ENCORE: Exercise and Nutritional Interventions for Cardiovascular Health
This study is an NIH-funded clinical trial conducted at Duke Medical Center evaluating the effects of the DASH diet alone and combined with a behavioral weight loss program on blood pressure and various vascular measures. Eligible patients must be unmedicated with blood pressure values ranging from approximately 130/85 to 159/99. Our primary hypothesis are as follows: (1) The DASH diet alone and combined with a behavioral weight management program will result in greater BP reductions than Usual Care controls at the end of the 4 month treatment period; (2) The DASH diet in combination with a behavioral weight management program will be more effective in lowering BP than the DASH diet alone; (3) The DASH diet alone and the DASH diet combined with the behavioral weight management program will result in greater improvements in cardiac, metabolic, and vascular function compared to the control condition; and (4) The combined DASH diet and weight management intervention also will be the most effective treatment in maintaining BP reductions at 1-year follow-up.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||Behavioral Treatment of High Blood Pressure|
- Blood pressure [ Time Frame: 4 months ] [ Designated as safety issue: No ]
- Ambulatory blood pressure,vascular function,left ventricular geometry, glucose tolerance,body composition, quality of life [ Time Frame: 4 months ] [ Designated as safety issue: No ]
|Study Start Date:||October 2003|
|Study Completion Date:||July 2013|
|Primary Completion Date:||July 2009 (Final data collection date for primary outcome measure)|
|Experimental: DASH diet||
Behavioral: DASH diet
Participants in the DASH diet condition receive instruction in modifying the content of their diet to meet DASH guidelines. Participants are explicitly asked not to exercise or to attempt weight loss at this time, and to focus their attention on what they eat. Following the 2-week feeding period, participants will receive instruction on the DASH diet and feedback on their adherence to the diet in a series of half-hour, weekly small group sessions (3 to 5 participants).
|Experimental: DASH diet plus Weight loss||
Behavioral: DASH diet plus Weight loss
Participants in the DASH diet plus weight loss condition will receive the DASH dietary intervention as described in the DASH diet intervention and will participate in a program to promote weight loss consisting of 2 components: Supervised Aerobic Exercise and CBWL (Cognitive Behavioral Weight loss). During supervised exercise participants will exercise 3x/week under medical supervision at the Duke Center for Living. A trained exercise physiologist will supervise all exercise sessions, and will obtain exercise BP measurements to make sure that BP is not abnormally elevated. For the CBWL participants will meet in small groups of 3-5 patients for instruction in weight management techniques. CBWL will include Appetite Awareness Training (AAT), a self-monitoring strategy developed to provide more specific guidelines regarding how much to eat. Individuals learn to identify moderate hunger and fullness and use these internal cues to guide their eating.
No Intervention: Usual Care
Usual Care Control Group: Patients in the Usual Care control group will be asked to maintain their usual dietary and exercise habits for 4 months until they are re-evaluated. At biweekly intervals we will ask patients to describe any spontaneous changes in their eating habits or food preferences. To ensure patient safety, BPs will also be monitored biweekly by our staff.
The present application seeks to extend previous findings by a) evaluating the efficacy of the DASH diet in a free-living situation; (b) considering the DASH diet alone and in combination with a behavioral weight loss program including aerobic exercise; (c) examining the impact of diet and exercise on cardiac, metabolic, and vascular function, including measures of arterial stiffness, endothelial function, baroreflex control, body composition, insulin resistance, cardiac hemodynamics, and left ventricular (LV) geometry and mass; and (d) following patients for one year to determine the longer term impact of the interventions on BP, body weight, and cardiovascular function.
|United States, North Carolina|
|Durham, North Carolina, United States, 27710|
|Principal Investigator:||James A. Blumenthal, Ph.D.||Duke University|