Blood Pressure Reduction is Associated With the Changes in Oxidative Stress and Endothelial Activation in Hypertension, Regardless of Antihypertensive Therapy

Abstract

Background/Aims: Hypertensive patients present with increased oxidative stress and frequently receive angiotensin II (ANGII) receptor type I blockers (ARB) for blood pressure (BP) reduction. Recent studies revealed an important role of ANGII in maintaining vascular oxidative homeostasis, including sustaining normal sodium dismutase activity. This study aimed to investigate the effects of antihypertensive therapy and also vitamin C/E supplementation on BP, oxidative stress and endothelial activation in patients with essential hypertension. Methods: Newly discovered patients received ARB/olmesartan or the Ca²⁺-channel blocker (CCB)/amlodipine, and additionally vitamin C/E or placebo throughout weeks 9-16. ELISA was used to determine 8-iso-prostaglendin F2-alpha (8iPGF2α) and endothelial activation markers. Results: In both groups BP was normalized during first 8 weeks of therapy. Vitamins C/E had no additional BP-lowering effect. The vitamins C/E supplementation was not effective in reducing absolute values of 8iPGF2α; however; the magnitude of 8iPGF2α reduction was significantly greater in patients taking vitamins C/E in the CCB group. Although plasma 8iPGF2α positively correlated to BP, a significant decrease occurred during an additional 8 weeks of treatment. There were no changes in endothelial activation markers related to the specific action of ARB or CCB. Conclusions: Present study suggests that observed oxidative stress is a consequence of hypertension. BP reduction is associated with the observed decrease in oxidative stress and changes in endothelial activation regardless of antihypertensive therapy.