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Diagnosis of Primary Aldosteronism: Comparison of Post Captopril Active Renin Concentration and Plasma Renin Activity

The recruitment status of this study is unknown because the information has not been verified recently.
Verified June 2009 by National Taiwan University Hospital.
Recruitment status was  Recruiting
Sponsor:
Collaborator:
Novartis
Information provided by:
National Taiwan University Hospital
ClinicalTrials.gov Identifier:
NCT00917345
First received: June 8, 2009
Last updated: June 9, 2009
Last verified: June 2009
History of Changes
  Purpose

Background: The most common pharmacologic test for diagnosis of primary aldosteronism (PA) is administration of captopril to examine whether abnormal aldosterone to plasma rennin activity (PRA)(ARR) persists, although active rennin concentration (ARC) in contrast to PRA may offers advantages with regard to processing and standardization.

Objective: To assess whether post captopril ARC offer any additional advantage in screening primary aldosteronism (PA) than PRA and establish thresholds for the diagnosis using ARC.


Condition Intervention
Primary Aldosteronism
 Drug: captopril test

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective

Resource links provided by NLM:

Drug Information available for: Captopril
U.S. FDA Resources

Further study details as provided by National Taiwan University Hospital:

Primary Outcome Measures:
  • Determination of ARC in contrast to PRA offers advantage with regard to processing and standardization, knowing the postcaptopril sensitivity and specificity [ Time Frame: 1 day ] [ Designated as safety issue: Yes ]

Estimated Enrollment: 150
Study Start Date: January 2008
Estimated Study Completion Date: May 2009
Estimated Primary Completion Date: January 2009 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
aldosteronism, hypertension Drug: captopril test
The blood samplings were obtained one hour after the administration of 50 mg of captopril.The testing is performed in the morning on a seated ambulatory patient
hypertension Drug: captopril test
The blood samplings were obtained one hour after the administration of 50 mg of captopril.The testing is performed in the morning on a seated ambulatory patient

Detailed Description:

Primary aldosteronism (PA), characterized by an inappropriate production of aldosterone, affects 5-13% of patients with hypertension(1, 2). The use of aldosterone-renin ratio (ARR) as screening test contributes to the increased diagnostic rate of this disease(2), but it is not standardized among laboratories. As the incidence of PA has increased since ARR has been used as a screening test (3, 4), the difficulty in establishing a diagnosis of PA may be encountered because of atypical manifestations. Administration of captopril to differentiate the normal renin-angiotensin- aldosterone axis from autonomous secretion of aldosterone has been proved to be a safe and effective test in confirmation of the diagnosis (5-8). Several studies have demonstrated that the ARR after a single dose of captopril is diagnostic (5-8) and as sensitive as the saline loading test for the identification of aldosterone- producing adenoma (APA)(8).

Active rennin concentration (ARC) is considerably easier to perform; being a single immunoradiometric assay as opposed to the initial generation of angiotensin I generated from angiotensinogen followed by radioimmunoassay of PRA(9). It was demonstrated as a reliable and convenient screening tool for ambulatory conditions, independent of body posture (10). Decreased angiotensinogen level is noted in pathological status ( e.g. liver cirrhosis, sever cardiac failure) (11, 12) that results in dissociate of PRA measurement. PAC when used in conjunction with aldosterone to produce an ARRARC , has been reported to classify aldosteronism correctly(13). Although PRA is highly sensitive, the measurement is time-consuming and measured values can vary considerably between laboratories(14). In aldosteronism with suppressed renin, the ratio of ARR is clearly dependent on the variants lower detection limit(15). Though determination of ARC in contrast to PRA offers advantage with regard to processing and standardization, knowing the postcaptopril sensitivity and specificity as well as the optimum cut off value of ARC is paramount (16) help to the diagnosis PA (15, 17, 18) and might serve better performance than ARRPRA.

  Eligibility

Ages Eligible for Study:   18 Years to 80 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

Patients were referred to the hypertension clinics for suspicious of aldosteronism after an initial evaluation, and recorded in the Taiwan Primary Aldosteronism Investigation (TAIPAI). The initial evaluation included (1) age at onset younger than 35 years, (2) hypertension that is difficult to control after initiating therapy, (3) clinical occurrence of a hypertensive crisis, (4) the presence of hypokaliemia or metabolic alkalosis, or a random aldosterone-renin ration (ARR) >30, and (5) evidence of adrenal incidentaloma and hypertension or hypokalemia. All patients with intention to confirm and received captopril test were recruited and data were prospectively collected.

Criteria

Inclusion Criteria:

  1. age at onset younger than 35 years,
  2. hypertension that is difficult to control after initiating therapy,
  3. clinical occurrence of a hypertensive crisis,
  4. the presence of hypokaliemia or metabolic alkalosis, or a random aldosterone-renin ration (ARR) >30, and
  5. evidence of adrenal incidentaloma and hypertension or hypokalemia.

Exclusion Criteria:

  1. chronic kidney disease with elevated estimated glomerular filtration rate (< 60, mL/min/1.73 m2)
  2. liver disease with elevated GPT (> 35)
  3. heart failure
  4. classified as more than NYHA II,
  5. hyperthyroidism
  6. malignancy with metastasis
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT00917345

Contacts
Contact: VinCent Wu, MD +886927223278 q91421028@ntu.edu.tw

Locations
Taiwan
National Taiwan University Hospital Recruiting
Taipei, Taiwan, 100
Contact: VinCent Wu, MD     +886937223278        
Sponsors and Collaborators
National Taiwan University Hospital
Novartis
  More Information

No publications provided by National Taiwan University Hospital

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):

Responsible Party: Yang PC, National Taiwan University Hospital
ClinicalTrials.gov Identifier: NCT00917345     History of Changes
Other Study ID Numbers: 200904076R
Study First Received: June 8, 2009
Last Updated: June 9, 2009
Health Authority: Taiwan: Department of Health

Keywords provided by National Taiwan University Hospital:
ARC
PRA
primary aldosteronism
 captopril test
aldosterone-renin ratio
Primary aldosteronism (PA) than PRA and establish thresholds for the diagnosis using ARC.

Additional relevant MeSH terms:
Hyperaldosteronism
Adrenocortical Hyperfunction
Adrenal Gland Diseases
Endocrine System Diseases
Captopril
Angiotensin-Converting Enzyme Inhibitors
Protease Inhibitors
 Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Antihypertensive Agents
Cardiovascular Agents
Therapeutic Uses

ClinicalTrials.gov processed this record on May 23, 2013