Protein and Blood Pressure (ProBP) Study A NIH-sponsored 2-center randomized placebo-controlled clinical trial to examine the effect of dietary protein supplementation on blood pressure. Investigators
Jiang He, MD, PhD, Principal Investigator
Leann Myers, PhD, Co-Investigator
Sathanur R. Srinivasan, PhD Co-Investigator
Paul K. Whelton, MD, MSc, Co-Investigator Funding Agent
National Heart, Lung, and Blood Institute, NIH Participating Institutes
Tulane University
University of Mississippi Medical Center Description
At least 50 million adult Americans have hypertension, one of the most important modifiable risk factors for coronary heart disease, stroke, and end-stage renal disease. Dietary nutrient intake has been related to the etiology of hypertension, and nutritional intervention has become an important approach for the treatment and prevention of hypertension. While the effect of dietary intake of sodium, potassium, and alcohol on blood pressure has been studied intensively, the effect of dietary macronutrients, such as protein, has not been as well studied.
The overall objective of this study is to examine the effect of dietary protein supplementation on blood pressure. We propose to conduct a randomized, double-blind, placebo controlled 2-center trial in 280 healthy participants with BP higher than optimal level or stage-1 hypertension (systolic blood pressure 120-159 mm Hg and diastolic blood pressure 80-95 mm Hg without clinical cardiovascular disease, chronic renal disease or diabetes). The trial will utilize a 3-phase cross-over design and have greater than 90% power to detect a 2.0 mm Hg reduction in systolic blood pressure and a 1.5 mm Hg reduction in diastolic blood pressure. The study participants will be recruited by mass mailing and work-site/community-based blood pressure screening in New Orleans, Louisiana, and Jackson, Mississippi. Following a 2-week run-in period, eligible participants will receive 40-gram soy protein, 40-gram milk protein, and 40-gram complex carbohydrates (control) per day for 8 weeks in a random order. A 3-week washout period will be applied between intervention/control phases. The primary outcome will be difference in systolic and diastolic blood pressure between soy protein supplementation, milk protein supplementation, and placebo control phases. In addition, differences in fasting plasma insulin, glucose, leptin, and homocysteine, serum lipids, waist and hip circumferences will be tested, and the impact of these variables on the mechanism of any blood pressure-lowering effect will be examined.
Results from the proposed study may provide the scientific evidence for protein supplementation recommendations for the prevention and treatment of hypertension in the general population.
China National Hypertension Survey Epidemiology Follow-up Study (CHEFS)
A large prospective cohort study to examine risk factors for cardiovascular and renal disease in a representative sample of 180,000 Chinese men and women aged 40 years and older
Investigators
Jiang He, MD, PhD, Principal Investigator
Paul K. Whelton, MD, MSc, Co-Investigator
Funding Agent
American Heart Association
Participating Institutes
Tulane University
Chinese Academy of Medical Sciences, Beijing, China
Description
Cardiovascular disease is the leading cause of death in the U.S. and most other countries. Epidemiological studies have demonstrated that high blood pressure and overweight are important modifiable risk factors for cardiovascular disease mortality. However, several studies have noted a J-shaped relationship between cardiovascular mortality and both blood pressure and body weight. Moreover, most cardiovascular risk factors have been identified from studies conducted in middle-aged men. Corresponding data for women and older persons are limited.
The China National Hypertension Survey Epidemiologic Follow-up (CHEF) study is a prospective cohort study designed to answer the two primary study questions:1). Are the associations between blood pressure (systolic and diastolic) and mortality from stroke, coronary heart disease, and all causes linear or J-shaped throughout the range of blood pressure? Are the associations consistent across different age and sex subgroups? 2). Are the associations between body mass index and mortality from stroke, coronary heart disease, and all causes linear or J-shaped throughout the entire range of body weight? Are the associations consistent across different age and sex subgroups? Secondary questions that will be addressed include: 3). Are these associations (hypotheses 1 and 2) observed in patients with a prior history of stroke or coronary disease? 4). Is cigarette smoking as well as environmental tobacco smoke associated with increased mortality from stroke, coronary disease, and all causes? Is this association consistent across different age and sex subgroups? 5). Is alcohol intake associated with increased mortality from stroke, coronary disease, and death from all causes? Is this association linear or J-shaped? Is this association consistent across different age and sex subgroups? 6). Is systolic or diastolic pressure more important in the prediction of mortality from stroke, coronary disease, and all causes?
Baseline risk factors were carefully collected during the 1991 China National Hypertension Survey. A follow-up study was conducted during 1999-2000, which included in-person interviews to ascertain disease status and vital information for all study participants and a review of hospital records and death certificates for cardiovascular and renal events. The follow-up rate was 95% over a period of 8 years.
The CHEF study will provide unique and important information for developing national prevention strategies to reduce the societal burden of cardiovascular and renal disease in China. |
