Genes of Hypertension in African Americans

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00063505
Recruitment Status : Completed
First Posted : July 1, 2003
Last Update Posted : April 24, 2014
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Theodore Kotchen, MD, Medical College of Wisconsin

Brief Summary:
To identify genes contributing to hypertension in African Americans by focusing on the physiological pathways that determine arterial pressure.

Condition or disease
Cardiovascular Diseases Heart Diseases Hypertension

Detailed Description:


Since the mid 1990s, the investigators have extensively characterized African Americans for phenotypes related to cardiovascular and renal function. Based on recently completed genome scans, they have identified several chromosomal regions likely to contain genes influencing hypertension-related phenotypes in hypertensive, African American sib pairs. For several phenotypes, overlapping QTLs have also been identified in related studies in a genetically isolated French Canadian population and/or in homologous chromosomal regions in the F2 cross of Dahl-salt sensitive x normotensive Brown Norway rats.


The investigators will extensively phenotype 500 hypertensive and 500 normotensive African American subjects to conduct a genetic association study, using a single nucleotide polymorphism (SNP) genomic scan approach. To achieve a clear separation of blood pressures from hypertensive subjects, normotensive subjects will be selected from the lower third of the population-based blood pressure distribution. Hypertensive (BMI), and age. Inclusion of phenotypes is based on their relevance to the pathophysiology of hypertension and prior evidence of "heritability." Candidate genes for SNP analysis will be selected within chromosomal regions of two quantitative trait loci (QTLs) that they have previously demonstrated to be linked to hypertension-related phenotypes--a QTL for body mass index on chromosome 1 and a QTL for microalbuminuria on chromosome 18. SNP analyses will be carried out in 15 percent of the genes within each of these QTLs, and genes will be selected on the basis of their relevance to hypertension, including documented sequence conservation for blood pressure related QTLs with rat or mouse. The final goal of the project is to determine if distinct clusters of blood pressure related phenotypes can be identified that will permit stratification of hypertensive individuals into distinct subgroups to facilitate the analysis of the genetic determinants of hypertension and/or provide mechanistic leads to genes contributing to these traits.

Study Type : Observational
Actual Enrollment : 5000 participants
Observational Model: Case Control
Time Perspective: Cross-Sectional
Official Title: Genes of Hypertension in African Americans
Study Start Date : December 2002
Actual Primary Completion Date : July 2008
Actual Study Completion Date : July 2008

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Primary Outcome Measures :
  1. genes of hypertension in African Americans [ Time Frame: One time data collection ]
    There is no intervention

Biospecimen Retention:   Samples With DNA
Blood cells and DNA

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 75 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
African Americans
African Americans, age 18-75 years

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00063505

Sponsors and Collaborators
Medical College of Wisconsin
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: Theodore Kotchen Medical College of Wisconsin

Responsible Party: Theodore Kotchen, MD, Professor, Asssociate Dean for Clinical Research, Medical College of Wisconsin Identifier: NCT00063505     History of Changes
Other Study ID Numbers: 1216
R01HL070111 ( U.S. NIH Grant/Contract )
First Posted: July 1, 2003    Key Record Dates
Last Update Posted: April 24, 2014
Last Verified: April 2014

Additional relevant MeSH terms:
Cardiovascular Diseases
Heart Diseases
Vascular Diseases