The Correlation Between Low High-density Lipoprotein Cholesterol And Symptomatic Intra-and Extracranial Atherosclerotic

Objective: Ischemic stroke has become one of the main causes of deathand disability all over the world, and large artery atherosclerosis (LAA) is oneof the most important causes of ischemic stroke. The locations of cerebralatherosclerosis vary among different populations.Intracranial atherosclerosis(ICAS) is more prevalent in Asians, blacks, and Hispanics, whereas extrac-ranial atherosclerosis (ECAS) is more common in Caucasians.There are many factors which can lead to the different prevalencesbetween races. In addition to the genetic susceptibility, living environment, theprevalence of atherosclerosis risk factors among ethnic groups may bedifferent. Recent study had found that, due to the living habits of westerni-zation, the prevalence of the ECAS raised year by year in Japan and SouthKorea. This changed lifestyle led hyperlipidemia, obesity prevalence increasedyear by year. Most studies had shown that high blood pressure, diabetes andthe metabolic syndrome contributed more to the ICAS，and hyperlipidemiawas closely associated with ECAS. Low HDL-C is the main form of lipidmetabolism disorders in China, the prevalence of low HDL-C is significantlyhigher than the United States and Australia, New Zealand. Whether LowHDL-C is the independent risk factors of LAA？Whether high prevalence oflow HDL-C is one of the risk factors of symptomatic ICAS？Whether thereis difference between the low HDL-C’s contributions to symptomatic ICASand ECAS remains to be confirmed.Based on this, our study was to discuss the correlation between lowhigh-density lipoprotein cholesterol (HDL-C) and LAA，then to elucidatewhether the the low HDL-C’s contributions to symptomatic ICAS and ECASis different. Method:1objects of studyOn the basis of TOAST classification, The1358subjects with symptom-matic large artery atherosclerosis(LAA) and small vascular disease (SVD)wereenrolled in the study in hebei medical university third hospital betweenDecember2006to December2012.Exclusion criteria:a, cardioembolism, stroke of other determined etiologyand stroke of undetermined etiology; B, the patients whose clinical data wasnot complete.2The evaluation method of atherosclerosis stenosisAll the patients underwent TCD, carotid ultrasound and (or) MRA, theatherosclerotic stenosis was diagnosed with artery luminal stenosis50%orhigher. Then we combined the medical history and other auxiliaryexaminations to diagnosed the atherosclerosis stenosis. The relevant diagnosisstandards of arterial stenosis refer to the literatures.Intracranial arteries including:the middle cerebral artery,anterior cerebralartery, posterior cerebral artery and basilar artery, and the intracranial portionsof the internal carotid artery and vertebral artery； extracranial arteriesincluding：the extracranial portions of the vertebral artery, innominate artery,subclavian artery and internal artery and common carotid artery.3Atherosclerosis risk factors(1) Hypertension was defined as current use of antihypertensive medic-ations or systolic blood pressure of140mm Hg or more and/or diastolic bloodpressure of90mm Hg or more.(2) Diabetes mellitus was defined as the use ofantidiabetic medication or a fasting serum glucose level of7.0mmol/L ormore.(3) Smoking habit was considered to be present in current smokers or ifthe time interval since abstinence was <5years.(4) Cardiovascular diseasewere defined based on Angina pectoris or Myocardial infarction.ATP III guidelines were used to identify people with low level of HDL-C(≤1.03mmol/L in men and women), high level of total cholesterol(TC,≥5.18mmol/L),high LDL-C level (≥2.59mmol/L), high level of triglycerides (TG≥1.7mmol/L) or the use of hyperlipidemia medication.4Statistical methodsStatistics were performed with the SPSS16.0statistical package. Theassociation of vascular risk factors with each location of atherosclerosis wasanalyzed by Pearson X2test. Multivariate logistic regression analyses wereperformed to identify vascular risk factors independently associated with eachlocation of atherosclerosis. P<0.05represented a statistically significantdifference.Result:1358patients with ischemic stroke met the inclusion standard,including795LAA patients,563SVD patients. the incidence of low HDL-Cpatients was57.2%in LAA group and48.3%in SVD group, there was asignificant difference between the two group (X2=10.54, P=0.001). LAA asdependent variable, univariate and multivariate logistic regression analysis,after adjusted for diabetes, low density lipoprotein cholesterol (LDL-C),HDL-C and statins application history, low HDL-C suffered from independentrisk factors for the development of LAA (OR=1.526,95%CI1.220-1.909,P<0.001). Symptomatic ICAS, ECAS as dependent variable, multiplelogistic regression analysis，adjusted for age, coronary heart disease, diabetes,TC, LDL-C, HDL-C, statin use history, low HDL-C levels were independentrisk factors of symptomatic ICAS, ECAS (OR=1.475,95%CI1.1591.878,P=0.002; OR=2.716,95%CI1.5434.779, P=0.001). In a direct comparisonbetween the symptomatic ECAS and symptomatic ICAS, symptomaticICAS as dependent variable, the symptomatic ECAS as control group, aftermultivariate logistic regression analysis, low HDL-C was less frequent in thesymptomatic ICAS group than in the ECAS group(OR=0.462,95%CI0.263-0.810,P=0.007).Conclusion: Low HDL-C is the independent risk factors of LAA andsymptomatic ICAS and ECAS. Low HDL-C confers a higher risk forsymptomatic ICAS than for symptomatic ECAS.