The Association of Plasma Amyloid-β and Cognitive Decline in Cognitively Unimpaired Population
Jin Wang, Ling Gao, Jie Liu, Liangjun Dang, Shan Wei, Ningwei Hu, Yao Gao, Wei Peng, Suhang Shang, Kang Huo, Jingyi Wang, Qiumin Qu
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