Exogenous Glucose Oxidation Breath Test (EGOBT)

Study of the Metabolism of 13C Labelled Glucose to 13CO2 in Human Breath

The purpose of this study is to determine if oxidation of 13C glucose to 13CO2 is changed in type 2 diabetic patients.

Study Overview

• Status: Completed
• Conditions: Diabetes Mellitus, Type 2
• Intervention / Treatment: Other: Oral glucose breath test

Detailed Description

Recruitment

- Non diabetic participants will be recruited from within the National University of Ireland, Galway student and staff community. Diabetic patients will be recruited from University College Hospital, Galway in collaboration with their hospital consultant.

Test- day

- They will undergo two separate, identical and simultaneous Oral Glucose Tolerance test and 13C-glucose breath tests on two separate occasions after an overnight fast of 12 hours starting at 8pm. On arrival their heart rate, blood pressure, height and weight will be recorded. Following a resting period of 10 minutes, samples will be obtained for fasting glucose and breath enrichment values (at t = -20 and -10mins). At t = 0 min, participants will consume a standard glucose solution. This glucose solution will consist of 150mg of 13C-glucose, 74.85g of glucose and 200ml of water and 25ml of orange flavoring. Breath samples will be obtained immediately after consumption of test solution and repeated every 15 min over a 4-h interval. Blood glucose concentrations will be taken every 15 min starting at t = 15 min, over a 2-h interval and every 30 min for another 2-h interval. Participants will remain at rest throughout the study.

Sample size assessment

- Target recruitment is 40 non-diabetics and 40 diabetic participants. This study will use a Student's t-test to determine difference, or otherwise, in glucose oxidation in breath 13CO2, in 2 different groups of individuals. With power arbitrarily set at 0.8, effect size of 1.21 reduction in breath, and Alpha set at 0.01 a final number of 35 participants is required for each group. The n=40 for each group is set to allow a 5 participant drop out in each group Dillon et al (2009).

• Study Type: Interventional
• Enrollment (Actual): 46
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Ireland
  • Galway, Ireland, 11111
    • Physiology Laboratory

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 35 years to 82 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• All research participants must be between 18 and 65 years
• Non-diabetic participants must not be taking any medication for diabetes
• Participants must speak English or Irish proficiently
• All participants must be males
• All participants must live within Galway City
• Type 2 diabetic participants must have been diagnosed within the last five years
• Type 2 diabetic participants must be treated by Metformin alone for their diabetes
• All participants must provide written informed consent to comply with every aspect of the study

Exclusion Criteria:

• Females

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Type 2 diabetes; Diabetic patients Oral glucose breath test	Other: Oral glucose breath test; Simultaneous oral glucose tolerance test and exogenous 13C-glucose breath test following a 12hr overnight fast. Fasting samples were obtained for plasma glucose, insulin, c-peptide, leptin, adiponectin, resistin, HbA1c and two breath 13CO2 abundance values (at t = -15 and -5min). At t = 0min, each subject drank a 75g glucose solution (Thornton & Ross, UK) containing 0.15g of 1-13C glucose. Further breath samples (every 15 min over a 240min interval) and further plasma blood glucose, insulin and c-peptide samples (90,120,180min) were also taken.
Experimental: Healthy controls; non-diabetic Oral glucose breath test	Other: Oral glucose breath test; Simultaneous oral glucose tolerance test and exogenous 13C-glucose breath test following a 12hr overnight fast. Fasting samples were obtained for plasma glucose, insulin, c-peptide, leptin, adiponectin, resistin, HbA1c and two breath 13CO2 abundance values (at t = -15 and -5min). At t = 0min, each subject drank a 75g glucose solution (Thornton & Ross, UK) containing 0.15g of 1-13C glucose. Further breath samples (every 15 min over a 240min interval) and further plasma blood glucose, insulin and c-peptide samples (90,120,180min) were also taken.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peak Delta over baseline in 13CO2 breath enrichment	The peak enrichment of 13CO2 in breath is calculated by identifying the highest abundance breath sample and subtracting the base line abundance from it.	at 0, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, 180, 195, 210, 225, 240 minutes after glucose ingestion.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Per cent dose recovered	The per cent dose recovered of 13C glucose at 240 minutes.	240 minutes

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diabetes classifications and measures of insulin resistance	Fasting plasma glucose and glucose tolerance at 120min, as defined by plasma glucose concentrations. Also measured Leptin/Adiponectin concentrations, Fasting insulin, calculated homeostatic model assessment and and quantitative insulin sensitivity check index.	0 and 120 minutes

Collaborators and Investigators

• Sponsor: National University of Ireland, Galway, Ireland
• Collaborators: Irish Endocrine Society
• Investigators: Principal Investigator: Amir Shafat, PhD, National University of Ireland, Galway

Publications and helpful links

General Publications

• Rating D, Langhans CD. Breath tests: concepts, applications and limitations. Eur J Pediatr. 1997 Aug;156 Suppl 1:S18-23. doi: 10.1007/pl00014264.
• Stellaard F, Koetse HA, Elzinga H, Boverhof R, Tjoonk R, Klimp A, Vegter D, Liesker J, Vonk RJ. 13C-carbohydrate breath tests: impact of physical activity on the rate-limiting step in lactose utilization. Scand J Gastroenterol. 2000 Aug;35(8):819-23. doi: 10.1080/003655200750023183.
• Lifschitz CH, Boutton TW, Carrazza F, Beyreiss K, Schmitz J, Ricour C, Shulman R, Nichols BL. A carbon-13 breath test to characterize glucose absorption and utilization in children. J Pediatr Gastroenterol Nutr. 1988 Nov-Dec;7(6):842-7. doi: 10.1097/00005176-198811000-00008.
• Mizrahi M, Lalazar G, Adar T, Raz I, Ilan Y. Assessment of insulin resistance by a 13C glucose breath test: a new tool for early diagnosis and follow-up of high-risk patients. Nutr J. 2010 May 27;9:25. doi: 10.1186/1475-2891-9-25.
• Dillon EL, Janghorbani M, Angel JA, Casperson SL, Grady JJ, Urban RJ, Volpi E, Sheffield-Moore M. Novel noninvasive breath test method for screening individuals at risk for diabetes. Diabetes Care. 2009 Mar;32(3):430-5. doi: 10.2337/dc08-1578. Epub 2008 Dec 15.

Study record dates

Study Major Dates

• Study Start: April 1, 2012
• Primary Completion (Actual): December 1, 2013
• Study Completion (Actual): October 1, 2014

Study Registration Dates

• First Submitted: May 1, 2013
• First Submitted That Met QC Criteria: May 1, 2013
• First Posted (Estimate): May 3, 2013

Study Record Updates

• Last Update Posted (Estimate): November 26, 2014
• Last Update Submitted That Met QC Criteria: November 25, 2014
• Last Verified: November 1, 2014

More Information

Terms related to this study

• Keywords: Diabetes mellitus; Breath test; 13CO2; Glucose oxidation
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Endocrine System Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 2
• Other Study ID Numbers: 13CGLU