Apolipoprotein E: Non-cognitive symptoms and cognitive decline in late onset Alzheimer's disease

Abstract

Objectives - To determine the association between the ε2 and ε4 alleles of apolipoprotein E (ApoE) and independent measures of cognitive decline and non-cognitive symptomatology in late onset Alzheimer's disease. Methods - The frequency of the ε2 and ε4 alleles of ApoE and their association with measures of cognitive decline and non-cognitive symptomatology were assessed in a population based case register study of 164 patients with late onset Alzheimer's disease from the east Lambeth and south Southwark districts of south London. Results - Analysis of a wide range of non-cognitive symptoms against ApoE ε4 genotype showed no significant association but a positive relation was found between ApoE ε2 genotype and depressive symptomatology (P = 0.004). No relation was found between measurements of cognitive decline and the presence of the ApoE ε4 allele. A trend for decreasing age at onset of 3 to 4 years in carriers of the ApoE ε4 allele was found, confirming earlier studies. Conclusion - Presence of the ε4 allele of ApoE is associated with an earlier age at onset but does not seem to be related to either a more severe psychopathology or a more rapid progression of the illness. The ε2 allele of ApoE is associated with depressive symptomatology in late onset Alzheimer's disease.