Association Plasma Aß42 Levels with Alzheimer's Disease and Its Influencing Factors in Chinese Elderly Population.

ABSTRACT

Background and Purpose: Intracerebral Aß protein deposition is an important pathological mechanism of Alzheimer's disease (AD) and is one of the indicators of early diagnosis of AD. However, invasive lumbar puncture and Aß PET are difficult to perform in primary units, resulting delays in early diagnosis of AD. In recent years, it has been found that plasma Aß can reflect the pathological state of AD in early stage, but the results are not consistent. The objective of this study was to explore the association between plasma Aß42 levels and AD cognitive impairment and its influencing factors in Chinese elderly population, so as to provide guidance for the clinical application of plasma Aß42 as a blood biomarker of AD. Methods: This is a cross-sectional study based on the community population. Plasma samples were collected from 604 healthy controls (HC), 508 mild cognitive impairment (MCI) and 202 dementia with Alzheimer's type (DAT) patients from three cities. We analyzed the correlation between plasma Aß42 levels and cognitive function and the influence of confounding factors on the relationship between plasma Aß42 levels and AD. The independent influencing factors of plasma Aß42 levels were determined by covariance and linear regression analysis. Results: Our results suggest that there is a special linear relationship between plasma Aß42 and cognitive impairment of AD in Chinese elderly population, with Aß42 levels slightly decreased in early AD and significantly increased in moderate-to-severe AD (P<0.01). There are many factors influencing the association between plasma Aß42 levels and AD cognitive impairment, and sample source, gender and BMI are independent influencing factors of plasma Aß42. Conclusion: This indentifies that plasma Aß42 may be a peripheral biomarker for AD screening in Chinese elderly population, but it is necessary to establish standardized detection methods and establish different demarcation criteria for various influencing factors.