Association of Plasma Oligomerized Amyloid-β and Cerebral White Matter Lesions in a Health Screening Population

Background: Cerebral white matter lesions (WML) are related to a higher risk of vascular and Alzheimer’s dementia. Moreover, oligomerized amyloid-β (OAβ) can be measured from blood for dementia screening. Objective: We aimed to investigate the relationship of plasma OAβ levels with clinical and radiological variables in a health screening population. Methods: WML, other volumetric parameters of magnetic resonance images, cognitive assessment, and plasma OAβ level were evaluated. Results: Ninety-two participants were analyzed. The majority of participants’ clinical dementia rating was 0 or 0.5 (96.7%). White matter hyperintensities (WMH) increased with age, but OAβ levels did not (r2 = 0.19, p < 0.001, r2 = 0.03, p = 0.10, respectively). No volumetric data, including cortical thickness/hippocampal volume, showed any significant correlation with OAβ. Log-WMH volume was positively correlated with OAβ (r = 0.24, p = 0.02), and this association was significant in the periventricular area. White matter signal abnormalities from 3D-T1 images were also correlated with the OAβ in the periventricular area (p = 0.039). Multivariate linear regression showed that log-WMH values were independently associated with OAβ (B = 0.879 (95% confidence interval 0.098 –1.660, p = 0.028)). Higher tertiles of WMH showed higher OAβ levels than lower tertiles showed (p = 0.044). Using a cutoff of 0.78 ng/mL, the high OAβ group had a larger WMH volume, especially in the periventricular area, than the low OAβ group (p = 0.036). Conclusion: Both WML and plasma OAβ levels can be early markers for neurodegeneration in the healthcare population. The lesions, especially in the periventricular area, might be related to amyloid pathogenesis, which strengthens the importance of WML in the predementia stage.