Acute Blood Pressure-lowering Effects of Beetroot Juice in Postmenopausal Women With and Without Hypertension
试验速览
- 阶段
- 2 期
- 状态
- 已完成
- 入组人数
- 16
- 试验地点
- 1
- 主要终点
- Resting Aortic Blood Pressures
研究概览
简要总结
In this study the investigators will test the hypothesis that acute consumption of inorganic nitrate (supplied in concentrated beetroot juice) reduces artery stiffness and resting blood pressure, and lessens the rise in blood pressure during handgrip exercise in postmenopausal women. Understanding and improving artery function and blood pressure regulation in women is important because they undergo accelerated arterial stiffening after menopause and have much larger increases in blood pressure when they exercise compared with either premenopausal women or men of similar age.
详细描述
Postmenopausal women have stiff central arteries and exaggerated blood pressure (BP) responses during exercise compared with either premenopausal women or men of similar age. Arterial stiffness and exaggerated BP responses to exercise are prognostic for heart wall thickening, future hypertension, adverse cardiovascular events, and mortality. Previous studies have reported that acute consumption of nitrate-rich beetroot juice can lower resting and exercising BP responses in older adults. However, these studies included both sexes and did not compare the effects of beetroot juice to a nitrate-depleted placebo (a true control). Thus, the potential BP lowering effects of nitrate supplementation per se have not been established in postmenopausal women. The present study examines the acute (single dose) effects of nitrate-rich beetroot juice on resting hemodynamics (peripheral and central BP, arterial wave properties, etc), and physiological responses to handgrip exercise in metabolically healthy post-menopausal women.
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)
盲法说明
Treatment order will be randomly assigned to participants by Clinical Research Center (CRC) staff using computer-based mathematical software. The generated list that determines each participants treatment order will be kept in a secure location in the CRC which cannot be accessed directly by research team members.
入排标准
- 年龄范围
- 55 Years 至 80 Years（Adult, Older Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •Resting systolic blood pressure less than or equal to 160 mmHg
- •Resting diastolic blood pressure less than or equal to 100 mmHg
排除标准
- •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)
- •Body mass index greater than 35
- •Total cholesterol greater than 239 mg/dl
- •LDL cholesterol greater than 159 mg/dl
- •Fasting blood triglycerides greater than 199 mg/dl
- •Fasting blood glucose greater than 109 mg/dl and HbA1c greater than 6.0%
- •Individuals currently 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 currently taking hormone replacement 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: 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: Beetroot juice placebo (Drug)
结局指标
主要结局
Resting Aortic Blood Pressures
时间窗: Resting systolic blood pressure at 90 minutes after beetroot juice ingestion
Aortic Blood pressures were measured in the arm (cuff) and estimated in the aorta (radial artery tonometry).
次要结局
- Resting Arterial Stiffness/Wave Properties(Change from baseline resting pulse wave velocity at 90 minutes after beet root juice ingestion)
- Handgrip Exercise Blood Pressure Responses (Relative Change From Baseline)(Approximately 180 minutes after ingestion of beetroot juice)
- Handgrip Exercise Tolerance(Approximately 90 minutes after ingestion of beetroot juice)
- Blood Measures of Nitrate Absorption and Conversion(Change from baseline measures of plasma nitrate and nitrite at 90 minutes and at approximately 6 hours)
- Peak Rate of Perceived Exertion Scores During Handgrip Exercise(Approximately 90 minutes after ingestion of beetroot juice)
研究者
David N. Proctor, PhD
Professor of Kinesiology, Physiology, and Medicine
Penn State University