Incretin Hormone Antagonism After Bariatric Surgery

Importance of Endogenous Glucagon-like Peptide-1 and Glucose-dependent Insulinotropic Polypeptide for Postprandial Glucose Metabolism After Roux-en-Y Gastric Bypass and Sleeve Gastrectomy Surgery

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT03950245

Acronym

INCA-BAR

Enrollment

Registered

2019-05-15

Start date

2019-07-01

Completion date

2021-04-16

Last updated

2022-02-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Bariatric Surgery

Keywords

glucagon-like peptide-1, glucose-dependent insulinotropic polypeptide, Roux-en-Y gastric bypass, sleeve gastrectomy, gastric bypass, bariatric surgery, glucose, diabetes, exendin(9-39), GIP(3-30)

Brief summary

Using the glucagon-like peptide-1 (GLP-1) antagonist exendin(9-39) and the glucose-dependent insulinotropic peptide (GIP) antagonist GIP(3-30), the purpose of this study is to clarify the importance of endogenous GLP-1 and GIP for postprandial glucose metabolism after RYGB and SG in subjects with normal glucose tolerance. We hypothesize that GLP-1 is more important after RYGB, and GIP is more important after SG, for postprandial glucose tolerance and beta-cell function. A group of un-operated subjects with normal glucose tolerance will serve as controls.

Interventions

OTHERPlacebo

Four-hour liquid mixed meal tests and a subsequent ad libitum meal during saline infusion.

OTHERGLP-1 antagonism

Four-hour liquid mixed meal tests and a subsequent ad libitum meal during exendin 9-39 and saline infusion.

OTHERGIP antagonism

Four-hour liquid mixed meal tests and a subsequent ad libitum meal during GIP(3-30) and saline infusion.

OTHERGLP-1 and GIP antagonism

Four-hour liquid mixed meal tests and a subsequent ad libitum meal during exendin and GIP(3-30) infusion.

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

BASIC_SCIENCE

Masking

SINGLE (Subject)

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Yes

Inclusion criteria

, surgery groups: * Age \> 18 years * RYGB or SG operation \> 12 months prior to inclusion * Weight stable (± 3 kg during the last month) * HbA1c \< 48 mmol/mol before surgery, and no history of diabetes * HbA1c \< 48 mmol/mol and fasting plasma glucose \< 6.1 mmol/l at inclusion Inclusion Criteria, control group: * Age \> 18 years * no former RYGB- or SG operation * Weight stable (± 3 kg during the last month) * HbA1c \< 48 mmol/mol, fasting plasma glucose \< 6.1 mmol/l and no history of diabetes

Exclusion criteria

* Thyrotoxicosis or inadequately treated hypothyreosis * Hemoglobin \< 6.5 mmol/l at inclusion * Pregnancy or breast feeding * Medication affecting the planned examinations Matching between groups * Age * Sex * BMI at inclusion and for surgery groups also pre-surgery BMI

Design outcomes

Primary

Measure	Time frame	Description
iAUC glucose	240 minutes	Main comparison between groups: delta iAUC glucose (iAUC exendin(9-39) test day - iAUC GIP(3-30) test day) in the RYGB group compared to the SG group

Secondary

Measure	Time frame	Description
Beta-cell glucose sensitivity (β-GS)	240 minutes	Main comparison between groups: delta β-GS (β-GS exendin(9-39) test day - β-GS GIP(3-30) test day) in the RYGB group compared to the SG group

Countries

Denmark

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026