Research Paper Title

Home Use of an Artificial Beta Cell in Type 1 Diabetes.

Background

The feasibility, safety, and efficacy of prolonged use of an artificial beta cell (closed-loop insulin-delivery system) in the home setting have not been established.

Methods

In two multi-centre, crossover, randomised, controlled studies conducted under free-living home conditions, the researchers compared closed-loop insulin delivery with sensor-augmented pump therapy in 58 patients with type 1 diabetes. The closed-loop system was used day and night by 33 adults and overnight by 25 children and adolescents. Participants used the closed-loop system for a 12-week period and sensor-augmented pump therapy (control) for a similar period. The primary end point was the proportion of time that the glucose level was between 70 mg and 180 mg per deciliter for adults and between 70 mg and 145 mg per deciliter for children and adolescents.

Results

Among adults, the proportion of time that the glucose level was in the target range was 11.0 percentage points (95% confidence interval [CI], 8.1 to 13.8) greater with the use of the closed-loop system day and night than with control therapy (P<0.001). The mean glucose level was lower during the closed-loop phase than during the control phase (difference, −11 mg per deciliter; 95% CI, −17 to −6; P<0.001), as were the area under the curve for the period when the glucose level was less than 63 mg per deciliter (39% lower; 95% CI, 24 to 51; P<0.001) and the mean glycated haemoglobin level (difference, −0.3%; 95% CI, −0.5 to −0.1; P=0.002). Among children and adolescents, the proportion of time with the night-time glucose level in the target range was higher during the closed-loop phase than during the control phase (by 24.7 percentage points; 95% CI, 20.6 to 28.7; P<0.001), and the mean night-time glucose level was lower (difference, −29 mg per deciliter; 95% CI, −39 to −20; P<0.001). The area under the curve for the period in which the day-and-night glucose levels were less than 63 mg per deciliter was lower by 42% (95% CI, 4 to 65; P=0.03). Three severe hypoglycaemic episodes occurred during the closed-loop phase when the closed-loop system was not in use.

Conclusions

Among patients with type 1 diabetes, 12-week use of a closed-loop system, as compared with sensor-augmented pump therapy, improved glucose control, reduced hypoglycaemia, and, in adults, resulted in a lower glycated haemoglobin level.

Reference

Thabit, H., Tauschmann, M., Allen, J.M. et al (2015) Home Use of an Artificial Beta Cell in Type 1 Diabetes. New England Journal of Medicine. 373, pp.2129-2140. DOI: 10.1056/NEJMoa1509351.