Insulin delivery via a hybrid closed-loop system (CLS) improves glycaemic control while reducing the risk of hypoglycaemia in type 1 diabetes, according to the results of the largest study of this technology in outpatients to date. There was significantly greater time-in-range and significantly lower HbA1c with the hybrid CLS than with sensor-augmented pumps in people with suboptimally-controlled type 1 diabetes at 12 weeks.
According to Dr Martin Tauschmann, who presented the results of the Cambridge hybrid closed-loop study at EASD, participants using the technology spent an average of 3 additional hours within target range compared to an extra 29 minutes in those using sensor-augmented pumps. A similar drop in the amount of time spent in hyperglycaemia each day was found for each of the two groups: 2.9 hours with hybrid CLS versus 29 minutes with a sensor-augmented pump. There was a between-group difference of 0.5 mmol/L (0.5%) in HbA1c readings, with the use of hybrid CLS resulting in a 0.6 mmol/L (0.6%) reduction in HbA1c. In addition to this, greater improvements were found in average blood glucose with hybrid CLS. However, the time spent in hypoglycaemia was similar in both groups and there was no difference in total daily insulin dose or bodyweight.
The home-based adults, adolescents and children aged at least 6 years had an average HbA1c of 66–67 mmol/mol (8.2–8.3%) at the start of the study. Forty-six were randomly assigned to hybrid closed-loop therapy and 40 to sensor-augmented pump therapy, with a primary endpoint of time within target range (3.9–10.0 mmol/L) 12 weeks after randomisation to a treatment arm. The hybrid CLS consisted of an Android phone using Cambridge model predictive control algorithm to predict future glucose levels along with the Medtronic MiniMed 640G and Enlite 3 sensor.