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
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
Treatments tested in this trial
- Insulin regular, 2.0-3.2 mU/m2/min (euinsulinemia)
- Insulin regular, 32 mU/m2/min (hyperinsulinemia)
- Octreotide Acetate, 6-45 ng/kg/min
- Dextrose 20 % in Water
- Glucagon, 0-0.5 ng/kg/min
Treatment groups
Sponsors and collaborators
Columbia University
Lead sponsor
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Collaborator
University of Pisa
Collaborator