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Completed

NCT Number: NCT03290612

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.

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Key information

Conditions

Cardiovascular Risk Factor

Age range

40 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Oregon Health & Science University

Portland, Oregon, 97239, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Vitamin C

Dietary Supplement

1.5g Ascorbic Acid

Other names: Ascorbic Acid

Placebo

Other

Inactive placebo to mimic 1.5g ascorbic acid.

Primary outcomes

  1. Vascular Endothelial Function

    Time frame: Approximately three months

    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.

  2. Oxidative stress

    Time frame: Approximately three months

    Oxidative stress will be measured as malondialdehyde (MDA) adducts from Ethylenediaminetetraacetic acid (EDTA) plasma. Higher values may indicate increased oxidative stress.

  3. Plasma Vitamin C and Tetrahydrobiopterin

    Time frame: Approximately three months

    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.

Secondary outcomes

  1. Platelet aggregation

    Time frame: Approximately three months

    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.

  2. Plasminogen activator inhibitor -1

    Time frame: Approximately three months

    Plasminogen activator inhibitor-1 (PAI-1) will be measured from plasma as a blood inflammatory marker. Higher values may indicate increased cardiovascular risk.

Sponsors and collaborators

Lead sponsor

Oregon Health and Science University

Other

Registry information

Official study title

Chronotherapeutic Use of Vitamin C to Reduce Morning Cardiovascular Risk

Important dates

Study start
2018
Primary completion
2022
Study completion
2022
First posted
Sep 25, 2017
Registry last updated
Mar 23, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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