Safety, metabolic and psychological outcomes of Medtronic MiniMed 670G in children, adolescents and young adults: a systematic review

Hybrid closed loop (HCL) systems are the combination of a pump for insulin delivery and a glucose sensor for continuous glucose monitoring. These systems are managed by an algorithm, which delivers insulin on the basis of the interstitial glucose levels. The MiniMed™ 670G system was the first HCL system available for clinical purpose. In this paper, we reviewed the literature about metabolic and psychological outcomes in children, adolescents and young adults with type 1 diabetes treated with MiniMed™ 670G. Only 30 papers responded to the inclusion criteria and thus were considered. All the papers show that the system is safe and effective in managing glucose control. Metabolic outcomes are available up to 12 months of follow-up; longer study period are lacking. This HCL system may improve HbA1c up to 7.1% and time in range up to 73%. The time spent in hypoglycaemia is almost neglectable. Better improvement in blood glucose control is observed in patients with higher HbA1c at HCL system start and larger daily use of auto-mode functionality.     Conclusion: The Medtronic MiniMed™ 670G is safe and well accepted, without any increase in the burden for patients. Some papers report an improvement in the psychological outcomes, but other papers do not confirm this finding. So far, it significantly improves the management of diabetes mellitus in children, adolescents and young adults. Proper training and support by the diabetes team are mandatory. Studies for a period longer than 1 year would be appreciated to better understand the potentiality of this system. What is Known: • The Medtronic MiniMedTM 670G is a hybrid closed loop system which combines a continuous glucose monitoring sensor with an insulin pump. • It has been the first hybrid closed loop system available for clinical purpose. Adequate training and patients support play a key role in diabetes management. What is New: • The Medtronic MiniMedTM 670G may improve HbA1c and CGM metrics up to 1-year of follow-up, but the improvement appears lower than advanced hybrid closed loop systems. This system is effective to prevent hypoglycaemia. • The psychosocial effects remain less understood in terms of improvement of psychosocial outcomes. The system has been considered to provide flexibility and independence by the patients and their caregivers. The workload required to use this system is perceived as a burden by the patients who decrease the use of auto-mode functionality over time.