Health TrialsbyHealthPanel

Graded Insulin Suppression Test P&F

ConditionsInsulin ResistanceHyperinsulinemiaObesityHealthy
Trial statusRecruiting
Trial phasePhase 1
Trial typeInterventional
Biological sexAll
Age18-65
SponsorColumbia University

About this trial

The goal of this study is to learn about how the hormone insulin controls blood sugar in a variety of people. The main question it aims to answer is about how much insulin the body actually needs to maintain a normal blood sugar level. Participants will be asked to come in for a one-day study visit in which they will undergo a "graded insulin suppression test" ("GIST"). The GIST involves intravenous (into the vein) infusions of octreotide, a medication that turns off the body's own production of insulin, as well as replacement of insulin at two different levels (low and high), with or without replacement of glucagon, and glucose (sugar). The study investigators will check blood sugar levels every few minutes during the procedure to determine the effect of the two different insulin levels. This study will evaluate the GIST in both healthy volunteers and those at higher risk for type 2 diabetes.

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

Body mass index of 18-25 and 30-45 kg/m2

Able to understand written and spoken English and/or Spanish

Fasting euinsulinemia (fasting serum insulin of 4-10 μU/mL) for reference group or hyperinsulinemia (fasting serum insulin ≥ 13 μU/mL) for hyperinsulinemic group on screening labs

Written informed consent (in English or Spanish) and any locally required authorization (e.g., Health Insurance Portability and Accountability Act) obtained from the participant prior to performing any protocol-related procedures, including screening evaluations.

Disqualifiers

Unable to provide informed consent in English or Spanish

Unwillingness to use only bedpan or urinal to void or to refrain from non-emergent mobile device use during the GIST

Documented weight loss of ≥ 5% of baseline within the previous 6 months

Systolic blood pressure < 90 mm Hg or > 160 mm Hg, and/or

Trial design

Design model

Parallel

Treatments tested in this trial

  • Insulin regular, 2.0-3.2 mU/m2/min (euinsulinemia)

    Drug

    Insulin infusion to recapitulate euinsulinemia (normal basal insulin)

  • Insulin regular, 32 mU/m2/min (hyperinsulinemia)

    Drug

    Insulin infusion to induce hyperinsulinemia for assessment of insulin sensitivity

  • Octreotide Acetate, 6-45 ng/kg/min

    Drug

    Suppression of endogenous insulin secretion

  • Dextrose 20 % in Water

    Drug

    Production of steady-state plasma glucose (SSPG) reflective of insulin sensitivity at hyperinsulinemia

  • Glucagon, 0-0.5 ng/kg/min

    Drug

    Replacement of endogenous glucagon suppressed by octreotide. (Use is optional at the PI's discretion.)

Treatment groups

15 Participants
are divided into 3 treatment groups
Group A: Reference (healthy control) groupExperimental treatment 5 interventions
Group B: Euinsulinemic groupExperimental treatment 5 interventions
Group C: Hyperinsulinemic groupExperimental treatment 5 interventions

Trial outcomes

Primary outcomes

1

Steady-state plasma glucose at euinsulinemia (ESS-G)

Plasma glucose level at steady state while insulin infusion rate is 2 mU/m2/min (units: mg/dL)

Time frame
150-180 minutes during GIST protocol
2

Steady-state plasma glucose at hyperinsulinemia (HSS-G)

Plasma glucose level at steady state while insulin infusion rate is 32 mU/m2/min and glucose infusion rate is 267 mg/m2/min, reflective of insulin sensitivity (units: mg/dL)

Time frame
270-300 minutes during GIST protocol

Secondary outcomes

1

Product of steady-state glucose and insulin at euinsulinemia (ESS-G x I)

Product of plasma glucose and serum insulin levels while infusion rate is 2 mU/m2/min (units: mU/L x mg/dL)

Time frame
150-180 minutes during GIST protocol
2

Product of steady-state glucose and insulin at hyperinsulinemia (HSS-G x I)

Product of plasma glucose and serum insulin levels while infusion rate is 32 mU/m2/min (units: mU/L x mg/dL)

Time frame
270-300 minutes during GIST protocol
3

GIST index

Ratio of ESS-G x I to baseline steady state glucose x insulin product (BSS-G x I). Expect GIST index of approximately 1-2 in controls. GIST index below the control range suggests primary hyperinsulinemia, values within the control range for baseline-hyperinsulinemic subjects could be consistent either with mild insulin resistance or mixed primary + secondary hyperinsulinemia, and values above the control range are consistent with more significant insulin resistance (secondary hyperinsulinemia).

Time frame
150-180 minutes during GIST protocol

Other outcomes

1

Steady-state serum insulin at euinsulinemia (ESS-I)

Serum insulin level at steady state while insulin infusion rate is 2 mU/m2/min (units: mU/L)

Time frame
150-180 minutes during GIST protocol
2

Steady-state serum insulin at hyperinsulinemia (HSS-I)

Serum insulin level at steady state while insulin infusion rate is 32 mU/m2/min and glucose infusion rate is 267 mg/m2/min (units: mU/L)

Time frame
270-300 minutes during GIST protocol
3

Steady-state serum C-peptide level at euinsulinemia (ESS-C)

Serum C-peptide level while insulin infusion rate is 2 mU/m2/min (units: ng/mL)

Time frame
180 minutes during GIST protocol
4

Steady-state serum C-peptide level at hyperinsulinemia (HSS-C)

Serum C-peptide level while insulin infusion rate is 32 mU/m2/min (units: ng/mL)

Time frame
300 minutes during GIST protocol

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Columbia University

Lead sponsor

University of Pisa

Collaborator

Source ClinicalTrials.gov
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