assessment scales between the subgroups. Furthermore, the subgroups of H-AD showed no difference in the rate of progression. In conclusion, there was a significant association of epsilon4 with AD. However, no relationships were found between epsilon4 and clinical characteristics in either C-AD or H-AD. Furthermore, the rate of progression did not vary with respect to the presence or absence of epsilon4 in H-AD. The severer symptoms observed in the hospitalized sample than in those at large might be explained by factors other than the impact of epsilon4.