Prevalence and risk factors of intracranial and extracranial artery stenosis in asymptomatic rural residents of 13 villages in China

Background: The present study aimed to investigate the prevalence and risk factors for extracranial carotid artery stenosis (ECAS) and intracranial carotid artery stenosis (ICAS) simultaneously in asymptomatic Chinese pure rural population. Methods: We analyzed 2589 asymptomatic subjects aged over 30 yr. by ultrasonography and transcranial Doppler simultaneously in 13 isolated villages by door-to-door investigation. Both ECAS and ICAS were defined as more than 50% stenosis. Demographics, medical history documentation, and investigation of biochemical results were performed for each subject. Univariate and multivariate logistic regression analyses were employed to assess the risk factors associated with ECAS and ICAS, respectively. Results: One hundred twenty-two (4.7%) residents with ICAS and 56 (2.2%) with ECAS were found in 2589 subjects. Three factors emerged as independent risk factors for ICAS: age (95% confidence interval [CI] = 1.01-1.04, odds ratio [OR] = 1.07), hypertension (95% CI = 1.98-4.37, OR = 2.94), and diabetes mellitus (95% CI = 1.72-4.38, OR = 2.75). As for ECAS, five factors presented as independent risk factors: age (95% CI = 1.09-1.11, OR = 1.10), male sex (95% CI = 1.01-1.02, OR = 1.01), diabetes mellitus (95% CI = 1.10-2.12, OR = 1.53), systolic blood pressure (95% CI = 1.95-2.88, OR = 2.37), and total cholesterol (95% CI = 1.00-1.13, OR = 1.06). Conclusions: ICAS and ECAS were relatively common among asymptomatic rural Chinese subjects. Although they shared similar risk factors, differences still existed between them.