The Effect of Continuous Sipping of a Glucose Solution on Markers of Oxidation in Men and Women (AOGI)

The objective of this study is to determine the effect of reducing the rate of glucose absorption on oxidative stress after eating and to compare it with the effects of vitamin C. The hypothesis is that reducing the rate of glucose absorption will reduce oxidative stress to a similar extent as 1g vitamin C.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Disease; Diabetes
• Intervention / Treatment: Dietary supplement: glucose bolus; Dietary supplement: Glucose sipping; Dietary supplement: Glucose bolus plus 1g vitamin C; Dietary supplement: Glucose sipping plus 1g vitamin C

Detailed Description

Recently, much attention has been paid to evidence that abnormalities of the postprandial state (hyperglycemia) are important contributing factors to the development of chronic disease. This attention has increased interest in the role low glycemic index (GI) foods could potentially play in preventing postprandial oxidative burst/stress. GI is a means by which to categorize carbohydrate according to their postprandial glycemic response. Low GI foods promote slow intestinal absorption, prolonged and less pronounced postprandial glycemia, may decrease risk of chronic disease, as well as provide metabolic benefit to people living with glucose abnormalities as well as those with normal glucose. Few studies have been conducted looking at the potential relationship between GI and oxidation and are limited by dietary/lifestyle confounders. The proposed study has been developed to eliminate these confounders. Hypotheses (3): 1. Sipping glucose slowly over 3h will result in less oxidative stress than ingesting the same amount of glucose as a bolus over 5min. 2. Sipping glucose will reduce oxidative stress to the same extent as 1g of oral vitamin C. 3. The effect of sipping glucose on oxidative stress will occur sooner than that of vitamin C.

• Study Type: Interventional
• Enrollment (Actual): 18
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• healthy males or females
• 18 to 75 years

Exclusion Criteria:

• diabetes
• recent hospitalization

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Glucose bolus alone; 50g glucose dissolved in water and consumed within 5 minutes.	Dietary supplement: glucose bolus; 50g anhydrous glucose dissolved in 300ml water consumed within 10min followed by a lunch (cheese sandwich, fruit and milk) at 4h.
Experimental: Glucose sipping alone; 50g glucose dissolved in water and consumed gradually over 3 hours.	Dietary supplement: Glucose sipping; 50g anhydrous glucose dissolved in 300ml water consumed at rate of 25ml per 15min followed by a lunch (cheese sandwich, fruit and milk) at 4h.
Active Comparator: Glucose bolus plus 1g vitamin C; 50g glucose dissolved in water and consumed in 5 minutes with 1g vitamin C	Dietary supplement: Glucose bolus plus 1g vitamin C; 50g anhydrous glucose dissolved in 300ml water consumed within 10min with 1g vitamin C followed by a lunch (cheese sandwich, fruit and milk) at 4h.
Experimental: Glucose sipping plus 1g vitamin C; 50g glucose dissolved in water and consumed gradually of 3 hours. In addition 1g vitamin C will be taken with the first mouthful of glucose solution.	Dietary supplement: Glucose sipping plus 1g vitamin C; 50g anhydrous glucose dissolved in 300ml water consumed at rate of 25ml per 15min. 1g vitamin C taken with first 25ml. Followed by a lunch (cheese sandwich, fruit and milk) at 4h.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Incremental Area Under the Curve over 4 hours in serum TRAP (total peroxyl radical-trapping potential)	Four (4) hours after starting to eat the test meal.

Secondary Outcome Measures

Outcome Measure	Time Frame
Change over 6 hours from baseline in Plasma glucose	Baseline and 30, 60, 120, 180, 240, 270, 300 and 360min
Change over 6 hours from baseline in Plasma insulin	Baseline and 30, 60, 120, 180, 240, 270, 300 and 360min
Change over 6 hours from baseline in Plasma free-fatty acids	Baseline and hourly for 6h
Change over 6 hours from baseline in Serum vitamin C	Baseline and 2, 4 and 6h
Change over 6 hours from baseline in C-reactive protein	Baseline and 2, 4 and 6h
Change over 6 hours from baseline in Blood pressure	Baseline and 1, 2, 4, 5 and 6h
Change over 6 hours from baseline in Pulse	Baseline and 1, 2, 4, 5 and 6h
Change over 6 hours from baseline in Pulse pressure	Baseline and 1, 2, 4, 5 and 6h
Change over 6 hours from baseline in Augmentation index	Baseline and 1, 2, 4, 5 and 6h
Change over 6 hours from baseline in Oxidized LDL	Baseline and hourly for 6hr
Change from baseline in serum TRAP over 6 hours	Baseline and 30, 60, 120, 180, 240, 270, 300 and 360min

Collaborators and Investigators

• Sponsor: University of Toronto
• Collaborators: Canadian Institutes of Health Research (CIHR)
• Investigators: Principal Investigator: Thomas MS Wolever, BMBCh PhD DM, University of Toronto; Study Director: Shannan Grant, MSc, RD, University of Toronto

Study record dates

Study Major Dates

• Study Start: August 1, 2010
• Primary Completion (Actual): June 1, 2011
• Study Completion (Actual): June 1, 2011

Study Registration Dates

• First Submitted: August 3, 2011
• First Submitted That Met QC Criteria: September 23, 2011
• First Posted (Estimate): September 27, 2011

Study Record Updates

• Last Update Posted (Estimate): March 12, 2013
• Last Update Submitted That Met QC Criteria: March 11, 2013
• Last Verified: March 1, 2013

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Protective Agents; Micronutrients; Antioxidants; Vitamins; Ascorbic Acid
• Other Study ID Numbers: 25401TW