Efficacy of Dietary Sodium Restriction of Improving Vascular Endothelial Function in Middle Aged and Older Adults
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 17
- 试验地点
- 1
- 主要终点
- Improved Flow Mediated Dilation
研究概览
简要总结
The investigators hypothesize that reducing salt in the diet will improve the function of blood vessels in middle aged and older adults with moderately elevated systolic blood pressure, by increasing the amount of BH4 and nitric oxide in your blood vessels and reducing the amount of oxidative stress.
详细描述
The improvement in blood vessel function will be determined over a 10 week period. Subjects will be randomly assigned to either a 'low salt' condition (placebo pills + 1200 mg dietary sodium) or a 'normal salt' condition (2300 mg sodium chloride pills + 1200 mg dietary sodium) and monitored for 5 weeks. After the initial set of 5 weeks, the subjects are switched into the opposite condition, completing the cross-over study design. During weeks 1-4 and 6-9, subjects are monitored weekly with 24 hour urine collections and diet logs. The assessment of the primary outcome (blood vessel function) is completed during weeks 5 and 10. BH4 and ascorbic acid are also administered during weeks 5 and 10 to measure the effects of sodium intake on endogenous BH4 levels and vascular oxidative stress.
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
- 50 Years 至 79 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •50-79 years of age
- •SBP 130-159 mmHg
排除标准
- •Have been sick with an infection in the past two weeks
- •Are currently sick or have ongoing health problems such as kidney or CVD
- •Have lost more than 11 lbs. in the last 3 months
- •Are taking any type of antioxidants
- •Smoke or have alcohol problems
- •Have blood glucose levels higher than 126 mg/dL
- •Have resting SBP below or less than 100 mmHg or greater than 159 mmHg
- •Have a resting diastolic blood pressure greater than 99 mmHg
- •Have a BMI greater than 40 kg/m^2
- •Are presently consuming less than 9 or greater than 18 grams of salt / day
- •Have a baseline FMD of greater than 6%
- •Are taking any of the following types of drugs: blood thinners, anti-seizure medications, ant-inflammatory drugs
- •Participate in any high endurance athletic training
- •Taking Hormone Replacement Therapy
- •Have not been post-menopausal for at least 1 year
研究组 & 干预措施
Normal sodium
Subjects on a 1200 mg sodium diet are given 2300 mg sodium in the form of slow sodium tablets to bring them back up to a normal salt intake. Subjects then cross-over to the low sodium condition in the second half of the study.
干预措施: Slow sodium tablets (Drug)
Low sodium
Subjects on a 1200 mg salt diet are given placebo pills in order to maintain them on a low salt diet. Subjects then cross-over to the normal sodium condition in the second half of the study.
干预措施: placebo (Other)
结局指标
主要结局
Improved Flow Mediated Dilation
时间窗: Week 5 (after first condition of low salt or normal salt), Week 10 (after second condition, opposite to first)
FMD is analyzed at weeks 5 and 10 or after each condition in this cross-over study design. Subjects are randomly assigned to a low salt or normal salt condition for the first set of 5 weeks and then crossed over to the other condition for the second set of 5 weeks.
次要结局
- Vascular Oxidative Stress(Immediately following acute infusion of ascorbic acid on Weeks 5 and 10)
- BH4 Bioavailability(Immediately following acute administration of BH4 on Weeks 5 and 10)
研究者
Douglas Seals
College Professor of Distinction
University of Colorado, Boulder