Feasibility Study of Automated Overnight Closed-Loop Glucose Control Under MD-Logic Artificial Pancreas in Patients with Type 1 Diabetes: The DREAM Project

Background: Artificial pancreas systems may offer a potential major impact on the normalization of metabolic control and preventing hypoglycemic events. This study aims to establish near-normal overnight glucose control and reduce the risk of nocturnal hypoglycemia using the MD-Logic Artificial Pancreas (MDLAP), an algorithm that was developed by our research group. This inpatient feasibility study is the first step towards implementing an overnight closed-loop MDLAP system at the patient's home. Subjects and Methods: Seven patients with type 1 diabetes (three adolescents and four adults; mean +/- SD age, 20.6 +/- 4.7 years; duration of diabetes, 9.6 +/- 2.6 years; body mass index, 24.3 +/- 3.9 kg/m(2); and glycated hemoglobin, 7.8 +/- 0.8%) participated in a total of 14 closed-loop overnight sessions. Each participant underwent two closed-loop inpatient sessions starting at dinner alone and at dinner following exercise. The closed-loop inpatient sessions were compared with data derived from nights spent at home with an open-loop system in a similar scenario to the study protocol. Results: The mean percentage of time spent in the near normal glucose range of 63-140mg/dL was 83 +/- 16%, and the median (interquartile range) was 85% (78-92%) for the overnight closed-loop sessions compared with 34 +/- 31% and 27% (6-57%) in the homecare open-loop setting, respectively. During the overnight closed-loop sessions at dinner alone 92 +/- 9% of the sensor values ranged within target range, compared with 73 +/- 19% for the sessions following exercise (P = 0.03). No hypoglycemic (< 63 mg/dL) events occurred during the closed-loop sessions. Conclusion: Closed-loop insulin delivery under MDLAP is a feasible and safe solution to control overnight glycemia.