Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT04571866 |
| Other study ID # |
120533 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
October 20, 2020 |
| Est. completion date |
February 15, 2021 |
Study information
| Verified date |
July 2021 |
| Source |
University of Bergen |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The rate of gastric emptying is proposed to be one of the major determinants of postprandial
glycemia. A slower gastric emptying will thus result in a less pronounced rise in blood
glucose, which is especially desirable in diabetes care as it will highly influence the
overall glycemic control. The present study aims to investigate the rate of gastric emptying
and postprandial blood glucose levels in response to the intake of bread with different
dietary fiber-content. Though bread is one of the major sources of dietary carbohydrates in
Central- and Northern Europe, the mechanism and the metabolic effects of bread consumption,
however, is investigated in a limited number of studies.
Description:
The rate of gastric emptying is related to small intestinal motility and absorption of
carbohydrates, and it is one of the major determinants of postprandial glycemia. A slower
rate of gastric emptying will thus result in a less pronounced rise in blood glucose.
Especially in diabetes care, reduced gastric emptying is desirable because of its effect on
the rise of postprandial blood glucose, which again highly influences the overall glycemic
control.
Bread is one of the most eaten food items in Central- and Northern Europe, being one of the
major sources of dietary carbohydrate intake. In addition, bread often contains a diverse
range of dietary fiber. The effect on gastric emptying and the amount of dietary
carbohydrates absorbed in the small intestine depends on the overall meal composition, the
degree of processing, and the type of dietary fiber, e.g., viscous or non-viscous. The
oat-derived dietary fiber beta-glucan may have favorable properties in this regard as adding
beta-glucan to a meal has been shown to slow down the rate of gastric emptying. However,
studies investigating the effect of beta-glucan on gastric emptying are scarce.
For assessment of gastric emptying, scintigraphy is seen as the "gold standard" as the method
readily can discriminate between gastric emptying and absorption of glucose in the small
intestine. However, this method is not often used due to its invasive nature and radiation.
High-resolution real-time ultrasonography is now the most preferred method and regarded as a
new "gold standard", proving good inter- and intra-observer agreement. Compared to
scintigraphy, ultrasound is a safe and non-invasive procedure widely available in clinical
settings.
Objectives
To establish whether a wheat bread with an optimized content of beta-glucan has a different
effect on gastric emptying, satiety, and postprandial glycemia compared to control bread.
Study procedures
Recruitment
Healthy adults (age range 18 to 40 years) with normal to overweight body mass index (BMI:
18.5-30 kg/m2) and no gastrointestinal diseases or other issues that can affect gastric
motility, are eligible and will be asked to participate. Health status will be briefly
checked during a screening examination.
Participants will be recruited through flyers, announcements, and advertisements in social
media, such as Facebook. The eligibility of participants will be addressed during a screening
visit. Participants will answer questionnaires including questions on general health status,
lifestyle habits, current medications, allergies, and gastrointestinal symptoms (using the
ROMA-IV questionnaire).
Study design: randomized cross-over design
The study will be conducted at the Research Unit for Health Surveys, University of Bergen, on
non-consecutive days, with at least 3 days (wash-out period) in between two study days.
Participants will consume bread with either beta-glucan or no additive at a quantity of 25 g
available carbohydrates within 10 minutes together with 250 ml water. Gastric emptying will
then be measured by ultrasound during the next 2 hours in 15 minute-intervals the first hour,
and then every 30th minute (15, 30, 45, 60, 90, and 120 minutes). Blood samples will be taken
for measurement of postprandial glucose and satiety hormones, and the participants will fill
in a Visual Analogue Scale (VAS) for satiety. Blood pressure, body weight, waist
circumference, and height will be measured during the study visit. The participants must be
fasting for at least 12 hours (overnight, usually from 8 pm the evening before the study
visit).
Study bread will be blinded to both the investigators and the participants, although it
cannot be excluded that participants may recognize the type of bread. Consumption of bread
occurs in a randomized order, according to a randomization scheme.
Gastric emptying by ultrasound
Measurement: The participant is to be placed in a standardized sitting position. The
cross-sectional area of the antrum of the stomach will be measured using 2D ultrasonography.
The outer profile of the antrum will be measured using a built-in caliper and a calculation
program available in the ultrasound apparatus. The gastric antrum, the mesenteric vein, and
the aorta have to be visualized in this section. A minimal amount of force must be applied
during each reading to prevent compression of the antrum. The measurement will be performed
when the participants are suspending their breathing in expiration, between antral
contractions. The average of the two measurements will be used.
The antral area will be measured at the fasting state (baseline), immediately following bread
and water intake, and during the next 2 hours at regular intervals.
Blood glucose and satiety hormones
The effect of gastric emptying on postprandial blood glucose will be measured by collecting
venous and capillary blood samples. Venous blood samples, sampled via a catheter inserted
into an arm vein, will be collected at baseline, and 15, 30, 45, 60, 90, and 120 minutes
after the participant starts to ingest the test meal. In addition, the venous blood samples
will be used for the determination of insulin, Glucagon-like peptide-1 (GLP-1), peptide YY
(PYY), ghrelin, and leptin. The capillary blood samples, collected at the same time intervals
as the venous blood samples, will be used to measure postprandial blood glucose levels.
Satiety
The participants will be asked to report satiety sensations by filling in a VAS at baseline,
and 15, 30, 45, 60, 90, and 120 minutes after consumption of the standardized meals, without
having the previous scale available.
Statistics
The primary outcome variable is the difference in gastric emptying (antral area, cm2) at
different time points and the calculated area under the curve for the entire study duration.
The comparison of the antral area following the different bread-options will be done at each
time point using a Tukey's multiple comparisons test. Each subject serves as her/his control
when comparing antral areas at different time points.
Secondary outcomes are the postprandial blood glucose concentrations at different time
points, subjectively reported satiety, insulin, and satiety hormones at different time
points.
Ethics
Participants will be provided with written and oral information about the study. Before
inclusion, the participants have to sign a consent form. The participants can withdraw from
the study at any time without explanation. The study will be performed following the
Declaration of Helsinki.
Overall, participation in the study implies very little risk. Some discomfort may occur when
drawing blood and bruising can occur. However, blood sample collection will be performed by
authorized personnel in a standardized matter. Participants will be covered by the Patient
Injury Act.
All study procedures will be conducted in accordance with Good Clinical Practice. All study
procedures will be described in standard operating procedures (SOPs).
