Title

Effects of an Apple Extract on Glycaemia: The GLU-Pomme Study
Dose-response Effect of an Apple Extract on Postprandial Glycaemia: a Randomised Controlled Trial. The GLU-POMME Study.
  • Phase

    N/A
  • Study Type

    Interventional
  • Intervention/Treatment

    apple ...
  • Study Participants

    34
Postprandial hyperglycaemia can lead to adverse modifications to functional proteins within the body and eventually lead to the development of type 2 diabetes. Previous research by this group has shown that an apple polyphenol extract reduced hyperglycaemia following a high-carbohydrate meal. The aim of this study is to investigate the effects of lower doses of the apple extract on postprandial glycaemia, insulinaemia and plasma gastric inhibitory polypeptide concentrations following a mixed carbohydrate test meal.
Introduction:

Sharp peaks in blood glucose levels can lead to adverse modifications to functional proteins, oxidative stress and pancreatic beta cell dysfunction. It is therefore desirable to consume a diet that will allow more gradual rises in blood glucose levels after meals. Fruit polyphenols may help to limit the glucose excursion following a high carbohydrate meal. Previous research by this research group has demonstrated that 1200 mg of apple polyphenols (Appl'In™) inhibited the average incremental area under the curve (T+0 to T+30 min) of plasma glucose by 54% relative to placebo. Possible mechanisms include inhibition of intestinal enzymes and inhibition of intestinal glucose absorption by decreasing SGLT1/GLUT2 transport activity. The literature also suggests that foods rich in polyphenols exert beneficial effects on risk factors of cardiovascular disease such as hypertension, lipid metabolism and vascular function.

Study design:

A randomised, controlled, double-blind, cross-over study will be conducted. Four matched test drinks will be consumed in random order on separate study visits immediately before a mixed-carbohydrate test meal, containing either: 1) 1.2 g, 2) 0.9 g 3). 0.6 g of apple polyphenols, or 4). placebo. Postprandial changes in plasma glucose, insulin, NEFA, GIP, GLP-1 concentrations as well as changes in vascular function will be measured. Twenty-four hour urine samples will be collected for analysis of urinary polyphenol metabolites and glucose. In a sub sample of participants, a paracetamol absorption test will be incorporated via addition of 1.5 g paracetamol into the test drink.
Study Started
Jan 31
2017
Primary Completion
Nov 30
2017
Study Completion
Feb 28
2018
Results Posted
Jun 17
2020
Last Update
Jun 17
2020

Dietary Supplement Apple polyphenols

Drinks will be delivered in random order at 4 separate study visits immediately before a high-carbohydrate meal. Seven days wash-out period will be required between study days.

Dietary Supplement Placebo

1.2 g apple polyphenols Experimental

1200 mg apple polyphenols delivered in a low sugar drink.

0.9 g apple polyphenols Experimental

900 mg apple polyphenols delivered in a low sugar drink.

0.6 g apple polyphenols Experimental

600 mg apple polyphenols delivered in a low sugar drink.

Placebo Placebo Comparator

No polyphenols delivered in a low sugar drink.

Criteria

Inclusion Criteria:

Age: 18-70 y
Male and female
Healthy (free of diagnosed diseases listed in the exclusion criteria)
Body Mass Index 18-35 kg/m2
Able to understand the information sheet and willing to comply with study protocol
Able to give informed written consent

Exclusion Criteria:

Those diagnosed with Phenylketonuria (PKU)
Those with known or suspected food and/or paracetamol intolerances, allergies or hypersensitivity
Women who are known to be pregnant or who are intending to become pregnant over the course of the study
Women who are breast feeding
Participation in another clinical trial
Those who have donated blood within 3 months of the screening visit and participants for whom participation in this study would result in having donated more than 1500 millilitres of blood in the previous 12 months.
Full Blood Counts and Liver Function test results outside of the normal range.
Current smokers, or reported giving up smoking within the last 6 months
History of substance abuse or alcoholism
Reported history of Cardiovascular disease, diabetes (or fasting glucose ≥ 7.1 mmol/L), cancer, kidney, liver or bowel disease, gastrointestinal disorder or use of drug likely to alter gastrointestinal function
Unwilling to restrict consumption of specified high polyphenol foods for 48 h before the study
Weight change >3kg in preceding 2 months and body mass index <18 or >35 kg/m2
Blood pressure ≥160/100 mmHg
Total cholesterol ≥ 7.5 mmol/L; fasting triacylglycerol concentrations ≥ 5.0 mmol/L
Medications that may interfere with the study: alpha-glucosidase inhibitors (acarbose: Glucobay), insulin sensitizing drugs (metformin: Glucophage, Glucophage SR, Eucreas, Janumet; thiazolidinediones: Actos, Competact), sulfonylureas (Daonil, Diamicron, Diamicron MR, Glibenese, Minodiab, Amaryl Tolbutamide), and lipid lowering drugs (statins, nicotinic acid, colestyramine anhydrous, ezetimibe, fibrates); and medications that may react unpredictably with paracetamol: ketoconazole, metoclopramide, carbamazepine, phenobarbital, phenytoin, primidone, warfarin and other products containing paracetamol. Other medications should be reviewed by medical representative from KCL on a case by case basis.
Nutritional supplements that may interfere with the study: higher dose vitamins/minerals (>200% Recommend Nutrient Intake), B vitamins, Vitamin C, calcium, copper, chromium, iodine, iron, magnesium, manganese, phosphorus, potassium and zinc. Subjects already taking vitamin or minerals at a dose around 100% or less up to 200% of the RNI, or evening primrose/algal/fish oil supplements will be asked to maintain habitual intake patterns, ensuring that they take them every day and not sporadically. They will be advised not to stop taking supplements or start taking new supplements during the course of the study.

