ANZCTR - Registration

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Trial registered on ANZCTR

Registration number

ACTRN12620000958987

Ethics application status

Approved

Date submitted

9/07/2020

Date registered

25/09/2020

Date last updated

25/09/2020

Date data sharing statement initially provided

25/09/2020

Type of registration

Retrospectively registered

Titles & IDs

Public title

Determining the gut bacteria in the setting of high blood pressure

Scientific title

Determining the gut microbiota in normotensive and hypertensive patients with ambulatory blood pressure

Secondary ID [1]

Nill known

Secondary ID [2]

None

Universal Trial Number (UTN)

Trial acronym

Linked study record

Health condition

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

hypertension

gut microbiota

Condition category

Condition code

Cardiovascular

Hypertension

Intervention/exposure

Study type

Observational

Patient registry

False

Target follow-up duration

Target follow-up type

Description of intervention(s) / exposure

Participants will have blood pressure measured in the office (over 3 times, after being seated for 5 minutes) and over 24 hours with an ambulatory blood pressure device (every 15 minutes during the day and every 30 minutes during the night), will have plasma collected (once), complete a food frequency questionnaire which covers a 12 month period (The Dietary Questionnaire for Epidemiological Studies - DQES v3.2), and will self-collect one fecal sample after the 24 hours blood pressure measurement. Participants saw the principal investigator, who has more than 8 years of experience in the field, or one of the research nurses. The visit was face-to-face, and we saw each participant once (day of the visit). Equipment and fecal samples were returned to the reception of the sites. Recruitment was performed at the Alfred Hospital, Melbourne, VIC, Australia, and at the Modern Clinic, Shepparton, VIC, Australia.

Intervention code [1]

Diagnosis / Prognosis

Comparator / control treatment

Participants with systolic blood pressure <140 mmHg and diastolic blood pressure <90 mmHg

Control group

Active

Outcomes

Primary outcome [1]

Changes in the gut microbiota (taxa and diversity by next-generation sequencing)

Timepoint [1]

24 hours after the study visit

Secondary outcome [1]

Gut metabolites (short-chain fatty acids in plasma and fecal samples, by gas chromatography)

Timepoint [1]

Once, from plasma collected during study visit

Eligibility

Key inclusion criteria

For normotensive participants:
• Diagnosis of normal blood pressure: Systolic blood pressure <140 mmHg and diastolic blood pressure <90 mmHg
• Age: 40-70 years old
• Gender: either
• Body mass index: 18.5-30

For hypertensive participants:
• Diagnosis of hypertension: Systolic blood pressure >140 mmHg and diastolic blood pressure >90 mmHg
• Age: 40-70 years old
• Gender: either
• Body mass index: 18.5-30

Minimum age

40 Years

Maximum age

70 Years

Sex

Both males and females

Can healthy volunteers participate?

Yes

Key exclusion criteria

Type 1 or type 2 diabetes, chronic kidney disease, gastrointestinal diseases (including history of intestinal surgery, inflammatory bowel disease, celiac disease, lactose intolerance, chronic pancreatitis or other malabsorption disorder), use of probiotics or antibiotics in the past 3 months, and taking medication for hypertension.

Study design

Purpose

Screening

Duration

Cross-sectional

Selection

Case control

Timing

Retrospective

Statistical methods / analysis

Recruitment

Recruitment status

Completed

Date of first participant enrolment

Anticipated

Actual

20/10/2016

Date of last participant enrolment

Anticipated

Actual

3/04/2018

Date of last data collection

Anticipated

Actual

5/04/2018

Sample size

Target

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

VIC

Recruitment hospital [1]

The Alfred - Melbourne

Recruitment postcode(s) [1]

3004 - Melbourne

Funding & Sponsors

Funding source category [1]

Other Collaborative groups

Name [1]

Baker Heart and Diabetes Institute

Address [1]

Baker Heart and Diabetes Institute
75 Commercial Rd, Melbourne VIC 3004

Country [1]

Australia

Primary sponsor type

Individual

Name

Dr Francine Marques

Address

Baker Heart and Diabetes Institute
75 Commercial Rd, Melbourne VIC 3004

Country

Australia

Secondary sponsor category [1]

Other Collaborative groups

Name [1]

Heart Failure Research Laboratory

Address [1]

Baker Heart and Diabetes Institute
75 Commercial Rd, Melbourne VIC 3004

Country [1]

Australia

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

Alfred Hospital Ethics Committee

Ethics committee address [1]

55 Commercial Rd, Melbourne VIC 3004

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

Approval date [1]

13/09/2016

Ethics approval number [1]

415/16

Summary

Brief summary

High blood pressure, also known as hypertension, is a disease where the blood inside the heart and blood vessels is pumped with more force than normal. This adds stress to these important tissues, increasing the chance of a heart attack, stroke and, as we age, heart failure. Hypertension affects one in three people in Australia, and is known as a ‘silent disease’ as it usually does not produce any symptoms until it might be too late. 

It is well known that our diet influences the risk to high blood pressure. While salt intake is associated with higher blood pressure, consumption of fruit, vegetables and other food rich in fibre is usually associated with lower blood pressure. New evidence from our laboratory has emerged that this may be due to the tiny microorganisms that live in our gut. While our bodies are incapable of digesting some types of fibre, they are fermented in gut, where they feed the community of ‘good’ bacteria. This results in the release of substances that can be detected in our blood and might be beneficial in lowering our blood pressure. 

The present study will expand our knowledge about the gut bacteria in the setting of normal and high blood pressure, to help us understand the types of bacteria present in hypertensive subjects and whether they could be contributing to the increase in blood pressure. This research has implications for cardiovascular health due to the relatively benign and cost effective nature of diet treatments. It will also inform on future intervention strategies and food guidelines.

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

A/Prof Francine Marques

Address

Monash University
25 Rainforest Walk, Clayton 3800 VIC

Country

Australia

Phone

+61425075884

Fax

[email protected]

Contact person for public queries

Name

Francine Marques

Address

Monash University
25 Rainforest Walk, Clayton 3800 VIC

Country

Australia

Phone

+61425075884

Fax

[email protected]

Contact person for scientific queries

Name

Francine Marques

Address

Monash University
25 Rainforest Walk, Clayton 3800 VIC

Country

Australia

Phone

+61425075884

Fax

[email protected]

Data sharing statement

Will individual participant data (IPD) for this trial be available (including data dictionaries)?

Yes

What data in particular will be shared?

Individual 16S (microbiome) sequencing from each participant data underlying published results only

When will data be available (start and end dates)?

Immediately following publication, no end date

Available to whom?

Anyone who wishes to access it

Available for what types of analyses?

Any purpose

How or where can data be obtained?

Access subject to approvals by Principal Investigator (A/Prof Francine Marques, [email protected], P: +61-03-85321916)

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

Source	Title	Year of Publication	DOI
Embase	Association between the Gut Microbiome and Their Metabolites with Human Blood Pressure Variability.	2022	https://dx.doi.org/10.1161/HYPERTENSIONAHA.122.19350

N.B. These documents automatically identified may not have been verified by the study sponsor.

Trial Review

Documents added manually

Documents added automatically