Intervention With a GABA Supplement in Prediabetics

Not Applicable

Completed

• Conditions: Prediabetes; Hypertension
• Interventions: Other: Placebo; Dietary Supplement: GABA

• Registration Number: NCT04303468
• Lead Sponsor: Wageningen University

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2020-03-04
• Study First Submitted QC: 2020-03-04
• Study First Posted: 2020-03-11
• Study Start: 2020-09-29
• Primary Completion: 2021-09-08
• Study Completion: 2021-09-08
• Status Verified: 2021-11
• Last Update Submitted: 2021-11-15
• Last Update Posted: 2021-11-16

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 52

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	The placebo consists of capsules containing powdered cellulose.
GABA	GABA	GABA is a nutrient commonly present in our diet in for example tomatoes and potatoes. It is also commercially sold as dietary supplement. A dose of 500 mg, 3 times daily is used

Primary Outcome Measures

Name	Time	Method
Postprandial glycaemic response during a 2 hour oral glucose tolerance test (OGTT)	blood will be drawn at baseline and after 30, 60 and 120 minutes, before and after the 12 weeks intervention	A 2 hour oral glucose tolerance test with 75gr glucose

Secondary Outcome Measures

Name	Time	Method
Postprandial insulin and glucagon response during a 2 hour OGTT,	blood will be drawn at baseline and after 30, 60 and 120 minutes, before and after the 12 weeks intervention	A 2 hour oral glucose tolerance test with 75gr glucose
Plasma free fatty acids	before and after the 12 weeks intervention
HbA1c	before and after the 12 weeks intervention
Glucose variability	5 days during which they eat their habitual diet, before and after the 12 weeks intervention	The participants wear a flash glucose monitoring sensor with which their interstitial glucose is measured every 15 minutes.
Blood pressure	Dynamic measurement: 24 hours, before and after the 12 weeks intervention	Single measurement and a dynamic measurement: * Mean day systolic and diastolic blood pressure; * Mean night systolic and diastolic blood pressure; * Time below or above 120/80 mmHg
Heart rate	before and after the 12 weeks intervention
Concentrion of markers of inflammation in blood	before and after the 12 weeks intervention	C-reactive protein and cytokines like IL-6 and TNF-alpha
Concentration of triglycerides in blood	before and after the 12 weeks intervention
Concentration of LDL and HDL cholesterol in blood	before and after the 12 weeks intervention
Concentration of ALAT and ASAT in blood	before and after the 12 weeks intervention
Acute effects of GABA on postprandial glucose	2 hours, after a single administration of 500 mg GABA	Assessed with an OGTT during which interstitial glucose is measured with flash glucose monitoring
Acute effects of GABA on blood pressure	for 24 hours during which GABA is taken 3 times, each time before the main meal	Assessed with an ambulatory blood pressure monitor
Sleep quality	before and after the 12 weeks intervention	Pittsburgh Sleep Quality Index (PSQI) questionnaire, the outcome is a global PSQI score (range: 0-21), with higher scores indicating poorer sleep quality.
Feelings of depression	before and after the 12 weeks intervention	Patient Health Questionnaire (PHQ-9), the higher the score the more depressed a person is.
Feelings of anxiety	before and after the 12 weeks intervention	General Anxiety Disorder (GAD-7) questionnaire, the higher the score, the more anxious a person is.
Plasma GABA concentration	before and after the 12 weeks intervention
Plasma glutamate concentration	before and after the 12 weeks intervention

Trial Locations

Locations (1)

Wageningen University, Division of Human Nutrition; 🇳🇱 Wageningen, Netherlands