Association of oxidative stress and endothelial dysfunction in hypertension

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.

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.

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.

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