Day and night closed-loop control in adults with type 1 diabetes: a comparison of two closed-loop algorithms driving continuous subcutaneous insulin infusion versus patient self-management

Diabetes Care. 2013 Dec;36(12):3882-7. doi: 10.2337/dc12-1956. Epub 2013 Oct 29.


Objective: To compare two validated closed-loop (CL) algorithms versus patient self-control with CSII in terms of glycemic control.

Research design and methods: This study was a multicenter, randomized, three-way crossover, open-label trial in 48 patients with type 1 diabetes mellitus for at least 6 months, treated with continuous subcutaneous insulin infusion. Blood glucose was controlled for 23 h by the algorithm of the Universities of Pavia and Padova with a Safety Supervision Module developed at the Universities of Virginia and California at Santa Barbara (international artificial pancreas [iAP]), by the algorithm of University of Cambridge (CAM), or by patients themselves in open loop (OL) during three hospital admissions including meals and exercise. The main analysis was on an intention-to-treat basis. Main outcome measures included time spent in target (glucose levels between 3.9 and 8.0 mmol/L or between 3.9 and 10.0 mmol/L after meals).

Results: Time spent in the target range was similar in CL and OL: 62.6% for OL, 59.2% for iAP, and 58.3% for CAM. While mean glucose level was significantly lower in OL (7.19, 8.15, and 8.26 mmol/L, respectively) (overall P = 0.001), percentage of time spent in hypoglycemia (<3.9 mmol/L) was almost threefold reduced during CL (6.4%, 2.1%, and 2.0%) (overall P = 0.001) with less time ≤2.8 mmol/L (overall P = 0.038). There were no significant differences in outcomes between algorithms.

Conclusions: Both CAM and iAP algorithms provide safe glycemic control.

Publication types

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

MeSH terms

  • Administration, Cutaneous
  • Adult
  • Algorithms*
  • Blood Glucose / metabolism*
  • Blood Glucose Self-Monitoring / methods*
  • Cross-Over Studies
  • Diabetes Mellitus, Type 1 / blood
  • Diabetes Mellitus, Type 1 / drug therapy*
  • Equipment Design
  • Female
  • Follow-Up Studies
  • Humans
  • Hypoglycemic Agents / administration & dosage
  • Infusion Pumps
  • Insulin / administration & dosage*
  • Insulin Infusion Systems*
  • Male
  • Self Care / methods*
  • Treatment Outcome


  • Blood Glucose
  • Hypoglycemic Agents
  • Insulin

Associated data

  • ISRCTN/ISRCTN62034905