Effect of hyperuricemia upon endothelial function in patients at increased cardiovascular risk

The aim of the present study was to evaluate the effect of increased serum uric acid (UA) levels and their therapeutic reduction with allopurinol on endothelium-dependent dilation in subjects with a high cardiovascular (CV) risk but who were free from clinical CV disease. Patients with hyperuricemia had impaired flow-mediated dilation (FMD) compared with matched controls with normal UA levels and elevated CV risk. Three-month therapy with allopurinol improved FMD in hyperuricemic subjects, showing an intrinsic negative effect of elevated UA levels on the arterial wall; conversely, FMD remained unchanged in controls, thus suggesting that the reduction of UA to less than a certain value does not affect endothelial function.