Chronotherapeutic Use of Vitamin C to Reduce Morning Cardiovascular Risk
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 10
- 试验地点
- 1
- 主要终点
- Vascular Endothelial Function
研究概览
简要总结
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.
详细描述
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Supportive Care
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
盲法说明
Vitamin C and Placebo doses will be blinded by the research pharmacy, so that participants and investigators are masked to the identity of the tablet. Data analysis will be blinded to the conditions as well until the completion of the study.
入排标准
- 年龄范围
- 40 Years 至 60 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Healthy participants
- •Normal weight or overweight but not obese (18.5<BMI<33 kg/m2)
排除标准
- •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.
研究组 & 干预措施
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.
干预措施: Placebo (Other)
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.
干预措施: Placebo (Other)
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.
干预措施: Vitamin C (Dietary Supplement)
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.
干预措施: Vitamin C (Dietary Supplement)
结局指标
主要结局
Vascular Endothelial Function
时间窗: 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.
Oxidative stress
时间窗: Approximately three months
Oxidative stress will be measured as malondialdehyde (MDA) adducts from Ethylenediaminetetraacetic acid (EDTA) plasma. Higher values may indicate increased oxidative stress.
Plasma Vitamin C and Tetrahydrobiopterin
时间窗: 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.
次要结局
- Plasminogen activator inhibitor -1(Approximately three months)
- Platelet aggregation(Approximately three months)
研究者
Steven A. Shea
Director, Oregon Institute of Occupational Health Sciences
Oregon Health and Science University