Post-Prandial Carbohydrate Metabolism in Individuals With and Without Post-Bariatric Surgery Hypoglycemia (PBH)

NCTNCT07818707Other idSTUDY00000341Other idR01DK137518

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Overview

Status: Recruiting
Phase: Phase 4
Enrollment: 40 participants (estimated)
Sponsor: Joslin Diabetes Center · Other
Design: Not randomized · Open label (no masking)
Countries: 1 country
United States
Start: 27 Jan 2026
Primary completion: Jan 2027 (estimated)
Completion: Jan 2027 (estimated)
First posted: 14 Sept 2026
Last update posted: 14 Sept 2026
Conditions: Hypoglycemia · Hypoglycemia, Reactive · Bariatric Surgery

Timeline

1 trial · 1 ongoing

Completed
Ongoing
Not yet recruiting
Stopped
Estimated dates (est.)
Results posted

202620272028

Ph 4
Post-Prandial Carbohydrate Metabolism in Individuals With and Without Post-Bariatric Surgery Hypoglycemia (PBH)
NCT07818707
27 Jan 2026 to est. Jan 2027

Registry summary

Text and fields below are the sponsor's entries at ClinicalTrials.gov, shown as posted.

In this study, the investigators will determine (a) whether metabolism (secretion and turnover) of glucagon is altered in patients with PBH, (b) whether this is affected by a meal, (c) whether PBH affects the ability of the body to produce glucose (endogenous glucose production), and (d) whether PBH affects the amount of glycogen in the liver (storage form of glucose) when fasting and after a meal. The investigators will determine the effect of glucagon to raise glucose levels after a meal. To answer these questions, participants will receive an infusion of a stable (nonradioactive) isotope of glucose and glucagon, and a meal containing a stable isotope of glucose. Glycogen will be measured by magnetic resonance imaging (MRI) of the liver before and after the meal. This information will be used to develop computer models for the glucagon pump system.

Interventions

Glucagon for Injection (Fresenius Kabi USA)Drug
[6,6-2H2] glucoseDrug
[13C9, 15N1]-glucagonDrug
[1-13C] glucoseDrug
[2-13C] glucoseDrug

Arms2

Active comparator
RYGB non-hypoglycemia
Individuals that underwent Roux-en-y gastric bypass (RYGB) at least 2 years prior to recruitment and do not have a diagnosis of PBH.
Experimental
Post-Bariatric Hypoglycemia (PBH)
Individuals that underwent RYGB at least 2 years prior to recruitment and have a diagnosis of PBH.

Primary outcomes1

Outcomes the sponsor listed as primary.

Between-group differences in iAUC for postprandial EGP
Time frame · During Visit 2, within 10 days of the baseline visit
Registry description
Between-group differences in endogenous glucose production (EGP) in the postprandial state, as quantified by iAUC for postprandial EGP. These measurements will be taken at baseline and after mixed-meal consumption, specifically at minutes 10, 20, 30, 60, 90, 120, 150, and 180.

Secondary outcomes(8)

