The International Diabetes Closed Loop (iDCL) Trial: Clinical Acceptance of the Artificial Pancreas
- Conditions
- Type 1 Diabetes Mellitus
- Interventions
- Device: Sensor-augmented pump (SAP)
- Registration Number
- NCT03563313
- Lead Sponsor
- University of Virginia
- Brief Summary
The objective of the study is to assess efficacy and safety of a closed loop system (t:slim X2 with Control-IQ Technology) in a large randomized controlled trial.
- Detailed Description
After consent is signed, eligibility will be assessed. Eligible participants not currently using an insulin pump and Dexcom CGM with minimum data requirements will initiate a run-in phase of 2 to 8 weeks that will be customized based on whether the participant is already a pump or CGM user. Participants who skip or successfully complete the run-in will be randomly assigned 2:1 to the use of closed-loop control (CLC group) using t:slim X2 with Control-IQ Technology vs. SAP for 6 months.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 168
- Clinical diagnosis, based on investigator assessment, of type 1 diabetes for at least one year and using insulin for at least 1 year.
- Familiarity and use of a carbohydrate ratio for meal boluses.
- Age ≥14.0 years old.
- For females, not currently known to be pregnant. If female and sexually active, must agree to use a form of contraception to prevent pregnancy while a participant in the study. A negative serum or urine pregnancy test will be required for all females of child-bearing potential. Participants who become pregnant will be discontinued from the study. Also, participants who during the study develop and express the intention to become pregnant within the timespan of the study will be discontinued.
- For participants <18 years old, living with one or more parent/legal guardian knowledgeable about emergency procedures for severe hypoglycemia and able to contact the participant in case of an emergency.
- Willingness to suspend use of any personal CGM for the duration of the clinical trial once the study CGM is in use.
- Willingness to use a regular insulin pump during the study with no automatic insulin adjustment based on glucose level when assigned to participate in an SAP group
- Investigator has confidence that the participant can successfully operate all study devices and is capable of adhering to the protocol.
- Willingness to switch to lispro (Humalog) or aspart (Novolog) if not using already, and to use no other insulin besides lispro (Humalog) or aspart (Novolog) during the study.
- Total daily insulin dose (TDD) at least 10 U/day.
- Willingness not to start any new non-insulin glucose-lowering agent during the course of the trial.
Exclusion Criteria
- Concurrent use of any non-insulin glucose-lowering agent other than metformin (including GLP-1 agonists, Symlin, DPP-4 inhibitors, SGLT-2 inhibitors, sulfonylureas).
- Hemophilia or any other bleeding disorder.
- A condition, which in the opinion of the investigator or designee, would put the participant or study at risk.
- Participation in another pharmaceutical or device trial at the time of enrollment or during the study.
- Employed by, or having immediate family members employed by Tandem Diabetes Care, Inc. or TypeZero Technologies, LLC, or having a direct supervisor at place of employment who is also directly involved in conducting the clinical trial (as a study investigator, coordinator, etc.); or having a first-degree relative who is directly involved in conducting the clinical trial.
Not provided
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Sensor-Augmented Pump (SAP) Sensor-augmented pump (SAP) Participants randomized to sensor-augmented pump (SAP) will use an insulin pump with no automated insulin delivery and a study CGM (Dexcom G6) for 6 months.
- Primary Outcome Measures
Name Time Method Time in Target Range 26 weeks The primary outcome is time in target range 70-180 mg/dL measured by CGM in CLC group vs. SAP group.
- Secondary Outcome Measures
Name Time Method CGM Hypoglycemia Events 26 weeks CGM-measured events of at least 15 consecutive minutes \<70mg/dL per week
CGM Time >300 26 weeks CGM-measured % \>300 mg/dL
Number of Participants With HbA1c Improvement From Baseline to 26 Weeks >1.0% 26 weeks HbA1c improvement from baseline to 26 weeks \>1.0%
HbA1c at 26 Weeks 26 weeks Hemoglobin A1c measured at 26 weeks
Coefficient of Variability 26 weeks CGM measured glucose variability measured with the coefficient of variation (CV)
LBGI 26 weeks Low blood glucose index by CGM with higher index indicating higher risk of hypoglycemia. Values \<1 suggest minimal risk. Index of risk of low blood glucose excursion based on a standard formula for non-linear transformation of the blood glucose scale (Kovatchev BP, Cox DJ, Gonder-Frederick LA, Young-Hyman D, Schlundt D, Clarke WL: Assessment of risk for severe hypoglycemia among adults with IDDM: validation of the low blood glucose index. Diabetes Care 21:1870-1875, 1998)
CGM Time >250 26 weeks CGM-measured % \>250 mg/dL
Number of Participants With HbA1c <7.0% at 26 Weeks 26 weeks Number of participants HbA1c \<7.0% at 26 weeks
