Safety of Outpatient Closed-Loop Control: First Randomized Crossover Trials of a Wearable

Artificial Pancreas

Featured Article:

Boris P. Kovatchev, Eric Renard, Claudio Cobelli, Howard C. Zisser,Patrick Keith-Hynes, Stacey M. Anderson, Sue A. Brown, Daniel R.

Chernavvsky, Marc D. Breton, Lloyd B. Mize, Anne Farret, Jérôme Place, Daniela Bruttomesso, Simone Del Favero, Federico Boscari, Silvia Galasso, Angelo Avogaro, Lalo Magni, Federico Di Palma, Chiara

Toffanin, Mirko Messori, Eyal Dassau, and Francis J. Doyle III

Diabetes Care Volume 37: 1789-1797

July, 2014

STUDY OBJECTIVE 

• To estimate the effect size of hypoglycemia risk reduction on closed-loop control (CLC) versus open-loop (OL) sensor-augmented insulin pump therapy in a supervised outpatient setting

Kovatchev B. P. et al. Diabetes Care 2014;37:1789-1797

STUDY DESIGN AND METHODS

• 20 patients with type 1 diabetes initiated the study at the Universities of Virginia, Padova, and Montpellier and Sansum Diabetes Research Institute

• 18 completed the entire protocol

• Each patient participated in two 40-h outpatient sessions, CLC versus OL, in randomized order

• Sensor (Dexcom G4) and insulin pump (Tandem t:slim) were connected to Diabetes Assistant (DiAs) (a smartphone artificial pancreas platform)

Kovatchev B. P. et al. Diabetes Care 2014;37:1789-1797

STUDY DESIGN AND METHODS

• The patient operated the system through the DiAs user interface during both CLC and OL

• Study personnel supervised onsite and monitored DiAs remotely

Kovatchev B. P. et al. Diabetes Care 2014;37:1789-1797

RESULTS

• The primary outcome [reduction in risk for hypoglycemia as measured by the low

• blood glucose (BG) index (LGBI)] resulted in an effect size of 0.64

• There was a twofold reduction of hypoglycemia requiring carbohydrate treatment: 1.2 vs. 2.4 episodes/session on CLC versus OL

• This result was accompanied by a slight decrease in percentage of time in the target range of 3.9–10 mmol/L and increase in mean BG on CLC versus OL

Kovatchev B. P. et al. Diabetes Care 2014;37:1789-1797

Kovatchev B. P. et al. Diabetes Care 2014;37:1789-1797

Kovatchev B. P. et al. Diabetes Care 2014;37:1789-1797

CONCLUSIONS

• CLC running on a smartphone (DiAs) in outpatient conditions reduced hypoglycemia and hypoglycemia treatments compared with sensor-augmented pump therapy

Kovatchev B. P. et al. Diabetes Care 2014;37:1789-1797