ANZCTR - Registration

Please note the ANZCTR will be unattended from Friday 20 December 2024 for the holidays. The Registry will re-open on Tuesday 7 January 2025. Submissions and updates will not be processed during that time.

Registering a new trial?

To achieve prospective registration, we recommend submitting your trial for registration at the same time as ethics submission.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers

Trial registered on ANZCTR

Registration number

ACTRN12606000128594

Ethics application status

Approved

Date submitted

29/03/2006

Date registered

7/04/2006

Date last updated

7/04/2006

Type of registration

Prospectively registered

Titles & IDs

Public title

Salt & Hypertension & Diabetes

Scientific title

Does habitual low dietary sodium intake augment the response to angiotensin receptor blockade and thiazide therapy in hypertensive patients with type 2 diabetes and elevated albumin excretion rate?

Universal Trial Number (UTN)

Trial acronym

Linked study record

Health condition

Health condition(s) or problem(s) studied:

Type 2 Diabetes

Hypertension

Microalbuminuria

Condition category

Condition code

Metabolic and Endocrine

Diabetes

Cardiovascular

Hypertension

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

Angiotensin 2 Receptor Agonists
Thiazide diuretics

Intervention code [1]

None

Comparator / control treatment

Salt and placebo capsules

Control group

Placebo

Outcomes

Primary outcome [1]

1. Change in ambulatory blood pressure

Timepoint [1]

From 0 to 4, 8 and from 14 to 18, 22 weeks

Primary outcome [2]

2. Change in albumin excretion rate

Timepoint [2]

From 0 to 4, 8, and from 14 to 18, 22 weeks

Secondary outcome [1]

1. Acute response of effective renal plasma flow (ERPF) to captopril.

Timepoint [1]

At baseline.

Secondary outcome [2]

2. Acute response of renal resistance index (RI) to captopril.

Timepoint [2]

At baseline.

Secondary outcome [3]

3. Fasting plasma glucose at the time of ERPF and RI measurements.

Timepoint [3]

Secondary outcome [4]

4. BMI.

Timepoint [4]

Secondary outcome [5]

5. 24 h urinary sodium, potassium and creatinine excretion.

Timepoint [5]

At 0, 4, 8, 14, 18, 22 weeks.

Secondary outcome [6]

6. Plasma urea, creatinine and electrolytes, renin activity and aldosterone and fasting glucose and C-peptide.

Timepoint [6]

At 0, 4, 8, 14, 18, and 22 weeks.

Secondary outcome [7]

7. Haemoglobin A1C.

Timepoint [7]

Eligibility

Key inclusion criteria

1. Type 2 diabetes mellitus.2. Hypertension (blood pressure >140/90 or taking antihypertensive therapy).3. Albumin excretion rate > 10 µg/min (median of three consecutive measurements).4. Urinary sodium excretion either > 200 mmole/24 hr on two out of three consecutive occasions (habitual high dietary sodium intake) or < 100 mmole/24 hr on two out of three consecutive occasions (habitual low dietary sodium intake). It is proposed to study 16 patients with habitual high dietary sodium intake and 16 patients with habitual low dietary sodium intake matched for BMI. Matching for BMI will be performed because of the documented association between total caloric intake and urinary sodium excretion in the DASH study.185. Caucasian ethnicity.

Minimum age

20 Years

Maximum age

80 Years

Sex

Both males and females

Can healthy volunteers participate?

Key exclusion criteria

1. Serum potassium > 5.0 mM.2. Serum creatinine > 200 µM.3. Albumin excretion rate > 200 µg/min.4. HbA1C > 10.0%.5. Major systemic illness.6. Drug dependence.7. Atrial fibrillation.8. Lactose intolerance (lactose capsules will be used as placebo).

Study design

Purpose of the study

Treatment

Allocation to intervention

Randomised controlled trial

Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)

Randomised by pharmacy, investigator blinded

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

Simple randomisation by using procedures such as coin-tossing and dice-rolling

Masking / blinding

Blinded (masking used)

Who is / are masked / blinded?

