Clinical trial NCT03467659: Whole Grains, Gastric Emptying and Glycemic Response
Official title: Glycemic Response of Whole Grain Wheat Meals
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Obesity
Diabetes Mellitus, Type 2
Appetitive Behavior
Lead sponsor: Purdue University
Sponsor class: OTHER
First posted: 2018-03-16
Enrollment: 16
Sex: ALL
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: Whole grains have been associated with controlled glycemic response and increased satiety compared to refined grains. However, the properties of whole grains which are responsible for these purported improved health outcomes are still unclear. The current study investigated the extent of whole grains' low glycemic property when food properties are controlled, and how this relates to gastric emptying rate and glycemic response.

Detailed description: It is generally assumed that whole grain foods confer a health benefit in regards to moderated glycemia and increased satiety compared to foods made from refined grains. However, the extent of whole grains' low glycemic property may be limited by certain factors. For example, physical properties such as viscosity or particle size and differing starch digestion rates of whole grain foods may strongly influence glycemic response and gastric emptying rate. In this study, whole and refined grain wheat porridges were prepared from materials originating from the same milling source, with matched pairs for viscosity, starch and dietary fiber contents, and particle size. Subjects consumed wheat porridges containing 13C-labeled octanoic acid for assessment of gastric emptying rate, and they wore a continuous glucose monitor for measuring postprandial glucose levels. The purpose of this research was to test the hypothesis that the purported moderated glycemic response and slow gastric emptying rate are dependent on how these foods are processed. This work highlights the need to consider specific properties of whole grain foods for desired health outcomes in order to optimize the design of whole grain-based foods.

Eligibility criteria: Inclusion Criteria:

* Aged between 18-50 years old
* Healthy, normal BMI (18.5 kg/m² \<BMI \< 25 kg/m²)
* Be free of any gastrointestinal diseases, diabetes, cardiovascular diseases
* Be free of any wheat allergies and gluten intolerances or sensitivities
* Not be pregnant or nursing

Exclusion Criteria:

* No medical problems
* No medication
* Pregnant or nursing

Primary outcomes:
measure: Gastric emptying
timeFrame: Acute study, 4 hours measurement after consumption of test food
measure: Glycemic response
timeFrame: Acute study, 4 hours measurement after consumption of test food
measure: Appetitive behavior
timeFrame: Acute study, 4 hours measurement after consumption of test food.
Secondary outcomes:
Other outcomes:
Locations:
city: West Lafayette
country: United States
facility: Purdue University
state: Indiana
Study officials:
References:
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citation: Clegg ME, Shafat A. Procedures in the 13C octanoic acid breath test for measurement of gastric emptying: analysis using Bland-Altman methods. Scand J Gastroenterol. 2010 Aug;45(7-8):852-61. doi: 10.3109/00365521.2010.483740.
citation: Christiansen M, Bailey T, Watkins E, Liljenquist D, Price D, Nakamura K, Boock R, Peyser T. A new-generation continuous glucose monitoring system: improved accuracy and reliability compared with a previous-generation system. Diabetes Technol Ther. 2013 Oct;15(10):881-8. doi: 10.1089/dia.2013.0077. Epub 2013 Jun 18.
citation: Ghoos YF, Maes BD, Geypens BJ, Mys G, Hiele MI, Rutgeerts PJ, Vantrappen G. Measurement of gastric emptying rate of solids by means of a carbon-labeled octanoic acid breath test. Gastroenterology. 1993 Jun;104(6):1640-7. doi: 10.1016/0016-5085(93)90640-x.
citation: Schoeller DA, Klein PD, Watkins JB, Heim T, MacLean WC Jr. 13C abundances of nutrients and the effect of variations in 13C isotopic abundances of test meals formulated for 13CO2 breath tests. Am J Clin Nutr. 1980 Nov;33(11):2375-85. doi: 10.1093/ajcn/33.11.2375.
citation: Pletsch EA, Hayes AMR, Chegeni M, Hamaker BR. Matched whole grain wheat and refined wheat milled products do not differ in glycemic response or gastric emptying in a randomized, crossover trial. Am J Clin Nutr. 2022 Apr 1;115(4):1013-1026. doi: 10.1093/ajcn/nqab434.