Fasting Glucose And HbA_1c Levels As Risk Factors For The Presence Of Intracranial Atherosclerotic Stenosis

Objective:Intracranial atherosclerotic stenosis（ICAS）is the most common cause of stroke globally,as well as in Asia,and symptomatic ICAS is associated with a higher risk of recurrent stroke compared with other stroke sbutypes.Progression of symptomatic ICAS is relative to an increased risk of recurrent stroke.But the relationship of ICAS with fasting blood glucose（FBG）and glycated hemoglobin A1c(HbA_1c)is unclear.This study aimed to investigate the effects of increased FBG and HbA_1c concentration on ICAS.Methods:A total of 4,012 subjects were recruited in the current study,including 1,434subjects without transient cerebral ischemia or ischemic stroke and 2,578ischemic stroke patients with transient cerebral ischemia or magnetic resonance imaging（MRI）confirmed acute ischemic stroke（within 7 days of onset）.ICAS was defined as the presence of≥50%stenosis in any intracranial artery in this study.According to imaging assessment and clinical data,participants were classified into four subgroups,（a）subjects without stroke or ICAS;（b）patients with asymptomatic ICAS but without stroke;（c）patients with stroke but without ICAS;（d）patients with stroke and ICAS.One-way ANOVA（analysis of variance）or Kruskal-Wallis test was used to compare intergroup difference for continuous variables,and Chi-square test was used to compare categorical variables.Univariate and multivariate logistic regression analysis was used to calculate odd ratios（ORs）and 95%confidence intervals（CIs）for the effects of risk factors on presence of ICAS.We excluded individuals in all groups who had intracerebral hemorrhage,extracranial atherosclerotic stenosis,atrial fibrillation and possible cardioembolism and had intracranial and/or extracranial artery stenosis due to non-atherosclerotic diseases,which could have influencedthe blood glucose levels.All statistical analyses were performed with R version 1.1.383.A two-tailed P-value<0.05 represented statistical difference.Results:Levels of fasting glucose and HbA_1cc in patients with ICAS were significantly higher than those in patients without ICAS among both stroke and non-stroke groups.Multivariate regression analysis showed that elevated levels of fasting glucose（OR 1.14,95%CI 1.11-1.18,P<0.001）and HbA_1c（OR 1.22,95%CI 1.16-1.28,P<0.001）were independent risk factors for ICAS.The levels of fasting glucose and HbA_1c were positively associated with ICAS（OR 1.24,95%CI 1.16-1.33;OR 1.45,95%CI 1.30-1.61;All P<0.001）in non-stroke group;And in stroke group,the levels of fasting glucose and HbA_1c were also correlated with ICAS positively（OR 1.12,95%CI 1.09-1.16;OR 1.16,95%CI 1.10-1.23;All P<0.001）.In addition,patients with the DM（FBG≥7.0mmol/L） were at the high risk of ICAS in both non-stroke（OR 2.90,95%CI 2.11-3.99,P<0.001）and stroke（OR 1.99,95%CI1.67-2.39,P<0.001）groups.And in stroke group impaired fasting glucose-2（6.1mmol/L≤FBG<7.0mmol/L）was associated with ICAS.Besides,subjects with the high risk of ICAS were found in the fourth HbA_1cc quartile in both non-stroke（OR 3.50,95%CI 2.23-5.61,P<0.001）and stroke（OR 1.98,95%CI 1.50-2.63,P<0.001）groups.Conclusion and significance:The results suggest that elevated fasting glucose and HbA_1clevels are independently associated with high risk for ICAS and ischemic stroke,suggesting that the risk of ICAS and ischemic stroke can be reduced by appropriate glycemic control.