Prevalence and Risk Factors of Asymptomatic Carotid Stenosis in Healthy Korean Population

ABSTRACT

PURPOSE: To investigate the prevalence and risk factors in stenosis of the extracranial carotid artery in a healthy Korean population. METHODS: Seventeen thousand two hundred and eighty one patients, without previous history of transient ischemic attacks, amaurosis of fugax and/or any neurologic deficit, who underwent carotid artery ultrasonography, were evaluated retrospectively. The patients were divided into six groups according to the degree of carotid artery stenosis, using real time B-mode high resolution ultrasonography; Group A-normal, Group B-from 1 to 15% carotid artery stenosis, Group C-from 16 to 49% carotid artery stenosis, Group D-from 50 to 79% carotid artery stenosis, Group E-from 80 to 90% carotid artery stenosis and Group F-carotid artery occlusion (100%). Medical the records of all patients were investigated for the following factors; age, gender, diabetes mellitus, hypertension, smoking, over weight, total cholesterol, HDL- cholesterol, LDL-cholesterol, TG (triglyceride), and HbA-1c (hemoglobinA-1c). RESULTS: There were 950 (5.5%) cases in Group A, 82 (0.5%) in Group B, 710 (4.1%) in Group C, 138 (0.8%) in Group D, 2 (0.01%) in Group E, 18 (0.1%) in Group F. The age, total cholesterol, LDL-cholesterol, and HbA-1c were higher in Groups B, C, D, E and F than in Group A, with statistical significance. Other factors, however, were no different among the groups. CONCLUSION: Asymptomatic carotid stenosis is not uncom mon in Korea. To prevent a stroke caused by carotid stenosis, carotid ultrasonography would be necessary in patients at high risk of atherosclerosis, such as hypertension, diabetes and a high serum cholesterol level.