The purpose of this study is to see whether low blood sugar at night can be reduced by using
a system that turns off the insulin pump automatically. The study system includes a
combination continuous glucose monitor (CGM)/ insulin pump made by Medtronic MiniMed, Inc and
a regular laptop computer that runs a computer program that predicts low blood sugar. It
works by (1) measuring the glucose levels under the skin with a continuous glucose monitor,
(2) using a computer program on a laptop to predict what will happen to the glucose level
over the next 35-55 minutes, and (3) turning off the insulin pump when the computer program
predicts that low blood sugar will occur.
This study has several phases and will take about 3 months for a patient to complete.
Patients will use the Medtronic CGM with the Enlite sensor at home for 10-15 days to be sure
that they are able and willing to use this system and to determine if they meet the
investigators study criteria to proceed with the next phase of the study. Patients will be
provided teaching on how to use CGM data in real time. If a patient is not using a Medtronic
CGM already, the patient will first use one at home for 10-15 days to be sure that he/she is
able and willing to use it. If a patient is already using a Medtronic CGM, then his/her most
recent 10-15 days of data will be used to find out if he/she is eligible. Those who need to
complete the CGM run-in phase will have an extra office visit for training.
If eligible to continue in the study, patients will need to use the study system for 5 nights
at home so that the investigators can make sure they are able to use it correctly. After
that, patients will be asked to use the study system each night for an additional 6 to 8
weeks. If the system is active and predicts that a patient's blood sugar will become low, the
insulin pump will shut off for up to 2 hours.
The study will include about 45 individuals at 3 clinical centers in the United States and