Evaluation of serum 8-isoprostane levels and arterial stiffness index in normotensive, prehypertensive and hypertensive subjects

Objective: To compare serum levels of 8-isoprostane and arterial stiffness index (ASI) in normotensive, prehypertensive and hypertensive subjects and to ascertain its correlation with ASI and blood pressure. Methodology: We studied a total of ninety male subjects ranging from 35-55 years of age. They were classified into normotensive, prehypertensive and hypertensive groups in light of JNC-8 Guidelines. Each group comprised of thirty subjects. Blood pressure was measured with mercury sphygmomanometer and digital volume pulse was recorded by photoplethysmography and ASI was calculated. Serum 8-isoprostane levels were measured by ELISA. Results: Serum 8-isoprostane levels and ASI were significantly (0.0001) different amongst the three groups. The Post Hoc Tukey’s Test revealed p-value of 0.006 between normotensive and prehypertensive groups and 0.0001 between prehypertensive and hypertensive as well as normotensive and hypertensive groups for ASI. Plasma 8-isoprostane levels were non-significant (0.113) between normotensive and prehypertensive groups while significant (0.0001) between prehypertensive and hypertensive as well as normotensive and hypertensive groups. In normotensive subjects, the relationship between serum 8-isoprostane levels was moderately (r=0.4) correlated with ASI while, it was relatively strongly related with ASI in prehypertensive (r = 0.5) and hypertensive (r = 0.5) subjects. Conclusion: The oxidative stress is involved in the development and worsening of arterial stiffness in prehypertensive and hypertensive patients.