Recruiting

Observational Study

Sponsor:

Pennington Biomedical Research Center

Code:

NCT04207619

Conditions

Diabetes

Hypoglycemia

Eligibility Criteria

Sex: All

Age: 18 - 40

Healthy Volunteers: Accepted

Interventions

hyperinsulinemic-hypoglycemic clamp

13C-MRS procedure/Acetate infusion

Study Details

Brief summary:

Hypoglycemic complications are a major impediment to the maintenance of healthy glucose levels in persons with diabetes. The investigators recently completed a clinical pilot and feasibility study (GLIMPSE, NCT02690168), which identified a novel biomarker, glial acetate metabolism, that appears to predict the susceptibility to hypoglycemia. By providing an assay to predict hypoglycemic events and therefore diabetic complications, the development of this biomarker could significantly improve the treatment of persons with diabetes.

The goal of this study is to determine the efficacy of our biomarker for predicting susceptibility to insulin-induced hypoglycemia. In order to accomplish this goal the investigatiors will pair our 13C magnetic resonance spectroscopy procedure to assess glial acetate metabolism, developed in the GLIMPSE study, with a hyperinsulinemic-hypoglycemic clamp procedure, developed in the HYPOCLAMP study (NCT03839511). The two procedures will be separated by a three day interval. The investigators will then correlate the participants' rates of glial acetate metabolism with their neuroendocrine responses to the hypoglycemic clamp. This proof of concept study will test the hypothesis that glial acetate metabolism is inversely proportional to the neuroendocrine response to hypoglycemia, that is, as glial acetate metabolism increases the neuroendocrine response will decrease.

Conditions

Diabetes

Hypoglycemia

Study ID

NCT04207619

Start date

Feb 19, 2020

Status verified date

Jul, 2025

Completion date

Sep, 2026

Anticipated

Primary completion date

Jun, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 40

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Healthy male or female
  • Ages 18-40 years
  • BMI between 20 kg/m2 and 30 kg/m2 (±0.5 kg/m2 will be accepted)
  • Medically cleared for participation in the study

Exclusion Criteria:

  • Contraindication to MRI
  • Consume >10 alcoholic drinks/week
  • History of chronic smoking or have quit less than 10 years ago
  • History of clinically diagnosed diabetes or a fasting blood glucose >126 mg/dL
  • Average screening blood pressure >140/90 mmHg
  • History of cardiovascular disease
  • Pregnant, planning to become pregnant, or breastfeeding
  • Use of medications affecting glucose metabolism, e.g., benzodiazepines, thiazide diuretics, cortisone, and prednisone.
  • Use of beta-adrenergic antagonists.
  • Based on the investigative team's clinical judgement, a subject may not be appropriate for participation in the study.

Study Design

Enrollment

10 participants

Anticipated

Intervention Model

Single group

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Arm 1

Participants will have their glial acetate metabolism measured by carbon-13 magnetic resonance spectroscopy as well as their neuroendocrine response to hypoglycemia 3 days later.

Interventions

hyperinsulinemic-hypoglycemic clamp

An intravenous catheter will be placed in an antecubital vein for infusion of insulin and glucose. A second catheter will be placed retrograde in a dorsal vein of the contra-lateral hand for blood withdrawal. The hand will be placed in a heating box or pad at 70°C for arterialization of venous blood. A primed infusion of regular insulin (120 mU/min/m2) will be initiated and continued for approximately 2 hours. Beginning 20 minutes prior to the start of the insulin infusion, arterialized venous blood glucose will be measured at 5 minute intervals via a Hemocue or YSI analyzer. Following initiation of insulin infusion, blood glucose will be allowed to fall to 50 mg/dL and then maintained at this level using a variable infusion of exogenous dextrose (20% solution). Our goal is to achieve steady-state (blood glucose stabilized at 50 +/- 5 mg/dL) within the first 45 minutes following the start of insulin infusion.

13C-MRS procedure/Acetate infusion

Glial metabolism will be measured via MRS utilizing a simultaneous intravenous infusion of 13C labeled acetate. An intravenous catheter will be placed in a vein of each arm, one to infuse 13C-acetate and the other to draw blood samples

Primary outcome measure

  • Percent 13C enrichment of bicarbonate measured via carbon-13 magnetic resonance spectroscopy (13C-MRS) [ Time Frame: Every ten minutes for 120 minutes following administration of 1-13C acetate ]

Central Contacts and Locations

Central contacts

Amber Dragg

225-763-3050amber.dragg@pbrc.edu

Bethany Gildersleeve

225-763-2709Bethany.Gildersleeve@pbrc.edu

Locations

Pennington Biomedical Research Center

Recruiting

Baton Rouge, Louisiana, United States, 70808-4124

Contacts

Department of Recruiting

225-763-3000recruiters@pbrc.edu

More Information

Sponsor

Pennington Biomedical Research Center

Last update posted

Jul 24, 2025

Last verified

Jul, 2025

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Pennington Biomedical Research Center on 2025-07-24.