Association of socioeconomic status with intracranial arterial plaque: mediated by cardiometabolic risk factors

BACKGROUND: Low socioeconomic status (SES) has been associated with atherosclerosis but few studies have explained its relationship with intracranial arterial plaque. The aim of this study is to investigate the association between SES and intracranial arterial plaque, as well as its possible pathogenetic mechanisms. METHODS: Data were obtained from the baseline cross-sectional survey of the PolyvasculaR Evaluation for Cognitive Impairment and vaScular Events study in China. SES was assessed and categorised into three groups based on the participants' educational level, occupational class and income level. Intracranial arteries were evaluated using vascular MRI. Mediation analyses were performed to estimate the indirect and direct effects of systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood-glucose (FG) and waist-hip ratio (WHR) on the association between SES and intracranial arterial plaque. RESULTS: A total of 3065 subjects were included. The mean age of participants was 61.2±6.7 years, and 53.5% (n=1639) were women. Compared with the high SES group, the intermediate and low SES groups were associated with higher odds of intracranial arterial plaques (OR: 1.85, 95% CI 1.37 to 2.49; OR: 1.68, 95% CI 1.24 to 2.28) and greater intracranial atherosclerotic burden (common OR (cOR): 1.79, 95% CI 1.33 to 2.40; cOR: 1.65, 95% CI 1.22 to 2.22) after adjusting for potential covariates. Cardiometabolic risk factors partially mediated the association between SES and intracranial arterial plaque (percentage mediated: 27.5%) and between SES and intracranial atherosclerotic burden (37.4%). Across both outcomes, SBP was the strongest mediator (23.29% for plaque; 30.33% for burden), followed by DBP (13.36% and 14.47%), FG (7.07% and 10.05%) and WHR (6.20% and 7.61%). CONCLUSION: SES was associated with higher odds of the presence of intracranial arterial plaque and atherosclerotic burden, with nearly one third of the association being explained by cardiometabolic risk factors.