Prevalence And Associated Cardiovascular Risk Factors Of Asymptomatic Intracranial Arterial Stenosis

Background:Intracranial atherosclerotic stenosis(ICAS)is one of the leading causes of ischemic stroke worldwide,especially amongst Asian populations.Asymptomatic ICAS(aICAS),even of mild to moderate severity,has been associated with ischemic stroke.Data from epidemiological studies showed that aICAS may develop and progress silently over years or even decades to become symptomatic.Therefore,early detection of aICAS is critical for effective preventive interventions and risk reduction of clinical stroke.Objective:This study aimed to investigate the prevalence and associated cardiovascular risk factors(CRFs)of aICAS amongst middle-aged and older adults living in rural communities in China,and to further explore the relationship of the prevalence of aICAS with CRFs numerical loads as well as the patterns of CRFs coexisting.Methods:This population-based study included 2019 subjects(aged>40 years)who were free of clinical stroke and living in rural communities in China.From October 2017 to May 2018,data on demographics,CRFs and health conditions were collected through face-to-face interviews,physical examination and laboratory tests.Asymptomatic ICAS was detected through a two-phase procedure:a screening phase with transcranial Doppler ultrasound,followed by a diagnostic phase with magnetic resonance angiography(MRA)and high-resolution magnetic resonance imaging(HRMRI)examination.Finally,the diagnosis of aICAS was made according to MRA and HRMRI findings,and the severity of aICAS was measured and recorded based on MRA findings.Multivariable logistic regression models were used to analyse the CRFs associated with aICAS.Results:Of the 2019 participants,aICAS was detected in 153 persons.The overall prevalence of alCAS was 7.6%.Moderate-to-severe aICAS was detected in 101 persons,therefore,the prevalence of moderate-to-severe aICAS was 5.0%.The multi-adjusted OR(95%CI)of aICAS associated CRFs in the multivariable logistic regression model was 2.40(1.56～3.69)for hypertension,1.91(1.32～2.76)for high level of hypersensitive C-reactive protein(hs-CRP),1.68(1.14～2.49)for diabetes and 1.61(1.08～2.41)for overweight or obesity.When these four CRFs were aggregated,compared with participants without any of these factors,the multi-adjusted ORs(95%CI)of aICAS for persons concurrently having one,two and three or more of these factors were 1.14(0.52～2.48),2.91(1.42～5.99)and 5.51(2.64～11.50),respectively(P for linear trend<0.001).In addition,the prevalence of aICAS was similar between participants with only one of the above four CRFs and participants without any of these factors(p>0.05);Among individuals with any two of the above four CRFs,individuals with hypertension and diabetes(OR:4.06,95%CI:1.35～12.23)had highest probability of suffering from aICAS.Among individuals with any three of the above four CRFs,individuals with coexistence of hypertension,high level of hs-CRP,and overweight or obesity(OR:5.71,95%CI:2.52-12.93)had highest likelihood of having aICAS.Compared with participants without any of these factors,individuals with the above four CRFs(OR:7.89,95%Cl:3.12～19.94)had more than 7-fold increased likelihood for having aICAS.Conclusions:Asymptomatic ICAS was common amongst rural-dwelling middle-aged and older Chinese inhabitants.Hypertension,diabetes,overweight or obesity and high level of hs-CRP,especially when coexisting,were strongly associated with aICAS.In addition,the patterns of CRFs coexisting were also associated with the probability of having aICAS.