ACBRD publishes a randomised crossover study.

by Dr Steven Trawley


People with type 1 diabetes face a difficult and delicate balancing act in managing their insulin doses and glucose levels. Interactions between insulin levels, food intake and physical activity are complex and, often unpredictably, affect insulin requirements. A ‘closed-loop’ insulin delivery system, commonly referred to as an ‘artificial pancreas’, offers a new, and potentially more effective, method of dealing with the challenges of managing type 1 diabetes. This new system processes glucose information continuously, through a glucose sensor inserted under the skin, and is designed to communicate automatically with an insulin pump to calculate and deliver the precise amount of insulin required.

Members of the ACBRD team (Prof. Jane SpeightDr Christel Hendrieckx and Dr Steven Trawley) have been working in collaboration with researchers from St Vincent’s Hospital in Melbourne on assessing the overnight benefits of using one of these new insulin delivery systems. This study, led by Associate Professor David O’Neal and Professor Tim Jones, recruited sixteen adults and twelve adolescents with type 1 diabetes to use this new system at home for four consecutive nights. In order to provide a comparison they were also given a sensor-augmented insulin pump to use for an additional four nights at home. The primary aim of the study was to investigate whether people were more likely to stay within target glucose range (4 to 8 mmol/L) overnight when using the closed-loop insulin delivery system than when using the sensor-augmented pump.

The study showed that adults did indeed spend more time within the target range while using the new closed-loop system, with both adults and adolescents being less likely to experience night-time low glucose. Furthermore, when compared with their usual diabetes treatment, adults were more satisfied with this new system. Sleep quality and cognitive functioning did not differ. In a follow-up to these promising results, the study team, including members of the ACBRD, are now evaluating use of a 24-hour closed-loop system over a longer time frame.

Sharifi A, De Bock MI, Jayawardene D, Loh MM, Horsburgh JC, Berthold CL, Paramalingam N, Bach L, Colman PG, Davis EA, Grosman B, Hendrieckx C, Jenkins AJ, Kumareswaran K, Kurtz N, Kyoong A, MacIsaac RJ, Speight JTrawley SL, Ward GM, Anirban R, Jones TW, & O’Neal DN. Glycemia, Treatment Satisfaction, Cognition and Sleep Quality in Adults and Adolescents with Type 1 Diabetes when using a Closed Loop System Overnight versus Sensor-Augmented Pump with Low Glucose Suspend: A Randomized Crossover StudyDiabetes Technology & Therapeutics, 18(12), 772-783. doi:10.1089/dia.2016.0288