Clinical Value of Serum Uric Acid in Patients with Suspected Coronary Artery Disease

BACKGROUND/AIMS: Although increased serum uric acid (SUA) concentrations are commonly encountered in patients with risk factors for coronary artery disease (CAD), the clinical value of SUA has not been established. METHODS: The study group comprised 687 consecutive patients with suspected CAD who had undergone coronary angiography. CAD was defined as stenosis ≥ 50% of the luminal diameter. CAD severity was expressed as 1-, 2-, or 3-vessel disease. Metabolic syndrome (MS) was defined according to National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III) criteria, and aortofemoral pulse wave velocity (PWV) was obtained by arterial catheterization invasively. RESULTS: In total, 395 patients had CAD. SUA was higher in patients with CAD as compared to those without CAD (5.5 ± 1.0 vs. 5.2 ± 1.0 mg/dL, p = 0.004). In addition, SUA was significantly associated with the severity of CAD (p = 0.002). However, after adjusting for significant confounding factors including age, diabetes, smoking, cholesterol, MS, and PWV, SUA was not an independent risk factor for CAD (p = 0.151). Based on a subgroup analysis, SUA was more closely associated with CAD in women than in men, and in the highest quartile (≥ 6.4 mg/dL) than in the first quartile (< 4.8 mg/dL); however, these results were not significant (p = 0.062, p = 0.075, respectively). In a multivariate regression analysis, the most important determinant of SUA was MS (i.e., insulin resistance syndrome), which is strongly associated with CAD. CONCLUSIONS: In patients with suspected CAD, SUA was not an independent risk factor for CAD and may be merely a marker of insulin resistance.