Intracranial Artery Stenosis and Its Association With Conventional Risk Factors in a General Population of Japanese Men

Background and Purpose— Few community-based studies have reported the prevalence of intracranial artery stenosis (ICAS) assessed with magnetic resonance angiography. The aim was to determine the prevalence of ICAS using magnetic resonance angiography in a general population of Japanese men and to investigate the associations between ICAS and conventional cardiovascular risk factors. Methods— The Shiga Epidemiological Study of Subclinical Atherosclerosis randomly recruited and examined participants from Kusatsu City, Shiga, Japan, in 2006 to 2008 (baseline); 740 men returned for follow-up and underwent 1.5 T brain magnetic resonance angiography in 2012 to 2015. Participants were categorized as having no-ICAS, mild-ICAS (1 to <50%), or severe-ICAS (≥50%) in any of the arteries examined. After excluding the men with a history of stroke, 709 men were analyzed using multivariable logistic regression to assess independent associations of conventional cardiovascular risk factors with reference to the no-ICAS group. Results— The participants’ mean age was 68.0 years. The age-standardized prevalences of mild and severe-ICAS were 20.7% and 4.5%, respectively (with the population of the 2010 Japanese vital statistics as the reference). Age, hypertension, diabetes mellitus, and dyslipidemia were associated with a higher prevalence of severe-ICAS after simultaneous adjustment for conventional cardiovascular risk factors. Conclusions— In a community-based sample of Japanese men, ICAS was estimated to be present in 25.2%, and related to metabolic risk factors, in addition to hypertension and age. These results support the importance of comprehensive management of conventional cardiovascular risk factors for stroke prevention.