ASSOCIATION OF SERUM URIC ACID LEVELS WITH ARTERIAL STIFFNESS AND ENDOTHELIAL DYSFUNCTION IN A POPULATION OF NORMOTENSIVE TO EARLY-STAGE HYPERTENSIVE INDIVIDUALS. (June 2018) - Gkaliagkousi, E.
Abstract : Objective: Objective: Hyperuricemia appears to be associated with increased cardiovascular risk. Both accelerated vascular stiffness and endothelial injury caused by increased oxidative stress have been postulated as contributing potential mechanisms. We investigated whether serum uric acid levels correlate with robust markers of arterial stiffness and endothelial dysfunction in a population of untreated individuals free from cardiovascular diseases, whose blood pressure ranged from normal to early-stage essential hypertension. Design and method: Design and Method: Individuals free from cardiovascular comorbidities, who received no medication for any reason, were eligible to participate. Arterial stiffness was estimated by the carotid-femoral pulse wave velocity (PWV) measurement with applanation tonometry using the Sphygmocor device. Serum samples were drawn for the measurement of uric acid levels and other biochemical parameters. Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, was measured in serum samples using commercially available competitive enzyme-linked immunosorbent assay (ELISA) kit. Results: Results: A total of 241 individuals, 144 males and 97 females, with a mean age of 45.0 ± 11.2 years and mean systolic/diastolic blood pressure 138.8 ± 18.4/88.7 ± 12.0 mmHg, participated in the study. Mean PWV was 7.9 ± 1.8 m/s, while serum uric acid and ADMA levels were 5.1 ± 1.4 mg/dl and 1.00 ± 0.39 μmol/l, respectively. Uric acid positively correlated with both PWV (r = 0.152, p = 0.025) and ADMA levels (r = 0.141, p = 0.029). After adjustment for other variables (age, gender, body mass index, HDL cholesterol, triglycerides, glomerular filtration rate) in the multivariate analysis for uric acid, an independent association between with ADMA levels was observed (beta = 0.200, p < 0001), whereas the association between uric acid and PWV was no longer significant. Conclusions: Conclusion: In a population of untreated normotensive- to- early-stage hypertensive individuals, increased levels of uric acid are independently associated with endothelial dysfunction. On the other hand, the observed association between uric acid and arterial stiffness appears to be mediated by traditional cardiovascular risk factors. Uric acid might be implicated in the pathogenesis of cardiovascular diseases through endothelium-dependent mechanisms.