Exogenous Glucose Oxidation Breath Test (EGOBT)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01846767
Recruitment Status : Completed
First Posted : May 3, 2013
Last Update Posted : November 26, 2014
Irish Endocrine Society
Information provided by (Responsible Party):
Amir Shafat, National University of Ireland, Galway, Ireland

May 1, 2013
May 3, 2013
November 26, 2014
April 2012
December 2013   (Final data collection date for primary outcome measure)
Peak Delta over baseline in 13CO2 breath enrichment [ Time Frame: at 0, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, 180, 195, 210, 225, 240 minutes after glucose ingestion. ]
The peak enrichment of 13CO2 in breath is calculated by identifying the highest abundance breath sample and subtracting the base line abundance from it.
Same as current
Complete list of historical versions of study NCT01846767 on Archive Site
Per cent dose recovered [ Time Frame: 240 minutes ]
The per cent dose recovered of 13C glucose at 240 minutes.
Same as current
Diabetes classifications and measures of insulin resistance [ Time Frame: 0 and 120 minutes ]
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.
Same as current
Exogenous Glucose Oxidation Breath Test
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.


- 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).

Not Applicable
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Diabetes Mellitus, Type 2
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: Type 2 diabetes
    Diabetic patients Oral glucose breath test
    Intervention: Other: Oral glucose breath test
  • Experimental: Healthy controls
    non-diabetic Oral glucose breath test
    Intervention: Other: Oral glucose breath test

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
October 2014
December 2013   (Final data collection date for primary outcome measure)

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
Sexes Eligible for Study: Male
35 Years to 82 Years   (Adult, Senior)
Contact information is only displayed when the study is recruiting subjects
Not Provided
Not Provided
Amir Shafat, National University of Ireland, Galway, Ireland
National University of Ireland, Galway, Ireland
Irish Endocrine Society
Principal Investigator: Amir Shafat, PhD National University of Ireland, Galway
National University of Ireland, Galway, Ireland
November 2014

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP