Apolipoprotein B/AI Ratio As An Independent Risk Factor For Intracranial Atherosclerotic Stenosis

Backgroud: Acute ischemic stroke accounts for more than 80% of all acute stroke events.Intracranial atherosclerotic stenosis(ICAS)is one of its major risk factors.The high incidence of stroke brings heavy economic burden to society,so prevention and identification of risk factors controlled by ICAS become crucial.The aim of our study was to demonstrate that the apolipoprotein B/AI(apoB/AI)ratio is an independent risk factor for ICAS in both stroke and non-stroke patients.Methods: We prospectively recruited 1138 patients with acute ischemic stroke(359 with ICAS,SICAS;779 without ICAS,SNCAS)and 1072 non-stroke controls(239 with ICAS,NICAS;833 without ICAS,NNCAS),which confirmed by neuroimaging.ICAS was defined as atherosclerotic stenosis >50% or the occlusion of the several main intracranial arteries.Wilcoxon test and chi-square test were used to access the differences of apoB/AI between groups.Multivariate logistic regression analyses were performed to explore whether level or quartile of apoB/AI ratio was independently associated with the presence of ICAS,all covariates were included in the model.The lowest quartile was defined as the reference group.We also conducted the power analysis using G*Power 3.1.9.4.Results: All covariates were incorporated into the multivariable logistic regression analysis of the SICAS and SNCAS groups.After adjusting these covariates,the apoB/AI ratio(OR=2.80,95%CI=1.45-5.42,p=0.002)was demonstrated to be an independent risk factor for ICAS against a background of stroke.Other risk factors included the presence of hypertension(OR=1.52,95%CI=1.12-2.08,p=0.008)and high level of glucose(OR=1.05,95%CI=1.01-1.10,p=0.015).Participants were stratified into quartiles according to the distribution of their serum apoB/AI ratio.For the SICAS and SNCAS groups,the regression analyses indicated that patients with higher apoB/AI ratio quartiles were more inclined to suffer ICAS,compared with the first quartile.Specifically,with the first quartile as the reference category,the ORs and 95%CI were 1.22(0.81-1.82)in the second quartile,1.71(1.11-2.63)in the third quartile and 2.06(1.27-3.35)in the fourth quartile.The third(p=0.014)and forth(p=0.003)apoB/AI ratio quartiles were significantly associated with SICAS.We also conducted the trend test and final got the p value for trend(p=0.002)which was significant and it also indicated a dose-response relationship between apoB/AI ratio and the risk of suffering ICAS.In NICAS and NNCAS groups,the regression analysis showed that the apoB/AI ratio(p<0.001)was still a significant risk factor of suffering ICAS.When referenced to the first quartile,ORs and 95%CI in the second quartile.were 1.15(0.71-1.86),in the third quartile were 1.71(1.04-2.82)and in the fourth quartile were 2.00(1.16-3.49).The third(p =0.033)and fourth(p=0.012)quartiles were different between the two groups,which supports the apoB/AI ratio was an independent risk factor for ICAS.The p value for trend(p =0.006)was still remarkable in non-stroke population.Similar to stroke groups,the presence of hypertension(OR 1.91,95%CI 1.31-2.82,p<0.001)and high level of glucose(OR 1.08,95%CI 1.01-1.16,p =0.021)were independent risk factors for ICAS in the present study.These associations were still robust after controlling for covariates.The group sample sizes of 359 and 779 in stroke patients achieve 85% power and the group sample sizes of 239 and 833 in non-stroke controls achieve 99% power to detect the difference of apoB/AI between ICAS and NCAS groups.Conclusions: The current study demonstrated that the apoB/AI ratio was an independent risk factor for ICAS in both stroke and non-stroke Chinese individuals,suggesting the effects of apoB/AI ratio on increasing the risk of ICAS were the same between stroke and non-stroke individuals.We found that the risk of suffering ICAS will increase when apoB/AI ratio increased.