Effects of Carbohydrase-inhibiting Polyphenols on Glycaemic Response in Vivo

NCT01994135 | Completed DMC

• 1 other identifier: MEEC 12-037
• Study Type: interventional
• Target: 26
• Locations: 1 country
• Sites: 1

Brief Summary

Consumption of carbohydrate containing foods or sugary drinks brings about changes to the blood glucose levels. After a meal or drink, blood glucose levels rise until it reaches a peak concentration usually after 30 minutes. When the body senses the increase in blood glucose, a hormonal process involving insulin takes place to ensure that the glucose is taken up from the blood for storage and where it is needed for energy in the body. This process then brings about a decrease in the concentration of glucose until it reaches approximately the starting concentration. The original concentration of glucose is attained approximately 2 hours after eating or drinking a carbohydrate food or sugary drink respectively. Different carbohydrates and sugary drinks have different effects on blood glucose response depending on the amount as well as the type of carbohydrate. Those that give rise to a high glucose response compared to a reference carbohydrate (usually glucose) are said to be high glycaemic index (GI) foods and those with a lower glucose response compared to a reference carbohydrate (usually glucose) are said to be low glycaemic index (GI) foods.(1) Research has shown that diets that give rise to a high glucose response are associated with a number of abnormalities like increased metabolic syndrome (2). Metabolic syndrome mostly comprises of insulin resistance and glucose intolerance which gives an increased risk of type 2 diabetes. (3) It also gives rise to other conditions like high blood pressure (arterial hypertension), elevated blood insulin levels (hyper-insulinemia), elevated amounts of fat in the liver (fatty hepatosis) and elevated amounts of lipids in the blood (dyslipidemia). After type 2 diabetes become clinically apparent, the risk of cardiovascular disease also rises. (4) Research has also shown that foods/drinks which raise blood glucose levels gradually (low GI) rather than rapidly (high GI) have health benefits which include reducing the risk of metabolic syndrome (5). In vitro studies have shown that polyphenols found in fruits, vegetables and plant based foods have a positive effect on carbohydrate metabolism and can lower the blood glucose levels. (6) This research will determine whether the presence of polyphenols in the diet has any lowering effect on the blood glucose levels and hence the glycaemic index of foods. This will be determined by asking volunteers to consume polyphenol rich drink/food together with white bread and determine the glycaemic response. The GI of bread will be determined initially as a reference. Analysis will be done by measuring blood glucose response to white bread alone as reference and then to white bread with test sample containing polyphenols and then determine GI and see how the GI of bread will be affected. Other analyses to be done are plasma insulin, glucagon, gastric inhibitory polypeptide (GIP) and glucagon like peptides-1 (GLP-1) as they all relate to glycaemic response. Study hypothesis is that glucose metabolism will be affected. NOTE:

1. 1.Only healthy participants undertook the study (Hence metabolic syndrome participants not part of the study)
2. 2.Only glucose and insulin were analysed in the plasma (hence GIP, GLP-1 and glucagon not part of end points)

Conditions

Hyperglycaemia

Outcome Measures

Primary Outcomes (1)

• Changes in Incremental Area Under the Curve for glucose and insulin

  Blood will be collected at different time points within 3 hours, twice a week, for two weeks per volunteer

Study Arms (3)

Reference food

ACTIVE COMPARATOR

The reference food is white bread

Other: Reference food

Test food dose 1

EXPERIMENTAL

Test food dose 1 response will be compared to reference test food

Other: Test food dose 1

Test food dose 2

EXPERIMENTAL

Test food dose 2 response will be compared to reference test food as well as to test food dose 1

Other: Test food dose 2

Interventions

Reference food OTHER

Reference food will be used to which test food samples will be compared to.

Reference food

Test food dose 1 OTHER

Will contain low dose of a mixture of polyphenols in addition to the reference food

Test food dose 1

Test food dose 2 OTHER

Will contain high dose (twice of the low dose) of a mixture of polyphenols in addition to the reference food

Test food dose 2

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Group 1 - Healthy subjects
• Not diabetic Fasting glucose (blood glucose level before breakfast) 3.9 -5.9mmol/L Not on long term prescribed medication (except contraceptives) Not pregnant or lactating Not on special diet (for losing weight or fruit extracts supplements) Aged 18-75
• Group 2 - Metabolic syndrome risk group
• Not diabetic With fasting glucose (blood glucose level before breakfast) in the range of 6.0 - 8.0mmol/l Not on long term prescribed medication (except contraceptives) Not pregnant or lactating Not on special diet (for losing weight or fruit extracts) Aged 18-75

You may not qualify if:

• Group 1 - Healthy subjects
• Not healthy Diabetic Fasting glucose (blood glucose level before breakfast) 3.9 -5.9mmol/L On long term prescribed medication (except contraceptives) Pregnant or lactating On special diet (for losing weight or fruit extracts supplements) Aged below 18years or above 75years
• Group 2 - Metabolic syndrome risk group
• Not diabetic With fasting glucose (blood glucose level before breakfast) above 8.0mmol/l On long term prescribed medication (except contraceptives) Pregnant or lactating On special diet (for losing weight or fruit extracts) Aged below 18years or above 75 years

Sponsors & Collaborators

• University of Leeds: lead

Study Sites (1)

School of Food Science and Nutrition

Leeds, West Yorkshire, LS2 9JT, United Kingdom

Location

MeSH Terms

Conditions

Hyperglycemia

Condition Hierarchy (Ancestors)

Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases

Study Officials

• Gary Williamson

  University of Leeds

  STUDY CHAIR

• Hilda Nyambe

  University of Leeds

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: PhD candidate

Study Record Dates

• First Submitted: November 19, 2013
• First Posted: November 25, 2013
• Study Start: August 1, 2014
• Primary Completion: March 1, 2015
• Study Completion: September 1, 2015
• Last Updated: December 4, 2015

Record last verified: 2015-11

Locations

GB (1)