title: Post-breakfast closed-loop glucose control is improved when accompanied with carbohydrate-matching bolus compared to weight-dependent bolus.
abstract: OBJECTIVE
  We compared post-breakfast closed-loop glucose control either matched with a carbohydrate-matching bolus or a weight-dependent bolus.
  
  
  METHODS
  Twelve adults with type 1 diabetes consumed a 75 g CHO breakfast on two occasions. In random order, the breakfast was accompanied by a full carbohydrate-matching insulin bolus (8.30 U [7.50 U-11.50 U]) or a partial weight-dependent insulin bolus (0.047 U/kg; 3.45 U [2.95 U-3.75 U]). Postprandial glucose was regulated by sensor-responsive insulin and glucagon delivery.
  
  
  RESULTS
  Glucose control after the weight-dependent bolus was safe and feasible (glucose values returned to pre-prandial levels after 5 h). However, 5-hr incremental area under the curve and percentage of time above 10 mmol/L were lower after the full bolus compared to the partial bolus (IAUC, 2.1 [0.8-4.2] mmol/L/hr vs 8.3 [6.5-11.4] mmol/L/hr; time in hyperglycaemia, 24% [6%-29%] vs 50% [25%-63%]; P < 0.001).
  
  
  CONCLUSIONS
  Post-breakfast closed-loop glucose control without carbohydrate counting, but based on weight-dependent bolus is feasible but a carbohydrate-matching bolus provides better glucose control.
  
  
  BACKGROUND
  NCT01519102.
authors.affiliation: Institut de Recherches Cliniques de Montréal, Montreal, Canada; Experimental Medicine, McGill University, Montreal, Canada. Electronic address: ahmad.haidar@mail.mcgill.ca.
authors.forename: A
authors.initials: A
authors.lastname: Haidar
authors.affiliation: Institut de Recherches Cliniques de Montréal, Montreal, Canada; Experimental Medicine, McGill University, Montreal, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Farid
authors.affiliation: Institut de Recherches Cliniques de Montréal, Montreal, Canada.
authors.forename: A
authors.initials: A
authors.lastname: St-Yves
authors.affiliation: Institut de Recherches Cliniques de Montréal, Montreal, Canada.
authors.forename: V
authors.initials: V
authors.lastname: Messier
authors.affiliation: Jaeb Center for Health Research, Tampa, FL, USA.
authors.forename: V
authors.initials: V
authors.lastname: Chen
authors.affiliation: Jaeb Center for Health Research, Tampa, FL, USA.
authors.forename: D
authors.initials: D
authors.lastname: Xing
authors.affiliation: Institut de Recherches Cliniques de Montréal, Montreal, Canada.
authors.forename: A-S
authors.initials: AS
authors.lastname: Brazeau
authors.affiliation: Institut de Recherches Cliniques de Montréal, Montreal, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Duval
authors.affiliation: Centre for Intelligent Machines, McGill University, Montreal, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Boulet
authors.affiliation: Montreal Children's Hospital, McGill University Health Centre, Montreal, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Legault
authors.affiliation: Institut de Recherches Cliniques de Montréal, Montreal, Canada; Nutrition department, Faculty of medicine, Université de Montréal, Montreal, Canada; Montreal diabetes research center, Montreal, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Rabasa-Lhoret
mesh_terms: D000328:Adult; D000465:Algorithms; D015415:Biomarkers / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism; D062408:Breakfast; D002170:Canada; D018592:Cross-Over Studies; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy* / Q000378:metabolism; D004040:Dietary Carbohydrates / Q000378:metabolism*; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000188:drug therapy* / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007328:Insulin / Q000008:administration & dosage*; D008297:Male; D019397:Pancreas, Artificial; D019518:Postprandial Period; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D004040:Dietary Carbohydrates; D007004:Hypoglycemic Agents; D007328:Insulin
keywords: Artificial pancreas; Closed-loop delivery; Glucagon; Postprandial control; Type 1 diabetes