A massive study involving 485 people with type 1 diabetes at 30 locations across North America shows that the combination of an insulin pump and a continuous glucose monitor helps patients achieve significantly lower A1c levels than multiple daily insulin injections.
The year-long STAR 3 study (Sensor-Augmented Pump Therapy for A1c Reduction) enrolled type 1 participants whose ages ranged from seven to 70 and who had never used insulin pump therapy. By the end of the study patients using the sensor/insulin pump combination saw their A1c levels drop from an average of 8.3 to 7.5. In contrast, the average A1c of members in the group receiving multiple daily injections of insulin dropped from 8.3 to 8.1. (The A1c target for most people with diabetes is 7.0.)
In addition, the sensor/insulin pump group experienced no increase in severe hypoglycemia despite the large drop in their average A1c’s.
The study, sponsored by Medtronic, Inc., and with support from by Novo Nordisk, Lifescan, Bayer Heathcare, and Becton Dickinson, used Medtronic’s Medtronic’s MiniMed Paradigm REAL-Time system. The system works by combining a sensor, insulin pump and management software. The under-the-skin sensor continuously monitors blood glucose levels throughout the day and sends readings to the insulin pump. Users can then determine from those readings whether to dose themselves with insulin, say, to stave off hypoglycemia, or adjust upcoming doses.
The system displays three and 24-hour glucose trends, including the speed and direction of trends, and vibrates or sounds when glucose trends too high or low.
In contrast, the standard routine of multiple daily injections requires people with diabetes monitor themselves throughout the day with blood glucose meters and then adjust their insulin doses according to how they think they are trending. Experienced insulin takers become pretty good and figuring their trends, but also know that trends can seem almost quirky at times and hard to anticipate.
STAR 3 is Medtronic’s third extensive test of pump technology. STAR 1 evaluated the safety and effectiveness of a sensor/pump combination in contrast to pump-only therapy. STAR 2 sought the best educational and training approaches to teaching people how to use a sensor/pump combination. STAR 3 then tested insights from the previous studies.
Highlights of the study, according to Medtronic, include:
- A four-times greater reduction in A1c levels over a year for the sensor/pump group versus the multiple daily injections group.
- A full 1 percent reduction in A1c levels, from 8.3 to 7.3, for adult STAR 3
- No increase in the rate of hypoglycemia among sensor/pump users. Hypoglycemia is a common risk in situations that call for intense insulin use.
- Consistent sensor/pump use reduced A1c levels even further. Patients who used the sensor more than 81 percent of the time reduced their A1c’s by an average of 1.2.
- Nearly 44 percent of pediatric patients using the sensor/pump combination achieved the age-specific blood glucose levels recommended by the American Diabetes Association, compared to 20 percent of youths using the multiple daily injection therapy.
Medtronic has published the results of STAR in the New England Journal of Medicine. The paper is entitled, “Effectiveness of Sensor-Augmented Insulin-Pump therapy in Type 1 Diabetes.”