Postmenopausal Women and Their Endothelium: Is Dietary Nitrate Supplementation Protective
试验速览
- 阶段
- 2 期
- 状态
- 已完成
- 入组人数
- 37
- 试验地点
- 1
- 主要终点
- Micro-vascular reactivity
研究概览
简要总结
The purpose of this study is to test the effects of a one time dose and 7-days of inorganic nitrate (supplied in the form of beetroot juice) on blood vessel function and resting blood pressure in healthy, postmenopausal women. Participants will drink beetroot juice and a placebo juice on separate visits where blood pressure and blood vessel function will be measured.
详细描述
Cardiovascular disease is the leading cause of death in the United States. Due to the loss of estrogen, women experience a unique accelerated rise in cardiovascular disease risk factors following menopause. Postmenopausal women represent a population at heightened risk for cardiovascular disease development. Function of the endothelium has been shown to decline across the menopause transition, resulting in less production of nitric oxide. As such the investigators are investigating a potential therapeutic strategy in women have recently undergone menopause to boost nitric oxide availability.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- — 至 70 Years（Child, Adult, Older Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •Early post-menopausal women who are within 1-6 years following their final menstrual cycle
- •Late post-menopausal women who are beyond 6 years following their final menstrual cycle
排除标准
- •Individuals with any overt cardiovascular, metabolic, hematologic, pulmonary, renal, musculoskeletal, and/or neurological disease(s).
- •Users of any tobacco and/or nicotine products (smokers, chewing tobacco, nicotine-containing patches/gum, smokeless cigarettes)
- •Individuals with a BMI > 35
- •Individuals with resting blood pressure > or = 130/80 mm Hg
- •Individuals with high blood lipids (total cholesterol > or = 240 mg/dl, LDL > or = 160 mg/dl, triglycerides > or = 200 mg/dl).
- •Postmenopausal women with hyperglycemia (fasting glucose > or = 110 mg/dl and HbA1c >6.0%).
- •Individuals taking any of the following medications:
- •blood pressure lowering medication (e.g., beta blockers, ACE inhibitors, angiotensin antagonists, calcium channel blockers, diuretics)
- •lipid- lowering medication (e.g., statins)
- •nitrates (e.g. nitroglycerin) for angina
- •phosphodiesterase inhibitors (e.g., Viagra)
- •anti-Inflammatory drugs
- •Individuals taking hormone therapy
研究组 & 干预措施
Nitrate rich beetroot juice
Subjects will consume 140 ml of beetroot juice (Beet-It Organic Shot) approximately 90 min before physiological testing.
干预措施: nitrate rich beetroot juice (Drug)
Nitrate depleted beetroot juice
Subjects will consume 140 ml of beetroot juice (Beet-It Organic Placebo) approximately 90 min before physiological testing.
干预措施: nitrate depleted beetroot juice (Drug)
结局指标
主要结局
Micro-vascular reactivity
时间窗: These measurements will take place before and after a ischemia-reperfusion injury (20 minutes inflation, 20 minutes deflation) induced in the upper arm to assess change in micro-vascular reactivity
Using near-infrared spectroscopy, a probe placed on the forearm muscle will be used to measure area under the curve for tissue saturation index re-perfusion following 5 minutes of forearm cuff occlusion.
Macro-vascular reactivity
时间窗: These measurements will take place before and after a ischemia-reperfusion injury (20 minutes inflation, 20 minutes deflation) induced in the upper arm to assess change in macro-vascular reactivity
Using near-infrared spectroscopy, a probe placed on the forearm muscle will be used to measure the tissue saturation index re-perfusion slope following 5 minutes of forearm cuff occlusion.
次要结局
- Brachial artery flow-mediated dilation(These measurements will take place before and after a ischemia-reperfusion injury (20 minutes inflation, 20 minutes deflation) induced in the upper arm to assess change in brachial artery flow-mediated dilation)
- Resting blood pressures(Change from baseline resting blood pressure and at 90 minutes after beet root juice ingestion)
- Recovery of micro-vascular function and brachial artery flow mediated dilation(Change in these measures from immediately after ischemia-reperfusion injury to 30 minutes following)
- Brachial ankle pulse wave velocity and ankle-brachial index(These measurements will take place before (day 1) and 24 hours after (day 8) 7 days of supplementation.)
研究者
David N. Proctor, PhD
Professor of Kinesiology, Physiology, and Medicine
Penn State University