Aging and APOE-ε4 are determinative factors of plasma A β 42 levels

Ann Clin Transl Neurol. 2018 Sep 7;5(10):1184-1191. doi: 10.1002/acn3.635. eCollection 2018 Oct.

Abstract

Objective: The aim of this study was to confirm determinative factors for plasma Aβ and its association with cognitive function.

Methods: Fasting plasma Aβ40 and Aβ42 levels were measured by ELISA in 1019 participants in the Iwaki Health Promotion Project. The relationships between plasma Aβ and health-related items, including physical characteristics, cognitive function tests, blood chemistry, and APOE-ε4 genotype were analyzed.

Results: The plasma levels of Aβ40 and Aβ42, and Aβ40/42 ratio were found to significantly increase with aging. The age-dependent increase in Aβ42 level was significantly suppressed by APOE-ε4. Renal function was an associated factor for the plasma Aβ40 level. The plasma Aβ42 level and Aβ40/42 ratio correlated with cognitive function.

Interpretation: Age and APOE-ε4 are major determinative factors of plasma levels of Aβ42 and the Aβ40/42 ratio. These factors are critical adjustment factors for the usage of plasma Aβ as a biomarker of central nervous system amyloidosis.

Grants and funding

This work was funded by Amyloidosis Research Committee Surveys and Research on Special Diseases grant ; Longevity Science Committee of the Ministry of Health and Welfare of Japan grant ; Ministry of Education, Science, and Culture of Japan grants 15K09305 and 18K07385; Hirosaki University Institutional Research grant ; Japan Science and Technology Agency grant .