A Double-blind, Randomised, Placebo-controlled Parallel Study to Investigate the Effect of Dietary Nitrate on a Model of Vascular Dysfunction in Healthy Volunteers
试验速览
- 阶段
- 1 期
- 状态
- 已完成
- 入组人数
- 78
- 试验地点
- 2
- 主要终点
- Flow mediated dilatation
研究概览
简要总结
The principal research objective is to determine whether inorganic nitrate in the form of beetroot juice compared to placebo control prevents the systemic inflammation that underlies typhoid vaccine-induced endothelial dysfunction
详细描述
We wish to determine in a prospective manner whether inorganic nitrate affects the endothelial dysfunction induced by systemic inflammation. At baseline we will measure flow-mediated dilatation (FMD) and peripheral augmentation index, as well as aortic stiffness, as measured by pulse wave velocity (PWV). Volunteers will then receive ~8 mmols of dietary nitrate or nitrate free placebo juice once daily for 6 days. After this, depending on availability, volunteers will receive a typhoid vaccine Typherix®, GlaxoSmithKline UK or Typhim Vi ™, AAH Pharmaceuticals Ltd). This vaccine generates a mild systemic inflammation that is associated with vascular dysfunction. All vascular function measures will be repeated at 8 hours and 32 hours after vaccine administration.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 45 Years（Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •Healthy volunteers
- •Volunteers who are willing to sign the consent form.
- •Normal resting blood pressure (<140/90 mmHg)
排除标准
- •Healthy subjects unwilling to consent
- •Pregnant, or any possibility that a subject may be pregnant unless in the latter case a pregnancy test is performed with a negative result
- •History of any serious illnesses, including recent infections or trauma
- •Subjects taking systemic medication (other than the oral contraceptive pill)
- •Subjects with self-reported use of mouthwash or tongue scrapes
- •Subjects with recent (3 months) or current antibiotic use
- •Subjects with a history, or recent treatment of (within last 3 months) any oral condition (excluding caries), including gingivitis, periodontitis and halitosis
- •Subjects with a history of typhoid vaccination in the last 6 months
- •Subjects with any history of a blood-borne infectious disease such Hepatitis B or C virus, or HIV
结局指标
主要结局
Flow mediated dilatation
时间窗: Day 1, Day 7 (8 hours post typhoid vaccine), Day 8 (32 hours post typhoid vaccine)
Comparison of change in FMD from baseline after typhoid vaccination following inorganic nitrate versus placebo supplementation
Plasma nitrite concentration
时间窗: Day 1, Day 7 (8 hours post typhoid vaccine), Day 8 (32 hours post typhoid vaccine)
Comparison of change in plasma nitrite concentration following inorganic nitrate versus placebo supplementation
次要结局
- Markers of acute inflammation(Day 1, Day 7 (8 hours post typhoid vaccine), Day 8 (32 hours post typhoid vaccine))
- Pulse wave velocity(Day 1, Day 7 (8 hours post typhoid vaccine), Day 8 (32 hours post typhoid vaccine))
- Platelet reactivity(Day 1, Day 7 (8 hours post typhoid vaccine), Day 8 (32 hours post typhoid vaccine))
- Plasma nitrate concentration(Day 1, Day 7 (8 hours post typhoid vaccine), Day 8 (32 hours post typhoid vaccine))
研究者
Amrita Ahluwalia
Director of The William Harvey Research Institute, Prof of Vascular Pharmacology
Queen Mary University of London