Does Dietary Nitrate Supplementation Attenuate the Cardiovascular Strain Elicited by Caffeine and Cold Exposure in Healthy Individuals?
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 24
- 试验地点
- 1
- 主要终点
- Brachial blood pressure
研究概览
简要总结
Dietary inorganic nitrate supplementation may have positive implications on cardiovascular function. The aim of this project is to determine if nitrate supplementation can attenuate the effects that caffeine and cold exposure have on the cardiovascular system.
详细描述
Acute caffeine consumption and cold exposure elicit negative effects on the cardiovascular system. Humans are regularly exposed to such conditions of increased cardiovascular strain, which may lead to elevated chronic cardiovascular risk. On the other hand, dietary inorganic nitrate supplementation is well established to improve cardiovascular function in healthy individuals. Thus, acute nitrate supplementation may compensate for the negative effects that caffeine and the cold place on the cardiovascular system. These effects will be measured using peripheral blood pressure, pulse wave analysis, heart rate variability, forearm blood flow, flow mediated dilation, and blood and saliva markers.
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)
盲法说明
Double-blinded using supplement placebos.
入排标准
- 年龄范围
- 18 Years 至 40 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Blood pressure < 130 mmHg systolic and < 85 mmHg diastolic. BMI between 18.5 and 29.9 kg/m
- •Females must be naturally menstruating (regular length cycle and menses) or using a form of combined hormonal contraception (for at least 6 months).
排除标准
- •Existing cardiovascular or metabolic conditions. Experience any adverse reactions to experimental procedures or supplements. Allergies to supplements or breakfast items. Involved in any other studies. Blood pressure > 130 mmHg systolic and > 85 mmHg diastolic.
研究组 & 干预措施
Nitrate, caffeine, and cold pressor test (CPT)
All outcome variables will be measured for 24 participants in a trial where they receive 400 mg nitrate in the form of beetroot extract, 6 mg/kg caffeine powder, and undergo a 3 min cold pressor test.
干预措施: TruBeet inorganic beetroot juice (Dietary Supplement)
Nitrate, caffeine, and cold pressor test (CPT)
All outcome variables will be measured for 24 participants in a trial where they receive 400 mg nitrate in the form of beetroot extract, 6 mg/kg caffeine powder, and undergo a 3 min cold pressor test.
干预措施: Cold pressor test (Other)
Nitrate, placebo caffeine, and CPT
All outcome variables will be measured for 24 participants in a trial where they receive 400 mg nitrate in the form of beetroot extract, 6 mg/kg cornflour (caffeine placebo), and undergo a 3 min cold pressor test.
干预措施: TruBeet inorganic beetroot juice (Dietary Supplement)
Nitrate, placebo caffeine, and CPT
All outcome variables will be measured for 24 participants in a trial where they receive 400 mg nitrate in the form of beetroot extract, 6 mg/kg cornflour (caffeine placebo), and undergo a 3 min cold pressor test.
干预措施: Cold pressor test (Other)
Placebo nitrate, caffeine, and CPT
All outcome variables will be measured for 24 participants in a trial where they receive nitrate-depleted beetroot extract (placebo), 6 mg/kg caffeine powder, and undergo a 3 min cold pressor test.
干预措施: Cold pressor test (Other)
Placebo nitrate, placebo caffeine, and CPT
All outcome variables will be measured for 24 participants in a trial where they receive nitrate-depleted beetroot extract (placebo), 6 mg/kg cornflour (caffeine placebo), and undergo a 3 min cold pressor test.
干预措施: Cold pressor test (Other)
Placebo nitrate, caffeine, and CPT
All outcome variables will be measured for 24 participants in a trial where they receive nitrate-depleted beetroot extract (placebo), 6 mg/kg caffeine powder, and undergo a 3 min cold pressor test.
干预措施: Caffeine (Dietary Supplement)
Nitrate, caffeine, and cold pressor test (CPT)
All outcome variables will be measured for 24 participants in a trial where they receive 400 mg nitrate in the form of beetroot extract, 6 mg/kg caffeine powder, and undergo a 3 min cold pressor test.
干预措施: Caffeine (Dietary Supplement)
结局指标
主要结局
Brachial blood pressure
时间窗: Mean of 5 readings taken pre-supplementation (0 hours) and post-supplementation (2.5 hours). 1 reading was taken pre- cold pressor test (3.5 hours). All measures were recorded on every experimental trial (4 trials with at least 48 h washout between).
Brachial blood pressure was collected using an automatic sphygmomanometer.
Flow mediated dilation
时间窗: Measured pre-supplementation (at 0 hours) and post-supplementation (at 2.5 hours) for every experimental trial (4 trials with at least 48 h washout between).
Baseline diameter, peak diameter, change in diameter, and shear stimulus following flow mediated dilation procedure of the brachial artery with post-occlusion reactive hyperaemia.
Central blood pressure and pulse wave variables
时间窗: Collected pre-supplementation (0 hours), post-supplementation (2.5 hours), and during the cold pressor test (3.5 h) for 4 experimental trials (4 trials with at least 48 hours washout in between).
Mean of 2-3 readings for aortic systolic BP, aortic diastolic BP, HR, Augmentation index, augmentation index corrected to HR of 75 bpm, pulse pressure, and augmentation pressure.
次要结局
- Forearm blood flow(Measured pre-supplementation (at 0 hours) and post-supplementation (at 2.5 hours) for every experimental trial (4 trials with at least 48 h washout between).)
- Salivary nitrate and nitrite(Measured pre-supplementation (at 0 hours) and post-supplementation (at 2.5 hours) for every experimental trial (4 trials with at least 48 h washout between).)
- Heart rate variability(Collected pre-supplementation (0 hours), post-supplementation (2.5 hours), and during the cold pressor test (3.5 h) for 4 experimental trials (4 trials with at least 48 hours washout in between).)
- NIBP continuous blood pressure(Collected pre-supplementation (0 hours), post-supplementation (2.5 hours), and during the cold pressor test (3.5 h) for 4 experimental trials (4 trials with at least 48 hours washout in between).)
- Whole blood RSNO(Collected pre-supplementation (0 hours), post-supplementation (2.5 hours), and immediately post- cold pressor test (3.5 h) for 4 experimental trials (4 trials with at least 48 hours washout in between).)
- Plasma nitrate, nitrite, cGMP(Collected pre-supplementation (0 hours), post-supplementation (2.5 hours), and immediately post- cold pressor test (3.5 h) for 4 experimental trials (4 trials with at least 48 hours washout in between))
研究者
Stephen Bailey
Principal Investigator
Loughborough University