How pancreatic (islet) GLP-1 affects blood sugar in prediabetes

The Role of Islet GLP-1 in the Pathogenesis of Prediabetes

Phase 2 Interventional Mayo Clinic · NCT06967558

We will test whether blocking the GLP-1 receptor changes insulin and glucagon release and fasting glucose in people with prediabetes.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment60 (estimated)
Ages25 Years to 70 Years
SexAll
SponsorMayo Clinic Academic / other
Locations1 site (Rochester, Minnesota)
Trial IDNCT06967558 on ClinicalTrials.gov

What this trial studies

This Phase 2 interventional trial uses a GLP-1 receptor blocker (exendin 9-39) versus saline to probe the role of endogenous islet GLP-1 in people with impaired fasting glucose or impaired glucose tolerance. Participants undergo metabolic testing including a 75 g oral glucose tolerance test and measures of islet hormone responses to determine effects on fasting glucose and alpha- and beta-cell function. The protocol enrolls adults 25–70 years old with prediabetes, stable weight, and no use of glucose-lowering drugs, and excludes those with prior major upper abdominal surgery, active illness or symptomatic vascular disease. All study procedures are performed at the Mayo Clinic in Rochester, Minnesota.

Who should consider this trial

Good fit: Adults aged 25–70 with prediabetes (impaired fasting glucose or impaired glucose tolerance), stable weight, fasting glucose under 126 mg/dL, 2-hour OGTT under 200 mg/dL, and not taking glucose-lowering medications are ideal candidates.

Not a fit: People with established type 2 diabetes, those taking glucose-lowering drugs, those outside the 25–70 age range, or with active systemic illness or prior qualifying upper abdominal surgery are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, the results could identify whether intra-islet GLP-1 helps maintain normal insulin and glucagon responses and point to new prevention strategies for progression to type 2 diabetes.

How similar studies have performed: Previous human and animal studies have shown that GLP-1 receptor blockade alters islet function—effects that were pronounced in early type 2 diabetes—but the role of this mechanism in prediabetes remains largely untested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* People with stable weight and no history of diabetes.
* Fasting glucose \< 126 mg/dL
* 2hr glucose after 75g OGTT \< 200 mg/dL

Exclusion Criteria:

* Age \< 25 or \> 70 years (to avoid studying subjects who could have latent type 1 diabetes, or the effects of age extremes in subjects with normal or impaired fasting glucose).
* HbA1c \> 6.5%
* Use of any glucose-lowering agents including metformin or sulfonylureas.
* For female subjects: positive pregnancy test at the time of enrollment or study
* History of prior upper abdominal surgery such as adjustable gastric banding, pyloroplasty and vagotomy.
* Active systemic illness or malignancy.
* Symptomatic macrovascular or microvascular disease.

Where this trial is running

Rochester, Minnesota

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions PreDiabetesImpaired Fasting GlucoseImpaired Glucose ToleranceGLP-1
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.