title: Unsupervised home use of an overnight closed-loop system over 3-4 weeks: a pooled analysis of randomized controlled studies in adults and adolescents with type 1 diabetes.
abstract: OBJECTIVE
  To compare overnight closed-loop and sensor-augmented pump therapy in patients with type 1 diabetes by combining data collected during free-living unsupervised randomized crossover home studies.
  
  
  METHODS
  A total of 40 participants with type 1 diabetes, of whom 24 were adults [mean ± standard deviation (s.d.) age 43 ± 12 years and glycated haemoglobin (HbA1c) 8.0 ± 0.9%] and 16 were adolescents (mean ± s.d. age 15.6 ± 3.6 years and HbA1c 8.1 ± 0.8%), underwent two periods of sensor-augmented pump therapy in the home setting, in combination with or without an overnight closed-loop insulin delivery system that uses a model predictive control algorithm to direct insulin delivery. The order of the two interventions was random; each period lasted 4 weeks in adults and 3 weeks in adolescents. The primary outcome was time during which sensor glucose readings were in the target range of 3.9-8.0 mmol/l.
  
  
  RESULTS
  The proportion of time when sensor glucose was in the target range (3.9-8.0 mmol/l) overnight (between 24:00 and 08:00 hours) was 18.5% greater during closed-loop insulin delivery than during sensor-augmented therapy (p < 0.001). Closed-loop therapy significantly reduced mean overnight glucose levels by 0.9 mmol/l (p < 0.001), with no difference in glycaemic variability, as measured by the standard deviation of sensor glucose. Time spent above the target range was reduced (p = 0.001), as was time spent in hypoglycaemia (<3.9 mmol/l; p = 0.014) during closed-loop therapy. Lower mean overnight glucose levels during closed-loop therapy were brought about by increased overnight insulin delivery (p < 0.001) without changes to the total daily delivery (p = 0.84).
  
  
  CONCLUSIONS
  Overnight closed-loop insulin therapy at home in adults and adolescents with type 1 diabetes is feasible, showing improvements in glucose control and reducing the risk of nocturnal hypoglycaemia.
authors.affiliation: Wellcome Trust-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK.
authors.forename: H
authors.initials: H
authors.lastname: Thabit
authors.forename: D
authors.initials: D
authors.lastname: Elleri
authors.forename: L
authors.initials: L
authors.lastname: Leelarathna
authors.forename: J M
authors.initials: JM
authors.lastname: Allen
authors.forename: A
authors.initials: A
authors.lastname: Lubina-Solomon
authors.forename: M
authors.initials: M
authors.lastname: Stadler
authors.forename: E
authors.initials: E
authors.lastname: Walkinshaw
authors.forename: A
authors.initials: A
authors.lastname: Iqbal
authors.forename: P
authors.initials: P
authors.lastname: Choudhary
authors.forename: M E
authors.initials: ME
authors.lastname: Wilinska
authors.forename: K D
authors.initials: KD
authors.lastname: Barnard
authors.forename: S R
authors.initials: SR
authors.lastname: Heller
authors.forename: S A
authors.initials: SA
authors.lastname: Amiel
authors.forename: M L
authors.initials: ML
authors.lastname: Evans
authors.forename: D B
authors.initials: DB
authors.lastname: Dunger
authors.forename: R
authors.initials: R
authors.lastname: Hovorka
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D001786:Blood Glucose / Q000378:metabolism; D015190:Blood Glucose Self-Monitoring / Q000379:methods; D018592:Cross-Over Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000188:drug therapy*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007003:Hypoglycemia / Q000188:drug therapy; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007328:Insulin / Q000008:administration & dosage*; D007332:Insulin Infusion Systems; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; C517652:hemoglobin A1c protein, human
keywords: clinical trial; closed-loop insulin delivery; glycaemic control; type 1 diabetes