UMIN-CTR Clinical Trial

Public title

Blood pressure-lowering effect of oral intake of gamma-aminobutyric acid (GABA) in normotensive and grade I hypertensive people: a systematic review with meta-analysis.

Acronym

Blood pressure-lowering effect of oral intake of gamma-aminobutyric acid (GABA)

Scientific Title

Blood pressure-lowering effect of oral intake of gamma-aminobutyric acid (GABA) in normotensive and grade I hypertensive people: a systematic review with meta-analysis.

Scientific Title:Acronym

Blood pressure-lowering effect of oral intake of gamma-aminobutyric acid (GABA)

Region

Japan

Condition

This study will be restricted to all original articles of healthy adults (people not suffering from any diseases). However, we will also include grade I hypertensive people as an exception. We will exclude minors, pregnant women, those planning a pregnancy, and lactating women.

Classification by specialty

Adult

Classification by malignancy

Others

Genomic information

NO

Narrative objectives1

The objective of this review is to assess blood pressure-lowering effect of oral intake of gamma-aminobutyric acid (GABA) in normotensive and grade I hypertensive people.

Basic objectives2

Efficacy

Basic objectives -Others

Trial characteristics_1

Others

Trial characteristics_2

Others

Developmental phase

Not applicable

Primary outcomes

We will evaluate the effect of oral intake of gamma-aminobutyric acid (GABA) on systolic blood pressure and diastolic blood pressure.

Key secondary outcomes

We will not define the secondary outcomes.

Study type

Others,meta-analysis etc

Basic design

Randomization

Randomization unit

Blinding

Control

Stratification

Dynamic allocation

Institution consideration

Blocking

Concealment

No. of arms

Purpose of intervention

Type of intervention

Interventions/Control_1

Interventions/Control_2

Interventions/Control_3

Interventions/Control_4

Interventions/Control_5

Interventions/Control_6

Interventions/Control_7

Interventions/Control_8

Interventions/Control_9

Interventions/Control_10

Age-lower limit

20

years-old

<=

Age-upper limit

Not applicable

Gender

Male and Female

Key inclusion criteria

(Study design)
We will include randomized and quasi randomized and non-randomized controlled trials, randomized crossover trials, cohort studies, and case-control studies.
We will include scientific papers and reports which give us enough research details.

(PICO)
Participant:
We will include people not suffering from any diseases and also include grade I hypertensive people as an exception. We will exclude minors, pregnant women, those planning a pregnancy, and lactating women.
Intervention:
We define oral intake of test food containing GABA as an intervention.
Comparison:
We define oral intake of test food not containing GABA or maintaining daily life as controls.
Outcome measurement:
We will evaluate systolic blood pressure and diastolic blood pressure.

(PECO)
Participant:
We will include people not suffering from any diseases and also include grade I hypertensive people as an exception. We will exclude minors, pregnant women, those planning a pregnancy, and lactating women.
Exposure:
We define oral intake of food containing GABA as an exposure.
Comparison:
We define eating no food containing GABA as non-exposure. If subgroup analysis of GABA intake amount has been conducted in a study, we define the least intake group as a non-exposure group.
Outcome measurement:
We will evaluate systolic blood pressure and diastolic blood pressure.

(Language)
Eligibility is not restricted by language.

Key exclusion criteria

We will exclude cross-sectional studies because it will be difficult to interpret causal relationships between exposure and outcome. We will also exclude proceedings and unpublished studies.

Target sample size

Name of lead principal investigator

1st name	Koichi
Middle name
Last name	Aizawa

Organization

Kagome Co., Ltd.

Division name

Innovation Division

Zip code

329-2762

Address

17 Nishitomiyama, Nasushiobara-shi, Tochigi

TEL

0287-36-2935

Email

Koichi_Aizawa@kagome.co.jp

Name of contact person

1st name	Koichi
Middle name
Last name	Aizawa

Organization

Kagome Co., Ltd.

Division name

Innovation Division

Zip code

329-2762

Address

17 Nishitomiyama, Nasushiobara-shi, Tochigi

TEL

0287-36-2935

Homepage URL

Email

Koichi_Aizawa@kagome.co.jp

Institute

Kagome Co., Ltd.

Institute

Department

Personal name

Organization

None

Organization

Division

Category of Funding Organization

Self funding

Nationality of Funding Organization

Co-sponsor

Review Team
Professor Hiroharu Kamioka, Department of Ecological Symbiotic Science, Tokyo University of Agriculture
Dr. Takahiro Yoshizaki, Department of Food and Nutritional Sciences, Toyo University
Ms. Mari Makishi, Narashino Media Center, Toho University
Mr. Takuro Inoue, Innovation Division,
Kagome Co., Ltd.
Ms. Erika Sasaki, Innovation Division, Kagome Co., Ltd.
Dr. Nobuhiro Yajima, Innovation Division, Kagome Co., Ltd.

Name of secondary funder(s)

Organization

Kagome Ethics Committee

Address

3-21-1, F tower, Hamacho, Nihonbashi, Tyuo-ku, Tokyo, Japan

Tel

03-5623-8501

Email

toshika_okuni@kagome.co.jp

Secondary IDs

NO

Study ID_1

Org. issuing International ID_1

Study ID_2

Org. issuing International ID_2

IND to MHLW

Institutions

Date of disclosure of the study information

2016

Year

12

Month

31

Day

URL releasing protocol

Publication of results

Published

URL related to results and publications

Number of participants that the trial has enrolled

Results

Results date posted

Results Delayed

Results Delay Reason

Date of the first journal publication of results

Baseline Characteristics

Participant flow

Adverse events

Outcome measures

Plan to share IPD

IPD sharing Plan description

Recruitment status

Main results already published

Date of protocol fixation

2016

Year

02

Month

24

Day

Date of IRB

Anticipated trial start date

2016

Year

02

Month

25

Day

Last follow-up date

Date of closure to data entry

Date trial data considered complete

Date analysis concluded

Other related information

(Searches)
A hospital librarian (e.g., MM) will search 19 databases for studies from the beginning of each database to the search date.

(Data extraction)
In order to make the final selection of studies for the review, two authors (e.g., TI, ES) will independently apply all criteria to the full text of articles that have passed the first eligibility screening. Then TI and ES will independently extract data from the included studies and cross-check the data.

(Risk of bias assessment)
In order to ensure that variation is not caused by systematic errors in the study or execution, two authors (e.g., TI, ES) will independently assess the quality of articles. A full quality appraisal of these papers will be made using modified check list (12 items) of Cochrane Handbook for interventional trials, or modified check list (5 items) of GRADE Handbook for observational trials. We will exclude papers with high risk of bias.

Disagreement and uncertainties will be resolved by discussion with other authors (e.g., TY, KA, NY). In addition, TY will calculate agreement rate and kappa coefficient.

(Inconsistency evaluation)
We will evaluate inconsistency of evidence according to the value of I2 and by a statistical test for heterogeneity of effect estimates in a meta-analysis.

(Imprecision assessment)
We will assess imprecision based on the total number of participants in all included studies.

(Meta-analysis)
Only when we will not find heterogeneity in randomized and non-randomized controlled trials, TY will conduct a meta-analysis using RevMan 5. If we will find missing data, we will make contact with the author to obtain the data.
We will assess heterogeneity according to the value of I2 in Forest plot and assess publication bias using Funnel plot.
We will conduct subgroup analyses:
i) restricting to normotensive people and to grade I hypertensive people,
ii) restricting to randomized controlled parallel-group trials.

Registered date

2016

Year

02

Month

24

Day

Last modified on

2023

Year

01

Month

11

Day

Link to view the page

Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000024420