APOE-epsilon4 and aging of medial temporal lobe gray matter in healthy adults older than 50 years

作者：Taylor Joy L^*; Scanlon Blake K; Farrell Michelle; Hernandez Beatriz; Adamson Maheen M; Ashford J Wesson; Noda Art; Murphy Greer M Jr; Weiner Michael W

来源：Neurobiology of Aging, 2014, 35(11): 2479-2485.

DOI：10.1016/j.neurobiolaging.2014.05.011

• Aging
• Apolipoprotein E4
• Alzheimer's disease
• Brain-derived neurotrophic factor
• Hippocampus
• Longitudinal studies
• Magnetic resonance imaging

Atrophy of the hippocampus and surrounding temporal regions occurs in Alzheimer's disease (AD). APOE epsilon 4, the major genetic risk factor for late-onset AD, has been associated with smaller volume in these regions before amyloidosis can be detected by AD biomarkers. To examine APOE epsilon 4 effects in relation to aging, we performed a longitudinal magnetic resonance imaging study involving cognitively normal adults (25 APOE epsilon 4 carriers and 31 epsilon 3 homozygotes), initially aged 51-75 years. We used growth curve analyses, which can provide information about APOE epsilon 4-related differences initially and later in life. Hippocampal volume was the primary outcome; nearby medial temporal regions were secondary outcomes. Brain-derived neurotrophic factor, val66met was a secondary covariate. APOE epsilon 4 carriers had significantly smaller initial hippocampal volumes than epsilon 3 homozygotes. Rate of hippocampal atrophy was not greater in the APOE epsilon 4 group, although age-related atrophy was detected in the overall sample. The findings add to the growing evidence that effects of APOE epsilon 4 on hippocampal size begin early in life, underscoring the importance of early interventions to increase reserve.

• 出版日期2014-11