Exogenous Glucose Oxidation Breath Test (EGOBT)

This study is currently recruiting participants. (see Contacts and Locations)
Verified May 2013 by National University of Ireland, Galway, Ireland
Irish Endocrine Society
Information provided by (Responsible Party):
Amir Shafat, National University of Ireland, Galway, Ireland
ClinicalTrials.gov Identifier:
First received: May 1, 2013
Last updated: NA
Last verified: May 2013
History: No changes posted

May 1, 2013
May 1, 2013
April 2012
June 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. ] [ Designated as safety issue: No ]
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
No Changes Posted
Per cent dose recovered [ Time Frame: 240 minutes ] [ Designated as safety issue: No ]
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 ] [ Designated as safety issue: No ]
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 Provided
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (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 ClinicalTrials.gov Identifier (NCT Number) in Medline.
July 2013
June 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
35 Years to 82 Years
Contact: Louise Lynch, BSc louise.lynch@nuigalway.ie
Contact: Amir Shafat, BSc PhD +353 91 494218 amir.shafat@nuigalway.ie
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
May 2013

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