Association of oxidative stress and endothelial dysfunction in hypertension

Background: Biomarkers of oxidative stress (OS) are involved in the pathophysiology of hypertension (HTN) and endothelial dysfunction is also related to HTN. Still, a significant association of OS, as well as endothelial function, remains unclear in HTN.

Methods: Totalling 222 North Indian peoples aged 18-80 participated in the study. Of these participants, 74 were elderly hypertensive subjects (age ≥60 years), and 128 were normotensive subjects (age ≥60 years-control I; n = 74, and <60 years-control II; n = 74). OS was assessed by measurement of total oxidant status (TOS) and total antioxidant status (TAS) using a colorimetric and automated method developed by Erel O. Endothelial dysfunction was assessed by measurement of flow-mediated dilation (FMD) using doppler ultrasound system.

Results: TOS and OSI were significantly increased and TAS and FMD significantly decreased in patients with HTN as compared to control I and control II. The increase in the level of TOS and a decrease in the level of TAS and FMD were also evident with advancing age. FMD was negatively correlated with TOS and positively correlated with TAS.

Conclusion: Decreased TAS level, increased TOS level reflect OS that may be the reason for reduced FMD in elderly hypertensive patients.