The aim of the study was to compare therapeutic effects of chosen antihypertensive drugs on arterial stiffness, shear stress in carotid arteries and metalloproteinases activity, moreover analysis of relationship of these variables in the course of treatment.
Methods: 95 patients with essential arterial hypertension stage 1 or 2 were randomized to 6 months monotherapy with: quinapril, amlodipine, hydrochlorothiazide, losartan or bisoprolol. Each therapeutic group consisted of 19 patients (N=19). Before and then after 1, 3 and 6 months of treatment carotid-femoral pulse wave velocity (PWV) by using a Complior device, ultrasound of carotid arteries were performed. Blood samples for the measurement of whole blood viscosity were taken during each visit. Shear stress (SS) was calculated using measured variables: blood viscosity and velocity of blood flow. Serum concentration of metalloproteinase 3 (MMP-3) and plasma concentration of tissue inhibitor of metalloproteinase I (TIMP-1) were measured at the initial visit and after 6 months of treatment.
Results: ANOVA for repeated measurements revealed for all groups significant decrease of PWV (ΔPWV) and MMP-3 (ΔMMP-3) concentration and increase of shear stress in carotid artery and TIMP-1 (ΔTIMP-1) concentration (p<0.05). No between groups differences appeared in above effects (p>0.05). The multiple regression analysis for the change of PWV (ΔPWV) in the study group considering all investigated variables at R2 = 0,27 revealed its significant relation to PWV at first visit, ΔTIMP-1, ΔMMP-3 and Δ shear stress counted for the maximum flow velocity in common carotid artery. Conclusion: Irrespectively of chosen drug we observed similar effect for PWV drop. Reduction of arterial stiffness as a result of antihypertensive therapy is strongly connected with shear stress increase that is secondary to blood flow velocity growth and changes in connective tissue metabolism.