In the Journals

Continuous use of closed-loop system increases time in range, decreases hypoglycemia

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April 14, 2016

Adults using a portable, wireless artificial pancreas system continuously in a home environment demonstrated reduced hypoglycemia and increased time in glycemic range vs. sensor-augmented pump use, both overnight and during the day, according to researchers.

Stacey Anderson, MD, an endocrinologist at the University of Virginia, and colleagues evaluated 30 adults (median age, 44 years; 43% women; 96% white; median type 1 diabetes duration, 19 years; median HbA1c, 7.3%) to determine the efficacy of a portable, wearable, wireless artificial pancreas system (the Diabetes Assistant running the Unified Safety System) on glucose control at home in overnight-only as well as continuous closed-loop control modes.

Participants underwent a 2-week baseline sensor-augmented pump period followed by 2 weeks of overnight-only closed-loop control and 2 weeks of continuous closed-loop control.

During the overnight-only closed-loop control, median time with glucose concentration at less than 70 mg/dL dropped from 3% during baseline sensor-augmented pump to 1.1% (P < .001), median time in target increased from 61% to 75% (P < .001), median time at more than 180 mg/dL decreased from 37% to 24% (P < .001), median glucose level decreased from 163 mg/dL to 150 mg/dL (P = .002) and median coefficient of variation decreased from 36% to 30% (P < .001).

Results were similar for continuous closed-loop control: median time at less than 70 mg/dL decreased from 4.1% at baseline to 1.7% (P < .001), median time in target increased from 65% to 73% (P < .001), median time at more than 180 mg/dL decreased from 32% to 25% (P = .001) and median coefficient of variation decreased from 38% to 34% (P < .001).

“Use of a completely portable, wireless hybrid [artificial pancreas] system in the home environment increases time in range and reduces hypoglycemia when the closed-loop system is active,” the researchers wrote. “Longer studies are needed to further establish safety, clinical outcomes over time, usability and system adaptation. Additional studies in children, those with hypoglycemia unawareness, and those with suboptimal control are presently ongoing.” – by Amber Cox

Disclosure: Anderson reports no relevant financial disclosures. Please see the full study for a list of all other authors’ relevant financial disclosures.