Cardiovascular and Renal Hemodynamics and the DASH Diet
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 44
- 主要终点
- Changes in central aortic stiffness, diastolic relaxation, renal blood flow,and vascular response to Ang II
研究概览
简要总结
The purpose of this study is to test the effects of the DASH diet in patients with isolated systolic hypertension.
详细描述
BACKGROUND:
The study expands upon the findings of the Dietary Approaches to Stop Hypertension (DASH) study, which showed that a dietary pattern emphasizing fruits, vegetables, and low fat dairy products and overall reduced in total and saturated fat significantly lowers blood pressure (BP). The DASH diet is particularly effective in African Americans and in individuals with systolic hypertension. However, it is not known if the DASH diet affects the pathophysiology of the hypertensive process. Preliminary data support the possibility that the DASH diet interrupts the renin-angiotensin system. This raises the intriguing possibility that the DASH diet will favorably impact on cardiovascular and renal hemodynamics in patients with isolated systolic hypertension. Therefore, the central hypothesis of this study is that the DASH diet affects central aortic stiffness, diastolic relaxation, and renal and vascular reactivity to angiotensin II (Ang II) by lowering tissue renin-angiotensin system activity.
DESIGN NARRATIVE:
A randomized, crossover design will be used to compare the DASH diet to a control diet as defined in the original DASH protocol (NEJM 1997; 336:1117). Fifty-five community-dwelling individuals age 20 and older with systolic blood pressure (SBP) 140-179 mmHg and diastolic blood pressure (DBP) less than 90 mmHg will enter a 1-week run-in period eating both the control and DASH diets for 3-4 days each. Following this, participants will begin two 4-week intervention feeding periods receiving either the DASH diet or the control diet in random order. Clinical measurements will be taken at the conclusion of each 4-week feeding period.
Outcome measures: Specific measurements will include peripheral and renal vascular response to Ang II infusions, renal blood flow measured by para-aminohippurate (PAH) clearance, conduit vessel hemodynamics, and tissue Doppler imaging (TDI). At the end of each intervention feeding period, the clinical measurements will be made before and after acute administration of captopril, an angiotensin converting enzyme (ACE) inhibitor.
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
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 20 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Isolated systolic hypertension: systolic blood pressure (SBP) in the range of 140-179 mm Hg and diastolic blood pressure (DBP) less than 90 mm Hg
- •Body mass index (BMI) less than 40
- •Current use of fewer than two blood pressure medications (which will be withdrawn prior to study)
排除标准
- •Major concomitant diseases that may include but are not limited to active pulmonary disease within the past 6 months
- •History of cardiovascular disorders such as angina, heart attack, heart failure, or stent placement
- •Active gastrointestinal disease, including prior gastrointestinal surgery
- •Renal disease with serum creatinine greater than 1.5 mg/dl (men) or 1.4 mg/dl (women)
- •Insulin-dependent diabetes mellitus
- •Current pregnancy
结局指标
主要结局
Changes in central aortic stiffness, diastolic relaxation, renal blood flow,and vascular response to Ang II
时间窗: Measured at 4 weeks
次要结局
未报告次要终点
研究者
Paul Conlin, MD
Principal Investigator
Brigham and Women's Hospital