the walls of arteries. • Measured indirectly with a special cuff over the brachial or femoral artery • There are two pressures measured: • the systolic pressure • the diastolic pressure Healthy individual: Systolic: <140 mmHg Diastolic <90 mmHg
as BP of 140/90 or higher. • It is a common disorder affect 24% of U.S. population.( 1997) • HTH is a systemic disease with no symptoms for years(silent killer). • It can be primary or essential ( 90- 95%) or secondary (5-10%).
thirsty volume overload. • More K decrease BP and decrease stroke by 24%. • Fruits, vegetables, unprocessed meat and fish rich in K. • Processes food removes potassium and adds salt. • Fat intake cause obesity which stimulate adrenal aldosterone • Calcium decrease intestinal absorption of lipids.
• 1st group: Sept. 1994 • Funded by • NHLBI • Office of Research on Minority Health • National Center for Research Resources of the National Institutes of Health • Design: Clinical trial Clinical center : Baltimore Baton Rouge Durham Boston John Hopkins University Louisiana University Brigham and Women’s Hospital John Hopkins University Recruitment strategy - Mass mailing - Work-based - Community-based Targeted to have 2/3 participants as minority
single molecule is hard to detect • Combining all nutrients = observable effects • Unknown nutrients/molecules • Unknown interactions • Natural > artificial The study also investigates the effects of the dietary interventions on changes in levels of serum lipids, renin, ionized and calcium. Also explores the effects of several baseline characteristics, Outcomes Ambu -latory Rest Systolic Diastolic Systolic Diastolic 1⁰ 2⁰ 2⁰ 2⁰ What is the effect of 3 different dietary pattern on the blood pressure in persons with high-normal and mild HTN? Study Question
Follow average American diet composition • Keep K+, Mg++, and Ca++ similar (25th percentile) 37 48 15 Total Fat Carbohydrates Protein Combination diets • Rich in fruits and vegetables • Lower total fat and cholesterol composition • Higher fiber and protein • K+, Mg++, and Ca++ (75th percentile) 27 55 18 Total Fat Carbohydrates Protein Fruits and Vegetables diets • Primarily fruits and vegetables • Fat, carbohydrates and protein are similar to control • K+, Mg++, and Ca++ (75th percentile) 37 48 15 Total Fat Carbohydrates Protein
2600 • 3100 7-day menu cycle (21 meals) Commonly available forms/variety • Fresh • Frozen • Canned • Dried Standardization: - Same brand - Prepared on the center kitchen Procedure: • On-site: lunch (weekdays) • Off-site: breakfast and dinner - provided with cooler and meal during visitation - Meals for weekend (received on Friday) Recording beverages and salt intakes; non-study foods Provided with 2 salt/day Weight measured/weekday
Control Efficacy from all minerals + macronutrients from ideal diet (Ideal = Veggie) > Control Efficacy from minerals from fruits and vegetables Ideal > Control Veggie = X Efficacy from either High Ca++ in dairy foods Dairy food <-> fruits & vegetables Macronutrients distribution of ideal diet Blood pressure lowering effect
between rest for 5 min. -Blood pressure (2x/visit) : - in seated position - by trained/certified staff - Random-zero sphygmomanometer -General dietary info -Stanford 7-Day Physical Activity Recall questionnaire Procedure:
separate days • Urine sample = 1x 24-hour • Symptoms questionnaire Exclusionbefore randomization - Non adherence to the protocol (Fail to attend 1x on-site OR 3x meals) Participants were randomized at the 3rd week Duration = 3 weeks Control diet only N started = 502 Nrandomized = 459 Randomized
50 60 Control Veggie Ideal Age distribution 0% 50% 100% Control Veggie Ideal Sex distribution M F 0% 50% 100% Control Veggie Ideal Race distribution Nonminority Black other 0 50 100 150 Systolic Diastolic Systolic Diastolic Resting Ambulatory Blood pressure distribution Control Veggie Ideal
N ITT = 459 NPP = 446 Intervention Measurement of ambulatory BP: - done only to the last 4/5 groups - At the end of Run-in & Intervention - Mean of 24-hour data/30-min interval - Space Labs 90207 device
are excluded from further participation if they are treated with medications. If BP: Systolic: > 170 mmHg Diastolic: > 105 mmHg OR Systolic: > 180 mmHg Diastolic: > 110 mmHg OR Rechecked: next visit (following week) Remain above limit: Physician referral Immediate referral
vegetable, low fat dairy, less saturated & total fat. • Ideal diet has similar effect of monotherapy used in mild HTN. • Applied for the prevention & treatment of HTN. • Ideal diet may reduce the occurrence of HTN-related cardiovascular diseases. Observation • Reduction of BP • started by 2nd week • But varied/increased around the last few weeks • Why smoking was not mentioned? • Unexpected Ca++ excretion on Veggie and Ideal diets
of foods to the participants is intended to maximize adherence. • Blindness of BP observers and subjects. • Standardized protocol and centralized training of food service. • Same menus offered in all field centers (validated and monitoring). • 60% of subjects were black (high risk population).
food pattern on the BP. • Meals available in 4 different energy levels according to the requirement to maintain the wt. • BP measured by same way and method by training staff in all center. • Assays related to study outcomes are measured in a central laboratory. • Subjects adherence to assigned diets was excellent. • Abstract is accurate. • Measurement of ambulatory BP add a confirmation of BP study measurement .
changes effort to accommodate the requirements of the study. Is it possible? • Procedure for evaluating of adherence (self report). • Trial was not design to identify the effective and ineffective component of diets. Limitation or strength?