Faster Compared With Standard Insulin Aspart During Day-and-Night Fully Closed-Loop Insulin Therapy in Type 1 Diabetes: A Double-Blind Randomized Crossover Trial

Diabetes Care. 2020 Jan;43(1):29-36. doi: 10.2337/dc19-0895. Epub 2019 Oct 1.


Objective: We evaluated the safety and efficacy of day-and-night fully closed-loop insulin therapy using faster (Faster-CL) compared with standard insulin aspart (Standard-CL) in young adults with type 1 diabetes.

Research design and methods: In a double-blind, randomized, crossover trial, 20 participants with type 1 diabetes on insulin pump therapy (11 females, aged 21.3 ± 2.3 years, HbA1c 7.5 ± 0.5% [58.5 ± 5.5 mmol/mol]) underwent two 27-h inpatient periods with unannounced afternoon moderate-vigorous exercise and unannounced/uncovered meals. We compared Faster-CL and Standard-CL in random order. During both interventions, the fuzzy-logic control algorithm DreaMed GlucoSitter was used. Glucose sensor data were analyzed by intention-to-treat principle with the difference (between Faster-CL and Standard-CL) in proportion of time in range 70-180 mg/dL (TIR) over 27 h as the primary end point.

Results: The proportion of TIR was similar for both arms: 53.3% (83% overnight) in Faster-CL and 57.9% (88% overnight) in Standard-CL (P = 0.170). The proportion of time in hypoglycemia <70 mg/dL was 0.0% for both groups. Baseline-adjusted interstitial prandial glucose increments 1 h after meals were greater in Faster-CL compared with Standard-CL (P = 0.017). The gaps between measured plasma insulin and estimated insulin-on-board levels at the beginning, at the end, and 2 h after the exercise were smaller in the Standard-CL group (P = 0.029, P = 0.003, and P = 0.004, respectively). No severe adverse events occurred.

Conclusions: Fully closed-loop insulin delivery using either faster or standard insulin aspart was safe and efficient in achieving near-normal glucose concentrations outside postprandial periods. The closed-loop algorithm was better adjusted to the standard insulin aspart.

Trial registration: NCT03212950.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Blood Glucose / drug effects
  • Blood Glucose / metabolism
  • Circadian Rhythm
  • Cross-Over Studies
  • Diabetes Mellitus, Type 1 / blood*
  • Diabetes Mellitus, Type 1 / drug therapy*
  • Double-Blind Method
  • Drug Administration Schedule
  • Female
  • Humans
  • Hypoglycemia / chemically induced
  • Hypoglycemic Agents / administration & dosage
  • Hypoglycemic Agents / adverse effects
  • Insulin / administration & dosage
  • Insulin / adverse effects
  • Insulin / standards
  • Insulin Aspart / administration & dosage*
  • Insulin Aspart / adverse effects
  • Insulin Infusion Systems*
  • Male
  • Meals
  • Postprandial Period
  • Young Adult


  • Blood Glucose
  • Hypoglycemic Agents
  • Insulin
  • Insulin Aspart

Associated data