Classic Risk Factors for Atherosclerosis Are Not Major Determinants for Location of Extracranial or Intracranial Cerebral Atherosclerosis

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.