Overnight glucose control with an automated, unified safety system in children and adolescents with type 1 diabetes at diabetes camp

Abstract

Objective: To determine the safety and efficacy of an automated unified safety system (USS) in providing overnight closed-loop (OCL) control in children and adolescents with type 1 diabetes attending diabetes summer camps.

Research design and methods: The Diabetes Assistant (DIAS) USS used the Dexcom G4 Platinum glucose sensor (Dexcom) and t:slim insulin pump (Tandem Diabetes Care). An initial inpatient study was completed for 12 participants to evaluate safety. For the main camp study, 20 participants with type 1 diabetes were randomized to either OCL or sensor-augmented therapy (control conditions) per night over the course of a 5- to 6-day diabetes camp.

Results: Subjects completed 54 OCL nights and 52 control nights. On an intention-to-treat basis, with glucose data analyzed regardless of system status, the median percent time in range, from 70-150 mg/dL, was 62% (29, 87) for OCL nights versus 55% (25, 80) for sensor-augmented pump therapy (P = 0.233). A per-protocol analysis allowed for assessment of algorithm performance. The median percent time in range, from 70-150 mg/dL, was 73% (50, 89) for OCL nights (n = 41) versus 52% (24, 83) for control conditions (n = 39) (P = 0.037). There was less time spent in the hypoglycemic range <50, <60, and <70 mg/dL during OCL compared with the control period (P = 0.019, P = 0.009, and P = 0.023, respectively).

Conclusions: The DIAS USS algorithm is effective in improving time spent in range as well as reducing nocturnal hypoglycemia during the overnight period in children and adolescents with type 1 diabetes in a diabetes camp setting.

© 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Figures

Figure 1

DIAS control to range system.

Figure 2

USS. Glycemic risk as a function of glycemia by time of night. Glycemic risk is depicted to be high (red), moderate (amber), or low (green).

Figure 3

Per-protocol analysis of percent time spent in range for OCL nights (n = 41) versus sensor-augmented pump nights (n = 39). Results are mean ± SD. *P < 0.05.

Figure 4

Per-protocol analysis of sensor glucose values over 8 h during OCL (n = 41) versus sensor-augmented pump nights (n = 39). Results are mean ± SD.