NCT03303404

24-hour Blood Pressure Measurements and Ischemic Conditioning

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 22 (actual)
• Sponsor: University of Texas at Austin · Academic / Other
• Sex: All
• Age: 30 Years – 60 Years
• Healthy volunteers: Accepted

Summary

To determine if 24-hr ambulatory blood pressure monitoring effects endothelial function, we will measure flow-mediated dilation before and after the blood pressure monitoring (ischemia conditioning).

Detailed description

Reestablishing blood flow (reperfusion) to organs that had their blood supply restricted (ischemia) can cause damage to the vasculature via injury and tissue death resulting in endothelial dysfunction. This ischemia-reperfusion (blood flow occlusion and resupply) triggered injury can be reduced or prevented by preceding brief periods of ischemia called preconditioning. Properly-performed preconditioning can exert a powerful protection against a subsequent sustained period of ischemia in a variety of organs in the body including the heart, kidney, and skeletal muscle. Preconditioning protocol involves repeated brief inflation and deflation of a blood pressure cuff. In many of human cardiovascular research studies, it is common to measure endothelial function and ambulatory (24-hour) blood pressure. The ambulatory blood pressure device takes repeated blood pressure readings every 15-30 minutes during the daytime and 30-60 minutes at night. It is possible that repeated bouts of inflation/deflation of the blood pressure cuff could induce preconditioning effects and influence endothelial function. Therefore, in the proposed study we aim to address this hypothesis.

Conditions

• Blood Pressure

Interventions

Type	Name	Description
DEVICE	Ambulatory (24-hour) Blood Pressure	Unlike casual blood pressure measurements, 24-hour ambulatory blood pressure monitoring provides an insight into blood pressure changes in everyday life and an estimate of the overall blood pressure load exerted on the cardiovascular system over 24 hours. Blood pressure recordings over a 24-hour period of normal daily activity will be made using a noninvasive ambulatory monitor (Spacelabs, Redlands, WA). The ambulatory system will be calibrated against a mercury sphygmomanometer, and the cuff will be programmed to inflate automatically every 15 min from 6 AM to 11 PM and every 20 min between 11 PM and 6 AM. For each individual subject, the nighttime period will be defined as the time when the subject goes to bed at night until rising in the morning. Daytime will be defined as the remainder of the 24-hour period. Daytime and nighttime states will be monitored by an Actiwatch (Mini-MItter, Bend, OR), a watch-like device placed on the wrist that measures gross motor activity.

Timeline

• Start date: 2017-09-12
• Primary completion: 2018-09-20
• Completion: 2018-09-20
• First posted: 2017-10-06
• Last updated: 2020-12-22
• Results posted: 2020-12-22

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated device study