Giving a Low Carbohydrate Diet to Overcome Hypertension

Study Overview
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Brief Summary
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This study will test the preliminary efficacy of adding a very low carbohydrate dietary intervention to the evidence-based DPP-GLB on blood pressure reductions for lower-income AA men and women in a community-based clinic.

Detailed Description
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This study will evaluate the effects of consuming a very low carbohydrate (VLC) diet in a sustainable community care setting, in addition to routine medical care, to African American (AA) with pre-hypertension, hypertension (stage 1-3), or cardiovascular disease risk factors. This study will also secondarily assess the feasibility of following a VLC diet in a low-income, AA population.

Official Title
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A Pilot Study Comparing Dietary Approaches to Decrease Hypertension in a Lower Income, African American Population at Risk for Cardiovascular Disease

Conditions
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Hypertension, African Americans, Diet, Carbohydrate-Restricted, Risk Reduction Behavior

Intervention / Treatment
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* Other: Very low carbohydrate diet
* Other: Standard DPP-GLB diet
* Behavioral: Standard DPP-GLB program modules


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 1) men and women aged ≥ 18 years 2) willingness to participate in a 10-month study 3) systolic blood pressure > 120 mm/Hg +/- diastolic blood pressure > 80 mm/Hg 4) African American race Exclusion Criteria: 1) diagnosed congestive heart failure 2) Hypertension stage 4 or higher (e.g., SBP >180 mm/Hg; DBP > 110 mm/Hg) 3) received or needing more than 3 anti-hypertensive medications 4) pregnant or planning to become pregnant 5) receiving or needing a heart transplant 6) Using injected long or short-acting insulin for diabetes treatment 7) not African American race 8) unable to speak and read English with fluency

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 74 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Prospective randomized 2-group study
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Standard GLB Control<br>Individuals will receive the standard Diabetes Prevention Program-Group Lifestyle Balance (GLB) program as outlined by the American Diabetes Association. This program will be taught at the Baylor Scott & White Health and Wellness Center by trained research staff. | Other: Standard DPP-GLB diet<br>* Participants will learn to follow a very low fat, calorie-restricted diet and track fat grams and caloric intake in standard GLB modules 2,3,5, & 10<br>Behavioral: Standard DPP-GLB program modules<br>* Participants will learn standard DPP-GLB modules for other lifestyle modifications for stress, physical activity, etc. in sessions 1,4,6-9, 11-22<br>|
| Experimental: VLC-GLB Intervention<br>Individuals will receive a version of the DPP-GLB program in which 4 of the 12 modules will teach a very low carbohydrate diet instead of the standard. All other components of the DPP-GLB will follow the standard. This program will be taught at the Baylor Scott & White Health and Wellness Center by trained research staff. | Other: Very low carbohydrate diet<br>* Participants will learn to follow a very low carbohydrate diet in modified versions of GLB modules 2,3,5 & 10. Participants will learn to track carbohydrate intake<br>Behavioral: Standard DPP-GLB program modules<br>* Participants will learn standard DPP-GLB modules for other lifestyle modifications for stress, physical activity, etc. in sessions 1,4,6-9, 11-22<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Systolic blood pressure | Measure changes in both systolic and diastolic blood pressure using digital sphygmomanometer; NOTE: Only Systolic BP is primary outcome, diastolic change will be a secondary outcome measure | Baseline; 12 weeks; 10 months | 
| Dietary changes in carbohydrate intake | Assess changes in diet using ASA24 online dietary recall | Baseline; 12 weeks; 10 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Fasting blood glucose | Finger stick measure of blood glucose levels collected after 8-12 hours fasting | Baseline; 12 weeks; 10 months | 
| Changes in Hemoglobin A1C | Finger stick measure of hemoglobin A1C collected after 8-12 hours fasting | Baseline; 12 weeks; 10 months | 
| Changes in Cholesterol and lipoproteins | Finger stick measure of blood levels of total cholesterol, HDL, LDL, and triglycerides collected after 8-12 hours fasting | Baseline; 12 weeks; 10 months | 
| Changes in % Body weight | Change in weight measured in lbs. with digital scale; % change calculated | Baseline; 12 weeks; 10 months | 
| Changes in Body mass index (BMI) | Change in calculated BMI based upon height (in.) with stadiometer & weight (lbs.) with digital scale | Baseline; 12 weeks; 10 months | 
| Dietary changes in fat intake | Assess changes in diet using ASA24 online dietary recall | Baseline; 12 weeks; 10 months | 
| Dietary changes in caloric intake | Assess changes in diet using ASA24 online dietary recall | Baseline; 12 weeks; 10 months | 
| Changes in Diastolic blood pressure | Measure changes in both systolic and diastolic blood pressure using digital sphygmomanometer; NOTE: Only Systolic BP is primary outcome, diastolic change will be a secondary outcome measure | Baseline; 12 weeks; 10 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hypertension, Low carbohydrate diet, African American race, Cardiovascular disease risk, Weight loss