The Effect of Dietary Nitrate on Blood Pressure, Insulin Resistance and Vascular Function in Type 2 Diabetes
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 44
- 试验地点
- 1
- 主要终点
- 24 hour Ambulatory Blood Pressure monitoring after 2 weeks placebo juice
研究概览
简要总结
Dietary nitrate supplementation has previously been shown to reduce blood pressure in healthy volunteers. The investigators wished to see whether this would be replicated in subjects with type 2 diabetes and age matched healthy controls.
详细描述
Double blind, randomised placebo control trial, with crossover design comparing the effect of beetroot juice (rich in nitrate) with placebo (nitrate depleted beetroot juice) on blood pressure, endothelial function and insulin sensitivity in subjects with type 2 diabetes. Healthy age matched subjects will have blood pressure measured.
Plan of Investigations: Study outcome measurements.
Blood pressure measured using ambulatory blood pressure monitoring (Spacelabs) for 24 hours.
Urine albumin excretion rate: in overnight samples using standard radioimmunoassay techniques.
Urine nitrate excretion will be used as a measure of adherence, and will be measured using an HPLC assay recently developed at St. Luke's in Professor Winyard's laboratory.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 35 Years 至 75 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Patients with type II diabetes (as defined by WHO) of at least 5 years duration between the ages of 35-75 known to have blood pressure above 125mmHg systolic and/or 85mmHg diastolic, or who are taking one or two antihypertensive drugs will be invited.
- •Healthy Control inclusion/
排除标准
- •Inclusion criteria
- •Age and sex matched for participants with diabetes
- •Not on any regular medication, excluding the oral contraceptive pill
- •Able to give informed consent
- •Exclusion Criteria:
- •Patients with significant renal impairment (eGFR<30), uncontrolled hypertension, BMI<25 or >35, are taking regular organic nitrates, nicorandil, glitazones, phosphodiesterase inhibitors, who have had a myocardial infarction or cerebro-vascular event, who smoke, or any other serious medical condition which would interfere with data interpretation or safety will be excluded
- •Exclusion Criteria
- •Antibiotic therapy within the preceding two weeks
- •Myocardial infarction or cerebro-vascular event within the preceding three months
- •Current smoker
- •Any other medical condition which would interfere with data interpretation or safety.
研究组 & 干预措施
Active
Nitrate rich beetroot juice (7.5 mmol nitrate in 250mls beetroot juice) once daily.
干预措施: Beetroot juice (Dietary Supplement)
Placebo
Nitrate depleted beetroot juice (0.002 mmol nitrate in 250 ml beetroot juice) once daily.
干预措施: Nitrate depleted beetroot juice (Dietary Supplement)
结局指标
主要结局
24 hour Ambulatory Blood Pressure monitoring after 2 weeks placebo juice
时间窗: 2 weeks
24 hour average systolic, diastolic blood pressure in mm Hg
24 hour Ambulatory Blood Pressure monitoring after 2 weeks active juice
时间窗: 2 weeks
24 hour average systolic, diastolic blood pressure in mm Hg
次要结局
- Cognitive function(After 2 weeks active juice and after 2 weeks placebo juice)
- Insulin sensitivity(After 2 weeks active juice and after 2 weeks placebo juice)
- Brachial artery Flow mediated vasodilation(After 2 weeks active juice and after 2 weeks placebo juice)
- Microvascular response to Iontophoresis of Acetylcholine and Sodium Nitroprusside(After 2 weeks active juice and after 2 weeks placebo juice)
- Peak reactive hyperemia(After 2 weeks active juice and after 2 weeks placebo juice)
- Maximum hyperemia in response to heating(After 2 weeks active juice and after 2 weeks placebo juice)