Multinight “Bedside” Closed-Loop Control for Patients with Type 1 Diabetes

Abstract

Background: Studies of closed-loop control (CLC) systems have improved glucose levels in patients with type 1 diabetes. In this study we test a new CLC concept aiming to ''reset'' the patient overnight to nearnormoglycemia each morning, for several consecutive nights. Subjects and Methods: Ten insulin pump users with type 1 diabetes (mean age, 46.4 -8.5 years) were enrolled in a two-center (in the United States and Italy) randomized crossover trial comparing 5 consecutive nights of CLC (23:00-07:00 h) in an outpatient setting versus sensor-augmented insulin pump therapy of the same duration at home. Primary end points included time spent in 80-140 mg/dL as measured by continuous glucose monitoring overnight and fasting blood glucose distribution at 7:00 h. Results: Compared with sensor-augmented pump therapy, CLC improved significantly time spent between 80 and 140 mg/dL (54.5% vs. 32.2%; P < 0.001) and between 70 and 180 mg/dL (85.4% vs. 59.1%; P < 0.001); CLC reduced the mean glucose level at 07:00 h (119.3 vs. 152.9 mg/dL; P < 0.001) and overnight mean glucose level (139.0 vs. 170.3 mg/dL; P < 0.001) using a marginally lower amount of insulin (6.1 vs. 6.8 units; P = 0.1). Tighter overnight control led to improved daytime control on the next day: the overnight/next-day control correlation was r = 0.52, P < 0.01. Conclusions: Multinight CLC of insulin delivery (artificial pancreas) results in significant improvement in morning and overnight glucose levels and time in target range, with the potential to improve daytime control when glucose levels were ''reset'' to near-normoglycemia each morning.

Multinational Home Use of Closed-Loop Control Is Safe and Effective

“…This pathway included several feasibility and safety trials in hotel settings (8,12,13), summer camp studies testing DiAs in children with diabetes (14,15), and the recently completed overnight (16) and 42-h dinner-overnight (17) trials of CLC at home. Here, we describe the first longer-term use of DiAs–USS Virginia at home using a completely wireless and portable, wearable AP system.…”

Predictive Hyperglycemia and Hypoglycemia Minimization: In-Home Evaluation of Safety, Feasibility, and Efficacy in Overnight Glucose Control in Type 1 Diabetes

“…In general, these systems use feedback from continuous glucose sensors to inform insulin delivery based upon current glucose values, rate of change, and various prediction models. Several approaches have demonstrated the feasibility of feedback-based insulin modulation, and advances in both sensor performance and algorithms have demonstrated a reduction in hypoglycemia, glucose variability, and decreased mean glucose levels in controlled inpatient settings (1–5) as well as outpatient studies (6–13) extending to 12 weeks of use in the home setting (14). …”

Hypoglycemia Reduction and Accuracy of Continuous Glucose Monitoring

“…10 It was also shown that real-time CGM reduced significantly severe hypoglycemia while improving hemoglobin A1c in patients with established hypoglycemia unawareness. 11 Moreover, virtually all contemporary studies of threshold 12 or predictive 13 low glucose suspend and closedloop control (known as the artificial pancreas) [14][15][16][17][18] report significant reduction of hypoglycemia achieved by real-time control algorithms using CGM data as their principal source of information. Thus, CGM data contain valuable information that, if sufficiently accurate and correctly interpreted by the patient or by automated algorithms, can help with optimization of diabetes control and with reducing the risk for hypoglycemia.…”