The Effects of Acute Melatonin Supplementation on Cardiovascular Responses to Sympathetic Activation

Healthy Clinical Trial

Official title:

The Effects of Acute Melatonin Supplementation on Cardiovascular Responses to Sympathetic Activation

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04831398
• Other study ID #: 13084
• Status: Recruiting
• Phase: Phase 4
• Start date: January 1, 2023
• Est. completion date: December 2024

Study information

• Verified date: May 2024
• Source: University of Oklahoma
• Contact: Jeremy M Kellawan, PhD
• Phone: 405 325 9028
• Email: kellawan[@]ou.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

the purpose of this experiment is to determine if acute melatonin supplementation alters central and peripheral cardiovascular responses to a cold pressor test at rest and during dynamic exercise.

Description:

After IRB approval, experiments will take place in the Human Circulation Research Laboratory in the Department of Health and Exercise on the University of Oklahoma Norman campus. All subjects will complete a total of 3 visits. The first is a screening visit to provide informed consent and to ensure the potential participant meets all inclusion criteria and no exclusion criteria. Once consented and enrolled, participants will be familiarized with experimental protocols. On separate days (visits 2 and 3), participants will complete placebo (PLA) and melatonin (MEL) in a randomly ordered, single-blind, counter-balanced design. PLA or MEL treatment will precede testing by 30min to maximize absorption into the circulation (Bartoli, 2013).

All experiments (PLA/MEL) will begin with the subject lying supine for 5 min of quiet rest where baseline measurements are taken, followed by activation of the lower body negative pressure (LBNP) device causing suction at -20 mmHg. Following LBNP participants will be given 10 minutes of rest to recover all variables to pre-LBNP values. After which participants will be given a hand grip dynamometer to complete 7 minutes of exercise at an intensity of 20% MVC at a 1s contraction to 2s relaxation cycle paced by a metronome. During the final 2 minutes of the 7 minutes of exercise the LBNP device will be activated again to -20mmHg such that the participant will be completing LBNP during rhythmic grip exercise. After the completion of exercise, the subject will remain supine for 10min. Then the a Total Labile Signal (TLS) procedure will be conducted. Where the experimental limb is occluded using a blood pressure cuff for 5min. The cuff is then rapidly deflated. The lowest oxyhemoglobin measured during the occlusion is recorded. After the TLS procedure, the subject will be de-instrumented and will leave the laboratory.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 100
• Est. completion date: December 2024
• Est. primary completion date: September 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 35 Years

Eligibility

Inclusion Criteria:

• Healthy men and women

• Women must be premenopausal with a regular menstrual cycle (26-30 days)

Exclusion Criteria:

• History of autonomic dysfunction

• Cardiovascular diseases

• Diabetes

• Tobacco/nicotine use

• Systolic Pressure >= 130 mmHg

• Diastolic Pressure >= 85 mmHg

• Regular melatonin use >= 1 use/week

• Allergy to melatonin

• Cardiometabolic medication use (e.g. anti-hypertensives, insulin-sensitizing, statins)

• Sex hormone replacement medical use (e.g. testosterone, estrogen, progesterone)

• Pregnancy

Related Conditions & MeSH terms

• Healthy

Intervention

Dietary Supplement:
• melatonin
A 5mg dose of melatonin spay will be delivered sublingually.

Other:
• Placebo
10 sprays of diluted mint extract. This mimics the sensation and taste of the melatonin spray

Locations

Country	Name	City	State
United States	Department of Health and Exercise Science	Norman	Oklahoma

Sponsors (1)

Lead Sponsor	Collaborator
University of Oklahoma

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Muscle Tissue Oxygenation	Concentrations of Total, Oxy, and deoxyhemoglobin of Flexor Digitorum Profundus muscle of the forearm	7 minutes of rest and 7 minutes of exercise
Primary	Mean Arterial Pressure	average pressure within the arteries	7 minutes of rest and 7 minutes of exercise
Secondary	Cerebral Oxygenation	Concentrations of Total, Oxy, and deoxyhemoglobin of the Prefrontal Cortex of the brain	7 minutes of rest and 7 minutes of exercise
Secondary	Heart Rate	number of heart beats per minute	7 minutes of rest and 7 minutes of exercise
Secondary	Respiratory Rate	number of breaths per minute	7 minutes of rest and 7 minutes of exercise
Secondary	Cardiac Output	volume of blood pumped by the heart per minute	7 minutes of rest and 7 minutes of exercise
Secondary	Stroke Volume	volume of blood pumped by the heart per heart beat	7 minutes of rest and 7 minutes of exercise
Secondary	Total peripheral resistance	amount of force affecting resistance to blood flow throughout the circulatory system	7 minutes of rest and 7 minutes of exercise
Secondary	Heart Rate Variability	measure of the variation in time between each heart beat	7 minutes of rest and 7 minutes of exercise