Table 1

AP road map in 2015: proof of concept of five of six steps of iteratively more sophisticated AP systems has been demonstrated in outpatient trials

Step123456
NameLGSPredictive LGS (PLGS)Hypoglycemia hyperglycemic minimizer (HHM)Hybrid closed loop (HCL)Fully automated insulin deliveryMultihormone (MH)
SynonymsThreshold suspend (TS)Predictive low-glucose management system (PLGM)Treat-to-range system (TTR)Treat-to-target system (TTT)Fully closed loop (FCL)Insulin-glucagon system, bionic pancreas
DescriptionInsulin shuts off upon crossing preset threshold such as 70 mg/dL and resumes after 2 hInsulin shuts off or is attenuated upon prediction of impending hypoglycemia and resumes delivery when hypoglycemia risk is goneSame as step 2 but with automatic insulin dosing to reduce hyperglycemia exposure. Does not target euglycemia, rather the minimization of time spent above a certain threshold, i.e., 180 mg/dLAlgorithm aims for euglycemic target, not range, but relies on mealtime insulin bolusFully automated insulin delivery with minimal human interactionFully automated multihormone approach; insulin plus glucagon, amylin, or other hormones/analogs
2015 statusCommercialized globallyRegulatory approval outside U.S., commercial availability in AustraliaIn commercial developmentIn commercial developmentProof of conceptIn commercial development
Example of supporting dataReduction in hypoglycemia, reduction in severe hypoglycemia, maintenance of A1C (29,43)Reduction in severe and moderate hypoglycemia (20,44)Reduction in time spent hyperglycemic and hypoglycemic and increased time in target range in outpatient settings (45)Reduction in time spent hyperglycemic and hypoglycemic and increased time in target range in outpatient settings (24,46)Reduction in hyperglycemia and hypoglycemia and increase in time in target in an inpatient settings (42,46)Reduction in hyperglycemia and hypoglycemia and increase time in target in outpatient setting (9)