CGM Intervention in Teens and Young Adults With Type 1 Diabetes (T1D)

Inclusion Criteria:

1. Clinical diagnosis of T1D, with either age of T1D diagnosis < 10 years of age OR a
history of positive T1D related antibodies in the medical record

2. Age 14-<25 years

3. Diabetes duration ≥ 1 year

4. Total daily insulin requirement ≥ 0.4 units/kg/day

5. HbA1c 7.5% to <11.0% (Point of care device or local lab measured as part of study at
screening visit)

6. Insulin regimen involves a consistent modality of insulin administration with either
use of an insulin pump or at least 3 multiple daily injections of basal and bolus
(meal time) analogue insulin. Insulin pump must not have been started within 3 months
of consent with no plans to change regimens in the next 6 months

7. Perform at least 2 blood glucose meter checks per day from self-report at screening
and an average of at least 2 checks per day from meter download during blinded CGM run
in

8. Blinded CGM must be used a minimum of 200 hours (equivalent to 8.3 days) with an
average of 1.8 calibrations per day during the blinded CGM screening period.

9. Participant comprehends written and spoken English

10. Participant understands the study protocol and agrees to it (if applicable)

Exclusion Criteria:

1. Use of unblinded personal CGM and/or flash CGM, outside of a research study, as part
of real-time diabetes management in the last 3 months

2. Unable to use CGM device for minimum number of hours during blinded pre-randomization
period or skin reaction from adhesive that would preclude participation in the
randomized trial

3. Started on non-insulin medication for blood glucose control within the past 3 months
or plans to begin within the next 6 months

4. The presence of a significant medical disorder that in the judgment of the
investigator will affect the wearing of the sensors (such as a skin condition), or the
completion of any aspect of the protocol.

5. More than 1 episode of DKA in the past 6 months as defined in the adverse events
chapter.

6. The presence of any of the following diseases:

- Asthma or any condition present in the last 6 months where treatment is a
systemic or daily inhaled corticosteroid (Intermittent treatment with inhaled
corticosteroids does not exclude subjects from enrollment)

- Cystic fibrosis

- Addison's disease (Adequately treated thyroid disease and celiac disease do not
exclude subjects from enrollment)

7. Inpatient psychiatric treatment in the past 6 months or daily intensive outpatient
psychiatric day treatment in the past 3 months.

8. Pregnant (positive test confirmed at screening) or planning to become pregnant in the
next 12 months.

9. Need for use of acetaminophen or acetaminophen-containing products on a regular basis
during the 6 months of the trial

10. Participation in a diabetes related intervention study in the past 6 weeks.

11. Any medical, psychological or social situation where per investigator discretion it
may be difficult for participant to participate fully in the intervention

12. Any condition, per investigator assessment, that could impact reliability of the A1C
measurement, such as (but not limited to) hemoglobinopathy, hemolytic anemia, chronic
liver disease; chronic GI blood loss, red blood cell transfusion or erythropoietin
administration within 3 months prior to screening