Clinical Trial of Protein and Blood Pressure
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Hypertension
- Sponsor
- Tulane University
- Enrollment
- 352
- Primary Endpoint
- Change From Baseline in Average Systolic Blood Pressure at 8 Weeks
- Status
- Completed
- Last Updated
- 3 years ago
Overview
Brief Summary
The purpose of this randomized, double-blind, controlled trial is to examine the effect of soybean protein supplementation on blood pressure in persons with prehypertension or stage-1 hypertension.
Detailed Description
Background: Epidemiologic studies suggest that vegetable protein intake is inversely related to blood pressure. Objectives: To examine the effect of soybean protein supplementation on blood pressure in persons with prehypertension or stage-1 hypertension Design: Randomized, double-blind, controlled trial Study Participants: 350 participants, aged 35-64 years, with an initial untreated systolic blood pressure of 130-159 mmHg and/or diastolic blood pressure of 80-99 mmHg Intervention: Study participants will be randomly assigned to take 40-grams of isolated soybean protein supplements per day or complex carbohydrate control for 12 weeks. Outcomes: Blood pressure measurements will be obtained using random-zero sphygmomanometers at baseline and during the trial at weeks 6 and 12. Net changes in systolic and diastolic blood pressure before and after the intervention is the primary outcome.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Systolic BP of 120 to 159 mm Hg and diastolic BP of 80 to 95 mm Hg (average of 6 measurements at 2 screening visits)
- •Willing to participate in all aspects of the study
Exclusion Criteria
- •Consumption of dietary protein greater than or equal to 1.63 grams/kg per day, as determined by two 24-hour dietary recalls
- •Stage-2 or higher severe hypertension (systolic BP greater than or equal to 160 mm Hg and/or diastolic BP greater than or equal to 95 mm Hg)
- •Use of antihypertensive medications or medications that affect BP
- •History of clinical heart disease (e.g., angina/heart attack, coronary revascularization, heart failure, stroke/transient ischemic attack, peripheral arterial disease)
- •Kidney disease (serum creatinine level greater than or equal to 1.7 mg/dL for men and greater than or equal to 1.5 mg/dL for women)
- •Current hypercholesterolemia (fasting serum total cholesterol greater than or equal to 240 mg/dL) or use of cholesterol-lowering medications
- •Current diabetes (fasting serum glucose greater than or equal to 126 mg/dL) or use of insulin or oral hypoglycemic agents
- •Severe obesity (body mass index greater than or equal to 40 kg/m²)
- •Current use of prescription weight loss medications, underwent weight loss surgery, and/or experienced weight loss greater than 15 pounds within the 6 months prior to study entry
- •Cancer (except non-melanoma skin cancer) that required treatment during the year prior to study entry
Outcomes
Primary Outcomes
Change From Baseline in Average Systolic Blood Pressure at 8 Weeks
Time Frame: Baseline and 8 Weeks
The change of systolic blood pressure was calculated as the mean of 6 blood pressure values from two 8-week visits minus the mean of 6 values from 2 baseline visits within each intervention phase. At each visit, 3 BP values were measured with a Hawksley random-zero sphygmomanometer by trained and certified observers who were masked to group assignment. BP readings were taken from the right arm with appropriately sized cuffs after the participant had been seated quietly for 5 minutes. The participant was instructed not to eat, smoke, drink alcohol, or exercise for at least 30 minutes before their BP measurements.
Secondary Outcomes
- Change From Baseline in Serum LDL-cholesterol at 8 Weeks(Baseline and 8 Weeks)
- Body Weight at 8 Weeks(Baseline and 8 Weeks)