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

Sponsor

University of Oklahoma (Other)

Overall Status

Not yet recruiting

CT.gov ID

NCT04831398

Collaborator

(none)

100

Enrollment

Location

Arms

Anticipated Duration (Months)

Patients Per Site Per Month

Study Details

Study Description

Brief 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.

Condition or Disease	Intervention/Treatment	Phase
Healthy	Dietary Supplement: melatonin Other: Placebo	Phase 4

Detailed 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.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

100 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Intervention Model Description:

This study is a single-blind crossover design.This study is a single-blind crossover design.

Masking:

Single (Participant)

Masking Description:

Participants will be blinded in two trials. Practitioners and operators will not be allowed to communicate with the participants concerning whether they are receiving placebo/melatonin. Outcome assessors and statisticians may not be blinded to experimental allocation. Our placebo should satisfy two conditions of an ideal placebo: a) it should be indistinguishable from the experimental supplement to blinded participants, and b) it should be physiologically inert. In this study, 1 microliter McCormicks Pure Mint Extract will be mixed with 29 ml of filtered water and given to participants as a sublingual spray. This mixture will be non-caloric and will mimic the taste and sensation of the commercially available melatonin spray that will be used in the study (Onnit Labs Inc., Mint Flavor).

Primary Purpose:

Basic Science

Official Title:

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

Anticipated Study Start Date :

Jul 1, 2022

Anticipated Primary Completion Date :

May 1, 2023

Anticipated Study Completion Date :

May 1, 2023

Arms and Interventions

Arm	Intervention/Treatment
Placebo Comparator: Placebo Placebo (PLA) is 10 sublingual sprays of a diluted (1 microliter/29ml filtered water) mint extract.	Other: Placebo 10 sprays of diluted mint extract. This mimics the sensation and taste of the melatonin spray
Experimental: Melatonin 5mg commercially available melatonin (MEL) spray will be given sublingually.	Dietary Supplement: melatonin A 5mg dose of melatonin spay will be delivered sublingually.

Arm

Intervention/Treatment

Placebo Comparator: Placebo

Placebo (PLA) is 10 sublingual sprays of a diluted (1 microliter/29ml filtered water) mint extract.

Other: Placebo

10 sprays of diluted mint extract. This mimics the sensation and taste of the melatonin spray

Experimental: Melatonin

5mg commercially available melatonin (MEL) spray will be given sublingually.

Dietary Supplement: melatonin

A 5mg dose of melatonin spay will be delivered sublingually.

Outcome Measures

Primary Outcome Measures

Muscle Tissue Oxygenation [7 minutes of rest and 7 minutes of exercise]
Concentrations of Total, Oxy, and deoxyhemoglobin of Flexor Digitorum Profundus muscle of the forearm
Mean Arterial Pressure [7 minutes of rest and 7 minutes of exercise]
average pressure within the arteries

Secondary Outcome Measures

Cerebral Oxygenation [7 minutes of rest and 7 minutes of exercise]
Concentrations of Total, Oxy, and deoxyhemoglobin of the Prefrontal Cortex of the brain
Heart Rate [7 minutes of rest and 7 minutes of exercise]
number of heart beats per minute
Respiratory Rate [7 minutes of rest and 7 minutes of exercise]
number of breaths per minute
Cardiac Output [7 minutes of rest and 7 minutes of exercise]
volume of blood pumped by the heart per minute
Stroke Volume [7 minutes of rest and 7 minutes of exercise]
volume of blood pumped by the heart per heart beat
Total peripheral resistance [7 minutes of rest and 7 minutes of exercise]
amount of force affecting resistance to blood flow throughout the circulatory system
Heart Rate Variability [7 minutes of rest and 7 minutes of exercise]
measure of the variation in time between each heart beat

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 35 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

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

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Department of Health and Exercise Science	Norman	Oklahoma	United States	73019

Sponsors and Collaborators

University of Oklahoma

Investigators

Principal Investigator: Jeremy M Kellawan, University of Oklahoma

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

Responsible Party:

University of Oklahoma

ClinicalTrials.gov Identifier:

NCT04831398

Other Study ID Numbers:

13084

First Posted:

Apr 5, 2021

Last Update Posted:

May 24, 2022

Last Verified:

May 1, 2022

Individual Participant Data (IPD) Sharing Statement:

Plan to Share IPD:

Studies a U.S. FDA-regulated Drug Product:

Studies a U.S. FDA-regulated Device Product:

Product Manufactured in and Exported from the U.S.:

Additional relevant MeSH terms:

Melatonin

Study Results

No Results Posted as of May 24, 2022