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.