The impact of uric acid serum levels on carotid artery structure and stiffness

Background: Elevated serum uric acid (UA) has been shown to be a strong predictor of cardiovascular morbidity and mortality. However, there is limited evidence about its association with carotid artery stiffness and structure. The aim of our study was to evaluate whether hyperuricaemia is associated with an increased risk of carotid atherosclerosis and stiffness. Methods: We evaluated 364 asymptomatic patients, aged ≤60 yrs old, that underwent our Preventive Cardiology Department for a comprehensive risk factors screening. All pts were free of overt coronary artery disease. Common carotid intima-media thickness (IMT) was measured at 1 cm from bifurcation using ultrasound. Plaque was defined as focal thickening of the arterial wall . 1.4 mm. Carotid stiffness index (b) was measured using a high-resolution echo-tracking system. Hyperuricaemia was defined as an serum UA ≥7 mg/dl in men and ≥6 mg/dl in women. Results: The mean age was 47+10 yrs (45.9% men). UA levels positively correlated with carotid b-index (p=.013) and IMT (p=.006). The prevalence of hyperuricemia was 21.42%. Hyperuricaemic patients had higher IMT (0.87+0.15 vs. 0.82+0.17 mm, p=.04) and carotid-b index (7.2+2.6 vs. 6.4+2.2, p=.01) than normouricaemic ones. The prevalence of plaques was higher in hyperuricaemic patients as compared to normouricaemic ones (57% vs. 44.2%, p=.006). In the hyperuricaemia group, the mean levels of fasting glucose (119.3+35.1 vs. 107+32.4, p=.004) and triglycerides (207+141 vs. 151.4+95.3, p,0.001) were as well significantly higher than in normouricaemic group. The mean levels of high-density lipoprotein cholesterol were significantly lower in hyperuricaemic patients (48.7+13.7 vs. 52.3+14, p=.044). Conclusions: Our data showed that UA, along with other risk factors related to atherosclerosis, played a role in the development of carotid atherosclerosis, in terms of both IMTand plaques, and it was also correlated with increased carotid artery stiffness.