Recruiting

Glucagon

Sponsor:

Joslin Diabetes Center

Code:

NCT07818707

Conditions

Hypoglycemia

Hypoglycemia, Reactive

Bariatric Surgery

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Accepted

Interventions

Glucagon for Injection (Fresenius Kabi USA)

[6,6-2H2] glucose

[13C9, 15N1]-glucagon

[1-13C] glucose

[2-13C] glucose

Study Details

Brief summary:

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.

Conditions

Hypoglycemia

Hypoglycemia, Reactive

Bariatric Surgery

Study ID

NCT07818707

Start date

Jan 27, 2026

Status verified date

Sep, 2026

Completion date

Jan, 2027

Anticipated

Primary completion date

Jan, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Accepted

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.

Study Design

Enrollment

40 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

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.

Interventions

Glucagon for Injection (Fresenius Kabi USA)

The investigators are assessing glucagon metabolism in individuals with and without PBH in fasting and post-prandial states.

[6,6-2H2] glucose

The investigators are using a stable isotope glucose tracer to assess glucose metabolism in individuals with and without PBH in fasting and post-prandial states.

[13C9, 15N1]-glucagon

The investigators are assessing the metabolism of glucagon in individuals with and without PBH in fasting and post-prandial states.

[1-13C] glucose

The investigators are assessing the metabolism of glucose in individuals with and without PBH in fasting and post-prandial states.

[2-13C] glucose

The investigators assessing the metabolism of glucose in individuals with and without PBH in fasting and post-prandial states.

Primary outcome measure

  • Between-group differences in iAUC for postprandial EGP [ Time Frame: During Visit 2, within 10 days of the baseline visit ]

Central Contacts and Locations

Locations

University of Alabama

Recruiting

Birmingham, Alabama, United States, 35294

Contacts

Ananda Basu, MD

205-975-0471anandabasu@uabmc.edu

Joslin Diabetes Center

Recruiting

Boston, Massachusetts, United States, 02215

Contacts

Mary-Elizabeth Patti, MD

617-309-2400mary.elizabeth.patti@joslin.harvard.edu

More Information

Sponsor

Joslin Diabetes Center

Last update posted

Sep 14, 2026

Last verified

Sep, 2026

Keywords

  • glucagon sensitivity

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-15. This information was provided to ClinicalTrials.gov by Joslin Diabetes Center on 2026-09-14.