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Early Metabolic Changes With Thiazide or Beta Blocker Therapy for Essential Hypertension

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified September 2006 by University of Cambridge.
Recruitment status was:  Recruiting
Cambridge University Hospitals NHS Foundation Trust
Information provided by:
University of Cambridge Identifier:
First received: September 22, 2006
Last updated: NA
Last verified: September 2006
History: No changes posted
Can the oral glucose tolerance test detect changes after 4 weeks treatment with thiazide diuretics or beta blockers or combination of the two?

Condition Intervention
Essential Hypertension
Drug: Thiazide and beta blocker

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double-Blind
Primary Purpose: Treatment
Official Title: Early Metabolic Changes With Thiazide or Beta Blocker Therapy for Essential Hypertension

Resource links provided by NLM:

Further study details as provided by University of Cambridge:

Primary Outcome Measures:
  • Can the oral glucose tolerance test detect changes after 4 weeks treatment with thiazide diuretics or beta blockers or combination of the two?

Secondary Outcome Measures:
  • Do patients show a similar change in glucose tolerance after thiazide or beta blocker therapy?
  • Does the combination of drugs cause a greater reduction in glucose tolerance than expected from the response to each drug taken alone?

Estimated Enrollment: 66
Study Start Date: September 2006
Detailed Description:

We will be comparing the two most commonly used drugs to treat hypertension, atenolol and bendrofluazide, in patients for whom the drugs (and the doses to be used) are licenced.

We propose an initial open label pilot study of 10-12 patients to confirm final doses to be tested, the duration of therapy for optimum timing of the OGTT and tolerability of doses selected. The pilot study will also be used to confirm sample size calculations for the main study.The protocol for the pilot study will be identical to the main study, but there will not be a placebo phase and the treatment will not be blinded.

The main study will be double-blind, placebo controlled, cross-over study, of approximately 66 patients in which each patient receives in random order, 4 weeks treatment with either Bendrofluazide 5-10mg daily, Atenolol 50-100mg daily or combination of Bendrofluazide 2.5-5mg and Atenolol 25-50mg daily. There will be a forced titration from the lower to the higher dose stated half way through each dosing period. There will be a 1 month placebo wash-out between each dosing period.

At 0, 2 and 4 weeks of each treatment phase, patients will attend the Clinical Investigation Ward (CIW), fasting, for performance of an oral glucose tolerance test (OGTT). Blood will be drawn from an intravenous cannula, for the measurements of glucose and insulin at 0, 0.5, 1 and 2 hours.

Blood pressure will be measured at each study visit using an Omron machine. The patients will also be given a blood pressure machine to take home and will be asked to measure and record their blood pressure at least twice per week. If their blood pressure is under 110/70mmhg or over 160/110mmHg at any time or if the patient has symptoms e.g. headache or dizziness, the patient will be asked to contact study staff. If the blood pressure remains over 160/110 for two measurements, then another antihypertensive therapy may be commenced, or the patient withdrawn from the study. If blood pressure is < 110/70 mmHg with symptoms then a decision may be made to terminate their participation in the study.


Ages Eligible for Study:   18 Years to 75 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Volunteers will be aged 18-75 years.
  • Hypertension- either

    • untreated, BP 140-170/90-110
    • treated for over 1 month with drugs other than beta blockers or diuretic and BP>140/85
    • treated for over 1 month with drugs other than beta blockers or diuretic and BP<140/85 and patient willing to change medication for eight months.

Exclusion criteria:

  • Any patient already taking thiazide diuretics or beta blockers in whom these drugs cannot be switched to alternative drugs with similar or better blood pressure control.
  • Any patient who is intolerant of these medications will be excluded from the study.
  • Patients with gout, asthma or any other contraindications to the study drugs will be excluded.
  • Women of child bearing age not using contraception.
  • Volunteers with heart failure, liver failure, renal failure, terminal illnesses (e.g. cancer)
  • Volunteers not able to give informed consent
  • Patients with diabetes
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00380289

Contact: Professor MJ Brown, MA MSC MD FRCP 01223 762577 (UK)
Contact: Dr A Stears, MBBS BSc MRCP 01223 586865 (UK)

United Kingdom
Clinical Pharmacology Unit, Box 110, Level 3 ACCI, Addenbrookes Hospital Recruiting
Cambridge, United Kingdom, CB2 2QQ
Contact: Mrs M Watts    01223 586865   
Contact: Dr A Stears, MBBS BSc MRCP    01223 586878   
Sponsors and Collaborators
University of Cambridge
Cambridge University Hospitals NHS Foundation Trust
Principal Investigator: Professor MJ Brown, MA MSC MD FRCP Addenbrookes Hosptal NHS Trust/ University of Cambridge
  More Information

Publications automatically indexed to this study by Identifier (NCT Number): Identifier: NCT00380289     History of Changes
Other Study ID Numbers: OGTT1
Study First Received: September 22, 2006
Last Updated: September 22, 2006

Keywords provided by University of Cambridge:
Essential hypertension
Glucose metabolism
Beta blockers

Additional relevant MeSH terms:
Vascular Diseases
Cardiovascular Diseases
Sodium Chloride Symporter Inhibitors
Adrenergic beta-Antagonists
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action
Natriuretic Agents
Physiological Effects of Drugs
Adrenergic Antagonists
Adrenergic Agents
Neurotransmitter Agents processed this record on April 27, 2017