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

Not Applicable

Completed

• Conditions: Carbohydrate Intolerance
• Interventions: Other: Glucose; Other: Glucose plus lactulose; Other: Hot Rice; Other: Cold Rice

• Registration Number: NCT03667963
• Lead Sponsor: University of Toronto

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2018-08-29
• Study First Submitted: 2018-09-10
• Study First Submitted QC: 2018-09-10
• Study First Posted: 2018-09-12
• Primary Completion: 2018-12-21
• Study Completion: 2018-12-21
• Status Verified: 2019-01
• Last Update Submitted: 2019-01-10
• Last Update Posted: 2019-01-11

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 40

Inclusion Criteria

• 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.

Exclusion Criteria

• 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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: FACTORIAL

Arm && Interventions

Group	Intervention	Description
High Salivary Amylase Activity	Glucose	Glucose Glucose plus lactulose Hot Rice Cold Rice
High Salivary Amylase Activity	Glucose plus lactulose	Glucose Glucose plus lactulose Hot Rice Cold Rice
Low Salivary Amylase Activity	Glucose	Glucose Glucose plus lactulose Hot Rice Cold Rice
Low Salivary Amylase Activity	Glucose plus lactulose	Glucose Glucose plus lactulose Hot Rice Cold Rice
Low Salivary Amylase Activity	Hot Rice	Glucose Glucose plus lactulose Hot Rice Cold Rice
Low Salivary Amylase Activity	Cold Rice	Glucose Glucose plus lactulose Hot Rice Cold Rice
High Salivary Amylase Activity	Hot Rice	Glucose Glucose plus lactulose Hot Rice Cold Rice
High Salivary Amylase Activity	Cold Rice	Glucose Glucose plus lactulose Hot Rice Cold Rice

Primary Outcome Measures

Name	Time	Method
Glycemic Index (GI)	0-2 hours	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.

Secondary Outcome Measures

Name	Time	Method
Breath hydrogen response	0-6 hours	Sum of breath hydrogen concentrations from the lowest in the first 3 hours to 6 hours.
Carbohydrate malabsorbed	0-6 hours.	For each test meal the sum of breath hydrogen concentrations from the lowest value over 0-3 hours to 6 hours (termed "H"). For each subject the amount of hydrogen per gram malabsorbed carbohydrate (H/g) is calculated as (GL-G)/10 where GL is H after the glucose plus lactose meal and G is H after the glucose meal. The amount of carbohydrate malabsorbed after the hot and cold rice meals, respectively, are HR/Hg and CR/Hg, where HR and Cr are H after the hot and cold rice meals.
Glycemic response	0-2 hours	The incremental area under the blood glucose response curve

Trial Locations

Locations (1)

Glycemic Index Laboratories; 🇨🇦 Toronto, Ontario, Canada