Type 1 Diabetes | Effect of Gain on Closed-Loop Insulin

Type 1 Diabetes research study

What is the primary objective of this study?

The purpose of this study is to test the ability of an advanced external Physiologic Insulin Delivery (ePID) algorithm (a step by step process used to develop a solution to a problem) to get acceptable meal responses over a range of gain. Gain is defined as how much insulin is given in response to a change in a patient's glucose level. This study also examines the effectiveness of the external Physiologic Insulin Delivery (ePID) closed-loop insulin delivery computer software. The investigators would like to assess whether fasting target levels can be achieved as the closed-loop gain increases or decreases, and to evaluate the system's ability to produce an acceptable breakfast meal response.

Who is eligible to participate?

Inclusion Criteria: - Type 1 diabetes for > 3 years - Manage diabetes using a continuous glucose monitor and continuous subcutaneous insulin infusion pump - Non obese (BMI < 30) - Aged 18 - 75 years old - HbA1c < 8 % Exclusion Criteria: - renal or hepatic failure - cancer or lymphoma - Malabsorption or malnourishment - Mypercortisolism - Alcoholism or drug abuse - Anemia (hematocrit < 36 in females and <40 in males) - Eating disorder - Dietary restrictions - Acetaminophen allergy - Chronic acetaminophen use - Glucocorticoid therapy - History of Gastropareisis - Use of Beta blockers

Which medical condition, disease, disorder, syndrome, illness, or injury is researched?

Type 1 Diabetes

Study Interventions

Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.

Device:Gain (reference)The latest revision of the PID algorithm to verify that the scaling factor used to set KP as a function of TDD is robust to the changes in gain and target resulting from over- or under-calibration of the glucose sensor.

Device:Gain decreased by a factor 0.8

Device:Gain increased by a factor 1.33

Study Arms

Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.

Gain increase or decreaseDecrease insulin gain by a factor 0.8 and the target increased by 1/0.8 or gain increased by a factor 1.33 with the target lowered by a factor 1/1.33

Study Status


Start Date: December 2013

Completed Date: April 2015

Phase: N/A

Type: Interventional


Primary Outcome: Glucose Area Under the Curve (AUC) Breakfast

Secondary Outcome: Peak and nadir postprandial glucose concentration

Study sponsors, principal investigator, and references

Principal Investigator: Howard Wolpert, MD

Lead Sponsor: Joslin Diabetes Center

Collaborator: Juvenile Diabetes Research Foundation

More information:

Steil GM, Panteleon AE, Rebrin K. Closed-loop insulin delivery-the path to physiological glucose control. Adv Drug Deliv Rev. 2004 Feb 10;56(2):125-44. Review.

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