Target Organ Damage and Blood Pressure, Retinal Vessels, Oxidative Stress and Polymorphisms Vav-2 and Vav-3 in Hypertensive Subjects (LOD-Hypertension)

Ambulatory blood pressure monitoring (ABPM): The ABPM will be performed on a day of standard activity, with an adequate cuff for the size of the patient's arm. A control system, SpaceLabs 90207 model (Spacelabs Healthcare, Issaquah, Washington, USA), validated according to the protocol of the British Hypertension Society, will be used [57]. The records in which the percentage of valid readings will be 80% of the total and with valid readings at all times were considered to be valid. Furthermore, for the records to be evaluable, at least 14 measurements will be required during the daytime period, or at least seven during the nightime or rest period. The monitor will be scheduled for obtaining blood pressure measurements every 20 min during the daytime period and every 30 min during the rest period. The average and dispersion estimators of SBP and DBP were calculated during the 24-h, daytime and nightime periods, defined based on the diary reported by the patient. The patient completes a form specifying bedtime and wake-up time.

Ambulatory arterial stiffness index (AASI) and Home arterial stiffness index (HASI): Arterial stiffness will be evaluated by the ambulatory and home arterial stiffness indices (AASI and HASI). For AASI and HASI estimation, the regression slope of diastolic on systolic blood pressure will be computed for each individual on the basis of 24-hour ABPM (AASI) and also HASI readings over 6 days. AASI as well as HASI were defined as one minus the respective regression slope of DBP on SBP [58]. AASI will also computed from waking or sleeping blood pressure.

Evaluation of retinal vessels: Retinography will be performed using a Topcon TRC NW 200 nonmydriatic retinal camera (Topcon Europe B.C., Capelle a/d Ijssel, The Netherlands), obtaining nasal and temporal images centered on the disk. The nasal image with the centered disk will be loaded into the developed software, AV Index calculator (Ciclorisk SL, Salamanca, Spain, registry no. 00/2011/589). The software automatically recognizes the disk and draws two external concentric circles which delimit area A, between 0 and 0.5 disk diameters from the optic disk margin, and area B, between 0.5 and 1 disk diameters from the margin. The software first identifies the limits of the different vessels, after which it automatically recognizes arteries and veins, and makes multiple measurements of the diameter of the section of the vessels circulating through area B. It finally estimates the mean caliber of veins and arteries in mm, and these measurements are summarized as an arteriole-venule ratio, AVIx. An AVIx of 1.0 suggests that arteriolar diameters will be on average the same as venular diameters in that eye, whereas a smaller AVR suggests narrower arterioles. We used the pairs of main vessels in the upper and lower temporal quadrants, rejecting all other vessels, to improve reliability and increase efficiency of the process, analyzing measures for each quadrant separately and together to estimate the mean measure in each eye. [64].

Laboratory:Determining the concentration of superoxide and catecholamines (adrenaline and noradrenaline) in plasma and urine anion will be determined by ELISA (CatCombi ELISA, IBL, Deventer, The Netherlands), following the manufacturers instructions. Superoxide dismutase activity in plasma will be also assessed using ELISA kits (Cu-Zn superoxid-dismutase ELISA, IBL), and the urinary excretion and plasma levels of lipid peroxides by measuring products react with thiobarbituric acid (TBARS) (OxiSelect TBARS Assay Kit, Cell Biolabs, Inc., San Diego, CA 92126).

In a sample of DNA from peripheral blood erythrocyte polymorphisms of VAV and VAV-2-3 genes in all study subjects are studied. To this end, 10cc of venous blood obtained with anticoagulant (EDTA: ethylene diamine tetra-acetic acid).