This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

Genetics of Cardiovascular Reactivity in Black Youth

This study has been completed.
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
University of Tennessee Identifier:
First received: July 10, 2003
Last updated: April 4, 2013
Last verified: April 2013
To evaluate individual differences in cardiovascular responses to acute stress in Black adolescents.

Cardiovascular Diseases Heart Diseases Hypertension

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Cross-Sectional
Official Title: Genetics of Cardiovascular Reactivity in Black Youth

Resource links provided by NLM:

Further study details as provided by University of Tennessee:

Primary Outcome Measures:
  • genes associated with hyperreactivity [ Time Frame: done ]
    several genes associated with reactivity

Biospecimen Retention:   Samples With DNA
buccal specimens stored at Med Coll Wisconsin

Enrollment: 500
Study Start Date: July 2003
Study Completion Date: June 2008
Primary Completion Date: June 2008 (Final data collection date for primary outcome measure)
Detailed Description:


The prevalence and severity of essential hypertension (EH) are greater among Black Americans than other ethnic groups in the U.S. Blacks are at increased risk for target organ damage from elevated blood pressure, including heart disease, stroke, and endstage renal failure. There are significant ethnic differences in cardiovascular reactivity (CVR) to stress, which is a risk factor for elevated blood pressure. Studies have shown that CVR to stress is stable over time, heritable, and predictive of future elevations in blood pressure and the development of essential hypertension. These properties make measures of CVR a valuable intermediate for genetic studies of hypertensive risk.


The genetic epidemiology study will test the hypothesis that individual differences in CVR to acute stress in Black youth are associated with well defined polymorphisms in candidate genes related to blood pressure including: 1) alpha- and beta-adrenergic receptor genes; 2) genes involved in catecholamine metabolism; 3) genes involved in endocrine function; 4) genes involved in the renin angiotensin system. By focusing on normotensive youth at risk for developing essential hypertension, the investigators hope to identify genes associated with the onset, rather than the sequelae, of hypertension. Moreover, given that CVR to acute stress is defined as a change in cardiovascular function evoked by an environmental manipulation of stress, the research is inherently a study of gene-environment interactions.

A total of 500 unrelated Black adolescents and young adults (equal numbers of males and females), 15-21 years of age will be studied. Buccal cell samples will be collected for DNA extraction from all subjects for genetic association analyses. Impedance cardiography and blood pressure monitoring will be used to assess components of CVR to stress during video game, mental arithmetic, cold pressor, and whole body cold exposure tasks, all of which have been utilized or developed in the laboratory. Various methods will be used to evaluate genetic associations with CVR to acute stress, including analyses of single nucleotide polymorphisms and haplotypes. Supplementary analyses will evaluate potential gene-gene interactions and additional gene-environment interactions involving chronic environmental stress.


Ages Eligible for Study:   15 Years to 21 Years   (Child, Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
500 African American youth
African American non-hypertensive, no chronic disease which would affect blood pressure
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00064675

Sponsors and Collaborators
University of Tennessee
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: Bruce Alpert University of Tennessee Health Science Center
  More Information

Responsible Party: University of Tennessee Identifier: NCT00064675     History of Changes
Other Study ID Numbers: 1229
R01HL072375 ( U.S. NIH Grant/Contract )
R01HL068971-04 ( U.S. NIH Grant/Contract )
Study First Received: July 10, 2003
Last Updated: April 4, 2013

Additional relevant MeSH terms:
Cardiovascular Diseases
Heart Diseases processed this record on September 19, 2017