By Steven Reinberg
The new pump automatically stops delivering insulin when the sensor finds blood sugar levels have reached a pre-set low level, and it reduced overnight episodes of low blood sugar (hypoglycemia) by a third, the researchers report.
"After years of hoping for a way to achieve our goal of getting good blood sugar control without a lot of low blood sugar, we are finally, with this new technology, getting close to our goal," said study lead author Dr. Richard Bergenstal, executive director of the International Diabetes Center at Park Nicollet in Minneapolis.
"Hypoglycemia has all of a sudden become an important topic," he said. "Now that we are able to keep blood sugar down, we are running up against hypoglycemia as being our biggest barrier to achieving the blood sugar control we want to get to prevent eye disease, kidney disease and amputations and heart disease."
The effects of hypoglycemia can range from dizziness to seizures to coma and death, according to Bergenstal. "Patients are scared to death saying, 'Am I going to go to sleep tonight and am I going to wake up tomorrow morning, or am I going to have a major problem in the night,'" he said.
This may also be another step to creating a so-called "artificial pancreas" for people with type 1 diabetes, who cannot make insulin on their own, Bergenstal added. "This is the first step that shows that the artificial pancreas can actually work," he said.
Although this device has been used in Europe, the new study is a move toward getting the device approved by the U.S. Food and Drug Administration.
The study was funded by Medtronic Inc., the maker of the device. The results of the study were published June 22 online in the New England Journal of Medicine, to coincide with a scheduled presentation at the American Diabetes Association annual meeting in Chicago.
"This is a very real difference for people with type 1 diabetes, because these patients often go to bed in fear of low blood sugar," said Dr. Ronald Tamler, director of the Mount Sinai Diabetes Center in New York City. He was not involved in the new study.
But he added that it remains to be seen whether patients are agreeable to wearing a sensor along with an insulin pump and whether they can trust the technology.
"Some patients may not be willing to wear a sensor in addition to an insulin pump and entrust themselves to devices that need to work accurately and in harmony to succeed," he said. "It's a matter of practically and trust."
For the study, 247 patients with type 1 diabetes who were subject to hypoglycemia during the night were randomly assigned to the new device or a standard insulin pump for three months.
Patients wore a sensor along with an insulin pump. When the sensor sensed that blood sugar was getting too low overnight, the software was programmed to stop the pump for a short while.
The researchers found that the new device cut the times patients experienced hypoglycemia by 37.5 percent, compared with patients who didn't have the new device.
In addition, patients using the new device had about 32 percent fewer bouts of hypoglycemia during the night and 31.4 percent fewer hypoglycemia events during the day, the researchers found.
Moreover, the device had no effect on blood sugar levels, which were controlled in both groups.
Dr. Spyros Mezitis, an endocrinologist at Lenox Hill Hospital in New York City, agreed that with the sensor, "we are one step closer to the artificial pancreas."
"This is an upgrade of the insulin pump and patients can avoid night-time low blood sugar, by using this technology," he said.