Summary

1.8 g Apple Extract

1.2 g Apple Extract

0.9 g Apple Extract

0 g Apple Extract

All Events

Event Type Organ System Event Term

Postprandial Glycaemia

Primary outcome: Area over baseline t+0-30 min for plasma glucose

1.8 g Apple Extract

11.3
mmol/L*min (Mean)
Standard Error: 1.2

1.2 g Apple Extract

15.2
mmol/L*min (Mean)
Standard Error: 1.5

0.9 g Apple Extract

17.8
mmol/L*min (Mean)
Standard Error: 1.6

0 g Apple Extract

27.1
mmol/L*min (Mean)
Standard Error: 2.5

Postprandial Insulinaemia

Peak postprandial insulin concentrations (Cmax) t +0-30 min and change from baseline data and areas over baseline t+0-30 min and t+0-240 min.

Outcome Measure Data Not Reported

Postprandial Glucose-dependent Insulinotropic Polypeptide (GIP) Concentrations

Peak postprandial GIP concentrations (Cmax) t +0-30 min and change from baseline data and areas over baseline t+0-30 min and t+0-240 min.

Outcome Measure Data Not Reported

Postprandial Glucagon-like Peptide-1 (GLP-1) Concentrations

Peak postprandial GLP-1 concentrations (Cmax) t +0-30 min and change from baseline data and areas over baseline t+0-30 min and t+0-240 min.

Outcome Measure Data Not Reported

Postprandial C-peptide Concentrations

Peak postprandial C-peptide concentrations (Cmax) t +0-30 min and change from baseline data and areas over baseline t+0-30 min and t+0-240 min.

Outcome Measure Data Not Reported

Postprandial Non-esterified Fatty Acid (NEFA) Concentrations

Peak postprandial NEFA concentrations (Cmax) t +0-30 min and change from baseline data and areas over baseline t+0-30 min and t+0-240 min

Outcome Measure Data Not Reported

Postprandial Triglyceride (TAG) Concentrations

Peak postprandial TAG concentrations (Cmax) t +0-30 min and change from baseline data and areas over baseline t+0-30 min and t+0-240 min.

Outcome Measure Data Not Reported

Postprandial Paracetamol Concentrations

Peak postprandial paracetamol concentrations (Cmax) t +0-30 min and change from baseline data and areas over baseline t+0-30 min and t+0-240 min (1.5 g paracetamol will be added to all test drinks in a sub-group of participants).

Outcome Measure Data Not Reported

Urinary Polyphenol Metabolites

Change in urinary polyphenol metabolite concentration following the test drink.

Outcome Measure Data Not Reported

Urinary Glucose

Change in urinary glucose concentration following the test drink.

Outcome Measure Data Not Reported

Postprandial Polyphenol Metabolite Concentrations

Peak postprandial polyphenol metabolites concentrations (Cmax) t +0-30 min and change from baseline data and areas over baseline t+0-30 min and t+0-240 min.

Outcome Measure Data Not Reported

Vascular Endothelial Function by Flow-mediated Dilation (FMD)

Change in FMD after the consumption of test drink.

Outcome Measure Data Not Reported

Vascular Function (Arteriograph Measurement)

Change in augmentation index following the test drink.

Outcome Measure Data Not Reported

Blood Pressure

Change in blood pressure following the test drink.

Outcome Measure Data Not Reported

Women's Health Questionnaire

Questionnaire to identify menstrual phase

Outcome Measure Data Not Reported

7-day Food Diary

Habitual dietary intake analysis

Outcome Measure Data Not Reported

Fasting glucose

5.18
mmol/L (Mean)
Standard Deviation: 0.39

Age, Customized

Age, Customized

Age, Customized

Region of Enrollment

Sex: Female, Male

Overall Study

Doses of Apple Extract