Association between metabolic syndrome and carotid atherosclerosis: A community-based study in Hong Kong

Background: Carotid atherosclerosis should not be neglected as a cause for stroke in China, despite its low prevalence. This study was performed to evaluate the association between ultrasonographic markers for different stages of carotid atherosclerosis and metabolic syndrome. Methods: This was a community-based study in Hong Kong. Metabolic syndrome was defined as having three or more of the following conditions or receiving specific treatment for these conditions: Abdominal obesity, elevated triglycerides, low high-density lipoprotein cholesterol, hypertension, and impaired fasting blood glucose. All subjects underwent carotid duplex ultrasonography. Mean carotid intima media thickness (CIMT) of bilateral common carotid arteries was used as the CIMT value for a single subject. CIMT within the 4^th quartile was regarded as increased CIMT. Carotid plaque was defined as a focal CIMT of >1.5 mm. A carotid plaque obstructing ≥50% of vessel lumen was considered as carotid stenosis. Results: A total of 653 subjects (mean age 55.1±10.4; 47.2% male) were recruited. Metabolic syndrome was found in 188 (28.8%) subjects (30.8% in males and 27.0% in females). Mean CIMT was 0.74±0.12 mm. Increased CIMT, carotid plaque, and carotid stenosis were detected in 163 (25.0%), 95 (14.5%), and 6 (1.4%) subjects, respectively. In multivariate linear regression, CIMT significantly increased with increasing numbers of metabolic syndrome components (P<0.001). In multivariate logistic regression analysis, metabolic syndrome was independently associated with increased CIMT [odds ratio (OR) 1.17; 95% confidence interval (CI) 1.11-2.64; P=0.014), but not presence of carotid plaque (OR 1.50; 95% CI 0.92-2.46; P=0.108). Conclusions: Metabolic syndrome may be independently associated with the early stage but not the later and advanced stages of carotid atherosclerosis in community residents in China.