Sensor-Augmented Insulin Pump Therapy Trumps Multiple Daily Injections in Type 1 Diabetes

Fran Lowry

June 30, 2010

June 30, 2010 (Orlando, Florida) — In patients with type 1 diabetes and poor glycemic control, the use of a sensor-augmented insulin pump significantly improved their glycated hemoglobin levels, compared with a regimen of multiple daily insulin injections, according to a new study presented in a late breaking session here at the American Diabetes Association (ADA) 70th Scientific Sessions and published online June 29 in the New England Journal of Medicine.

Treatment with a sensor-augmented insulin pump not only provided superior glucose control, it did so without any increase in hypoglycemia, said lead author Richard M. Bergenstal, MD, from the International Diabetes Center, Park Nicollet, Minneapolis, Minnesota.

"The pump is considered an advanced way to deliver insulin for many people with type 1 diabetes," Dr. Bergenstal told Medscape Medical News in an interview. "But what we looked at in this study is the next level — of pump and sensor together. Pumps are great, but sensors are adding another level."

People with type 1 diabetes all learn how to do multiple daily injections and the principles of managing their condition, including carbohydrate counting and blood glucose testing. But if they are not at goal after all of this, the question becomes what to do next, he said. "Should we just add a pump or just add a sensor? Or should we add a sensor and a pump? We decided to use the most advanced technology together to see how much improvement it would generate."

Sensor-augmented pump therapy integrates 2 technologies — an insulin pump and continuous glucose monitoring — into one system. It allows patients and their physicians to monitor treatment and response through Internet-based software.

The Sensor-Augmented Pump Therapy for A1c Reduction (STAR 3) study involved 329 adults and 156 children between the ages of 7 and 70 years who had been on multiple daily injections that included a long-acting analogue insulin for the previous 3 months. They had a glycated hemoglobin level between 7.4% and 9.5%, and had been under the care of Dr. Bergenstal or a referring physician for at least 6 months.

The patients had to have access to a computer to participate in the trial.

They were randomly assigned to receive either pump therapy with the MiniMed Paradigm REAL-Time System (Medtronic) or to continue with their regimen of multiple daily injections under close supervision for the duration of the 1-year study.

All patients in the study also received training in intensive diabetes management, including carbohydrate counting and the administration of correction doses of insulin. Patients randomized to pump therapy were put on it for 2 weeks, and then, once they had become comfortable with the pump, the glucose sensor was added. This group used insulin aspart.

The injection-therapy group used both insulin glargine and insulin aspart.

All patients were seen at 3, 6, 9, and 12 months and used Carelink, a diabetes-management software program, to relay their blood glucose data to and communicate with their physicians from home.

"Here you see the importance of not only the technology, but the communication of the data back and forth. Sometimes, we give a patient a technology and then we send them home, with a 'good luck and hope it works.' In this trial, we wanted to know how things were working so we could help the patients adjust their treatment," Dr. Bergenstal said.

At 1 year, the investigators found that patients on pump therapy had hemoglobin A1c levels that were significantly lower than the injection-therapy group. The baseline mean glycated hemoglobin level, which was 8.3% in the 2 study groups, had decreased to 7.5% in the pump therapy group, compared with 8.1% in the injection therapy group (P < .001).

The proportion of patients who reached the glycated hemoglobin target of below 7% was greater in the pump therapy group than in the injection therapy group. Among adults, the absolute reduction in the mean glycated hemoglobin level was 1.0% ± 0.7% in the pump-therapy group and 0.4% ± 0.8% in the injection-therapy group, for a between-group difference in the pump-therapy group of –0.6% (95% confidence interval, –0.8 to 0.4%; P < .001).

Rates of severe hypoglycemia and diabetic ketoacidosis were similar in both groups. There was no significant weight gain in either group or in either adults or children.

"It is the longest and largest randomized controlled study of sensor-augmented insulin pump therapy in type 1 diabetes. We feel really good about the results we have obtained," Dr. Bergenstal said.

"These technologies have been under development for a while, but tying them together has been the challenge," said David Kendall, MD, chief scientific and medical officer of the ADA in Alexandria, Virginia.

"It's very exciting to see that the technologies can be applied and that, first and foremost, patients are well served. In this case, they achieved good control of their diabetes with excellent safety."

Dr. Kendall added that he was encouraged by the fact that the sensor-augmented insulin pump was not associated with increased hypoglycemia. "We know that hypoglycemia limits both enthusiasm for and adherence to treatment. Having 2 very useful technologies tied together to do this safely and effectively is very good news."

The study was supported by Medtronic, Novo Nordisk, LifeScan, Bayer Healthcare, and Becton Dickinson. Dr. Bergenstal reports that the International Diabetes Center has received consulting fees from Abbott Diabetes Care, Amylin, Bayer, Calibra, Eli Lilly, Intarcia, MannKind, Medtronic, Novo Nordisk, Pfizer, ResMed, Roche, Sanofie-Aventis, and Takeda for his services; and reports financial relationships with Abbott Diabetes Care, Amylin, Bayer, Biodel, Calibra, Eli Lilly, Hygieia, Intarcia, Intuity, LifeScan, MannKind, Medtronic, Novo Nordisk, Pfizer, ResMed, Roche, Sanofi-Aventis, Takeda, UnitedHealthGroup, and Valeritas. Dr. Kendall reports financial relationships with Amylin Pharmaceuticals, Inc., Bayer Vital Pharma, Daiichi-Sankyo, Eli Lilly and Company, Intarcia Therapeutics Inc., Merck & Co, Inc., Roche Pharmaceuticals, Takeda Pharmaceuticals North America Inc., UnitedHealthGroup/i3 Drug Safety, Abbott Diabetes Care, Dexcom, MannKind Corporation, Medtronic MiniMed, and Sanofi-Aventis.

N Engl J Med. Published online June 29, 2010.

American Diabetes Association (ADA) 70th Scientific Sessions. Presented June 29, 2010.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.