Effect of Genetic Variation in Starch-digesting Enzymes on Digestibility and Glycemic Index of Cold and Hot Rice

NCT03667963 | Completed

• 1 other identifier: RIS protocol number 33593
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

This study evaluates the effect of different methods of preparation (cooked and consumed hot vs cooked, cooled overnight and consumed cold) and variation in the activity of salivary amylase on the glycemic index and carbohydrate digestibility in healthy human subjects. The effect of genetic variation in small intestinal starch digesting enzymes on glycemic index and starch digestibility will also be assessed.

Conditions

Carbohydrate Intolerance

Outcome Measures

Primary Outcomes (1)

• Glycemic Index (GI)

  For each subject, the incremental area under the glucose response curve over 2 hours (iAUC) after each rice test meal is expressed as a percentage of the mean iAUC elicited by the 2 glucose test meals.

  0-2 hours

Secondary Outcomes (3)

• Carbohydrate malabsorbed

  0-6 hours.

• Glycemic response

  0-2 hours

• Breath hydrogen response

  0-6 hours

Study Arms (2)

Low Salivary Amylase Activity

OTHER

Glucose Glucose plus lactulose Hot Rice Cold Rice

Other: Glucose; Other: Glucose plus lactulose; Other: Hot Rice; Other: Cold Rice

High Salivary Amylase Activity

OTHER

Glucose Glucose plus lactulose Hot Rice Cold Rice

Other: Glucose; Other: Glucose plus lactulose; Other: Hot Rice; Other: Cold Rice

Interventions

Glucose OTHER

50g glucose dissolved in 250ml water

High Salivary Amylase Activity; Low Salivary Amylase Activity

Glucose plus lactulose OTHER

50g glucose plus 10g lactulose dissolved in 250ml water

High Salivary Amylase Activity; Low Salivary Amylase Activity

Hot Rice OTHER

Freshly cooked polished rice containing 50g available carbohydrate (approximately 2/3 cup cooked rice) and consumed hot.

High Salivary Amylase Activity; Low Salivary Amylase Activity

Cold Rice OTHER

Cooked polished rice containing 50g available carbohydrate (approximately 2/3 cup cooked rice) cooled overnight in a refrigerator and consumed cold.

High Salivary Amylase Activity; Low Salivary Amylase Activity

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Males or non-pregnant females aged 18-75 years and in good health
• Eligible to receive income in Canada
• Have Ontario Health Insurance Plan or equivalent medical coverage.
• Previous donor of saliva using protocol reference number # 31093 or GIL-1670 (in which subject consents to measurement of salivary amylase activity and genetic variation in AMY1, SI and MGAM genes).
• Salivary amylase activity in the lowest tertile (\<50 U/ml) or highest tertile (\>105 U/ml) of salivary amylase activity of 40 subjects previously measured.

You may not qualify if:

• known history of AIDS, hepatitis, diabetes or a heart condition
• Allergy to rice, canola oil or sesame oil.
• use of medications (including, but not limited to, insulin or other antidiabetic drugs, systemic steroids, antipsychotics, protease inhibitors, antivirals, immunosuppressive agents and drugs affecting gut motility or digestion) or with any condition which might, in the opinion of Dr. Wolever, the Medical Director or GI Labs, either: 1) make participation dangerous to the participant himself (or herself) or to others, or 2) affect the results.
• individuals who cannot or will not comply with the experimental procedures or do not follow the instructions of GI Labs staff related to the safe performance of the experimental procedures

Sponsors & Collaborators

• University of Toronto: lead
• Glycemic Index Laboratories, Inc: collaborator

Study Sites (1)

Glycemic Index Laboratories

Toronto, Ontario, M5C 2X3, Canada

Location

Related Publications (1)

• Wolever TMS, El-Sohemy A, Ezatagha A, Zurbau A, Jenkins AL. Neither low salivary amylase activity, cooling cooked white rice, nor single nucleotide polymorphisms in starch-digesting enzymes reduce glycemic index or starch digestibility: a randomized, crossover trial in healthy adults. Am J Clin Nutr. 2021 Nov 8;114(5):1633-1645. doi: 10.1093/ajcn/nqab228.

  PMID: 34293081 DERIVED

MeSH Terms

Conditions

Glucose-Galactose Malabsorption

Interventions

Glucose; Lactulose

Intervention Hierarchy (Ancestors)

Hexoses; Monosaccharides; Sugars; Carbohydrates; Disaccharides; Oligosaccharides; Polysaccharides

Study Officials

• Thomas MS Wolever, MD, PhD

  President, Medical Director

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: DOUBLE
• Who Masked: INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: FACTORIAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: September 10, 2018
• First Posted: September 12, 2018
• Study Start: August 29, 2018
• Primary Completion: December 21, 2018
• Study Completion: December 21, 2018
• Last Updated: January 11, 2019

Record last verified: 2019-01

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)