Preventing hypoglycemia using predictive alarm algorithms and insulin pump suspension.
BACKGROUND
Nocturnal hypoglycemia is a significant problem. From 50% to 75% of hypoglycemia seizures occur at night. Despite the development of real-time glucose sensors (real-time continuous glucose monitor [CGM]) with hypoglycemic alarms, many patients sleep through these alarms. The goal of this pilot study was to assess the feasibility using a real-time CGM to discontinue insulin pump therapy when hypoglycemia was predicted.


METHODS
Twenty-two subjects with type 1 diabetes had two daytime admissions to a clinical research center. On the first admission their basal insulin was increased until their blood glucose level was <60 mg/dL. On the second admission hypoglycemic prediction algorithms were tested to determine if hypoglycemia was prevented by a 90-min pump shutoff and to determine if the pump shutoff resulted in rebound hyperglycemia.


RESULTS
Using a statistical prediction algorithm with an 80 mg/dL threshold and a 30-min projection horizon, hypoglycemia was prevented 60% of the time. Using a linear prediction algorithm with an 80 mg/dL threshold and a 45-min prediction horizon, hypoglycemia was prevented 80% of the time. There was no rebound hyperglycemia following pump suspension.


CONCLUSIONS
Further development of algorithms is needed to prevent all episodes of hypoglycemia from occurring.
Buckingham
Bruce
B
Department of Pediatric Endocrinology, Stanford University, Stanford, California 94305-5208, USA. buckingham@stanford.edu
Cobry
Erin
E
Clinton
Paula
P
Gage
Victoria
V
Caswell
Kimberly
K
Kunselman
Elizabeth
E
Cameron
Fraser
F
Chase
H Peter
HP
D000465:Algorithms; D001786:Blood Glucose / Q000378:metabolism; D003920:Diabetes Mellitus / Q000097:blood / Q000188:drug therapy; D004343:Drug Implants; D006801:Humans; D007003:Hypoglycemia / Q000517:prevention & control*; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D007328:Insulin / Q000008:administration & dosage / Q000627:therapeutic use; D007332:Insulin Infusion Systems / Q000706:statistics & numerical data*; D008991:Monitoring, Physiologic / Q000379:methods
D001786:Blood Glucose; D004343:Drug Implants; D007004:Hypoglycemic Agents; D007328:Insulin