NCT01713374

Physiological Assessment of the Endothelium - Circadian Rhythm and Role of the Sympathetic Nervous System

Studies on the Physiological Meaning of Flow-mediated Constriction, Flow-mediated Dilatation and Vasomotion/Flowmotion: Circadian Variability and Role of the Sympathetic Nervous System.

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 40 (actual)
• Sponsor: Johannes Gutenberg University Mainz · Academic / Other
• Sex: Male
• Age: 18 Years – 40 Years
• Healthy volunteers: Accepted

Summary

The purpose of this study is to determine whether interventions aimed at increasing sympathetic tone modify endothelial function measures as assessed by the measurement of flow-mediated dilation (FMD) and constriction (FMC). The investigators hypothesize that the three interventions under study will increase FMC while causing a blunting in FMD. Further, the investigators plan to study the circadian variability of FMC and FMD. The investigators hypothesize a peak of FMD in the late hours of the day and a peak of FMC in the early hours.

Conditions

• Endothelial Function

Interventions

Type	Name	Description
PROCEDURE	Mental stress	Subjects will be asked to perform complex mathematic operations at a very fast pace
OTHER	no intervention	control visit
PROCEDURE	Myogenic activation	A pneumatic cuff will be inflated to suprasystolic pressure around both thighs and the subjects will be asked to perform plantar flexion exercises.
PROCEDURE	Cold pressure test	A hand will be placed in ice-cold water.

Timeline

• Start date: 2012-10-01
• Primary completion: 2013-03-01
• Completion: 2014-03-01
• First posted: 2012-10-24
• Last updated: 2015-04-01

Locations

1 site across 1 country: Germany