Blood Pressure Level Is Associated With Changes in Plasma Aβ1 -40 and Aβ1-42 Levels: A Cross-sectional Study Conducted in the Suburbs of Xi'an, China.

Meilin She,Chen Chen,Qiumin Qu,Jin Wang,Shan Wei,Liangjun Dang,Ningwei Hu,Jingyi Wang,Kang Huo,Suhang Shang,Ling Gao

doi:10.3389/fnagi.2021.650679

Abstract

Objectives: Amyloid-β (Aβ) deposition in the brain is the hallmark of Alzheimer’s disease (AD) pathology. Hypertension is a risk factor for AD, but the effects of hypertension on Aβ deposition are not fully determined. Considering peripheral Aβ closely relates to Aβ deposition in the brain, we investigated the relationships between blood pressure (BP) level and plasma Aβ concentrations.Methods: One-thousand and sixty-nine participants (age above 45) from a village in the suburbs of Xi’an, China were enrolled. Questionnaires and validated Chinese versions of the Mini-Mental State Examination (MMSE) were used to collect information about vascular risk factors and assess cognition function. The apolipoprotein E (ApoE) genotype was detected using PCR and sequencing. Plasma Aβ levels were measured using ELISA. The associations between BP and plasma Aβ levels were analyzed by using multivariate linear regression.Results: Plasma Aβ1–40 level was higher in high BP group than that in normal BP group (53.34 ± 8.50 pg/ml vs. 51.98 ± 8.96 pg/ml, P = 0.013), in high SBP group than that in normal SBP group (53.68 ± 8.69 pg/ml vs. 51.88 ± 8.80 pg/ml, P = 0.001) and in high MABP group than that in normal MABP group (54.05 ± 8.78 pg/ml vs. 52.04 ± 8.75 pg/ml, P = 0.001). After controlling for the confounding factors, SBP (b = 0.078, P < 0.001), DBP (b = 0.090, P = 0.008) and MABP (b = 0.104, P < 0.001) correlated with plasma Aβ1–40 level positively in ApoE ε4 non-carriers, but not ApoE ε4 carriers.Conclusions: Elevated BP levels were associated with increased plasma Aβ1–40 levels in middle-aged and elderly ApoE ε4 non-carriers.

Highlights

Alzheimer’s disease (AD) is the most common cause of dementia, affecting more than 33.9 million people worldwide (Barnes and Yaffe, 2011)
Elevated blood pressure (BP) levels were associated with increased plasma Aβ1–40 levels in middle-aged and elderly apolipoprotein E (ApoE) ε4 non-carriers
Plasma Aβ1–40 level was higher in the high systolic blood pressure (SBP) group (53.68 ± 8.69 pmol/L vs. 51.88 ± 8.80 pmol/L, P = 0.001) and high mean arterial blood pressure (MABP) group (54.05 ± 8.78 pmol/L vs. 52.04 ± 8.75 pmol/L, P = 0.001), but Aβ1–42/Aβ1–40 ratio was lower in the high SBP (0.79 ± 0.19 vs. 0.81 ± 0.19, P = 0.038), high diastolic blood pressure (DBP) (0.78 ± 0.19 vs. 0.81 ± 0.19, P = 0.023), and high MABP (0.78 ± 0.20 vs. 0.81 ± 0.19, P = 0.009) groups

Summary

Introduction

Alzheimer’s disease (AD) is the most common cause of dementia, affecting more than 33.9 million people worldwide (Barnes and Yaffe, 2011). Studies have found that elevated blood pressure (BP) levels in midlife may be related to the development and progression of AD in later life (Kivipelto et al, 2001; Qiu et al, 2005; Gottesman et al, 2017; Walker et al, 2019). Hypertension is associated with an increased Aβ burden in the brain (Ingmar and Deborah, 2013). A complex equilibrium is believed to exist between the amyloid burden in the brain and plasma Aβ levels in both animal models and healthy individuals (DeMattos et al, 2002b; Giedraitis et al, 2007). We investigated the relationships between the parameters of BP and plasma Aβ levels in middle-aged and older individuals in the general population

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Conclusion