Islet Function in Gestational Diabetes

September 4, 2026 updated by: Aoife Egan, Mayo Clinic
The purpose of this research is to understand how the function of the human pancreas changes during and after pregnancy.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
90

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Minnesota
      • Rochester, Minnesota, United States, 55905
        • Recruiting
        • Mayo Clinic
        • Contact:
          • Jeanette Laugen
          • Phone Number: 507-255-8110
        • Contact:
          • Amy Zipse
          • Phone Number: 507-255-9278

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Pregnant individuals with a viable singleton pregnancy who have completed second trimester gestational diabetes screening and are eligible for classification as either gestational diabetes mellitus or no gestational diabetes mellitus.
  • Participants must be willing and able to provide informed consent and complete planned pregnancy and postpartum study visits.

Exclusion Criteria:

  • Active systemic illness (e.g. chronic kidney disease, hypertension)
  • Pre-pregnancy diabetes mellitus
  • Multiple gestation, major fetal anomaly, or non-viable pregnancy on ultrasound
  • Fasting glucose ≥ 100 mg/dL or HbA1c ≥ 5.7% in early pregnancy
  • One abnormal value on the 3-hour 100 g oral glucose tolerance test
  • Glucose at least 190 mg/dL on glucose challenge testing without subsequent 3-hour oral glucose tolerance testing
  • Use of medication affecting glucose metabolism before pregnancy or in early pregnancy
  • Use of glucose-lowering medication (e.g. metformin, glyburide) other than insulin to treat gestational diabetes mellitus in the current pregnancy
  • History of upper gastrointestinal surgery that alters gastric emptying (e.g. bariatric surgery)
  • Hemoglobin < than 11 g/dL

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Women With Gestational Diabetes Mellitus
Pregnant participants diagnosed with gestational diabetes mellitus who complete pregnancy and postpartum metabolic study visits.
Drug: Exendin 9-39
Exendin 9-39 will be administered during one postpartum study day as an intravenous infusion at 300 pmol/kg/min for 4 hours, beginning 60 minutes before the graded glucose infusion and continuing through the end of the 180-minute glucose infusion study period
Experimental: Women Without Gestational Diabetes Mellitus
Pregnant participants without gestational diabetes mellitus, matched to the gestational diabetes group by parity, age, ethnicity, gestational week at diagnosis comparator timepoint, and first trimester body mass index.
Drug: Exendin 9-39
Exendin 9-39 will be administered during one postpartum study day as an intravenous infusion at 300 pmol/kg/min for 4 hours, beginning 60 minutes before the graded glucose infusion and continuing through the end of the 180-minute glucose infusion study period

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
G50
Time Frame: During pregnancy at approximately 26 to 32 weeks gestation and during the postpartum period at approximately 6 weeks to 3 months after delivery.
The change in glucose concentration necessary to suppress glucagon secretion rate by 50%. A measurement of α-cell function.
During pregnancy at approximately 26 to 32 weeks gestation and during the postpartum period at approximately 6 weeks to 3 months after delivery.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Glucagon Secretion Rate
Time Frame: During pregnancy at approximately 26 to 32 weeks gestation and during the postpartum period at approximately 6 weeks to 3 months after delivery.
The amount of glucagon produced over time expressed as pmol/min. A measurement of α-cell function.
During pregnancy at approximately 26 to 32 weeks gestation and during the postpartum period at approximately 6 weeks to 3 months after delivery.
delta insulin secretion rate/delta glucose
Time Frame: During pregnancy at approximately 26 to 32 weeks gestation and during the postpartum period at approximately 6 weeks to 3 months after delivery.
This measurement quantifies the change in insulin secretion in response to rising glucose concentrations. it is a surrogate of β-cell function. Insulin secretion rate will be calculated from C-peptide concentrations using nonparametric deconvolution and population-based measures of C-peptide kinetics.
During pregnancy at approximately 26 to 32 weeks gestation and during the postpartum period at approximately 6 weeks to 3 months after delivery.
β-Cell responsivity (Φ)
Time Frame: During pregnancy at approximately 26 to 32 weeks gestation and during the postpartum period at approximately 6 weeks to 3 months after delivery.
This index quantifies the relationship between fasting glucose and fasting insulin secretion rate. This will allow us to assess and quantify fasting β-cell function.
During pregnancy at approximately 26 to 32 weeks gestation and during the postpartum period at approximately 6 weeks to 3 months after delivery.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Mayo Clinic

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Aoife Egan, MB, BCh, PhD, Mayo Clinic

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 1, 2030

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2030

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 1, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 4, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 8, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 4, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 26-007703
  • 1R01DK148528-01 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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