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.

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.

Artificial Pancreas Project, Diabetes Mellitus, Type 1, Insulin pump therapy, Continuous Glucose Monitors (CGM), Juvenile-Onset Diabetes, Autoimmune Diabetes, Closed-to-Range, Diabetes Assistant (DiAs)

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.

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.

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.

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.

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.

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.

Inclusion Criteria: 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 The diagnosis of type 1 diabetes is based on the investigator's judgment; C peptide levels and antibody determinations are not required. Age 10.0 - 35 years Willingness to use a Sure-T or Contact Detach infusion set while at camp Exclusion Criteria: Diabetic ketoacidosis in the past month Hypoglycemic seizure or loss of consciousness in the past 3 months History of seizure disorder (except for hypoglycemic seizure) Using an OmniPod insulin infusion pump History of any heart disease including coronary artery disease, heart failure, or arrhythmias Cystic fibrosis 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. History of ongoing renal disease (other than microalbuminuria). Insulin pump users who supplement with injected intermediate or long acting insulin. Subjects who take other anti-diabetic medications other than insulin.. Medical or psychiatric condition that in the judgment of the investigator might interfere with the completion of the protocol such as: Inpatient psychiatric treatment in the past 6 months Uncontrolled adrenal disorder Abuse of alcohol Pregnancy (verbal denial of pregnancy obtained with telephone informed consent, pregnancy test performed at camp before study devices are assigned). Sexually active females who do not practice acceptable contraceptive methods to prevent pregnancy.

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.