Intervention assignment

Crossover

Other design features

Phase

Type of endpoint/s

Efficacy

Statistical methods / analysis

Recruitment

Recruitment status

Not yet recruiting

Date of first participant enrolment

Anticipated

1/05/2006

Actual

Date of last participant enrolment

Anticipated

Actual

Date of last data collection

Anticipated

Actual

Sample size

Target

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

Funding & Sponsors

Funding source category [1]

Government body

Name [1]

Austin Health

Address [1]

Country [1]

Funding source category [2]

University

Name [2]

University of Melbourne

Address [2]

Country [2]

Primary sponsor type

Individual

Name

Researcher Initiated Study- Professor George Jerums - Endocrine Centre of Excellence, Austin Health & University of Melbourne

Address

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Nil

Address [1]

Country [1]

Ethics approval

Ethics application status

Approved

Summary

Brief summary

Lay Summary
Project Title: Does habitual low dietary sodium intake augment the response to angiotensin receptor blockade and thiazide therapy in hypertensive patients with type 2 diabetes and elevated albumin excretion rate?
Rationale:
One of the complications of type 2 (adult) diabetes and high blood pressure (BP) is diabetic kidney disease. In this disorder, the kidneys leak protein (albumin) into the urine and  in early stages this is known as microalbuminuria. In some patients this progressively worsens, leading to kidney failure.
Some groups of blood pressure lowering medications also lower the blood pressure in the kidneys. This protects against kidney damage by slowing the progression of the protein leakage into the urine. The effectiveness of these groups of blood pressure tablets is reduced when the salt intake in the diet is high.  
Aims of this study: 
To determine if the effectiveness of the antihypertensive drug telmisartan, alone, and in combination  with the drug hydrochlorothiazide, is increased by a low dietary salt (sodium chloride) intake, and if there is an additional beneficial effect on kidney function; 
In this study, participants with type 2 diabetes, high blood pressure and early diabetic kidney disease (microalbuminuria) will be recruited. Two groups will be compared - those who usually have a high salt intake in their diet versus those who usually have a low salt intake in their diet, as determined by previous urine sodium test results. All patients will take antihypertensive medication to control their blood pressure called verapamil, prazosin and methyldopa, these medications do not interfere with the test results. The participants will continue their usual diet and dietary salt intake throughout the study, however they will take salt and placebo capsules at various times during the study to look at the effects of additional salt intake on blood pressure and kidney function in patients with high versus those with low dietary sodium intake.
Participants:
The participants (n=32) includes men and non-pregnant women aged 20-80, with type 2 diabetes, high blood pressure, early diabetic kidney disease and a high or low dietary salt intake. 
Study Design and Procedures:
Cross-over double blind study design.  The study involves 12 scheduled visits over 28 weeks. 
The study consists of 3 phases: Two 8 week phases separated by a 6 week washout.  Patients commence on verapamil ± prazosin ± methyldopa therapy and this is  maintained throughout the 28 study period. The effect of telmisartan will be studied in each 8 week phase, and a thiazide will be added at week 4 to 8.  The effect of salt or  placebo will be examined in the last 2 weeks of each 4 week cycle.
During the study, a total of approximately 210 ml (10 tablespoons) of blood will be collected. 

Potential side effects:
There are potential side effects of blood pressure lowering medications however as all the patients have high blood pressure, they will be on blood pressure lowering medications.  This study involves exposure to a very small amount of radiation during nuclear medicine MAG 3 tests to look at kidney function. This has been approved by the radiation research subcommittee. 

Provision of test results:
Participants (and their general practitioner with their consent) will have access to all laboratory tests and when the final study report is produced by the investigator, this will be forwarded to study participants in lay terms.

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

Address

Country

Phone

Fax

Contact person for public queries

Name

Dr Elif I Ekinci

Address

Endocrine Centre of Excellence
Heidelberg Repatriation Hospital
Austin Health
Level 2
Centaur Building
PO Box 5444
300 Waterdale Rd
West Heidelberg VIC 3081

Country

Australia

Phone

+61 3 94962410

Fax

+61 3 94963365

ah-endo@unimelb.edu.au

Contact person for scientific queries

Name

Dr Elif I Ekinci

Address

Endocrine Centre of Excellence
Heidelberg Repatriation Hospital
Austin Health
Level 2
Centaur Building
PO Box 5444
300 Waterdale Rd
West Heidelberg VIC 3081

Country

Australia

Phone

+61 3 94962410

Fax

+61 3 94963365

ah-endo@unimelb.edu.au

No information has been provided regarding IPD availability

What supporting documents are/will be available?

No Supporting Document Provided

Results publications and other study-related documents

Documents added manually

No documents have been uploaded by study researchers.

Documents added automatically

No additional documents have been identified.

Trial Review

Registering a new trial?

Documents added manually

Documents added automatically