Selective reductions in plasma Abeta 1-42 in healthy elderly subjects during longitudinal follow-up: a preliminary report

Objective Longitudinal changes in plasma beta amyloid protein 1-42 and 1-40 (Aβ42 and Aβ40) levels and possible relationships with cognitive decline and apolipoprotein (APOE) genotype were studied in healthy elderly individuals. Methods Authors determined cognitive level and plasma Aβ40 and Aβ42 levels twice, approximately 4 years apart, in 34 elderly subjects. Results Analyses revealed a selective reduction in Aβ42 levels at follow-up, which were not modulated by the ɛ4 allele. Greater reductions and higher baseline plasma Aβ42 levels were associated with reductions in cognitive scores. Conclusions Alterations in plasma Aβ42 levels may be associated with subtle cognitive decline in elderly subjects without dementia.