Day and night home closed-loop insulin delivery in adults with type 1 diabetes: three-center randomized crossover study

Diabetes Care. 2014 Jul;37(7):1931-7. doi: 10.2337/dc13-2911.


Objective: To evaluate the feasibility of day and night closed-loop insulin delivery in adults with type 1 diabetes under free-living conditions.

Research design and methods: Seventeen adults with type 1 diabetes on insulin pump therapy (means ± SD age 34 ± 9 years, HbA1c 7.6 ± 0.8%, and duration of diabetes 19 ± 9 years) participated in an open-label multinational three-center crossover study. In a random order, participants underwent two 8-day periods (first day at the clinical research facility followed by 7 days at home) of sensor-augmented insulin pump therapy (SAP) or automated closed-loop insulin delivery. The primary end point was the time when sensor glucose was in target range between 3.9 and 10.0 mmol/L during the 7-day home phase.

Results: During the home phase, the percentage of time when glucose was in target range was significantly higher during closed-loop compared with SAP (median 75% [interquartile range 61-79] vs. 62% [53-70], P = 0.005). Mean glucose (8.1 vs. 8.8 mmol/L, P = 0.027) and time spent above target (P = 0.013) were lower during closed loop, while time spent below target was comparable (P = 0.339). Increased time in target was observed during both daytime (P = 0.017) and nighttime (P = 0.013).

Conclusions: Compared with SAP, 1 week of closed-loop insulin delivery at home reduces mean glucose and increases time in target without increasing the risk of hypoglycemia in adults with relatively well-controlled type 1 diabetes.

Trial registration: NCT01666028.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blood Glucose / drug effects
  • Cross-Over Studies
  • Diabetes Mellitus, Type 1 / drug therapy*
  • Feasibility Studies
  • Female
  • Humans
  • Hypoglycemia / epidemiology
  • Hypoglycemic Agents / administration & dosage
  • Hypoglycemic Agents / therapeutic use*
  • Insulin / administration & dosage
  • Insulin / therapeutic use*
  • Insulin Infusion Systems*
  • Male


  • Blood Glucose
  • Hypoglycemic Agents
  • Insulin

Associated data