Between-group differences in the integrated postprandial response (iAUC) of Ra glucagon
Time frame · During Visit 2, within 10 days of the baseline visit
Registry description
Between-group differences in glucagon secretion (Ra glucagon) in the postprandial state during mixed meal testing, as quantified by integrated postprandial response (iAUC) of Ra glucagon. These measurements will be taken at baseline and after mixed-meal consumption, specifically at minutes 10, 20, 30, 60, 90, 120, 150, and 180.
Between-group differences in EGP in the fasting state
Time frame · During Visit 2, within 10 days of the baseline visit
Registry description
Between-group differences in EGP in the fasting state, as quantified by fasting EGP. Samples will be collected at baseline before consumption of a mixed meal. This will be measured at baseline.
Between-group differences in iAUC for glucose levels for 60 minutes after postprandial glucagon administration
Time frame · During Visit 2, within 10 days of the baseline visit
Registry description
Between-group differences in glycemic response to exogenous glucagon administration in the postprandial state, following mixed meal testing, as quantified by iAUC glucose for 60 minutes after postprandial glucagon administration. This will be measured at the end of mixed meal testing (180 minutes) and then every 10 minutes for up to 60 minutes.
Between-group differences in insulin sensitivity, as estimated by postprandial SI derived from oral glucose minimal model
Time frame · During Visit 2, within 10 days of the baseline visit
Registry description
Between-group differences in insulin sensitivity, as estimated by postprandial SI derived from oral glucose minimal model. This will be measured after mixed-meal consumption (timepoints 0 minutes).
Between-group differences in insulin secretion, as estimated by postprandial phi total
Time frame · During Visit 2, within 10 days of the baseline visit
Registry description
Between-group differences in insulin secretion, as estimated by postprandial phi total, derived from oral glucose minimal model. This will be measured after mixed-meal consumption (timepoint 0 minutes).
Between-group differences in disposition index derived from oral glucose minimal model
Time frame · During Visit 2, within 10 days of the baseline visit
Registry description
Between group differences in disposition index, as estimated by postprandial DI, derived from oral glucose minimal model. This will be measured after mixed-meal consumption (timepoint 0 minutes).
Between-group differences in basal glycogen content, measured by MRI
Time frame · During Visit 2, within 10 days of the baseline visit.
Registry description
Glycogen content will be measured using magnetic resonance imaging (MRI). Spectroscopy will be performed using a 3-Tesla whole-body MR imager/spectrometer. Absolute glycogen concentrations will be calculated from the integrated area of the C1-glycogen signal at 100.1 parts per million referenced to a glycogen phantom, corrected for receiver gain and reception sensitivity. This measurement by MRI will only occur at the University of Alabama at Birmingham.
Between-group differences in meal-stimulated changes in glycogen content, measured by change from baseline
Time frame · During Visit 2, within 10 days of the baseline visit
Registry description
Glycogen content will be measured using magnetic resonance imaging (MRI). Spectroscopy will be performed using a 3-Tesla whole-body MR imager/spectrometer. Absolute glycogen concentrations will be calculated from the integrated area of the C1-glycogen signal at 100.1 parts per million referenced to a glycogen phantom, corrected for receiver gain and reception sensitivity. This measurement by MRI will only occur at the University of Alabama at Birmingham.

Posted results

Values are shown as posted at ClinicalTrials.gov, with their units. PepBank has not converted, pooled or compared them.

No results are posted for this trial.

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Studies0

Studies that cite this trial.

No study cites this trial.

Eligibility

Who could join, as posted.

Sex: All
Age: from 18 Years up to 70 Years
Healthy volunteers: Accepted

Inclusion and exclusion criteria, as posted

Inclusion Criteria: * Age 18-70 years of age, inclusive, at screening. * Willingness to provide informed consent and follow all study procedures, including attending all scheduled visits. * Males or females at least 2 years following Roux-en-Y gastric bypass (RYGB) * For patients recruited to PBH group: diagnosed with ongoing PBH, with documented episodes of hypoglycemia, and history of fulfillment of Whipple's triad. Exclusion Criteria: * Documented hypoglycemia occurring only in the fasting state (\>12 hours fast); * Current diabetes, defined as hemoglobin A1c \>6.5% or use of diabetes medications, except for acarbose or miglitol; * Chronic kidney disease stage 4 or 5 (including end-stage renal disease); * Hepatic disease, including serum ALT or AST greater than 2 times the upper limit of normal; hepatic synthetic insufficiency as defined as serum albumin \< 3.0 g/dL; or serum bilirubin \> 2.0; * Congestive heart failure, NYHA class II, III or IV; * History of myocardial infarction, unstable angina or revascularization within the past 6 months. * Two or more risk factors for coronary artery disease including diabetes, uncontrolled hypertension, uncontrolled hyperlipidemia, and active tobacco use. * History of recurrent syncope (unrelated to hypoglycemia) or active diagnosis of a cardiac arrhythmia; * Current administration of β-blocker therapy; * History of a cerebrovascular accident; * Seizure disorder (other than with suspect or documented hypoglycemia); * Active treatment with long-acting (LAR) octreotide or pasireotide; * Active malignancy, except basal cell or squamous cell skin cancers; * Personal or family history of pheochromocytoma or disorder with increased risk of pheochromocytoma (MEN 2, neurofibromatosis, or Von Hippel-Lindau disease); * Known insulinoma; * Major surgical operation within 30 days prior to screening; * Clinically significant anemia as defined as a hematocrit \< 33%; * Bleeding disorder, treatment with warfarin, or platelet count \<50,000; * Blood donation (1 pint of whole blood) within the past 2 months; * Active alcohol abuse or substance abuse; * Current administration of oral or parenteral corticosteroids; * Pregnancy and/ or lactation: For persons of childbearing potential: there is a requirement for a negative urine pregnancy test before any procedures. * Not enrolled in another study that uses an investigational drug for this condition.

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