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Cardiovascular DiseasesGERANCT00005520

Genetic Epidemiology of Responses to Antihypertensives

An observational study of Cardiovascular Diseases and Heart Diseases, run by Mayo Clinic at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

To determine whether measured variation in genes coding for components of vasoconstriction and volume regulating systems predict interindividual differences in blood pressure response to therapy with a thiazide diuretic, hydrochlorothiazide, or an angiotensin II receptor blocker, candesartan, in hypertensive… Read more about this study

Who is it for?
Ages 18 to 60 years
What is being tested?
Hydrochlorothiazide and Candesartan
How many people
1,200 participants
Where
1 siteUnited States
Study dates
Feb 1997to Jan 2008
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 60 years
  • All sexes
  • No healthy volunteers
  • Adult

Study population: Adult African American men and women with previously diagnosed primary hypertension were recruited from Atlanta, Georgia; and adult European American man and women with previously diagnosed primary hypertension were recruited from Rochester, Minnesota.

Primary (essential) hypertension

Trial locations and contacts

1 site in 1 country.

United States1 site

  • Mayo Clinic

    Rochester, Minnesota

Other trials in United States

About this study

To determine whether measured variation in genes coding for components of vasoconstriction and volume regulating systems predict interindividual differences in blood pressure response to therapy with a thiazide diuretic, hydrochlorothiazide, or an angiotensin II receptor blocker, candesartan, in hypertensive African-Americans (N=300 treated with each drug) and in hypertensive European Americans (N=300 treated with each drug).

Read the detailed description

BACKGROUND:

Essential hypertension is a common disorder that contributes to morbidity, mortality, and cost of health care, especially among African-Americans. Although a single-drug therapy is commonly prescribed for treatment of hypertension, blood pressure levels are controlled in some individuals but not in others. The study has the potential to identify genes contributing to the etiology of interindividual differences in blood pressure response to diuretic therapy in African-Americans and European Americans.

DESIGN NARRATIVE:

Hypertensive adults were treated with the diuretic hydrochlorothiazide, 25 mg/day, for four weeks; or with the angiotensin II receptor blocker candesartan, 16 mg/day for 2 weeks followed by 32 mg/day for 4 weeks. Interindividual variations in blood pressure responses and in candidate genes coding for components of systems regulating vasoconstriction and volume were measured. In addition, a panel of 500,000 single nucleotide polymorphisms genome-wide was measured in subsets of the most extreme responders and nonresponders to each drug for genome-wide association of analyses.

Being tested
Hydrochlorothiazide, Candesartan
Keywords
Hypertension, Pharmacogenetics, Hydrochlorothiazide, Candesartan
Medical subject headings
Cardiovascular Diseases, Heart Diseases, Hypertension

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • HydrochlorothiazideDrug

  • CandesartanDrug

Study groups in NCT00005520
Study groupRoleWhat they receive
African American hydrochlorothiazide300 African American hypertensives were treated with hydrochlorothiazide 25 mg daily for 4 weeks.
Receives: Drug: Hydrochlorothiazide
European American hydrochlorothiazide300 European American hypertensives were treated with hydrochlorothiazide 25 mg daily for 4 weeks
Receives: Drug: Hydrochlorothiazide
African American candesartan300 African American hypertensives were treated with candesartan 16 mg daily for 2 weeks followed by 32 mg daily for 4 weeks
Receives: Drug: Candesartan
European American candesartan300 European American hypertensives were treated with candesartan 16 mg daily for 2 weeks followed by 32 mg daily for 4 weeks
Receives: Drug: Candesartan

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in blood pressure

    The blood pressure response to antihypertensive drug therapy was defined by the difference between blood pressure levels prior to and at the end of drug therapy.

    Measured: 4 weeks for hydrochlorothiazide; 6 weeks for candesartan

Secondary outcomes (1)

  1. Adverse metabolic changes

    Potentially adverse metabolic changes in response to hydrochlorothiazide include changes in fasting serum glucose and insulin; serum potassium; serum lipids (triglycerides, HDL-cholesterol, total cholesterol); and serum uric acid.

    Measured: 4 weeks for hydrochlorothiazide only

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted26 May 2000 (estimated)
  2. Study startFeb 1997
  3. Primary completionJan 2008
  4. Study completionJan 2008

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
1,200 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00005520
Sponsor's protocol ID
05-004017
Other IDs
R01HL053330, R01HL074735
Acronym
GERA
Status last verified
Jan 2013
First submitted
25 May 2000
Last updated
17 Jan 2013
Results posted
No
Data monitoring committee
No

Publications

  • Turner ST, Schwartz GL, Chapman AB, Boerwinkle E. C825T polymorphism of the G protein beta(3)-subunit and antihypertensive response to a thiazide diuretic. Hypertension. 2001 Feb;37(2 Pt 2):739-43. doi: 10.1161/01.hyp.37.2.739.

