Association of uric acid and carotid artery disease in patients with ischemic stroke

Background and purpose Some previous studies reported an independent association between uric acid and coronary artery disease, while little is known on the association among uric acid and carotid artery disease (CAD). To address this issue, we investigated the association between CAD and higher uric acid level because of the well-known importance of the carotid artery pathologies for ischemic stroke. Methods Between 2009 and 2012, we conducted a study among 406 consecutive first-ever ischemic stroke patients to assess the relationship between uric acid and carotid artery. A mean intima-media thickness IMT was calculated for the wall of the left and right common carotid arteries (CCA) and IMT of the bifurcation of the carotid arteries. CAD was assessed by neuroimaging techniques in patients with carotid artery stenosis more than 50%. Logistic regression models were used to determine the relation among pathological changes of the carotid artery and higher uric acid level. Results In patients with hyperuricemia, the frequency of age (>60years), hypertriglyceridemia, higher apo B, renal failure were significantly higher than those with normal uric acid level. CAD was more frequent in patients with hyperuricemia than those with normal uric acid level (OR, 1.8, 95% CI, 1.1-3.1; P=0.01). In patients with higher uric acid level, the mean of the IMT of the CCA and of the bifurcation of the carotid artery were higher than those with normal uric acid level (P=0.001 for each). Covariance matrix analysis displayed a strong correlation between CAD and age (>60years) (P<0.05), sex (P<0.01), hyperuricemia (P<0.01), hypertension (P<0.05), and hypercholesterolemia (P<0.05). In the models of regression analysis, a strong association was found among patients with CAD and sex, renal failure, hyperuricemia, number of plaques, and size of plaques. Conclusion Our study demonstrated that higher uric acid level is strongly associated with CAD. Elevated uric acid might be injurious for large cerebral arteries with some probable confounding risk factors. Further prospective large clinical trials will determine whether lowering uric acid level reduces the frequency of CAD and ischemic stroke.