In the frame of this proposal investigators will test the hypothesis that high normal blood pressure (prehypertension; PreHT) induces systemic endothelial dysfunction and endothelial activation in both micro- and macrocirculation, reduces re-endothelialization potential of human endothelial progenitor cells (EPCs) and increases the level of endothelial extracellular vesicles (EVs), which are accompanied by increased oxidative stress level. Furthermore, initial vascular and left ventricle (LV) remodeling contributes to changes in systemic hemodynamics and may be influenced by altered regulatory role of renin-angiotensin system (RAS) and autonomic nervous system (ANS) in PreHT but otherwise healthy individuals. To distinguish high normal blood pressure effect from those considered normal or high, study will be performed in three groups of individuals: prehypertensive (BP 130-139/85-89 mmHg), hypertensive (stage I, BP 140-150/90-100 mmHg), and controls (BP less than or equal to 129/85 mmHg). Altogether, the impairment of normal vascular relaxation mechanisms, endothelial activation as well as vascular and LV remodeling could play crucial role in increased cardiovascular risk and CVDs incidence in PreHT individuals. Moreover, the prognostic significance of assessing endotehlial dysfunction in hypertension (as well as in PreHT) is yet to be established.

Inclusion Criteria:

• adults of both sexes with normotensive, prehypertensive and grade I hypertension blood pressure values

Exclusion Criteria:

• cardiovascular diseases, but grade I hypertension (BP 140-150/90-100 mmHg)
• diabetes
• kidney disease
• cerebrovascular diseases
• peripheral artery disease
• taking oral contraceptives or any drugs that could affect the endothelium

Healthy subjects will be divided in the three study groups based on BP assessment using ambulatory blood pressure monitoring (ABPM). Hypertensive group will include only newly diagnosed patients who have not taken antihypertensive therapy.