Researchers from the University of Melbourne, St Vincent’s Hospital Melbourne and Royal Melbourne Hospital have undertaken the first randomised clinical trial examining effects of ‘closed-loop’ automated insulin delivery for older individuals with type 1 diabetes. Findings from the Older Adult Closed-Loop (ORACL) trial revealed that closed-loop therapy achieved better glucose management than sensor-augmented (open loop) pump therapy, and that “older age is not a barrier to closed-loop therapy.”  

Pump systems can involve communication between CGMs (continuous glucose monitors) and insulin pumps which continuously deliver insulin at variable doses. In open-loop systems (sensor-augmented pumps) this communication is not automated and the insulin doses delivered are manually determined.

In closed-loop systems (also known as an ‘artificial pancreas’), CGMs and insulin pumps ‘talk’ to each other to automate insulin delivery. Such systems are considered ‘closed-loop’ since they do not always require user input (such as pressing buttons); instead, the sensor can direct how much insulin the pump delivers.

Findings from the four-month intervention in the ORACL trial, led by Dr Sybil McAuley, revealed that “closed-loop insulin delivery provided significantly better glucose control than sensor-augmented pump therapy” and “no serious adverse events occurred during the closed-loop stage.”

The closed-loop therapy resulted in important clinical benefits, such as reducing hyperglycaemia and hypoglycaemia (high and low blood glucose levels) and increasing the time glucose levels remained within the recommended range.

These outcomes were “achieved with no overall change in insulin dose delivered, though with greater within-day variability in dosing during closed-loop than sensor-augmented pump.” Notably, the benefits of closed-loop therapy were greatest overnight, with a “fourfold reduction in the time overnight spent below all hypoglycemia thresholds.” Such results are consistent with trials involving younger individuals.

Additionally, “participants were positive about using closed-loop therapy before starting, and remained positive about the impact of closed-loop delivery on living with diabetes at the end of the closed-loop stage.”

These findings are certainly promising; however, closed-loop technology is still being developed. Further research is needed to examine the long-term effects of closed-loop use among older adults.

This research was proudly supported by the Diabetes Australia Research Program. You can help support more important studies like this by joining The Cure Club, our regular giving program. Join today.

The full findings of this study can be accessed here.

Key Messages

• Closed-loop therapy enables glucose monitors and insulin pumps to ‘communicate’ and automate insulin delivery, whereas open-loop therapy (sensor-augmented therapy) requires human input for insulin dosing.
• Closed-loop therapy can safely improve all CGM (continuous glucose monitoring) outcomes beyond the levels seen with sensor-augmented pump therapy. With closed-loop therapy, glucose levels spent a higher proportion of time within the recommended range. 
• During clinical research, closed-loop therapy was found to be an effective and safe treatment option for older adults with long-duration type 1 diabetes.
• Further research on the effects of long-term closed-loop therapy among different cohorts is needed.