Recruiting

KATP Channel Loss

Sponsor:

Washington University School of Medicine

Code:

NCT06830096

Conditions

Obesity and Type 2 Diabetes

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Accepted

Interventions

10 mg glipizide ingestion

Study Details

Brief summary:

Insulin is a hormone that is made by β-cells in the pancreas and when released into the bloodstream helps control blood sugar levels. Insulin release is regulated by electrical activity in the β-cell which is generated by the ATP-sensitive potassium (KATP) channel. While reduced KATP activity is associated with increased insulin secretion, animals lacking KATP exhibit reduced secretion. This crossover from hypersecretion to undersecretion with KATP loss mirrors insulin secretion during type 2 diabetes. Intriguingly, evidence from cell and animal models suggest that chronically stimulated β-cells can lose KATP revealing a possible role for KATP loss in the failure of insulin secretion and poor control of blood sugar observed in type 2 diabetes. This study will therefore examine insulin responses following ingestion of a single dose of a sulfonylurea called glipizide that inhibits KATP channels in people with and without type 2 diabetes. The goal is to determine whether KATP channel activity is reduced during type 2 diabetes progression.

Conditions

Obesity and Type 2 Diabetes

Study ID

NCT06830096

Start date

Mar 7, 2025

Status verified date

Aug, 2026

Completion date

Mar 31, 2027

Anticipated

Primary completion date

Dec 31, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Lean-normoglycemic group (n=10): BMI ≥18.5 and <25.0 kg/m², fasting plasma glucose concentration <95 mg/dl, 2-hr oral glucose tolerance test plasma glucose concentration ≤140-mg/dl, and hemoglobin A1C (HbA1C) ≤5.6%.
  • Obesity-normoglycemic group (n=10): BMI ≥30 and <50 kg/m², fasting plasma glucose concentration <95 mg/dl, 2-hr oral glucose tolerance test plasma glucose concentration ≤140 mg/dl, and hemoglobin A1C (HbA1C) ≤5.6%.
  • Obesity-impaired fasting glucose group (n=10): BMI ≥30 and <50 kg/m², fasting plasma glucose concentration 100-125 mg/dl, and 2-hr oral glucose tolerance test plasma glucose concentration <200 mg/dl.
  • Obesity-type 2 diabetes group (n=10): BMI ≥30 and <50 kg/m²; HbA1C 6.5-9.5%, fasting plasma glucose ≥126 mg/dl, 2-hr oral glucose tolerance test plasma glucose concentration ≥200 mg/dl and/or medical history of T2DM and currently using anti-diabetic medications.

Exclusion Criteria:

  • Diabetes therapy with insulin at >0.5 units/kg/day.
  • Any change in diabetes medication in previous 3 months.
  • Unstable weight (>2% change during the last 2 months before entering the study).
  • Evidence of significant organ system dysfunction or disease other than obesity and T2D.
  • Regular use of tobacco products.
  • Excessive consumption of alcohol (≥3 drinks/day for men and ≥2 drinks/day for women).
  • Use of medications that are known to affect the study outcome measures (e.g., steroids, non-statin lipid-lowering medications) or increase the risk of study procedures (e.g., anticoagulants) and that cannot be temporarily discontinued for this study.
  • Anemia (Hemoglobin <10.0 g/dL).
  • Pregnant or breastfeeding.
  • Unable or unwilling to follow the study protocol or for any reason the research team believes the volunteer is not an appropriate candidate for this study, including non-compliance with screening appointments or previous medical visits.

Study Design

Enrollment

40 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Lean with normal glucose tolerance

Body mass index ≥18.5 and <25.0 kg/m², fasting plasma glucose concentration <95 mg/dl, 2-hr oral glucose tolerance test plasma glucose concentration ≤140-mg/dl, and hemoglobin A1C (HbA1C) ≤5.6%.

experimental: Obesity with normal glucose tolerance

Body mass index ≥30 and <50 kg/m², fasting plasma glucose concentration <95 mg/dl, 2-hr oral glucose tolerance test plasma glucose concentration ≤140 mg/dl, and hemoglobin A1C (HbA1C) ≤5.6%.

experimental: Obesity with impaired fasting glucose

Body mass index ≥30 and <50 kg/m², fasting plasma glucose concentration 100-125 mg/dl, and 2-hr oral glucose tolerance test plasma glucose concentration <200 mg/dl.

experimental: Obesity with type 2 diabetes

Body mass index ≥30 and <50 kg/m²; HbA1C 6.5-9.5%, fasting plasma glucose ≥126 mg/dl, 2-hr oral glucose tolerance test plasma glucose concentration ≥200 mg/dl and/or medical history of type 2 diabetes and currently using anti-diabetic medications.

Interventions

10 mg glipizide ingestion

A single dose of 10 mg glipizide will be ingested

Primary outcome measure

  • Insulin secretion [ Time Frame: 90 minutes after glipizide ingestion ]

Central Contacts and Locations

Central contacts

Kyle Timmons

314-273-1879nutritionresearch@wustl.edu

Locations

Washington University in St. Louis

Recruiting

St Louis, Missouri, United States, 63110

Contacts

Kyle Timmons

314-362-8699timmons@wustl.edu

Principal Investigator:

Nathaniel York, PhD

More Information

Sponsor

Washington University School of Medicine

Last update posted

Aug 10, 2026

Last verified

Aug, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Washington University School of Medicine on 2026-08-10.