Dual-hormone artificial pancreas: benefits and limitations compared with single-hormone systems

Technological advances have made the artificial pancreas a reality. This has the potential to improve the lives of individuals with Type 1 diabetes by reducing the risk of hypoglycaemia, achieving better overall glucose control, and enhancing quality of life. Both single-hormone (insulin-only) and dual-hormone (insulin and glucagon) systems have been developed; however, a focused review of the relative benefits of each artificial pancreas system is needed. We reviewed studies that directly compared single- and dual-hormone systems to evaluate the efficacy of each system for preventing hypoglycaemia and maintaining glycaemic control, as well as their utility in specific situations including during exercise, overnight and during the prandial period. We observed additional benefits with the dual-hormone artificial pancreas for reducing the risk of hypoglycaemic events overall and during exercise over the study duration. The single-hormone artificial pancreas was sufficient for maintenance of euglycaemia in the overnight period and for preventing late-onset post-exercise hypoglycaemia. Future comparative studies of longer duration are required to determine whether one system is superior for improving mean glucose control, eliminating severe hypoglycaemia, or improving quality of life. What's new? We review the literature comparing the relative efficacy and utility of single- and dual-hormone artificial pancreas systems. The pharmacokinetic profile of glucagon, with rapid onset and short duration of action, confers the major benefit of the dual-hormone artificial pancreas. The dual-hormone artificial pancreas is superior to single-hormone systems in reducing hypoglycaemia overall and during exercise in short-term studies, whereas there is no strong evidence of added benefit for preventing nocturnal or post-exercise hypoglycaemia. The relative benefit of each system over the long term for improving HbA(1c), preventing severe hypoglycaemia, and affecting quality of life remains unknown.