Automated fully closed-loop (CL) insulin delivery system without meal-bolusing was evaluated in medical and surgical non-critical care wards of two acute hospitals in Switzerland and United Kingdom. In a randomised controlled parallel design study, 136 adults with inpatient hyperglycaemia requiring subcutaneous (s/c) insulin were randomised to receive either CL-directed s/c insulin delivery (n=70) or conventional s/c insulin therapy as per local practice with masked continuous glucose monitoring (n=66) for up to 15-days. Participants consumed self-selected hospital meals and were matched for age (68±10 vs. 67±13 years; CL vs. control), HbA1c (7.8±2.5 vs. 8.0±1.9%) and BMI (32.7±8.2 vs. 32.3±8.1kg/m2). During CL, participant’s usual insulin and sulphonylurea therapy were withheld. In an intention to treat analysis, the proportion of time when sensor glucose was in target range from 5.6 to 10.0mmol/l was significantly higher during CL (p<0.001, Table). CL reduced time spent above target (p<0.001), and reduced mean and standard deviation of sensor glucose (p<0.001). Time spent hypoglycaemic was low and comparable. Total daily insulin delivery was not different. No severe hypoglycaemia or serious adverse events occurred in either group.

In conclusion, fully closed-loop without meal-bolusing is safe, and may improve glucose control in a heterogeneous inpatient population.

 Closed-loop insulin delivery (n=70) Conventional insulin therapy (n=66) P 
Time spent at sensor glucose levels (%) 
5.6 to 10.0 mmol/l 65.7±16.8 41.5±16.9 <0.001 
>10.0 mmol/l 23.7±16.6 49.5±22.8 <0.001 
<5.6 mmol/l 10.6±6.7 9.0±13.3 0.37 
<3.0 mmol/l 0.0 (0.0, 0.1) 0.0 (0.0, 0.0) 0.80 
Mean sensor glucose (mmol/l) 8.5±1.6 10.5±2.4 <0.001 
SD of sensor glucose (mmol/l) 2.6±1.0 3.2±1.1 <0.001 
Total daily insulin (U) 44.0 (27.5, 73.3) 40.2 (26.5, 65.6) 0.36 
Data are mean ± SD or median (IQR). 
 Closed-loop insulin delivery (n=70) Conventional insulin therapy (n=66) P 
Time spent at sensor glucose levels (%) 
5.6 to 10.0 mmol/l 65.7±16.8 41.5±16.9 <0.001 
>10.0 mmol/l 23.7±16.6 49.5±22.8 <0.001 
<5.6 mmol/l 10.6±6.7 9.0±13.3 0.37 
<3.0 mmol/l 0.0 (0.0, 0.1) 0.0 (0.0, 0.0) 0.80 
Mean sensor glucose (mmol/l) 8.5±1.6 10.5±2.4 <0.001 
SD of sensor glucose (mmol/l) 2.6±1.0 3.2±1.1 <0.001 
Total daily insulin (U) 44.0 (27.5, 73.3) 40.2 (26.5, 65.6) 0.36 
Data are mean ± SD or median (IQR). 

Disclosure

L. Bally: None. H. Thabit: None. S. Hartnell: Speaker’s Bureau; Self; Medtronic, Roche Pharma. E. Andereggen: None. Y. Ruan: None. M.E. Wilinska: None. M. Evans: Advisory Panel; Self; Novo Nordisk A/S, Eli Lilly and Company, Cellnovo, Roche Pharma. Speaker’s Bureau; Self; Abbott, Novo Nordisk A/S. M.M. Wertli: None. A.P. Coll: None. C. Stettler: None. R. Hovorka: Speaker’s Bureau; Self; Novo Nordisk A/S. Advisory Panel; Self; Novo Nordisk A/S. Speaker’s Bureau; Self; Eli Lilly and Company, AstraZeneca. Other Relationship; Self; B. Braun Medical Inc.. Research Support; Self; Medtronic. Other Relationship; Self; Medtronic. Research Support; Self; Abbott, JDRF, Diabetes UK, National Institute of Diabetes and Digestive and Kidney Diseases.

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