Day and Night Closed-Loop Control in Adults With Type 1 Diabetes Mellitus

A comparison of two closed-loop algorithms driving continuous subcutaneous insulin infusion versus patient self-management

  1. on behalf of the AP@home consortium
  1. 1Department of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
  2. 2Department of Statistics, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
  3. 3Wellcome Trust-MRC Institute of Metabolic Science and NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge, U.K.
  4. 4Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Graz, Austria
  5. 5Department of Endocrinology, Diabetes, and Nutrition and INSERM Clinical Investigation Center CIC 1001, Centre Hospitalier Regional Universitaire Montpellier and University of Montpellier I, Montpellier, France
  6. 6Department of Information Engineering, University of Padova, Padova, Italy
  7. 7Department of Medicine, University of Padova, Padova, Italy
  8. 8Department of Computer Engineering and System Sciences, University of Pavia, Pavia, Italy
  9. 9Profil Institute for Metabolic Research, Neuss, Germany
  1. Corresponding author: Yoeri M. Luijf, y.m.luijf{at}


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, 8.27, 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.

  • Received September 25, 2012.
  • Accepted July 10, 2013.

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  1. Diabetes Care
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