Real-world data on hybrid closed loop is supporting the clinical trial data and cementing the technology as “a game changer” for patients with type 1 diabetes.

The Australasian Diabetes Congress 2022 meeting in Brisbane heard a number of local studies showing hybrid closed loop (HCL) improves glycaemic control and time in range.

Dr Laura Donaldson, from St Vincent’s Hospital Melbourne, presented a retrospective audit of medical records of adults with type 1 diabetes at two tertiary hospitals between February 2019 and December 2021.

The analysis included 91 patients with a mean age of 44 years and diabetes duration of 25 years starting first generation Medtronic MinMed 670G or 770G systems.

It found the initiation of HCL therapy resulted in an immediate decrease in HbA1c by about 7% overall and stabilising at about 5% over the study period. Patients with a low baseline HbA1c demonstrated no improvement but those with a high baseline HbA1c >8.5% had improvements of 10-15%.

Dr Donaldson said the initiation of HCL therapy also had an immediate impact on CGM metrics of time in target range (9% increase) and time in hyperglycaemia (8.6% decrease) but not on time in hypoglycaemia.

She said 18% of patients discontinued HCL due to factors such as dissatisfaction in their glycaemic control or technical difficulties.

Few patients (2%) experienced severe hypoglycaemia and there was a single report of pump failure necessitating a hospital admission.

She said the next generation HCL systems, with increased CGM accuracy and user-friendliness, could further improve type 1 diabetes outcomes in Australia.

“In future, improved technology design and access should hopefully reduce barriers to use of these systems and real world studies will need to be completed on these new closed loop therapy systems to assess their effectiveness in our community.”

‘Game changer’

Ms Connie Luo, from the Royal Prince Alfred Hospital Diabetes Centre, presented data on 33 adults with type 1 diabetes started on HCL therapy. Patients had a mean age of 35 and a diabetes duration of 21 years.

She told the meeting that time in target range improved significantly from 57% to 67% within 2 weeks, while time in high range decreased.

“Importantly, this was achieved without an increase in time below range,” she said.

The proportion of patients achieving at least 70% TIR improved from 21% at baseline to 42%. There was also an improvement in HbA1 and a reduction in glucose management indicator (GMI) from 7.6 to 7.2.

As per the Melbourne study, patients with less optimal glucose control at baseline benefitted the most from HCL therapy.

The improvements in CGM metrics that were seen at two weeks persisted through the 12-month follow-up.

“In this real world study in our Diabetes Centre, hybrid closed loop improved glycaemic control in adults with type 1 diabetes within two weeks and the benefit is seen in pre-existing CGM users and pre-existing pump users.”

Ms Luo told the limbic the technology was a game-changer for people with type 1 diabetes.

“This is just the first generation of the hybrid closed loop. So now with the 780G, the Control-IQ with autocorrections which is a more advanced hybrid closed loop technology… hopefully that will improve time in range even further. I’m confident the data will be very positive.”