Islet Function in Gestational Diabetes

The purpose of this research is to understand how the function of the human pancreas changes during and after pregnancy.

Study Overview

• Status: Recruiting
• Conditions: Gestational Diabetes Mellitus
• Intervention / Treatment: Drug: Exendin 9-39

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Jeanette Laugen; Phone Number: 507-255-8110; Email: laugen.jeanette@mayo.edu
• Study Contact Backup: Name: Amy Zipse; Phone Number: 507-255-9278; Email: zipse.amy@mayo.edu

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

Eligibility Criteria

• 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

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
G50	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

Outcome Measure	Measure Description	Time Frame
Glucagon Secretion Rate	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	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)	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

• Sponsor: Mayo Clinic
• Collaborators: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
• Investigators: Principal Investigator: Aoife Egan, MB, BCh, PhD, Mayo Clinic

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): March 1, 2030
• Study Completion (Estimated): December 1, 2030

Study Registration Dates

• First Submitted: September 1, 2026
• First Submitted That Met QC Criteria: September 4, 2026
• First Posted (Actual): September 8, 2026

Study Record Updates

• Last Update Posted (Actual): September 8, 2026
• Last Update Submitted That Met QC Criteria: September 4, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Endocrine System Diseases; Female Urogenital Diseases and Pregnancy Complications; Metabolic Diseases; Pregnancy Complications; Glucose Metabolism Disorders; Diabetes Mellitus; Nutritional and Metabolic Diseases; Diabetes, Gestational; exendin (9-39)
• Other Study ID 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