Exploring Buckwheat's Glucose Lowering Potential

Type 2 Diabetes Clinical Trial

Official title:

A Double-Blind, Randomized, Controlled Study to Determine Buckwheat's Glucose Lowering Effects in Healthy Volunteers and Volunteers With Type 2 Diabetes

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00841503
• Other study ID #: buckwheat study
• Status: Completed
• Phase: N/A
• First received: February 10, 2009
• Last updated: March 20, 2012
• Start date: September 2008
• Est. completion date: March 2012

Study information

• Verified date: March 2012
• Source: St. Boniface General Hospital Research Centre
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Health Canada
• Study type: Observational

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 24
• Est. completion date: March 2012
• Est. primary completion date: March 2012
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years to 70 Years

Eligibility

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

Study Design

Observational Model: Cohort, Time Perspective: Prospective

Related Conditions & MeSH terms

• Diabetes Mellitus, Type 2
• Type 2 Diabetes

Intervention

Other:
• buckwheat, rice crackers, glucose, sugar substitute
crackers contain equal amounts of available carbohydrates; 50 mls of oral solution for both glucose and Splenda

Locations

Country	Name	City	State
Canada	I.H. Asper Clinical Research Institute	Winnipeg	Manitoba

Sponsors (2)

Lead Sponsor	Collaborator
St. Boniface General Hospital Research Centre	University of Manitoba

Country where clinical trial is conducted

Canada, 

References & Publications (23)

Adachi T, Yasuda K, Okamoto Y, Shihara N, Oku A, Ueta K, Kitamura K, Saito A, Iwakura I, Yamada Y, Yano H, Seino Y, Tsuda K. T-1095, a renal Na+-glucose transporter inhibitor, improves hyperglycemia in streptozotocin-induced diabetic rats. Metabolism. 2000 Aug;49(8):990-5. — View Citation

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Kawa JM, Taylor CG, Przybylski R. Buckwheat concentrate reduces serum glucose in streptozotocin-diabetic rats. J Agric Food Chem. 2003 Dec 3;51(25):7287-91. — View Citation

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Lu C et al. (1992) Proceedings of the 5th International Symposium on Buckwheat; Lin R, Zhou M, Tao Y, Li J, Zhang, Z. Eds; Agriculture Publishing House: Beijing,China; pp 458-464.

Nawano M, Oku A, Ueta K, Umebayashi I, Ishirahara T, Arakawa K, Saito A, Anai M, Kikuchi M, Asano T. Hyperglycemia contributes insulin resistance in hepatic and adipose tissue but not skeletal muscle of ZDF rats. Am J Physiol Endocrinol Metab. 2000 Mar;278(3):E535-43. — View Citation

Obendorf RL, Steadman KJ, Fuller DJ, Horbowicz M, Lewis BA. Molecular structure of fagopyritol A1 (O-alpha-D-galactopyranosyl-(1 --> 3)-D-chiro-inositol) by NMR. Carbohydr Res. 2000 Oct 6;328(4):623-7. — View Citation

Oku A, Ueta K, Arakawa K, Ishihara T, Nawano M, Kuronuma Y, Matsumoto M, Saito A, Tsujihara K, Anai M, Asano T, Kanai Y, Endou H. T-1095, an inhibitor of renal Na+-glucose cotransporters, may provide a novel approach to treating diabetes. Diabetes. 1999 Sep;48(9):1794-800. — View Citation

Qureshi AA, Sami SA, Khan FA. Effects of stabilized rice bran, its soluble and fiber fractions on blood glucose levels and serum lipid parameters in humans with diabetes mellitus Types I and II. J Nutr Biochem. 2002 Mar;13(3):175-187. — View Citation

Scheepers A, Joost HG, Schürmann A. The glucose transporter families SGLT and GLUT: molecular basis of normal and aberrant function. JPEN J Parenter Enteral Nutr. 2004 Sep-Oct;28(5):364-71. Review. — View Citation

Skrabanja V, Liljeberg Elmståhl HG, Kreft I, Björck IM. Nutritional properties of starch in buckwheat products: studies in vitro and in vivo. J Agric Food Chem. 2001 Jan;49(1):490-6. — View Citation

Steadman KJ, Burgoon MS, Schuster RL, Lewis BA, Edwardson SE, Obendorf RL. Fagopyritols, D-chiro-inositol, and other soluble carbohydrates in buckwheat seed milling fractions. J Agric Food Chem. 2000 Jul;48(7):2843-7. — View Citation

Steadman KJ, Fuller DJ, Obendorf RL. Purification and molecular structure of two digalactosyl D-chiro-inositols and two trigalactosyl D-chiro-inositols from buckwheat seeds. Carbohydr Res. 2001 Mar 9;331(1):19-25. — View Citation

Thompson LU, Robb P, Serraino M, Cheung F. Mammalian lignan production from various foods. Nutr Cancer. 1991;16(1):43-52. — View Citation

Ueta K, Ishihara T, Matsumoto Y, Oku A, Nawano M, Fujita T, Saito A, Arakawa K. Long-term treatment with the Na+-glucose cotransporter inhibitor T-1095 causes sustained improvement in hyperglycemia and prevents diabetic neuropathy in Goto-Kakizaki Rats. Life Sci. 2005 Apr 22;76(23):2655-68. — View Citation

Varela-Nieto I, León Y, Caro HN. Cell signalling by inositol phosphoglycans from different species. Comp Biochem Physiol B Biochem Mol Biol. 1996 Oct;115(2):223-41. Review. — View Citation

Wang J et al. (1992) Proceedings of the 5th International Symposium on Buckwheat; Lin R, Zhou M, Tao Y, Li J, Zhang, Z. Eds; Agriculture Publishing House: Beijing, China; pp 465-467.

* Note: There are 23 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	determine glucose-lowering potential of the buckwheat bioactive compound during acute phase testing in volunteers with Type 2 diabetes		3 hour testing	No
Secondary	determine bioavailability of buckwheat bioactive compounds		7 days	No

External Links

•   Canadian Centre for Agri-Food Research in Health & Medicine