Abstract 174: Remote Ischemic Preconditioning Improves Digital Vascular Endothelial Function and Enhances Circulating Nitric Oxide Formation in Healthy Volunteers

Abstract

Background: Remote ischemic preconditioning (RIPC) induced by brief episodes of ischemia of the limb protects against organ damage by ischemia-reperfusion. It has been reported that RIPC improves endothelial function of the forearm in normal subjects and patients with coronary artery disease. However, the digital vascular endothelial response to RIPC has not been determined in healthy volunteers. Methods: This study was performed to examine effect of RIPC on fingertip digital vascular endothelial function by using endothelial pulse amplitude tonometry (EndoPAT) device and alteration in circulating nitric oxide(NO) level in peripheral blood. Ten healthy adult subjects (5 men, 5 women, mean age 25.2 years) had 3 cycles of 5 min ischemia alternating with 5 min reperfusion of the forearm. Another 10 healthy volunteers (6 men, 4 women, mean age 26.2 years) were used as the control group of sham and the cuff was inflated for 3 times at 10 mmHg for 5 minutes with 5-minute intervals. Fingertip digital vascular endothelial function of the ipsilateral arm was measured prior to first ischemia, 3h and 6h after the last episode of ischemia. Blood samples were taken from the contralateral arm prior to first ischemia, 3h and 6h after the last episode of ischemia. Results: Fingertip digital vascular endothelial function was significantly increase in 3h and 6h after the last RIPC intervention compared with the baseline condition(p<0.05). In parallel the RIPC stimulus increased circulating NO formation(p<0.05). There is a close association between finger vascular endothelial function and NO formation(p<0.05). Conclusion: The present findings demonstrate for the first time that transient RIPC contributes to improvement of digital vascular endothelial function and increase in circulating NO production in healthy volunteers. Our data provide a novel evidence to support that RIPC might gain even wider application not only in disease but also in health.