Affiliations: [a] Department of Neurology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China | [b] Weinan Central hospital, Shaanxi, China | [c] Huxian Hospital of Traditional Chinese Medicine, Xi’an, China
Correspondence:
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Correspondence to: Qiumin Qu, Department of Neurology, The First Affiliated Hospital of Xi’an Jiaotong University, 277 West Yanta Rd, Xi’an 710061, China. Tel./Fax: +86 29 8532 4083; E-mail: quqiumin@126.com.
Abstract: Background:Aggregation and deposition of amyloid-β (Aβ) in the brain is the main pathological change of Alzheimer’s disease (AD). Decreased Aβ42 in the cerebrospinal fluid has been confirmed as a biomarker of AD; however, the relationship between plasma Aβ and cognitive impairment is currently unclear. Objective:The aim was to explore the relationship between plasma Aβ and cognitive impairment in a cross-sectional study. Methods:A total of 1,314 subjects (age above 40) from a village in the suburbs of Xi’an, China were enrolled between October 8, 2014 and March 30, 2015. A validated Chinese version of the Mini-Mental State Examination and neuropsychological battery were used to assess cognition. Levels of plasma Aβ42 and Aβ40 were tested using commercial enzyme-linked immunosorbent assay. Relationship of plasma Aβ and cognitive impairment was analyzed using logistic regression analysis. Results:Of the enrolled subjects, 1,180 (89.80%) had normal cognition, 85 (6.47%) had possible cognitive impairment and 49 (3.73%) had probable cognitive impairment. Logistic regression analysis showed that the Aβ42/Aβ40 ratio (OR = 4.042, 95% CI: 1.248–11.098, p = 0.012) and plasma Aβ42 (OR = 1.036, 95% CI: 1.003–1.071, p = 0.031) was higher in the possible cognitive impairment than that in the normal cognition group. Furthermore, the plasma Aβ42/Aβ40 ratio was higher in the possible cognitive impairment group than that in the probable cognitive impairment group (OR = 0.029, 95% CI: 0.002–0.450, p = 0.011). Conclusions:Levels of plasma Aβ42 and Aβ42/Aβ40 ratio were elevated in patients with possible cognitive impairment, indicating that plasma Aβ42 and Aβ42/Aβ40 ratio increases may be more pronounced in early stage of cognitive impairment.
