title: Efficacy of dual-hormone artificial pancreas to alleviate the carbohydrate-counting burden of type 1 diabetes: A randomized crossover trial.
abstract: OBJECTIVE
  Carbohydrate-counting is a complex task for many patients with type 1 diabetes. This study examined whether an artificial pancreas, delivering insulin and glucagon based on glucose sensor readings, could alleviate the burden of carbohydrate-counting without degrading glucose control.
  
  
  METHODS
  Twelve adults were recruited into a randomized, three-way, crossover trial (ClinicalTrials.gov identifier No. NCT01930097). Participants were admitted on three occasions from 7AM to 9PM and consumed a low-carbohydrate breakfast (women: 30g; men: 50g), a medium-carbohydrate dinner (women: 50g; men: 70g) and a high-carbohydrate lunch (women: 90g; men: 120g). At each visit, glucose levels were randomly regulated by: (1) conventional pump therapy; (2) an artificial pancreas (AP) accompanied by prandial boluses, matching the meal's carbohydrate content based on insulin-to-carbohydrate ratios (AP with carbohydrate-counting); or (3) an AP accompanied by prandial boluses based on qualitative categorization (regular or large) of meal size (AP without carbohydrate-counting).
  
  
  RESULTS
  The AP without carbohydrate-counting achieved similar incremental AUC values compared with carbohydrate-counting after the low- (P=0.54) and medium- (P=0.38) carbohydrate meals, but yielded higher post-meal excursions after the high-carbohydrate meal (P=0.004). The AP with and without carbohydrate-counting yielded similar mean glucose levels (8.2±2.1mmol/L vs. 8.4±1.7mmol/L; P=0.52), and both strategies resulted in lower mean glucose compared with conventional pump therapy (9.6±2.0mmol/L; P=0.02 and P=0.03, respectively).
  
  
  CONCLUSIONS
  The AP with qualitative categorization of meal size could alleviate the burden of carbohydrate-counting without compromising glucose control, although more categories of meal sizes are probably needed to effectively control higher-carbohydrate meals.
authors.affiliation: Institut de recherches cliniques de Montréal, Montreal, Quebec, Canada; Department of nutrition, Université de Montréal, Montreal, Quebec, Canada.
authors.forename: V
authors.initials: V
authors.lastname: Gingras
authors.affiliation: Institut de recherches cliniques de Montréal, Montreal, Quebec, Canada; Department of nutrition, Université de Montréal, Montreal, Quebec, Canada; Montreal Diabetes Research Center (MDRC), Montreal, Quebec, Canada; Research Center of the Université de Montréal Hospital Center (CRCHUM), Montreal, Quebec, Canada; Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada. Electronic address: remi.rabasa-lhoret@ircm.qc.ca.
authors.forename: R
authors.initials: R
authors.lastname: Rabasa-Lhoret
authors.affiliation: Institut de recherches cliniques de Montréal, Montreal, Quebec, Canada.
authors.forename: V
authors.initials: V
authors.lastname: Messier
authors.affiliation: Research Center of the Université de Montréal Hospital Center (CRCHUM), Montreal, Quebec, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Ladouceur
authors.affiliation: Montreal Children's Hospital, McGill University Health Center, Montreal, Quebec, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Legault
authors.affiliation: Institut de recherches cliniques de Montréal, Montreal, Quebec, Canada; Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Haidar
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis*; D018592:Cross-Over Studies; D003922:Diabetes Mellitus, Type 1 / Q000628:therapy*; D003927:Diet, Diabetic / Q000379:methods*; D004040:Dietary Carbohydrates; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019397:Pancreas, Artificial
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates
keywords: Artificial pancreas; Carbohydrate-counting; Closed-loop hormonal delivery systems; Continuous glucose monitoring; Type 1 diabetes