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.
Department of Pediatric Endocrinology, Stanford University, Stanford, California 94305-5208, USA. buckingham@stanford.edu
Bruce
B
Buckingham
Erin
E
Cobry
Paula
P
Clinton
Victoria
V
Gage
Kimberly
K
Caswell
Elizabeth
E
Kunselman
Fraser
F
Cameron
H Peter
HP
Chase
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