The Association of Plasma Amyloid-β and Cognitive Decline in Cognitively Unimpaired Population

Abstract

Purpose

This study investigates the relationship between baseline plasma Aβ and cognitive decline during follow-up in cognitively unimpaired population.

Materials and Methods

Cognitively unimpaired population was selected from people who lived in the suburbs of Xi’an, China. The levels of plasma Aβ_1-42 and Aβ_1-40 were tested using commercial enzyme-linked immunosorbent assay (ELISA). The mini-mental state examination (MMSE) and neuropsychological battery were used to assess cognition. Two years later, MMSE was tested again, and significant cognitive decline was defined as a decrease in MMSE scores ≥5 points. Logistic regression analysis was performed to analyze the relationship between baseline plasma Aβ and cognitive change during the two-year follow-up.

Results

A total of 1144 participants completed the study, among whom 59 subjects (5.2%) presented significant cognitive decline. The high plasma Aβ_1-42 level group had more significant cognitive decline (P = 0.023). Multivariable logistic regression analysis showed that significant cognitive decline was associated with the high levels of baseline plasma Aβ_1-42 (OR = 1.043, 95% CI: 1.005–1.083, P = 0.026). However, significant cognitive decline was not associated with baseline plasma Aβ_1-40 levels and Aβ_1-42 /Aβ_1-40 ratio.

Conclusion

Population with high level of baseline plasma Aβ_1-42 manifested significant cognitive decline over 2 years; however, further investigation on the dynamics of plasma Aβ and long-term follow-up are needed.

Keywords:

• Alzheimer’s disease
• cognitive decline
• plasma amyloid β
• cohort study
• plasma biomarker

Abbreviations

Aβ, amyloid-β; AD, Alzheimer’s disease; APOE, apolipoprotein E; APP, amyloid precursor protein; BBB, blood-brain barrier; CNS, central nervous system; DNA, deoxyribonucleic acid; EDTA, ethylene diamine tetraacetic acid; ELISA, enzyme-linked immunosorbent assay; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; MCI, mild cognitive impairment; MMSE, mini-mental state examination; PCR, polymerase chain reaction; TC, total cholesterol; TG, triglyceride.

Data Sharing Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Acknowledgments

The authors thank the participants and the team members of the study for their participation and support given.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors have no conflict of interest to report.

Additional information

Funding

The study was supported by the First Affiliated Hospital of Xi’an Jiaotong University Foundation (Grant Numbers: 2019QN-22) and the Nature Science Foundation of China (No.81771168) and the Key Research & Development Programs of Shaanxi Province (No. 2018ZDXM-SF-052 and No.2019SF-227) and Clinical research award of the First Affiliated Hospital of Xi’an Jiaotong University (No. XJTU1AF-CRF-2018-004).