Clinical trial NCT00841503: Exploring Buckwheat's Glucose Lowering Potential
Official title: A Double-Blind, Randomized, Controlled Study to Determine Buckwheat's Glucose Lowering Effects in Healthy Volunteers and Volunteers With Type 2 Diabetes
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Type 2 Diabetes
Keywords: functional food study
Lead sponsor: St. Boniface Hospital
Sponsor class: OTHER
Collaborators: name: University of Manitoba
First posted: 2009-02-11
Enrollment: 24
Sex: ALL
Minimum age (years): 18
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: A total of 24 volunteers were recruited from the community; 12 healthy volunteers and 12 volunteers with Type 2 Diabetes

Brief summary: Bioactive components in buckwheat enhance insulin sensitivity in Type 2 diabetes by improving glucose uptake and utilization through a unique mechanism that operates independent of insulin.

Detailed description: This is a single site, double-blind, randomized, controlled study designed to explore buckwheat's glucose lowering effects in healthy volunteers and volunteers with type 2 diabetes. A total of 24 volunteers consisting of 12 volunteers (healthy and diabetic) per group for both the acute and chronic phases of testing will be recruited through advertisement from the local community.

In the acute testing phase, volunteers (healthy and diabetic) will be asked to attend 4 visits one week apart for the duration of 3 hours per visit. A fasting blood sample will be collected at each visit. At each visit, all volunteers will consume in random order 1 of the following 4 products: i) crackers containing buckwheat; ii) crackers without buckwheat); iii) 50 mls of oral solution containing glucose; or iv) 50 mls of oral solution containing the sugar substitute Splenda. The crackers will contain equal amounts of available carbohydrates. Blood sampling will occur at 15, 30, 45, 60 minutes, and then every 60 minutes for the remainder of the visit. Sampling (pre and post product consumption) will measure insulin, glucose, and various incretins. Open venous access will be secured after the first sample has been obtained to minimize the number of needle pricks. Total amount of blood obtained will not exceed 30 mls per visit.

In the chronic testing phase, volunteers (healthy and diabetic) will receive the crackers containing buckwheat for consumption each day for 7 days. Prior to food consumption, a fasting blood sample will be obtained each day and a urine sample will be collected on Days 1, 3, and 7 to assess bioavailability of buckwheat compounds (concentrations in blood and urine), insulin and glucose. Sampling for a lipid profile (total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides), liver (ALT), kidney (creatinine), adipose function (adipokines), various incretins, as well as inflammatory status (various cytokines) will be done on Day 1 and Day 7. Total amount of blood obtained will not exceed 30 mls per visit.

Eligibility criteria: Inclusion Criteria:

* aged 18 to 70 years
* normal glycated hemoglobin (\<6% healthy, \<7.5% diabetic)
* absence of chronic conditions (except Type 2 diabetes)
* must be able to read and sign consent
* must be able to comply with protocol requirements

Exclusion Criteria:

* allergies to eggs, buckwheat, rice flour, or sugar substitutes (Splenda)
* acute or chronic conditions (except Type 2 diabetes)
* blood glucose \>10mmol/L at beginning of test session
* medications that affect glycemic control

Primary outcomes:
measure: determine glucose-lowering potential of the buckwheat bioactive compound during acute phase testing in volunteers with Type 2 diabetes
timeFrame: 3 hour testing
Secondary outcomes:
measure: determine bioavailability of buckwheat bioactive compounds
timeFrame: 7 days
Other outcomes:
Locations:
city: Winnipeg
country: Canada
facility: I.H. Asper Clinical Research Institute
state: Manitoba
Study officials:
affiliation: Canadian Centre for Agri-Food Research in Health & Medicine
name: Peter C Zahradka, PhD
role: PRINCIPAL_INVESTIGATOR
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