Diabetes Assistant (DiAs) Control-to-Range (CTR) Nocturnal Closed-Loop Camp Study

The primary goal is to test the function of the Diabetes Assistant (DiAs) enhanced control-to-range (CTR) controller in a closely monitored diabetes camp setting. The camp setting will allow us to obtain pilot efficacy data.

Study Overview

• Status: Completed
• Conditions: Diabetes Mellitus, Type 1
• Intervention / Treatment: Device: Diabetes Assistant (DiAs); Device: Tandem t:slim Insulin Pump; Device: Dexcom G4 Platinum sensor

Detailed Description

The first phase of this study will test the feasibility of initializing the DiAs CTR system in a clinical research center. We will test the procedures that will occur with the camp studies, from consenting the subjects, obtaining morning glucose readings, initializing the sensor in the early afternoon, having some light activity in the evening, a bedtime snack, and initializing the closed-loop system within 30 minutes before they go to bed. We will also test how the system performs using the same calibration and blood glucose monitoring that will be done at camp. In the inpatient study we will mimic some camp activities by having the subjects have 20-30 minutes of aerobic activity in the afternoon and in the evening after dinner. The data from the inpatient studies will be reviewed by the Data Safety Monitoring Board (DSMB) before we proceed with the Phase 2 summer camp studies.

The second phase of this proposal is the "in-camp" studies. The same health care providers that conducted the inpatient studies will be conducting the camp studies. They will be monitoring all campers on closed-loop control in real-time. Participants will be randomized to either closed-loop (experimental) or sensor-augmented therapy (control) for the first night and then crossed over every other night to the other therapy over the course of the 5- to 6-day camp session (i.e. on DiAs CTR every other night). Those assigned to DiAs CTR control will be remotely monitored throughout the night. Those assigned to the control group will not have remote monitoring overnight, but they will be wearing a Dexcom G4Platinum sensor with active low and high sensor glucose alarms. Initial studies will be done at a camp with older children and camp staff who are aged 15-35 years of age, with at least 5 subjects between 15 to 18 years old. If these studies are safe (after DSMB review) we will do additional camps and include children 10-14 years old.

• Study Type: Interventional
• Enrollment (Actual): 32
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Los Gatos, California, United States, 95032
      • Stanford University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 10 years to 35 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Clinical diagnosis of type 1 diabetes and using daily insulin therapy for at least one year and a Medtronic, Animas or Tandem insulin infusion pump for at least 3 months
2. The diagnosis of type 1 diabetes is based on the investigator's judgment; C peptide levels and antibody determinations are not required.
3. Age 10.0 - 35 years
4. Willingness to use a Sure-T or Contact Detach infusion set while at camp

Exclusion Criteria:

1. Diabetic ketoacidosis in the past month
2. Hypoglycemic seizure or loss of consciousness in the past 3 months
3. History of seizure disorder (except for hypoglycemic seizure)
4. Using an OmniPod insulin infusion pump
5. History of any heart disease including coronary artery disease, heart failure, or arrhythmias
6. Cystic fibrosis
7. Current use of oral/inhaled glucocorticoids, beta-blockers or other medications, which in the judgment of the investigator would be a contraindication to participation in the study.
8. History of ongoing renal disease (other than microalbuminuria).
9. Insulin pump users who supplement with injected intermediate or long acting insulin.
10. Subjects who take other anti-diabetic medications other than insulin..
11. Medical or psychiatric condition that in the judgment of the investigator might interfere with the completion of the protocol such as:
12. Inpatient psychiatric treatment in the past 6 months
13. Uncontrolled adrenal disorder
14. Abuse of alcohol
15. Pregnancy (verbal denial of pregnancy obtained with telephone informed consent, pregnancy test performed at camp before study devices are assigned).
16. Sexually active females who do not practice acceptable contraceptive methods to prevent pregnancy.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Closed-Loop Control with DiAs System; Subjects will use the Diabetes Assistant (DiAs) and will wear a Tandem t:slim insulin pump and a Dexcom G4 Platinum sensor with active low and high sensor glucose alarms. Subjects will be remotely monitored throughout the night in real time.	Device: Diabetes Assistant (DiAs); The Control-to-Range (CTR) algorithm that will be used in DiAs will automatically adjusts insulin delivery in response to CGM values that have exceeded or are predicted to exceed the bounds of a pre-specified blood glucose range.; Device: Tandem t:slim Insulin Pump; FDA, market-approved insulin pump.; Device: Dexcom G4 Platinum sensor; FDA, market-approved continuous glucose monitor (CGM)
Placebo Comparator: Control Group, Sensor-Augmented Pump Therapy; Subjects will wear a Tandem t:slim insulin pump and a Dexcom G4 Platinum sensor with active low and high sensor glucose alarms. They will not use the Diabetes Assistant (DiAs) nor have remote monitoring.	Device: Tandem t:slim Insulin Pump; FDA, market-approved insulin pump.; Device: Dexcom G4 Platinum sensor; FDA, market-approved continuous glucose monitor (CGM)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percent Time Near Normoglycemia	Percent of time in a glucose target range of 70-150 mg/dl during camp study. Participants were randomized to either closed-loop (experimental) or sensor-augmented pump therapy (control) for the first night and then crossed over every other night to the other therapy over the course of the 5- to 6-day camp session. Thus there were ~60 nights of data for each intervention. However, data from closed-loop nights during which there were technical problems such as infusion set failure, sensor error >20%, or pump failure resulting in a >60-min interruption to closed-loop control were removed to allow for analysis of algorithm performance. Only nights with a minimum of 5 hours of closed-loop were included, and all glucose data were included in the analysis. For comparison, only data from nights during which sensor error was, <20% with a minimum of 5 hours were included in the control group.	6 nights

