ASSOCIATION OF SERUM URIC ACID WITH AORTIC STIFFNESS IN UNTREATED HYPERTENSIVE SUBJECTS.

Abstract

INTRODUCTION: Recent studies have reported an association between serum uric acid (SUA) and reduced arterial elasticity. However, in these studies arterial elastic properties have been assessed chiefly by measuring brachial-ankle pulse wave velocity (PWV) or peripheral PWV and only sometimes by using aortic PWV, that is considered the gold standard for measuring arterial stiffness. Moreover, the studies exploring the influence of SUA on aortic distensibility in subjects with arterial hypertension yielded conflicting results. AIM: The purpose of our study was to evaluate the relationships between SUA and aortic stiffness in a group of essential hypertensive patients. METHODS: We enrolled 222 untreated hypertensive subjects (mean age: 44 ± 10 years; 60 % males), free from cardiovascular complications and without severe renal insufficiency. In all subjects SUA determination and albumin excretion rate (AER) assay were obtained. Moreover, measurement of carotid-femoral pulse wave velocity (c-f PWV), by an automatic computerised method (Complior) was performed. RESULTS: Patients with c-f PWV [12 m/s (n = 44) showed SUA levels significantly higher than those with lower values of PWV (5.9 ± 1.2 vs 5.3 ± 1.1 m/s; p = 0.002). This difference held after correction by ANCOVA for various confounding factors (p = 0.02), but not after further adjustment for AER. Univariate analysis of correlation disclosed a significant association of SUA with c-f PWV (r = 0.23; p = 0.001). This correlation lost statistical significance when AER was added in a multiple regression model including, as covariates, age, gender, mean arterial pressure, serum creatinine, metabolic syndrome and SUA. CONCLUSIONS: The results of our study showed that, in hypertensive subjects, a positive relationship between SUA and aortic stiffness exists This association may be mediated by endothelial dysfunction, as suggested by the loss of its statistical significance, after adjustment for AER.