Blood Triglyceride and High-Density Lipoprotein Levels Are Associated with Plasma Amyloid-ß Transport: A Population-Based Cross-Sectional Study.

ABSTRACT

BACKGROUND: Studies have found that blood lipids are associated with plasma amyloid-ß (Aß) levels, but the underlying mechanism is still unclear. Two Aß transporters, soluble form of low-density lipoprotein receptor related protein-1 (sLRP1) and soluble receptor of advanced glycation end products (sRAGE), are crucial in peripheral Aß transport. OBJECTIVE: The aim was to investigate the effects of lipids on the relationships between plasma Aß and transporter levels. METHODS: This study included 1,436 adults aged 40 to 88 years old. Blood Aß, sLRP1, sRAGE, and lipid levels were measured. Univariate and multivariate analyses were used to analyze the relationships between lipids and plasma Aß, sLRP1, and sRAGE. RESULTS: After adjusting for all possible covariates, high-density lipoprotein (HDL-c) was positively associated with plasma Aß42 and sRAGE (ß= 6.158, p = 0.049; ß= 121.156, p < 0.001, respectively), while triglyceride (TG) was negatively associated with plasma Aß40, Aß42, and sRAGE (ß= -48.389, p = 0.017; ß= -11.142, p = 0.020; ß= -147.937, p = 0.003, respectively). Additionally, positive correlations were found between plasma Aß and sRAGE in the normal TG (Aß40 ß= 0.034, p = 0.005; Aß42 ß= 0.010, p = 0.001) and HDL-c groups (Aß40 ß= 0.023, p = 0.033; Aß42 ß= 0.008, p = 0.002) but not in the high TG and low HDL-c groups. CONCLUSION: Abnormal levels of TG and HDL-c are associated with decreased Aß and sRAGE levels. Positive correlations between plasma Aß and sRAGE were only found in the normal TG and HDL-c groups but not in the high TG and low HDL-c groups. These results indicated that dyslipidemia contributing to plasma Aß levels might also be involved in peripheral Aß clearance.