Effects of the Dietary Approaches to Stop Hypertension(DASH) Sodium-restricted Diet in Diastolic Heart Failure (DASH-DHF)
Recruitment status was: Recruiting
Heart failure with preserved systolic function (HF-PSF, or 'diastolic heart failure') accounts for half of hospitalizations for heart failure in patients over the age of 65. Most HF-PSF patients have systemic hypertension (HTN), and characteristic HTN-induced cardiovascular changes contribute to HF-PSF. However, it is unclear why most patients with HTN never develop HF-PSF or which specific aspects of HTN predispose to HF-PSF.
In the Dahl S rat, the primary animal model of HF-PSF, high dietary sodium intake suppresses the systemic renin-angiotensin-aldosterone system, but upregulates renal and cardiac renin-angiotensin-aldosterone system by inducing oxidative stress. In humans, the magnitude of blood pressure response to sodium ingestion and depletion can categorize subjects as "salt-resistant" and "salt-sensitive." Human salt sensitivity is associated with structural and loading conditions that increase the risk for HF-PSF, including HTN, ventricular hypertrophy and diastolic dysfunction, arterial stiffening, and increased plasma volume. High dietary sodium intake induces oxidative stress in salt-sensitive humans. In humans with HTN and normal ventricular systolic function that do not have heart failure, increased oxidative stress predicts impaired exercise capacity, ventricular hypertrophy, diastolic dysfunction, arterial stiffening, and vascular endothelial dysfunction. The investigators have proposed that "salt sensitivity" and the accompanying oxidative stress on the typical high-sodium Western diet may contribute to the initiation and progression of HF-PSF.
In patients with HF-PSF, the investigators will relate dietary changes to biochemical and cardiovascular functional measures. The investigators will study subjects on ad-lib diet and and following three weeks of rigorous dietary modification with the Dietary Approaches to Stop Hypertension (DASH)/sodium-restricted diet (SRD). This diet is richer in natural antioxidants and lower in sodium than the usual American diet. The DASH/SRD is recommended to lower blood pressure in patients with HTN, and is particularly effective in elderly, obese, and salt-sensitive hypertensives. Dietary sodium restriction is recommended for all HF patients including those with HF-PSF. The investigators hypothesize that the DASH/SRD will have favorable effects on oxidative stress, ventricular and vascular function, and blood pressure control in patients with hypertensive HF-PSF.
Diastolic Heart Failure
Hypertensive Heart Disease
Behavioral: DASH/sodium-restricted diet (SRD)
|Study Design:||Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Effects of the Dietary Approaches to Stop Hypertension(DASH) Sodium-restricted Diet on Ventriculovascular Function in Heart Failure With Preserved Systolic Function|
- Brachial artery flow-mediated dilation (FMD) [ Time Frame: Pre- and post three weeks of dietary intervention ]
- Mean 24-hour blood pressure [ Time Frame: Pre- and post three weeks of dietary intervention ]
- Diurnal variation in ambulatory blood pressure [ Time Frame: Pre- and post three weeks of dietary intervention ]
- Aortic augmentation index [ Time Frame: Pre- and post three weeks of dietary intervention ]
- EndoPAT arterial endothelial function [ Time Frame: Pre- and post three weeks of dietary intervention ]
- Carotid-femoral pulse wave velocity [ Time Frame: Pre- and post three weeks of dietary intervention ]
- Ventricular diastolic function [ Time Frame: Pre- and post three weeks of dietary intervention ]
- Six minute walk test distance [ Time Frame: Pre- and post three weeks of dietary intervention ]
- Estimated glomerular filtration rate, serum potassium, serum calcium-phosphorus product [ Time Frame: Pre- and post three weeks of dietary intervention ]
- Urinary 8-isoprostanes [ Time Frame: Pre- and post three weeks of dietary intervention ]
|Study Start Date:||July 2009|
|Estimated Study Completion Date:||March 2011|
|Estimated Primary Completion Date:||December 2010 (Final data collection date for primary outcome measure)|
Active Comparator: Dietary intervention
Diet patterned after the intervention in the DASH-Sodium trial (Sacks FM et al. New Engl J Med 2001;344(1):3-10). The diet includes higher quantities of fresh fruits and vegetables, whole grain products, and low-fat dairy products than the standard American diet. The target sodium content is 50 mmol per 2100 kcal, and the caloric content is intended to maintain body weight. The diet is designed, prepared, and packaged by research dietitians and all food and beverages are provided for study participants.
Behavioral: DASH/sodium-restricted diet (SRD)
Baseline diet will be assessed via Block Food Frequency Questionnaire, and 24-hour urinary sodium, potassium, and 8-isoprostanes will be measured. Subjects will then be assigned to 21 days of the DASH/SRD, with all food and beverages provided. Adherence will be assessed through a three-day food diary at the midpoint of the intervention, and at the end of the study urinary sodium, potassium, and 8-isoprostanes will again be measured.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00939640
|United States, Michigan|
|University of Michigan|
|Ann Arbor, Michigan, United States, 48109|
|Principal Investigator:||Scott L Hummel, MD MS||University of Michigan|