Objective: Longitudinal changes in plasma beta amyloid protein 1-42 and 1-40 (Abeta42 and Abeta40) levels and possible relationships with cognitive decline and apolipoprotein (APOE) genotype were studied in healthy elderly individuals.
Methods: Authors determined cognitive level and plasma Abeta40 and Abeta42 levels twice, approximately 4 years apart, in 34 elderly subjects.
Results: Analyses revealed a selective reduction in Abeta42 levels at follow-up, which were not modulated by the epsilon4 allele. Greater reductions and higher baseline plasma Abeta42 levels were associated with reductions in cognitive scores.
Conclusions: Alterations in plasma Abeta42 levels may be associated with subtle cognitive decline in elderly subjects without dementia.