Abstract
BACKGROUND: Uric acid may be involved in the pathogenesis of hypertension. We investigated the roles of four major hemodynamic parameters of blood pressure, including arterial stiffness, wave reflections, cardiac output (CO), and total peripheral resistance (TPR), in the association between uric acid and central systolic blood pressure (SBP-c). METHODS: A sample of 1303 normotensive and untreated hypertensive Taiwanese participants (595 women, aged 30-79 years) was drawn from a community-based survey. Study subjects' baseline characteristics, biochemical parameters, carotid-femoral pulse wave velocity (cf-PWV), amplitude of the backward pressure wave decomposed from a calibrated tonometry-derived carotid pressure waveform (Pb), CO, TPR, and SBP-c were analyzed. RESULTS: In multi-variate analyses adjusted for age, waist circumference, body mass index, creatinine, total cholesterol, smoking, and heart rate, uric acid significantly correlated with Pb and cf-PWV in men, and Pb and TPR in women. The correlation between uric acid and Pb remained significant in men and women when cf-PWV was further adjusted. In the final multi-variate prediction model (model r(2)=0.839) for SBP-c, the significant independent variables included uric acid (partial r(2)=0.005), Pb (partial r(2)=0.651), cf-PWV (partial r(2)=0.005), CO (partial r(2)=0.062), TPR (partial r(2)=0.021), with adjustment for age, sex, waist circumference, body mass index, creatinine, total cholesterol, smoking, and heart rate. CONCLUSIONS: Uric acid was significantly independently associated with wave reflections, which is the dominant determinant of SBP-c. Uric acid was also significantly associated with SBP-c independently of the major hemodynamic parameters.