Uric acid and endothelial dysfunction in essential hypertension.

Recent epidemiologic and experimental evidence suggests that serum uric acid (UA) is an independent risk factor for cardiovascular and renal diseases. However, endothelial dysfunction is an early predictor of cardiovascular events, particularly in hypertensive patients. For assessment of the association between UA and endothelial function, 217 (108 men, 109 women; aged 48.0 +/- 10.6 yr) white never-treated hypertensive patients were studied. All patients underwent the following procedures: BP measurements, laboratory tests (C-reactive protein [CRP], insulin resistance by homeostasis model assessment, serum creatinine, and UA), and endothelial function evaluated by intra-arterial infusion of acetylcholine (ACh). Serum creatinine, CRP, and maximal vasodilatory response to ACh were related to the UA (all P < 0.0001). In the multiple regression analysis, serum UA ranked as the third correlate of peak of forearm blood flow predictor, after homeostasis model assessment and CRP. The data show an independent link between UA and endothelial function, also in a statistical model that included CRP. In conclusion, the data demonstrate an inverse and significant relationship between UA and ACh-stimulated vasodilation in patients with uncomplicated, untreated essential hypertension, independent of traditional cardiovascular risk factors. Probably, the chronic inflammation that was documented in these patients may be considered the mechanistic link between serum UA and vascular damage.