OBJECTIVE 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 > or = 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 (> or = 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.