Racial and Aging Effects of Acute Antioxidant Supplementation
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 93
- 试验地点
- 1
- 主要终点
- Arm blood flow
研究概览
简要总结
This research is,being done to better understand how antioxidants (vitamins C, E and Alpha Lipoic Acid) af,f,ect the heart,and arteries. For this study, we will obtain blood samples to measure oxidative stress markers (substances in the blood that are linked to oxidative stress), cholesterol, insulin and blood glucose (sugar), as well as measure how well the heart and arteries are working following supplementation with the antioxidants.
Our central hypothesis is that acute antioxidant supplementation will improve arterial function at rest and during exercise in African Americans without an impact of age, whereas aging will modify these effects in Caucasians.
详细描述
The overall goal of this application is to investigate the effect of aging on how acute antioxidant supplementation affects decrements in arterial function observed in African Americans (AA). Additionally, this application will facilitate the applicant's emergence as an independent investigator in integrative clinical physiology. Oxidative stress (OS), contributes to hypertension, diabetes, heart failure, atherosclerosis, sepsis and aging. Increased OS leads to the development of endothelial dysfunction and subsequent development of cardiovascular disease through the inactivation of nitric oxide (NO) by superoxide (O2) and other free radicals. African Americans (AA) have increased OS and inflammation in vivo and in vitro, and have a lower serum concentration of most antioxidants. Endothelial cells of AAs have steady state NO/ O2/ONOO- balance that is close to redox state, which is a characteristic of endothelium impaired function disorders. Endothelium-derived NO is a vasodilator and inhibits monocyte adhesion and platelet activity and therefore is important in the maintenance of vascular homeostasis. These specific differences in OS could be a contributing mechanism to the high prevalence of cardiovascular disease, especially hypertension and heart failure, observed in AA. Aging causes increases in OS, endothelial dysfunction, and decreased arterial compliance, thus increasing the risk of cardiovascular disease. Acute supra-physiological dosages of antioxidants have been shown to transiently restore endothelial function in older adults and patients with coronary artery disease and hypertension by scavenging free radicals.However, it is unknown if acute antioxidant supplementation can diminish differences in vascular function between AA and Caucasians (CA). It is also unknown if acute antioxidant supplementation with known efficacy will differentially affect blood flow in AA vs CA during exercise.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Prevention
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 18 Years 至 75 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •18-35 or 55-75 years of age
- •General Good health
- •Without diagnosed atherosclerotic disease
- •Without metabolic or inflammatory disease
- •Do not use antioxidant vitamin supplementation
- •Do not use anti-inflammatory medication within last 2 weeks
- •Do not use steroidal substances within past 2 weeks
- •Participants on medications (not listed in the
排除标准
- •) will take medication as normal on all days of study visits.
- •Exclusion Criteria:
- •Current smoker
- •Severe obesity (BMI>40 kg/m2)
- •Blood pressure greater than 140/90 mmHg
- •Diabetes (fasting glucose >110 mg/dl)
- •Hyperlipidemia (total cholesterol >240 mg/dl)
- •Inflammatory disease (rheumatoid arthritis, systemic lupus erythematosus, etc)
- •Diagnosed atherosclerotic heart disease
- •Diagnosed cardiac arrhythmia
- •Bacterial, viral or upper respiratory infection within past 1 month
- •Bleeding disorder
- •Anticoagulant medication
- •Pregnant women
研究组 & 干预措施
Placebo
Placebo will be ingested in front of laboratory personnel in two doses, separated by 30 minutes to increase absorption, consumed 90 and 60 minutes before the testing protocol. Placebo microcrystalline cellulose capsules will be of similar taste, color and appearance.
干预措施: Placebo (Other)
Antioxidant
Supplementation will be ingested in front of laboratory personnel in two doses, separated by 30 minutes to increase absorption, consumed 90 and 60 minutes before the testing protocol. The first dose will consist of 300 mg of α-lipoic acid, 500 mg of vitamin C, and 200 IU of vitamin E, and the second dose will be 300 mg of α-lipoic acid, 500 mg of vitamin C, and 400 IU.
of vitamin E.
干预措施: Placebo (Other)
Antioxidant
Supplementation will be ingested in front of laboratory personnel in two doses, separated by 30 minutes to increase absorption, consumed 90 and 60 minutes before the testing protocol. The first dose will consist of 300 mg of α-lipoic acid, 500 mg of vitamin C, and 200 IU of vitamin E, and the second dose will be 300 mg of α-lipoic acid, 500 mg of vitamin C, and 400 IU.
of vitamin E.
干预措施: Antioxidant (Dietary Supplement)
Placebo
Placebo will be ingested in front of laboratory personnel in two doses, separated by 30 minutes to increase absorption, consumed 90 and 60 minutes before the testing protocol. Placebo microcrystalline cellulose capsules will be of similar taste, color and appearance.
干预措施: Antioxidant (Dietary Supplement)
结局指标
主要结局
Arm blood flow
时间窗: 2 weeks
A second primary outcome is arm blood flow at rest and during two different intensities of hand grip exercise
Endothelial function
时间窗: 2 weeks
A third primary outcome is endothelial function assessed through brachial artery flow mediated dilation.
Arterial stiffness
时间窗: 2 weeks
The overall aim of this study is to examine the effects of an acute dose of an antioxidant cocktail on arterial stiffness (measured by ventral pulse wave velocity) in younger and older African Americans in comparison to younger and older Caucasians.
次要结局
- Blood pressure(2 weeks)
研究者
Bo Fernhall
Dean
University of Illinois at Chicago