Basal:Bolus Insulin Ratio 26 weeks Basal:Bolus Insulin Ratio
CGM Time Below 54 26 weeks CGM-measured % below 54 mg/dL
CGM Time Below 60 26 weeks CGM-measured % below 60 mg/dL
BMI 26 weeks Body Mass Index (BMI) kg/m\^2
CGM Time in Range 70-140 mg/dL 26 weeks CGM-measured % in range 70-140 mg/dL
HBGI 26 weeks High blood glucose index by CGM with higher values indicating higher risk of hyperglycemia. Index of risk of high blood glucose excursion based on a standard formula for non-linear transformation of the blood glucose scale (Kovatchev BP, Cox DJ, Kumar A, Gonder-Frederick L, Clarke WL. Algorithmic evaluation of metabolic control and risk of severe hypoglycemia in type 1 and type 2 diabetes using self-monitoring blood glucose data. Diabetes Technol Ther 2003;5:817-828pmid:14633347)
Number of Participants With HbA1c Improvement From Baseline to 26 Weeks >0.5% 26 weeks HbA1c improvement from baseline to 26 weeks \>0.5%
HbA1c Relative Improvement From Baseline to 26 Weeks >10% 26 weeks HbA1c relative improvement from baseline to 26 weeks \>10%
CGM Time Above 180 26 weeks CGM-measured % above 180 mg/dL
CGM Mean Glucose 26 weeks CGM-measured mean glucose
HFS-II 26 weeks For adults, teens and parents items on this survey are rated on a 5 point Likert scale from never (0) to almost always (4). The survey is scored by summing item responses. Fear of Hypoglycemia Survey (HFS-II) for adults has a total score that is summed from the two subscale scores (33 items) and ranges from 0 to 132 with higher scores indicating greater degrees of fear of hypoglycemia. The teen survey has a total of 25 items and the range of Total scores is 0 to 100. The parent version of the survey has a total of 26 items with Total scores that range from 0 to 108.
Clarke Hypoglycemia Awareness Scores 26 weeks Clarke Hypoglycemia Awareness Scores (0-7 score with higher scores associated with impaired awareness)
System Usability Scores (SUS) 26 weeks System Usability Scores (SUS)-composite score from 0 to 100 with higher scores indicate better perceived usability
Technology Acceptance Questionnaire 26 weeks Technology Acceptance Survey measures the user's perceptions regarding the burdens and the barriers associated with a technology with a higher score indicates increased technology acceptance. There total score uses 37 items with items are rated on a 5 point scale ranging from 1 (strongly disagree) to 5 (strongly agree) for total score range of 37-185.
Total Daily Insulin 26 weeks Total Daily Insulin (units)
CGM Time Below 70 26 weeks CGM-measured % below 70 mg/dL
Standard Deviation of CGM 26 weeks CGM measured glucose variability measured with the standard deviation (SD)
Number of Participants With HbA1c <7.5% at 26 Weeks 26 weeks Number of Participants with HbA1c \<7.5% at 26 weeks
Number of Participants With HbA1c Improvement From Baseline to 26 Weeks >1.0% or HbA1c <7.0% at 26 Weeks 26 weeks HbA1c improvement from baseline to 26 weeks \>1.0% or HbA1c \<7.0% at 26 weeks
Hyperglycemia Avoidance Scale 26 weeks Hyperglycemia Avoidance Scale total score is the sum of 21 items rated on a 4 point Likert scale from 0 (never) to 4 (almost always) and ranges from 0 to 84 with a higher score indicating greater degrees of avoiding hyperglycemia.
Hypoglycemia Confidence Scale 26 weeks Hypoglycemia Confidence Scale has 20 items which are rated on a 4-point Likert Scale ranging from 1 (not confident at all) to 4 (very confident) with higher scores indicating higher confidence in dealing with hypoglycemia. A single score is computed by calculating the mean of the sum of all items and ranges from 1 to 4.
INSPIRE Survey Scores 26 weeks The INSPIRE questionnaire assesses user expectations and experiences with Insulin Delivery Systems: Perceptions, Ideas, Reflections, Expectations (INSPIRE). Survey total scores are computed by calculating the mean of the sum of all item ratings then multiplying the mean by 25 to scale the score to a range from 0 to 100. Higher scores indicate a more positive perception of insulin delivery systems. Items are rated on a 5 point Likert scale ranging from 0 (strongly disagree) to 4 (strongly agree). The Adult survey has 22 items, the Teens/Adolescents survey has 17 items and the Parent survey has 21 items.
Diabetes Distress Scale 26 weeks Diabetes Distress Scale for adults has 28 items rated on a 6 point Likert scale that ranges from 1 (not a problem) to 6 (a very serious problem). The total score is the mean of the sum of responses and ranges from 1 to 6 where a higher score indicates greater degrees of diabetes distress.
Weight 26 weeks Weight (kg)
Trial Locations
- Locations (7)
Sansum Diabetes Research Institute
🇺🇸Santa Barbara, California, United States
Stanford University
🇺🇸Stanford, California, United States
Barbara Davis Center, University of Colorado
🇺🇸Aurora, Colorado, United States
Harvard University (Joslin Diabetes Center)
🇺🇸Boston, Massachusetts, United States
Mayo Clinic
🇺🇸Rochester, Minnesota, United States
University of Virginia Center for Diabetes Technology
🇺🇸Charlottesville, Virginia, United States
Icahn School of Medicine at Mount Sinai
🇺🇸New York, New York, United States