Prevalence and cardiovascular risk factors of asymptomatic intracranial arterial stenosis: the Kongcun Town Study in Shandong, China

Background and purpose This study was to investigate the prevalence and cardiovascular risk factors (CRFs) of asymptomatic intracranial atherosclerotic stenosis (aICAS) amongst middle-aged and older adults living in rural communities in China. Methods This population-based study included 2019 subjects (aged >= 40 years, 52.3% women) who were free of stroke and living in rural communities in China. From October 2017 to May 2018, data on demographics, CRFs and health conditions were collected through face-to-face interviews, physical examination and laboratory tests. Asymptomatic ICAS was detected through a two-phase procedure: a screening phase with transcranial Doppler ultrasound, followed by a diagnostic phase with magnetic resonance angiography examination. Multivariable logistic regression models were used to analyse CRFs associated with aICAS. Results Of the 2019 participants, aICAS was detected in 153 persons. The overall prevalence of aICAS was 7.6%, and the prevalence of moderate-to-severe aICAS was 5.0%. The multi-adjusted odds ratio (95% confidence interval) of aICAS associated with CRFs was 2.40 (1.56-3.69) for hypertension, 1.91 (1.32-2.76) for high hypersensitive C-reactive protein, 1.68 (1.14-2.49) for diabetes and 1.61 (1.08-2.41) for overweight or obesity. When these four CRFs were aggregated, compared with participants without any of these factors, the multi-adjusted odds ratios (95% confidence interval) of aICAS for persons concurrently having one, two and three or more of these factors were 1.14 (0.52-2.48), 2.91 (1.42-5.99) and 5.51 (2.64-11.50), respectively (P for linear trend <0.001). Conclusions Asymptomatic ICAS is common amongst rural-dwelling middle-aged and older Chinese people. Hypertension, diabetes, overweight or obesity and high hypersensitive C-reactive protein, especially when coexisting, are strongly associated with aICAS.