Relationships between Serum Uric Acid, Malondialdehyde Levels, and Carotid Intima-Media Thickness in the Patients with Metabolic Syndrome

Oxidative stress is the major cause of atherosclerosis and cardiovascular diseases. This cross-sectional study is aimed at determining if parallel serum markers of oxidative stress are related to carotid intima-media thickness (IMT). We enrolled 134 participants with varied metabolic syndrome (Met-S) scores (zero, n = 21; one, n = 19; two, n = 27; three, n = 26; four, n = 25; five, n = 16). Biochemical profiles and potential oxidative stress biomarkers malondialdehyde (MDA) and uric acid were measured in fasting plasma. We found that carotid IMT positively correlated with both MDA and uric acid levels. Multivariate analysis revealed that both MDA (p < 0.05) and uric acid (p < 0.01) levels were significantly associated with carotid IMT in participants whose Met-S scores were ≥1 or ≥2. However, only uric acid (p < 0.01) levels were positively associated with carotid IMT in patients with metabolic syndrome. Linear regression model analysis revealed that the prediction accuracies for carotid IMT from MDA combined with uric acid and from a combination of MDA, uric acid, and Met-S score were 0.176 and 0.237, respectively. These were better than the predication accuracies from MDA (r(2) = 0.075) and uric acid (r(2) = 0.148) individually. These results suggest that measuring uric acid levels along with MDA biomarkers and Met-S scores may be a promising step in the development of an effective model for monitoring the severity of carotid IMT and atherosclerosis in the patients with metabolic syndrome.