Effect of Pulsatile Hormone Administration on Insulin Action

Summary

In humans, insulin is secreted in pulses from the pancreatic beta-cells, and these oscillations help to maintain fasting plasma glucose levels within a narrow normal range. Given the fluctuations in insulin concentrations, oscillations enhance precision of control. The hyperinsulinemic euglycemic clamp test (clamp) involves a continuous infusion of insulin and is the gold standard for measuring insulin sensitivity. In this study, insulin sensitivity measured using the standard clamp will be compared with a clamp in which the same total amount of insulin as the standard clamp is infused every five minutes instead of continuously.

Detailed Description

Participants with obesity and insulin resistance completing a randomized, controlled, two-arm parallel trial (Motivate) will be enrolled in this cross-sectional study. Twelve participants from the Motivate study will return within two weeks to complete two clamp tests within a week of each other. At these clamps, the insulin will be infused continuously at a dose of 40mU/m2/min during the first clamp test and the same total amount of insulin will be infused every five minutes at the second clamp. The day following the clamps, participants will return to the clinic in a fasted state and blood will be drawn for measurement of glucose and insulin.

Eligibility Criteria

Interventions