Background: Blood glucose levels are physiologically controlled by insulin and counter-regulatory hormones, mainly glucagon. Type 1 diabetes patients are deficient in insulin and some level also glucagon. Therefore, bi-hormonal closed-loop system seems to be the best way to control glycemia.
Objective and hypotheses: There are two main approaches to add glucagon: (a) as safety measures for rescue in case of hypoglycemia (2) as a mean to optimize metabolic control. Glucagon has the potential to better control hypoglycemic events than insulin alone.
Method: The advantages and disadvantages of bi-hormonal closed-loop system will be discussed.
Results: Several studies that compared closed-loop system with single hormone (insulin) and bi-hormone (insulin and glucagon) may suggest an advantage of the bi-hormonal over single-hormone. Insulin activity has a relatively long duration; hence suspension of insulin delivery alone may not be sufficient to prevent hypoglycemia. The add-on of glucagon may reduce those unavoidable hypoglycemic events. This approach is beneficial mainly to those susceptible to hypoglycemia, i.e. young children, subjects with hypoglycemia unawareness or physically active. Glucagon can also be used to improve postprandial hyperglycemia, namely, insulin over-delivery for reducing prandial glucose excursion and then compensating with glucagon. Some may argue that bi-hormonal closed-loop system is more complex and expensive. Nevertheless, technology overcomes it by a combined pump infusion device and new formulation of stable glucagon.
Conclusion: Addition of glucagon to insulin in closed-loop system is feasible, safe, well tolerated and may help to mitigate the risk of hypoglycemia, improve metabolic control as well as allow patients to be more spontaneous in their daily activities.
10 Sep 2016 - 12 Sep 2016