title: Evaluation of a Predictive Low-Glucose Management System In-Clinic.
abstract: Predictions based on continuous glucose monitoring (CGM) data are the basis for automatic suspension and resumption of insulin delivery by a predictive low-glucose management feature termed "suspend before low," which is part of the Medtronic MiniMed®640G combined insulin pump and CGM system. This study assessed the safety and performance characteristics of the system in an in-clinic setting at eight sites.
  
  
  
  In-clinic standardized increases in basal insulin delivery rates were used to induce nocturnal hypoglycemia in subjects (14-75 years) with type 1 diabetes wearing the MiniMed 640G system. The "suspend before low" feature was set at 65 mg/dL, and as a result, the predictive algorithm suspended insulin delivery when the forecasted glucose was predicted to be ≤85 mg/dL in 30 min (a 20 mg/dL safety buffer). Reference plasma glucose values (Yellow Springs Instruments [YSI], Yellow Springs, OH) were used to establish hypoglycemia and were defined as ≥2 consecutive values ≤65 mg/dL.
  
  
  
  Eighty subjects were screened. Among the 69 successful completers, 27 experienced a hypoglycemic event and 42 did not, a prevention rate of 60%. The mean (±standard deviation) YSI value at the time of pump suspension was 101 ± 18.5 mg/dL, and the mean duration of the 68 "suspend before low" events was 105 ± 27 min. At 120 min after the start of the pump suspension events, the mean YSI value was 102 ± 34.6 mg/dL.
  
  
  
  The MiniMed 640G "suspend before low" feature prevented 60% of induced predicted hypoglycemic events without significant rebound hyperglycemia.
authors.affiliation: 1 Department of Pediatric Endocrinology, Stanford University , Stanford, California.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Buckingham
authors.affiliation: 2 AMCR Institute , Escondido, California.
authors.forename: Timothy S
authors.initials: TS
authors.lastname: Bailey
authors.affiliation: 3 Diablo Clinical Research , Walnut Creek, California.
authors.forename: Mark
authors.initials: M
authors.lastname: Christiansen
authors.affiliation: 4 Barbara Davis Center for Diabetes , Aurora, Colorado.
authors.forename: Satish
authors.initials: S
authors.lastname: Garg
authors.affiliation: 5 Department of Pediatrics, Yale University School of Medicine , New Haven, Connecticut.
authors.forename: Stuart
authors.initials: S
authors.lastname: Weinzimer
authors.affiliation: 6 Atlanta Diabetes Center , Atlanta, Georgia .
authors.forename: Bruce
authors.initials: B
authors.lastname: Bode
authors.affiliation: 7 UVA Center for Diabetes Technology , Charlottesville, Virginia.
authors.forename: Stacey M
authors.initials: SM
authors.lastname: Anderson
authors.affiliation: 8 Rainier Clinical Research Center , Renton, Washington.
authors.forename: Ronald
authors.initials: R
authors.lastname: Brazg
authors.affiliation: 1 Department of Pediatric Endocrinology, Stanford University , Stanford, California.
authors.forename: Trang T
authors.initials: TT
authors.lastname: Ly
authors.affiliation: 9 Medtronic, Northridge, California.
authors.forename: Francine R
authors.initials: FR
authors.lastname: Kaufman
mesh_terms: D000046:Academic Medical Centers; D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D001786:Blood Glucose / Q000032:analysis*; D018592:Cross-Over Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000628:therapy*; D006801:Humans; D007003:Hypoglycemia / Q000139:chemically induced / Q000517:prevention & control*; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D007328:Insulin / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D007332:Insulin Infusion Systems / Q000009:adverse effects; D008422:Materials Testing; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000009:adverse effects; D019397:Pancreas, Artificial / Q000009:adverse effects; D014481:United States; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin
keywords: Artificial pancreas; Hypoglycemia; Sensor-augmented pump