Clinical trial NCT01846767: Exogenous Glucose Oxidation Breath Test
Official title: Study of the Metabolism of 13C Labelled Glucose to 13CO2 in Human Breath
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Diabetes Mellitus, Type 2
Keywords: 13CO2
Breath test
Glucose oxidation
Diabetes mellitus
Lead sponsor: National University of Ireland, Galway, Ireland
Sponsor class: OTHER
Collaborators: name: Irish Endocrine Society
First posted: 2013-05-03
Enrollment: 46
Sex: MALE
Minimum age (years): 35
Maximum age (years): 82
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

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

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).

Eligibility criteria: 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

Primary outcomes:
measure: Peak Delta over baseline in 13CO2 breath enrichment
timeFrame: at 0, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, 180, 195, 210, 225, 240 minutes after glucose ingestion.
Secondary outcomes:
measure: Per cent dose recovered
timeFrame: 240 minutes
Other outcomes:
measure: Diabetes classifications and measures of insulin resistance
timeFrame: 0 and 120 minutes
Locations:
city: Galway
country: Ireland
facility: Physiology laboratory
Study officials:
affiliation: National University of Ireland, Galway
name: Amir Shafat, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Rating D, Langhans CD. Breath tests: concepts, applications and limitations. Eur J Pediatr. 1997 Aug;156 Suppl 1:S18-23. doi: 10.1007/pl00014264.
citation: 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.
citation: 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.
citation: 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.
citation: 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.