The Performance of an Artificial Pancreas at Home in People With Type 1 Diabetes

The Impact of the Overnight Closed Loop System on Glycemia, Subsequent Day-time Metabolic Control, Insulin Delivery, Counter Regulatory Hormones, Sleep Quality, Cognition and Satisfaction With Treatment, Compared to Open Loop System (Sensor Augmented Pump Therapy) in Both the Clinical Trial Centre and in the Home Setting in Type 1 Diabetes

The overall aim of the study is to evaluate the performance of Artificial Pancreas or Closed Loop Glucose-Sensing Insulin-Delivery system in comparison to current best available technology represented by Sensor Augmented Pump Therapy (SAPT) in patients with Type 1 Diabetes.

At present, decisions regarding insulin dosing are made by the patient with intermittent support from their medical team. Even with glucose sensor augmented insulin pump therapy (SAPT), representing the most advanced technology currently available, there are emotional and intellectual demands placed upon the patient with the most well-educated, intelligent and diligent patients often unable to perfectly match insulin delivery with their varying requirements. SAPT does improve glycaemia in comparison with insulin pump therapy alone though a significant proportion of patients will still not meet target HbA1c (<7.0%). A Closed Loop (CL) system whereby a computerised algorithm reviews continuous glucose information to determine a T1D patient's insulin requirements and controls insulin delivery will potentially have a major impact upon acute and chronic complications of diabetes as well as upon their quality of life. Overnight glycaemic control, without the added challenge of meals, physical activity and stress, is a realistic initial application of CL in clinical practice.

This study aims to evaluate insulin pump therapy with an overnight CL system in comparison with current best available technology represented by SAPT in Type 1 Diabetes (T1D) patients, in both hospital and then at home. Outcomes of interest will include metabolic control and performance of the Medtronic CL overnight system compared with SAPT (OL), in both the Clinical Trials Centre (CTC) and in the home setting; the relationship between night-time and day-time metabolic control with CL and OL and nocturnal clinical, hormonal and inflammatory factors that may influence subsequent daytime metabolic control; anti-insulin antibody titres and dissociation constants (Rd) upon CL algorithm performance; sleep quality, cognition, satisfaction with treatment and psychological parameters.

A two phase randomised crossover study design is to be employed with the first phase conducted for a single night in the clinical trials centre and the second phase over 5 days in an ambulatory setting.

Inclusion Criteria:

• Adults aged greater than 14 years able to provide informed consent.
• T1 Diabetes for a minimum of 6 months (fasting C-peptide levels less than 50 pmol/L).
• HbA1c less than 8.5%.
• Experience with a continuous glucose sensor with established basal insulin infusion patterns, insulin to carbohydrate ratios, regular use of the insulin bolus calculator, can insert/ change sensor by themselves, can recharge transmitter, and has experience in reading real time continuous glucose monitoring (RT-CGM) data.
• Accurate carbohydrate counting.
• Experience in uploading pump information to web.
• Residing in Melbourne or Perth.
• Willing to comply with the study protocol requirements inclusive of those requirements related to participant safety.

Exclusion Criteria:

• Requiring greater than 150 units of insulin/day.
• Diabetic ketoacidosis (DKA) within the past 4 weeks.
• Hypoglycaemic unawareness (Gold score = 4) while on SAPT
• More than 2 severe hypoglycaemic episodes within the last 12 months
• Pregnant or planning pregnancy within study period.
• Renal impairment (eGFR less than 60ml/min).
• Current or recent (less than 4 weeks) inhaled or oral steroid therapy.
• Dermatological conditions (eg psoriasis) involving the region of glucose sensor/ insulin delivery cannula insertion.
• Subject has physical limitations (eg impaired vision) that would compromise operation of the closed loop system.
• Currently involved in another investigational study.