Effect of Ghrelin on Sympathetic Nervous System

Effect of Ghrelin on Sympathetic Nervous System and Stress Reactivity

Ghrelin is a newly discovered peptide that is secreted by the stomach. Its main role is to stimulate food intake but recent studies indicate that it also acts on the cardiovascular system to confer beneficial effects. The mechanism of action is unclear but experimental studies suggest that ghrelin decreases the sympathetic nervous system. Beside there is new evidence in animal models that ghrelin may also be involved in stress reaction as ghrelin injection seems to protect against symptoms of stress. Given that circulating levels of ghrelin are reduced in obesity, this suggests that the effect of ghrelin may differ between lean and obese subjects. Ghrelin could represent an attractive therapeutic strategy for the treatment of cardiovascular diseases. The aim of the study if to gain more knowledge of the effect of ghrelin on the sympathetic nervous system and stress reactivity in both lean and obese subjects.

Study Overview

• Status: Completed
• Conditions: Healthy; Obesity
• Intervention / Treatment: Drug: ghrelin

Detailed Description

This study will investigate the effect of intravenous administration of ghrelin on blood pressure, heart rate, muscle sympathetic nervous activity and baroreflex control in lean and obese individuals and will investigate whether ghrelin administration can influence the response to stress. Both lean and obese individuals will be recruited and will receive an intravenous administration of ghrelin at increasing doses for 1 hour. Their blood pressure, heart rate and sympathetic activity (small recording electrode in the peroneal nerve) will be recorded and subjects will be submitted to a mental arithmetic stress towards the end of the infusion. Blood samples will be taken at regular intervals for various metabolic tests. These responses will be compared to those when submitted to saline infusion.

• Study Type: Interventional
• Enrollment (Estimated): 46
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Australia
  • Victoria
    • Melbourne, Victoria, Australia, 3004
      • Alfred & Baker Medical Unit

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• healthy lean subjects with a BMI < 25 kg/m2 and subjects with central obesity (according to IDF definition)

Exclusion Criteria:

• any current medication
• a history of diabetes
• hypertension
• cardiovascular, cerebrovascular, liver, thyroid disease
• mental illness

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Sympathetic nervous activity	60 min

Secondary Outcome Measures

Outcome Measure	Time Frame
blood pressure	60 min

Collaborators and Investigators

• Sponsor: Baker Heart and Diabetes Institute

Study record dates

Study Major Dates

• Study Start: June 1, 2009
• Primary Completion (Actual): May 1, 2010
• Study Completion (Actual): May 1, 2010

Study Registration Dates

• First Submitted: June 1, 2009
• First Submitted That Met QC Criteria: June 2, 2009
• First Posted (Estimated): June 3, 2009

Study Record Updates

• Last Update Posted (Actual): September 14, 2023
• Last Update Submitted That Met QC Criteria: September 13, 2023
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: 2009/119; 11/09