Objective: As known, hypertension has relation with increased peripheral vascular resistance. Vascular tone is regulated by multiple mediators; among them is Endothelin-1. Endothelin-1 (ET-1) is one of the most potent vasoconstrictors known to date. While its plasma /serum concentrations are elevated in some forms of hypertension. Prehypertension is one step towards hypertension, hence the same factor is involved in it. Oxidative stress is also found to be involved in pathogenesis of hypertension .Therefore our present study is designed to find the relationship between ET-1 levels and Total antioxidant capacity (TAC) in Prehypertension.

Methods: Total 100 prehypertensive cases and 100 sex matched controls were enrolled in this study. Inclusion criteria include patients with systolic blood pressure (SBP) in the range of 120 to 139 mmHg and diastolic blood pressure (DBP) in the range 80-90 mmHg, while patients with BP ≥ 140/90 mmHg, diabetes mellitus (DM), Stroke, coronary artery disease (CAD) and myocardial infarction (MI) were excluded. Plasma ET -1 and plasma total antioxidant capacity were measured .We estimated ET -1 levels and TAC levels in Prehypertensive cases and Normotensive controls. Students T test were used for statistical analyses.

Results: Plasma ET-1 levels were found significantly (p:0.001) higher in prehypertensive cases as compared to normotensive controls. In contrary to this, Plasma Total Antioxidant capacity was found extremely significantly lower in prehypertensive cases as compared to normotensive controls(p<0.0001).

Conclusion: The study demonstrated that in Prehypertensives, there is an inverse relationship between Endothelin-1 and Total antioxidant capacity.