Clinical trial NCT04303468: Intervention With a GABA Supplement in Prediabetics
Official title: The Effects of a GABA Supplement Versus a Placebo on Glucose Tolerance and Blood Pressure in Prediabetics
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Prediabetes
Hypertension
Lead sponsor: Wageningen University
Sponsor class: OTHER
Collaborators: name: Nunhems
name: Agrico Research
name: Avebe
First posted: 2020-03-11
Enrollment: 52
Sex: ALL
Minimum age (years): 50
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Randomized placebo controlled double blind parallel study design
Primary purpose: PREVENTION

Brief summary: In this double-blind parallel placebo controlled intervention study the effects of 3 times daily 500 mg gamma-aminobutyric acid (GABA) supplementation on glucose tolerance and cardiovascular health will be assessed in prediabetics.


Eligibility criteria: Inclusion Criteria:

* Age between 50 and 70
* BMI higher or equal to 27 kg/m2
* Impaired fasting glucose (fasting glucose ≥ 6.1 and ≤ 6.9 mmol/L) or/and
* Impaired glucose tolerance (glucose levels ≥ 7.8 and ≤ 11.1 mmol/L, 2-hours after an OGTT or/and glucose levels ≥8.6 mmol/L, 1-hour after an OGTT)

Exclusion Criteria:

* Has been diagnosed with diabetes
* Having other conditions, like liver, pancreatic, cardiovascular, gastro-intestinal or endocrine diseases, that could influence the study results
* Use of medications or supplements that could influence the study results
* Sensitive to medical skin adhesives
* More than 5kg weight change in the past 12 weeks
* Excessive alcohol consumption (\>21 glasses/week for men and \>14 glasses/week for women on average)
* Being an employee of Wageningen University, division Human Nutrition and Health
* Currently a research subject in other research

Primary outcomes:
measure: Postprandial glycaemic response during a 2 hour oral glucose tolerance test (OGTT)
timeFrame: blood will be drawn at baseline and after 30, 60 and 120 minutes, before and after the 12 weeks intervention
Secondary outcomes:
measure: Postprandial insulin and glucagon response during a 2 hour OGTT,
timeFrame: blood will be drawn at baseline and after 30, 60 and 120 minutes, before and after the 12 weeks intervention
measure: Plasma free fatty acids
timeFrame: before and after the 12 weeks intervention
measure: HbA1c
timeFrame: before and after the 12 weeks intervention
measure: Glucose variability
timeFrame: 5 days during which they eat their habitual diet, before and after the 12 weeks intervention
measure: Blood pressure
timeFrame: Dynamic measurement: 24 hours, before and after the 12 weeks intervention
measure: Heart rate
timeFrame: before and after the 12 weeks intervention
measure: Concentrion of markers of inflammation in blood
timeFrame: before and after the 12 weeks intervention
measure: Concentration of triglycerides in blood
timeFrame: before and after the 12 weeks intervention
measure: Concentration of LDL and HDL cholesterol in blood
timeFrame: before and after the 12 weeks intervention
measure: Concentration of ALAT and ASAT in blood
timeFrame: before and after the 12 weeks intervention
measure: Acute effects of GABA on postprandial glucose
timeFrame: 2 hours, after a single administration of 500 mg GABA
measure: Acute effects of GABA on blood pressure
timeFrame: for 24 hours during which GABA is taken 3 times, each time before the main meal
measure: Sleep quality
timeFrame: before and after the 12 weeks intervention
measure: Feelings of depression
timeFrame: before and after the 12 weeks intervention
measure: Feelings of anxiety
timeFrame: before and after the 12 weeks intervention
measure: Plasma GABA concentration
timeFrame: before and after the 12 weeks intervention
measure: Plasma glutamate concentration
timeFrame: before and after the 12 weeks intervention
Other outcomes:
Locations:
city: Wageningen
country: Netherlands
facility: Wageningen University, Division of Human Nutrition
Study officials:
affiliation: Wageningen University
name: Renger Witkamp, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: de Bie TH, Balvers MGJ, de Vos RCH, Witkamp RF, Jongsma MA. The influence of a tomato food matrix on the bioavailability and plasma kinetics of oral gamma-aminobutyric acid (GABA) and its precursor glutamate in healthy men. Food Funct. 2022 Aug 15;13(16):8399-8410. doi: 10.1039/d2fo01358d.