The effects of angiotensin II on pulse wave velocity in healthy humans

Objectives: To examine the dose response relationship between Ang II and pu lse wave velocity (an index of arterial stiffness) in healthy human volunte ers. Design and methods: We studied 9 healthy male volunteers (mean age 24. 7 +/- 0.66 years) in a double-blind, randomized, cross-over, placebo-contro lled design. We measured carotid-femoral PWV using a novel device complior. Subjects received placebo, 0.5, 1 and 5 ng/kg/min Ang II as infusions over 30 minutes under standardized conditions. Heart rate, blood pressure and P WV were recorded at baseline and then every 10 minutes during the infusion and twice after the end of the infusion. Results: Systolic blood pressure ( SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) in mm Hg increased significantly with the 5 ng/kg/min dose compared to placebo (p = 0.004, p = 0.007, p = 0.003, respectively). There was no significant dif ference in SBP, DBP and MAP between 1 and 0.5 ng/kg/min compared to placebo . There was a significant increase in PWV with 5 ng/kg/min dose only compar ed to placebo (p = 0.02). However, less than 30% of the total Ang II-induce d rise in PWV was explained by the Ang II-induced rise in blood pressure (R -2 = 0.257). Conclusions: Ang II increases PWV in healthy human only when g iven in doses that significantly increase blood pressure. Not all the incre ase in Ang II-induced rise in PWV can be explained due to Ang II-induced ri se in BP.