A post-marketing study of Medtronic's MiniMed 530G insulin pump showed the device reduced hypoglycemia in patients without significantly increasing hyperglycemia. The study focused on the device's Threshold Suspend feature that, when enabled, suspends insulin delivery for up to two hours when the sensor glucose value reaches a preset threshold.

Overall hypoglycemia was reduced by 69% during patient-days where the Threshold Suspend feature was enabled, compared to patient-days when the feature was not enabled.

Night-time hypoglycemia was reduced by 73% when the feature was enabled. The reduction in hypoglycemia seen on Threshold Suspend-enabled days was more pronounced during nighttime than during daytime hours.

"The Threshold Suspend feature on the MiniMed 530G system has been a critical milestone toward Medtronic's goal to develop a fully automated artificial pancreas," said Alejandro Galindo, vice president and general manager of the Intensive Insulin Management business at Medtronic.  "Our integrated insulin delivery systems are the only ones that can take action, mimicking the functioning of a healthy pancreas, to help people with diabetes enjoy greater freedom and better health."

These results are similar to outcomes observed in the ASPIRE In-Home study, which was published in The New England Journal of Medicine in July of 2013. In both datasets, there were significantly fewer sensor glucose values in the hypoglycemic range in subjects using the Threshold Suspend feature compared to those in the control group using sensor-augmented pump therapy. 

About the retrospective study
The effectiveness of the Threshold Suspend feature in the real-world setting was conducted by retrospectively analyzing anonymized, aggregated data from more than 20,000 users of the MiniMed 530G system who uploaded to the CareLink Personal Therapy Management Software for Diabetes. MiniMed 530G users have discretion to turn Threshold Suspend on and off. The study design calculated the amount of time that users spent with Threshold Suspend turned on (82%) and compared performance data from that segment against user time spent with the feature turned off. Study endpoints were to evaluate Threshold Suspend impact on overall hypoglycemia and impact on night-time hypoglycemia.

CareLink allows patients and their health care providers to view critical information from the patient's insulin pump, CGM and blood glucose meter in order to optimize their diabetes management. The online software displays the information in charts, graphs and tables, making it easy to discover glucose patterns and trends and make therapy adjustments, as needed.