Apolipoprotein E4 and memory decline in the elderly

The objective of this study was to investigate whether the association between Apolipoprotein E4 (ApoE4) and memory decline is modified by baseline general cognitive impairment and age in a population-based elderly sample. Subjects were participants in the Longitudinal Aging Study Amsterdam (LASA). The study sample consisted of 1,243 subjects, 62-85 years old, with a Mini-Mental State Examination (MMSE) score between 21-30 and known ApoE phenotypes. Memory performance was measured with a short version of the Auditory Verbal Learning Test (AVLT) at baseline and repeated after three years (N = 854). Memory decline was defined as a decrease of at least one standard deviation from the mean change score on immediate recall, delayed recall and retention. ApoE4 was associated with memory decline in cognitively impaired subjects (MMSE 21-26), but not in cognitively normal subjects (MMSE 27-30). In particular cognitively impaired E4 carriers older than 75 years were at high risk of memory decline. Contrary to AD studies, our study suggests that the risk of ApoE4 on memory decline does not decrease with ageing.