    PubMed 11230366

  • Turner ST, Boerwinkle E. Genetics of hypertension, target-organ complications, and response to therapy. Circulation. 2000 Nov 14;102(20 Suppl 4):IV40-5. doi: 10.1161/01.cir.102.suppl_4.iv-40. No abstract available.

    PubMed 11080130

  • Turner ST, Schwartz GL, Chapman AB, Hall WD, Boerwinkle E. Antihypertensive pharmacogenetics: getting the right drug into the right patient. J Hypertens. 2001 Jan;19(1):1-11. doi: 10.1097/00004872-200101000-00001.

    PubMed 11204288

  • Montori VM, Schwartz GL, Chapman AB, Boerwinkle E, Turner ST. Validity of the aldosterone-renin ratio used to screen for primary aldosteronism. Mayo Clin Proc. 2001 Sep;76(9):877-82. doi: 10.4065/76.9.877.

    PubMed 11560297

  • Turner ST, Schwartz GL, Chapman AB, Boerwinkle E. Use of gene markers to guide antihypertensive therapy. Curr Hypertens Rep. 2001 Oct;3(5):410-5. doi: 10.1007/s11906-001-0059-x.

    PubMed 11551376

  • Schwartz GL, Chapman AB, Boerwinkle E, Kisabeth RM, Turner ST. Screening for primary aldosteronism: implications of an increased plasma aldosterone/renin ratio. Clin Chem. 2002 Nov;48(11):1919-23.

    PubMed 12406976

  • Garovic VD, Joyner MJ, Dietz NM, Boerwinkle E, Turner ST. Beta(2)-adrenergic receptor polymorphism and nitric oxide-dependent forearm blood flow responses to isoproterenol in humans. J Physiol. 2003 Jan 15;546(Pt 2):583-9. doi: 10.1113/jphysiol.2002.031138.

    PubMed 12527744

  • Turner ST, Boerwinkle E. Genetics of blood pressure, hypertensive complications, and antihypertensive drug responses. Pharmacogenomics. 2003 Jan;4(1):53-65. doi: 10.1517/phgs.4.1.53.22587.

    PubMed 12517286

  • Schwartz GL, Turner ST. Pharmacogenetics of antihypertensive drug responses. Am J Pharmacogenomics. 2004;4(3):151-60. doi: 10.2165/00129785-200404030-00002.

    PubMed 15174896

  • Frazier L, Turner ST, Schwartz GL, Chapman AB, Boerwinkle E. Multilocus effects of the renin-angiotensin-aldosterone system genes on blood pressure response to a thiazide diuretic. Pharmacogenomics J. 2004;4(1):17-23. doi: 10.1038/sj.tpj.6500215.

    PubMed 14735111

  • Turner ST, Chapman AB, Schwartz GL, Boerwinkle E. Effects of endothelial nitric oxide synthase, alpha-adducin, and other candidate gene polymorphisms on blood pressure response to hydrochlorothiazide. Am J Hypertens. 2003 Oct;16(10):834-9. doi: 10.1016/s0895-7061(03)01011-2.

    PubMed 14553962

  • Finkielman JD, Schwartz GL, Chapman AB, Boerwinkle E, Turner ST. Lack of agreement between office and ambulatory blood pressure responses to hydrochlorothiazide. Am J Hypertens. 2005 Mar;18(3):398-402. doi: 10.1016/j.amjhyper.2004.10.021.

    PubMed 15797660

  • Turner ST, Schwartz GL. Gene markers and antihypertensive therapy. Curr Hypertens Rep. 2005 Feb;7(1):21-30. doi: 10.1007/s11906-005-0051-y.

    PubMed 15683583

  • Schwartz GL, Turner ST. Screening for primary aldosteronism in essential hypertension: diagnostic accuracy of the ratio of plasma aldosterone concentration to plasma renin activity. Clin Chem. 2005 Feb;51(2):386-94. doi: 10.1373/clinchem.2004.041780.

    PubMed 15681560

  • Maitland-van der Zee AH, Turner ST, Schwartz GL, Chapman AB, Klungel OH, Boerwinkle E. A multilocus approach to the antihypertensive pharmacogenetics of hydrochlorothiazide. Pharmacogenet Genomics. 2005 May;15(5):287-93. doi: 10.1097/01213011-200505000-00003.

    PubMed 15864129

Questions about this trial

What is this clinical trial studying?

An observational study of Cardiovascular Diseases and Heart Diseases, run by Mayo Clinic at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 17 Jan 2013. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in blood pressure (time frame: 4 weeks for hydrochlorothiazide; 6 weeks for candesartan). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00005520, which also lists 19 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Jan 2013; AzTrials last refreshed its copy on 8 Nov 2026.

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