The objective of this pilot study is (i) to test the use of an Artificial Pancreas (AP) System as a viable therapy treatment for two vulnerable populations: 6 to 10 year-old and adults older ≥65 years old with T1D; (ii) to assess cognitive function in children and older adult patients with T1D and examine whether improved glycemic control defined by stable (more than 70% of the day in glycemic range 70-180 mg/dL) control positively influences cognitive function; and (iii) obtain preliminary data to apply to funds to continue with larger and longer clinical trials.

This study will evaluate up to 15 subjects in each age group for a period of 8-10 weeks performing neurocognitive tests before and after each intervention. The first study phase will be up to 2 weeks of a training period to allow participants to get acquainted with the use of the CGM if they are not familiar with the use of the device. This training period will be followed by a 4-week sensor-augmented pump (SAP) period using a study CGM and the subject's personal insulin pump. The subjects will return to clinic at the completion of the SAP period and will be trained on the Tandem t:slim X2 with Control-IQ and G6 CGM. At the completion of the system training session, subjects will begin 4-weeks of Closed-Loop Control (CLC). Questionnaires will be completed by the study subject at screening, after completion of SAP and after completion of CLC. Ecological Momentary Assessments (EMAs) and actigraphy data will be collected in the last 14 days of the SAP and CLC periods.

A parent/guardian of the enrolled children will also be asked to participate in all trainings, complete parental Patient-Report Outcomes (PRO) Questionnaires, and collect sleep patterns while wearing the actigraph watch.

Inclusion Criteria:

• Clinical diagnosis, based on investigator assessment, of type 1 diabetes for at least one year, using insulin for at least 1 year and using an insulin pump for at least 6 months.
• Familiarity and use of a carbohydrate ratio for meal boluses by participants and families participating.
• Age 6-10 years old or 65 years or older
• Hemoglobin A1c <10%
• For females of child-bearing potential, not currently known to be pregnant:

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.
• Willing to disable any automated insulin delivery functionality on a personal insulin pump during study, such as Medtronic 670G in auto mode. Predictive low blood glucose suspend, such as Tandem insulin pump with Basal-IQ, will be allowed.
• Investigator has confidence that the participant and family can successfully operate all study devices and is capable of adhering to the protocol.
• Willingness to switch to lispro (Humalog) or aspart (Novolog) 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:

• Severe hypoglycemia resulting in seizure or loss of consciousness in the 12 months prior to enrollment.
• Diagnosis of Diabetic Ketoacidosis in the 12 months prior to enrollment.
• Uncontrolled cardiac disease (e.g. recent myocardial infarction, severe congestive heart failure).
• Cerebrovascular accident in the 12 months prior to enrollment.
• Uncontrolled resting arterial hypertension (>160/90 mm Hg).
• Conditions that would make use of a CGM difficult (e.g., blindness, severe arthritis, immobility).
• Current use of oral/inhaled glucocorticoids or other medications, which in the judgment of the investigator would be a contraindication to participation in the study.
• Concurrent use of any non-insulin glucose-lowering agent other than metformin (including GLP-1 agonists, pramlintide, 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 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.

Will follow the NIH Data Sharing Policy and Implementation Guidance on sharing research resources for research purposes to qualified individuals within the scientific community.

Generally after publications are complete.

Will follow data sharing policy.

Duration of trial: approximately 10 weeks

Adverse Event Collection was obtained for Older Adults and Children who were on the investigational CLC device. It was not obtained for parents who were not on the investigational CLC device.