Independent relationships of uric acid and homocysteine serum levels with early carotid atherosclerosis in untreated newly diagnosed by ambulatory blood pressure monitoring hypertensives

Several serum markers have been recognized as risk factors for target organ damage, while carotid intima-media thickness (IMT) has been established as an independent risk factor for cardiovascular events. In our study, we sought to validate the measurement of several biochemical risk factors as markers of carotid atherosclerosis in essential hypertensive subjects. This study included 24 untreated, mild essential, non-smokers hypertensive patients (13 men, mean age: 50 ±11.7 years) who underwent 24h ambulatory blood pressure monitoring in order to exclude white-coat hypertension. All subjects underwent B-mode ultrasonography of the carotid arteries to determine IMT and the presence of atheroma plaques of the common and internal carotid artery and carotid bulb. Venous blood samples were drawn from all participants in order to evaluate lipid and lipoprotein-a (Lp-a), apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB), fibrinogen, uric acid, homocysteine and hsCRP levels, by standard methodology. For the pooled population, BMI was 27.6±5.1 kg/m2, cholesterol was 211.2±43.3 mg/dl, triglycerides were 115±56.2 mg/dl, HDL was 57.1±15 mg/dl, LDL was 139±31 mg/dl, Lp-a was 46±78 mg/dl, ApoA1 levels were 124.1±15.2 mg/dl, ApoB was 101.6±18.7, hs-CRP levels were 2.16±2 mg/l, fibrinogen was 270.8±49 mg/dl, uric acid levels were 5.8±1.4 mg/dl, homocysteine was 13.2±6.2 μmol/l. In the univariate model, IMT of the internal carotid artery was correlated with levels of triglycerides (r=0.432, p=0.039), uric acid (r=0.610, p=0.002), homocysteine (r=0.507, p=0.014) and ApoA1 (r=-0.457, p=0.028). Furthermore, in stepwise regression analysis only serum levels of uric acid and homocysteine remained significant after adjustment for all parameters analyzed (p=0.002 and p=0.016 respectively). In essential hypertensive subjects, serum levels of uric acid and homocysteine are closely related to carotid IMT, independently of a wide range of established proatherogenic and inflammatory mediators.