Angiotensinogen Gene and Human Hypertension
Primary Purpose
Cardiovascular Diseases, Heart Diseases, Hypertension
Status
Completed
Phase
Locations
Study Type
Observational
Intervention
Sponsored by

About this trial
This is an observational trial for Cardiovascular Diseases
Eligibility Criteria
No eligibility criteria
Sites / Locations
Outcomes
Primary Outcome Measures
Secondary Outcome Measures
Full Information
NCT ID
NCT00063492
First Posted
June 30, 2003
Last Updated
July 23, 2013
Sponsor
University of Utah
Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
1. Study Identification
Unique Protocol Identification Number
NCT00063492
Brief Title
Angiotensinogen Gene and Human Hypertension
Study Type
Observational
2. Study Status
Record Verification Date
July 2013
Overall Recruitment Status
Completed
Study Start Date
January 2003 (undefined)
Primary Completion Date
December 2007 (Actual)
Study Completion Date
December 2007 (Actual)
3. Sponsor/Collaborators
Name of the Sponsor
University of Utah
Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
4. Oversight
5. Study Description
Brief Summary
To determine the role of the angiotensinogen gene in human hypertension.
Detailed Description
BACKGROUND:
Essential hypertension affects at least 25 percent of American adults, and it is a primary risk factor for heart failure, stroke, and kidney disease. Many, but not all, studies have shown that variants of the angiotensinogen gene (AGT) affect the risk of hypertension, but association studies conducted to date have been compromised by genetic heterogeneity and by the inherent complexity of hypertension as a phenotype.
DESIGN NARRATIVE:
A comprehensive study of the angiotensinogen (AGT) gene will be conducted in data collected from several large groups of individuals. The investigators will sequence or genotype a 14.4 kb region including AGT in more than 1,600 individuals sampled from populations throughout the world. This will permit them to explore fully the extent of allelic heterogeneity, haplotype variation, and potential for population stratification in the AGT gene. Approximately 600 of these individuals are clinically uncharacterized and will represent a broad range of worldwide human variation. Another 500 subjects are members of 40 Utah pedigrees that are part of the Centre d'Etude du Polymorphisme Humain (CEPH) collection. These unique families have been heavily characterized genetically, and they are now being phenotyped for variables that include anthropometrics, blood chemistries, blood pressure measures, and plasma and urinary angiotensinogen. They will address the issue of genetic heterogeneity by testing associations between multi-SNP AGT haplotypes, angiotensinogen levels, and blood pressure. In addition, linkage disequilibrium patterns will be assessed to determine the density and nature of SNPs best suited for localizing a gene underlying a complex trait. They will address the issue of phenotypic heterogeneity in hypertension by performing extensive SNP typing on a set of 400 hypertensives and 100 normotensives collected by Dr. Gordon Williams. These clinically well-characterized subjects have been tested for their response to infused angiotensin-II under high and low sodium intake. This direct probe provides a hypertension endophenotype that is closer to the function of the AGT gene, yielding a more realistic and informative assessment of the relationship between AGT haplotype variation and hypertension risk. A phylogenetic analysis of AGT sequence variation in the worldwide sample will help to assess population stratification in association studies. In addition, this sample will allow testing the hypothesis that the ancestral T235 AGT allele provided a selective advantage in the sodium-poor environment of sub-Saharan Africa. The results of this analysis may help to explain why African-Americans have elevated rates of hypertension. In summary, the extensive analysis of AGT variation in more than 1,600 subjects will clarify the role of this gene in essential hypertension and will test specific hypotheses about the evolution of AGT.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Cardiovascular Diseases, Heart Diseases, Hypertension
7. Study Design
10. Eligibility
Sex
All
Accepts Healthy Volunteers
No
Eligibility Criteria
No eligibility criteria
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Lynn Jorde
Organizational Affiliation
University of Utah
12. IPD Sharing Statement
Citations:
PubMed Identifier
15889130
Citation
Nakajima T, Wooding S, Satta Y, Jinnai N, Goto S, Hayasaka I, Saitou N, Guan-Jun J, Tokunaga K, Jorde LB, Emi M, Inoue I. Evidence for natural selection in the HAVCR1 gene: high degree of amino-acid variability in the mucin domain of human HAVCR1 protein. Genes Immun. 2005 Aug;6(5):398-406. doi: 10.1038/sj.gene.6364215.
Results Reference
background
Learn more about this trial
Angiotensinogen Gene and Human Hypertension
We'll reach out to this number within 24 hrs