Asymptomatic intracranial vascular lesions and cognitive function in a general population of Japanese men: Shiga Epidemiological Study of Subclinical Atherosclerosis (SESSA)

Introduction: Intracranial subclinical vessel diseases are considered important indicators of cognitive impairment. However, a comprehensive assessment of various types of vessel disease, particularly in Asian populations, is lacking. We aimed to compare multiple types of intracranial vessel disease in association with cognitive function among a community-based Japanese male population. Methods: The Shiga Epidemiological Study of Subclinical Atherosclerosis (SESSA) randomly recruited and examined a community-based cohort of Japanese men from Shiga, Japan. We analyzed those who underwent the Cognitive Abilities Screening Instrument (CASI) assessment and cranial magnetic resonance imaging/angiogram (MRI/MRA) in 2010–2015. Using MRI/MRA, we assessed lacunar infarction, microbleeds, periventricular hyperintensity (PVH), deep subcortical white matter hyperintensity (DSWMH), and intracranial artery stenosis (ICAS). We divided these subclinical cerebrovascular diseases (SCDs) into three categories according to severity. Using linear regression, we calculated the CASI score according to the grade of each vessel disease, adjusted for age and years of education. Results: In the adjusted models, CASI scores were significantly associated with both PVH and DSWMH. Specifically, multivariable-adjusted CASI scores declined across increasing severity categories of DSWMH (91.7, 91.2, and 90.4; p for trend = 0.011) and PVH (91.5, 90.4, and 89.7; p for trend = 0.006). Other SCDs did not show significant associations. In stratified analyses based on the presence or absence of each SCD, both DSWMH and PVH demonstrated significant inverse trends with CASI scores in the absence of lacunar infarcts and microbleeds and in the presence of ICAS. Additionally, among participants with PVH (+), ≥moderate ICAS was significantly associated with lower CASI scores. Conclusion: PVH and DSWMH showed significant dose-response relationships with cognitive function among community-based Japanese men. These findings suggest that white matter lesions may be an important indicator of early cognitive impairment, and severe ICAS may also play a role in those with PVH.