Ignite Creation Date:
2024-05-05 @ 11:46 AM
Last Modification Date:
2024-10-26 @ 9:12 AM
Study NCT ID:
NCT00123006
Status:
COMPLETED
Last Update Posted:
2016-01-13
First Post:
2005-07-20
Brief Title:
Effectiveness of the DASH Diet at Reducing High Blood Pressure
Sponsor:
Brigham and Womens Hospital
Organization:
Brigham and Womens Hospital
Study Overview
Official Title:
Cardiovascular and Renal Hemodynamics and the DASH Diet
Status:
COMPLETED
Status Verified Date:
2016-01
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
The purpose of this study is to test the effects of the DASH diet in patients with isolated systolic hypertension
Detailed Description:
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 3361117 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
The study will test whether the DASH diet 1 lowers central aortic stiffness as measured by vascular impedance and carotid-femoral pulse wave velocity 2 improves diastolic relaxation as measured by early diastolic myocardial velocities across the mitral valve Ea 3 vasodilates renal blood flow and enhances vascular responses to Ang II and 4 affects central aortic stiffness diastolic relaxation renal blood flow and renal and vascular reactivity to Ang II by altering target tissue responsiveness to Ang II similar to ACE inhibition
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 3361117 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
The study will test whether the DASH diet 1 lowers central aortic stiffness as measured by vascular impedance and carotid-femoral pulse wave velocity 2 improves diastolic relaxation as measured by early diastolic myocardial velocities across the mitral valve Ea 3 vasodilates renal blood flow and enhances vascular responses to Ang II and 4 affects central aortic stiffness diastolic relaxation renal blood flow and renal and vascular reactivity to Ang II by altering target tissue responsiveness to Ang II similar to ACE inhibition
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| R01HL077234 | NIH | None | httpsreporternihgovquickSearchR01HL077234 |