title: Classic risk factors for atherosclerosis are not major determinants for location of extracranial or intracranial cerebral atherosclerosis.
abstract: BACKGROUND
  The prevalence of extracranial (EC) and intracranial (IC) atherosclerosis varies among races. Although several studies have sought to identify specific vascular risk factors that are associated with EC or IC atherosclerosis, the exact relationships are uncertain. This study aimed to determine if there are any specific risk factors for EC or IC atherosclerosis.
  
  
  METHODS
  For this study, we considered 3,349 consecutive patients who had been entered into a stroke registry between January 1999 and June 2007. After the exclusion of patients who had not undergone angiography, patients with cardiac sources of embolism or other causes of stroke, and non-Koreans, we had a total of 2,169 patients of single ethnicity with an angiographic analysis. Patients with atherosclerosis in both the IC and EC arteries (856 patients) were excluded. Finally, we identified 1,313 patients who had EC atherosclerosis (EC group, n = 256), IC atherosclerosis (IC group, n = 566) or normal angiographic findings (no-lesion group, n = 488). The frequency of risk factors and the demographic parameters were compared among these groups.
  
  
  RESULTS
  When compared to the normal group, the IC group was associated with older age and hypertension, and the EC group was associated with older age, higher initial blood sugar and low-density lipoprotein cholesterol levels. However, in a direct comparison between the IC and EC groups, we did not observe any significant risk factors or variables except for a higher frequency of males and higher total cholesterol levels in the EC group.
  
  
  CONCLUSIONS
  Vascular risk factors may not be major determinants of location for atherosclerosis in the EC or IC arteries.
authors.affiliation: Department of Neurology, National Core Research Center for Nanomedical Technology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young Dae
authors.initials: YD
authors.lastname: Kim
authors.forename: Hye Yeon
authors.initials: HY
authors.lastname: Choi
authors.forename: Yo Han
authors.initials: YH
authors.lastname: Jung
authors.forename: Chung Mo
authors.initials: CM
authors.lastname: Nam
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Yang
authors.forename: Han Jin
authors.initials: HJ
authors.lastname: Cho
authors.forename: Hyo Suk
authors.initials: HS
authors.lastname: Nam
authors.forename: Kyung-Yul
authors.initials: KY
authors.lastname: Lee
authors.forename: Ji Hoe
authors.initials: JH
authors.lastname: Heo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000145:classification / Q000453:epidemiology / Q000209:etiology; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000453:epidemiology; D002537:Intracranial Arteriosclerosis / Q000145:classification* / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D012042:Registries; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D055815:Young Adult