Vitamin C to Reduce Morning Cardiovascular Risk

Chronotherapeutic Use of Vitamin C to Reduce Morning Cardiovascular Risk

This study will test the efficacy of Vitamin C to counteract morning cardiovascular (CV) risk markers in a randomized, double blind, placebo controlled crossover pilot study. The participants will also perform morning typical behaviors such as arousal from sleep, change in posture (getting out of bed) and mild intensity physical activity; identical to the stressors encountered in everyday life. Primary dependent variables are markers of cardiovascular risk including vascular endothelial function and oxidative stress.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Risk Factor
• Intervention / Treatment: Dietary supplement: Vitamin C; Other: Placebo

Detailed Description

The investigators plan to test the efficacy of Vitamin C to counteract morning cardiovascular (CV) risk markers in a randomized, double blind, placebo controlled crossover pilot study. The participants will also perform morning typical behaviors such as arousal from sleep, change in posture (getting out of bed) and mild intensity physical activity; identical to the stressors encountered in everyday life. This pilot study is in healthy middle aged adults without a history of CV disease.

Participants will spend two nights in an inpatient hospital suite at Hatfield Research Center. Upon awakening in the morning, they will either ingest Vitamin C or placebo in a randomized order. This will be followed by moderate intensity exercise, recovery, and discharge.

• Study Type: Interventional
• Enrollment (Actual): 10
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Oregon
    • Portland, Oregon, United States, 97239
      • Oregon Health & Science University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years to 60 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Healthy participants
• Normal weight or overweight but not obese (18.5<BMI<33 kg/m2)

Exclusion Criteria:

• History of smoking/tobacco use
• Current prescription/non-prescription medications or drugs of abuse
• Acute, chronic, or debilitating medical conditions
• History of working irregular day and night hours, regular night work, or rotating shift work for the six months prior to the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Vitamin C then Placebo; Participants will receive a 1.5g dose of Ascorbic Acid upon wake for the first visit, and a placebo tablet on the second visit.	Dietary supplement: Vitamin C; 1.5g Ascorbic Acid; Other Names: Ascorbic Acid; Other: Placebo; Inactive placebo to mimic 1.5g ascorbic acid.
Experimental: Placebo then Vitamin C; Participants will receive a placebo tablet upon wake for the first visit, and a 1.5g dose of Ascorbic Acid on the second visit.	Dietary supplement: Vitamin C; 1.5g Ascorbic Acid; Other Names: Ascorbic Acid; Other: Placebo; Inactive placebo to mimic 1.5g ascorbic acid.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Vascular Endothelial Function	Vascular endothelial function will be measured as flow-mediated dilation (FMD). We will measure brachial artery FMD immediately upon awakening in a constant posture following an overnight fast using the standard guidelines and protocol.	Approximately three months
Oxidative stress	Oxidative stress will be measured as malondialdehyde (MDA) adducts from Ethylenediaminetetraacetic acid (EDTA) plasma. Higher values may indicate increased oxidative stress.	Approximately three months
Plasma Vitamin C and Tetrahydrobiopterin	We will measure Vitamin C levels in the plasma to ensure that the levels are increased after supplementation, and to control for baseline levels. We will measure tetrahydrobiopterin (BH4) from plasma to test if levels are increased upon administration of Vitamin C.	Approximately three months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Platelet aggregation	Platelet aggregation will be measured using Chronolog 560 VS Platelet aggregometer as an indicator of how well blood clots or clumps together. Higher values may indicate increased cardiovascular risk.	Approximately three months
Plasminogen activator inhibitor -1	Plasminogen activator inhibitor-1 (PAI-1) will be measured from plasma as a blood inflammatory marker. Higher values may indicate increased cardiovascular risk.	Approximately three months

Collaborators and Investigators

• Sponsor: Oregon Health and Science University

Study record dates

Study Major Dates

• Study Start (Actual): February 13, 2018
• Primary Completion (Actual): March 1, 2022
• Study Completion (Actual): March 1, 2022

Study Registration Dates

• First Submitted: September 18, 2017
• First Submitted That Met QC Criteria: September 19, 2017
• First Posted (Actual): September 25, 2017

Study Record Updates

• Last Update Posted (Actual): March 23, 2023
• Last Update Submitted That Met QC Criteria: March 21, 2023
• Last Verified: March 1, 2023

More Information

Terms related to this study

• Keywords: Sleep; Vitamin C
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Protective Agents; Micronutrients; Vitamins; Antioxidants; Ascorbic Acid
• Other Study ID Numbers: IRB 00017294

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No