This closed-loop insulin delivery system monitors blood glucose continuously and utilizes an algorithm that senses glucose levels and autonomously delivers the required insulin dose. In contrast, conventional insulin pumps contain computer chips that allow patients to program insulin doses for scheduled delivery throughout the day.
Short of a cure, the artificial pancreas represents the best possible treatment option for diabetes. This closed-loop insulin delivery system monitors blood glucose continuously and utilizes an algorithm that senses glucose levels and autonomously delivers the required insulin dose. In contrast, conventional insulin pumps contain computer chips that allow patients to program insulin doses for scheduled delivery throughout the day.
Presently, several closed-loop systems are in development and testing. Although the pace of development has been brisk over the last few years, researchers have reported obstacles. To start, available rapid-acting insulin has delayed pharmacokinetics and may not reach maximum glucose-lowering capacities as quickly as endogenous insulin. Occasionally, investigational closed-loop systems experience calibration or sensor drift, so inaccuracy is a continual concern, alongside rare yet serious hypoglycemia.
A team of researchers from Wellcome Trust-MRC Institute of Metabolic Science at the University of Cambridge in the United Kingdom recently published a comprehensive review of the state of science regarding closed-loop insulin delivery systems in the online version of Current Opinions in Endocrinology, Diabetes and Obesity.
The investigators examined studies conducted in controlled research facility settings that demonstrated closed-loop systems are superior to conventional insulin pump therapy, in terms of tightening glycemic control and reducing the risk of hypoglycemia.
For the most part, studies have been conducted in children and adults treated at hospitals and diabetes camps. In children, the evidence indicates closed-loop systems may reduce the risk of nocturnal hypoglycemia following daytime exercise — a significant problem in this active group. In adults, researchers have seen an approximately 3-fold reduction in time spent with hypoglycemia when closed-loop systems are utilized. Redundant monitoring sensors have also been employed and are being considered as a fail-safe device to alert patients.
To mitigate delayed insulin kinetics and hypoglycemia risk, experimental dual-hormone closed-loop systems are being studied. These closed-loop systems combine insulin delivery with subcutaneous glucagon to ensure systemic glucose stability.
Closed-loop systems are currently being examined in home settings to determine whether they are safe and effective during longer periods of unregulated daily activities. The researchers offered hope that a portable, safe, and effective artificial pancreas may be available soon.