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overnight Glucose	Mean overnight glucose during camp study. Participants were randomized to either closed-loop (experimental) or sensor-augmented pump therapy (control) for the first night and then crossed over every other night to the other therapy over the course of the 5- to 6-day camp session. Thus there were ~60 nights of data for each intervention. However, data from closed-loop nights during which there were technical problems such as infusion set failure, sensor error >20%, or pump failure resulting in a >60-min interruption to closed-loop control were removed to allow for analysis of algorithm performance. Only nights with a minimum of 5 hours of closed-loop were included, and all glucose data were included in the analysis. For comparison, only data from nights during which sensor error was, <20% with a minimum of 5 hours were included in the control group.	6 nights
Glycemic Events	Number of nights with >= 1 hypo- and hyperglycemic event occurring overnight during the camp study. Participants were randomized to either closed-loop (experimental) or sensor-augmented pump therapy (control) for the first night and then crossed over every other night to the other therapy over the course of the 5- to 6-day camp session. Thus there were ~60 nights of data for each intervention. However, data from closed-loop nights during which there were technical problems such as infusion set failure, sensor error >20%, or pump failure resulting in a >60-min interruption to closed-loop control were removed to allow for analysis of algorithm performance. Only nights with a minimum of 5 hours of closed-loop were included, and all glucose data were included in the analysis. For comparison, only data from nights during which sensor error was, <20% with a minimum of 5 hours were included in the control group.	6 nights

Collaborators and Investigators

• Sponsor: University of Virginia
• Collaborators: Stanford University
• Investigators: Principal Investigator: Marc Breton, PhD, University of Virginia Center for Diabetes Technology

Publications and helpful links

General Publications

• Ly TT, Breton MD, Keith-Hynes P, De Salvo D, Clinton P, Benassi K, Mize B, Chernavvsky D, Place J, Wilson DM, Kovatchev BP, Buckingham BA. Overnight glucose control with an automated, unified safety system in children and adolescents with type 1 diabetes at diabetes camp. Diabetes Care. 2014 Aug;37(8):2310-6. doi: 10.2337/dc14-0147. Epub 2014 May 30.

Study record dates

Study Major Dates

• Study Start: July 1, 2013
• Primary Completion (Actual): August 1, 2013
• Study Completion (Actual): August 1, 2013

Study Registration Dates

• First Submitted: October 24, 2013
• First Submitted That Met QC Criteria: October 24, 2013
• First Posted (Estimate): October 31, 2013

Study Record Updates

• Last Update Posted (Estimate): April 24, 2015
• Last Update Submitted That Met QC Criteria: April 3, 2015
• Last Verified: April 1, 2015

More Information

Terms related to this study

• Keywords: Artificial Pancreas Project; Diabetes Assistant (DiAs); Autoimmune Diabetes; Diabetes Mellitus, Type 1; Insulin pump therapy; Continuous Glucose Monitors (CGM); Juvenile-Onset Diabetes; Closed-to-Range
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Immune System Diseases; Autoimmune Diseases; Endocrine System Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 1; Hypoglycemic Agents; Physiological Effects of Drugs; Insulin
• Other Study ID Numbers: 001-Stanford