Is an automatic pump suspension feature safe for children with type 1 diabetes? An exploratory analysis with a closed-loop system.

OBJECTIVES

It has been proposed that the first step towards a closed-loop artificial pancreas might be to use a continuous glucose sensor to automatically suspend the basal insulin delivery based on projected low sensor glucose values.

METHODS

We reviewed our recent experience with an artificial pancreas system, utilizing a proportional-integrative-derivative (PID) algorithm, in 17 adolescents with type 1 diabetes (T1D) to assess the safety and efficacy of this maneuver.

RESULTS

During 34 h of closed-loop automated insulin delivery, 18 pump suspensions > or =60 min (90 +/- 18 min) occurred in eight subjects. Sensor glucose levels fell from 159 +/- 42 mg/dL to a nadir of 72 +/- 13 mg/dL. Corresponding plasma glucose levels fell from 168 +/- 51 to 72 +/- 16 mg/dL, with values <60 mg/dL recorded in only four of the 18 events.

CONCLUSIONS

These data suggest that automatic pump suspension using the PID algorithm may be an effective means to prevent hypoglycemia in youth with T1D.