Relationship between serum uric acid and arterial stiffness in a sample of adult-elderly subjects: data from the brisighella heart study

Purpose: The role of uric acid on atherosclerosis phenomena is a vexed question. The antioxidant properties of uric acid are well known, on the other hand several studies shown an association between higher level of uric acid and hypertension, diabetes, metabolic syndrome and cardiovascular diseases. The aim of this study was to verify the relationship between uric acid values and arterial stiffness and subclinical atherosclerosis. Methods: The Brisighella Heart Study is a prospective, population-based longitudinal epidemiological investigation involving 2939 randomly selected subjects (1491 men and 1448 women), aged 14 to 84 years, free of cardiovascular disease at enrolment, resident in the northern Italian rural town of Brisighella. From this historical cohort, we randomized a sub-sample of 619 subjects (248 males), aged 53.5±11.2. Preclinical atherosclerosis was detected by carotid intima-media thickness (IMT) measurement. Arterial stiffness was determined by measuring the carotid-femoral pulse wave velocity (PWV) by means of a validated tonometer. Results: A linear regression analysis shown a significant relationship between acid uric levels and IMT (r:0.20, p<0.0001) and PWV (r:0.12, p=0.003). All subjects were subdivided into quartiles in relation with acid uric values in males and females. The age-adjusted relationship between the uric acid values and PWV and IMT values was analysed. IMT was significantly higher in 3rd and 4th quartiles in relation with 1st and 2nd quartiles (p>0.001) (global trend: P<0.0001). With regard to aortic PWV values, these were higher in 3rd quartiles (p<0.05) and 4th quartiles (p<0.001) in relationship with 2nd quartile, but not with the 1st one (global trend: P=0.04). A stepwise regression analysis shown that uric acid was one of the main factors affecting IMT (standard coeff. 0.09, p=0.01) together with age (p<0.001), smoking (p<0.001), BMI (p<0.05), LDL-cholesterol (p<0.01), mean arterial pressure (p<0.01), and low level of heart rate (p<0.01). This model accounted for 42% of the variance in IMT. On the contrary, uric acid was not an independent factor affecting PWV. The main factors affecting PWV (R2:42%) were age, BMI, heart rate, mean arterial pressure and low level of cholesterol LDL. Conclusions: This study has shown an association between acid uric high level and arterial stiffness and a possible independent role of uric acid on atherosclerotic deases.