Genes of Hypertension in African Americans

NCT ID: NCT00063505

Last Updated: 2014-04-24

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 5000 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2002-12-31
• Study Completion Date: 2008-07-31

Brief Summary

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

Detailed Description

BACKGROUND:

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.

DESIGN NARRATIVE:

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.

Conditions

Cardiovascular Diseases; Heart Diseases; Hypertension

Study Design

• Observational Model Type: CASE_CONTROL
• Study Time Perspective: CROSS_SECTIONAL

Eligibility Criteria

Inclusion Criteria

African Americans, age 18-75 years

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 75 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Heart, Lung, and Blood Institute (NHLBI)

NIH

Sponsor Role: collaborator

Medical College of Wisconsin

OTHER

Sponsor Role: lead

Responsible Party

Theodore Kotchen, MD

Professor, Asssociate Dean for Clinical Research

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Theodore Kotchen

Role: PRINCIPAL_INVESTIGATOR

Medical College of Wisconsin

References

Grim CE, Cowley AW Jr, Hamet P, Gaudet D, Kaldunski ML, Kotchen JM, Krishnaswami S, Pausova Z, Roman R, Tremblay J, Kotchen TA. Hyperaldosteronism and hypertension: ethnic differences. Hypertension. 2005 Apr;45(4):766-72. doi: 10.1161/01.HYP.0000154364.00763.d5. Epub 2005 Feb 7.

Reference Type: BACKGROUND

PMID: 15699471 (View on PubMed)

Other Identifiers

R01HL070111

Identifier Type: NIH

Identifier Source: secondary_id

View Link

1216

Identifier Type: -

Identifier Source: org_study_id