BACKGROUND: In patients with diabetes, hospitalization can complicate the achievement of recommended glycemic targets. There is increasing evidence that a closed-loop delivery system (artificial pancreas) can improve glucose control in patients with type 1 diabetes. We wanted to investigate whether a closed-loop system could also improve glycemic control in patients with type 2 diabetes who were receiving noncritical care.
METHODS: In this randomized, open-label trial conducted on general wards in two tertiary hospitals located in the United Kingdom and Switzerland, we assigned 136 adults with type 2 diabetes who required subcutaneous insulin therapy to receive either closed-loop insulin delivery (70 patients) or conventional subcutaneous insulin therapy, according to local clinical practice (66 patients). The primary end point was the percentage of time that the sensor glucose measurement was within the target range of 100 to 180 mg per deciliter (5.6 to 10.0 mmol per liter) for up to 15 days or until hospital discharge.
RESULTS: The mean (±SD) percentage of time that the sensor glucose measurement was in the target range was 65.8±16.8% in the closed-loop group and 41.5±16.9% in the control group, a difference of 24.3±2.9 percentage points (95% confidence interval [CI], 18.6 to 30.0; P<0.001); values above the target range were found in 23.6±16.6% and 49.5±22.8% of the patients, respectively, a difference of 25.9±3.4 percentage points (95% CI, 19.2 to 32.7; P<0.001). The mean glucose level was 154 mg per deciliter (8.5 mmol per liter) in the closed-loop group and 188 mg per deciliter (10.4 mmol per liter) in the control group (P<0.001). There was no significant between-group difference in the duration of hypoglycemia (as defined by a sensor glucose measurement of <54 mg per deciliter; P=0.80) or in the amount of insulin that was delivered (median dose, 44.4 U and 40.2 U, respectively; P=0.50). No episode of severe hypoglycemia or clinically significant hyperglycemia with ketonemia occurred in either trial group.
CONCLUSIONS: Among inpatients with type 2 diabetes receiving noncritical care, the use of an automated, closed-loop insulin-delivery system resulted in significantly better glycemic control than conventional subcutaneous insulin therapy, without a higher risk of hypoglycemia. (Funded by Diabetes UK and others; ClinicalTrials.gov number, NCT01774565 .).
Good data to support a study looking at length-of-stay as an outcome, but premature to put into practice.
Sliding scale insulin therapy is a poor way to treat diabetes. Closed loop insulin therapy will require training clinicians, though as we are accustomed to sliding scale.
The authors detected a 24% improvement in the (disease-oriented) primary outcome for the closed-loop group. Although there was no significant difference in hypoglycemia or amounts of insulin administered, there was a reduction of hyperglycemic events (glucose >360 mg/dL, 18 vs 41 [p=0.03]). From a safety perspective, there were three device deficiencies over the course of the trial. It's premature to consider a cost-effectiveness analysis, but understanding the resource savings might help hospitals consider this as an option in the future. Although this trial is not enough to change clinical practice by itself, it represents another step on the journey to consider closed-loop glucose delivery for patients with type 2 diabetes in the ambulatory setting. Most general internists would benefit from tracking this work as it will directly impact their patients with type 2 diabetes.
As a practicing hospital medicine attending, I find controlling blood sugars optimally in the hospitalized patients can be particularly challenging. The discussion about the delivery of automated insulin is very interesting and yet another way technology can be used for better patient care.