Insulin Pump With Blood Sugar Sensor May Improve on Injections
TUESDAY June 29, 2010 -- Type 1 diabetics who used an insulin pump and a sensor that continuously monitored their blood sugar levels had better control over their illness than people taking insulin injections, a large clinical trial finds.
Researchers divided 485 people aged 7 to 70 into two groups. One group performed multiple daily insulin injections and tested their blood sugar throughout the day, the standard treatment for type 1 diabetes.
The other group was taught to use an insulin pump and a blood glucose sensor from device maker Medtronic, which helped fund the study. The pump, about the size of a pager, delivers small amounts of insulin through a tiny tube inserted under the skin. Insulin is delivered throughout the day and can be adjusted according to food intake, while the sensor reads blood sugar levels every five minutes.
Even though the sensor can relay information to the pump, the sensor does not control the amount of insulin being delivered -- that is still calibrated and adjusted by the patient, the researchers explained. The sensor also has adjustable alarms for high and low blood sugar.
After one year, the group using the pump and sensor had significantly better blood sugar readings than those using injections, the study found.
At the start of the study, A1C levels (a measure of long-term blood sugar control) were 8.3 percent for both groups.
For those on the pump, A1C levels dropped to 7.5 percent compared to 8.1 percent for those using injections.
The A1C target for adults with diabetes is under 7 percent, while for teens the target is 7.5 percent and for children aged 6 to 12, it's 8 percent, explained study author Dr. Richard Bergenstal, executive director of the International Diabetes Center at Park Nicollet in Minneapolis and president of the American Diabetes Association. Studies suggest those thresholds can prevent many of the long-term complications of high blood sugar, while also helping to prevent dangerously low blood sugar levels.
Importantly, there was no difference in the incidence of hypoglycemia, or dangerously low blood sugar episodes, between the two groups, the authors found.
"This is a really important study that shows that a sensor and pump together can help people with type 1 diabetes in all age groups," Bergenstal said. "That children, adolescents and adults can improve their blood sugars without causing an increase in hypoglycemia or weight gain is a dramatic finding."
The study was published online June 29 in the New England Journal of Medicine and was to be presented at the American Diabetes Association annual meeting in Orlando, Fla.
The findings are especially good news for children and teens whose blood sugar can be more difficult to manage due to physiological changes and behavioral issues, Bergenstal said. A lot of teens don't want to be bothered with managing their diabetes, nor are children and teens known for thinking about the long-term implications of their behaviors.
In the study, nearly 44 percent of pediatric patients using the sensor-augmented pump achieved glucose control targets, compared to only 20 percent of pediatric patients in the injection group.
While the pump/sensor combination could improve the ability of diabetics to manage their blood sugar, the key to making the technology work are the patients who use it, said Dr. Howard Wolpert, a senior physician at the Joslin Diabetes Center in Boston.
Diabetics have to be willing to wear the devices, change the cannula (inserted tube) every few days, monitor what the sensor is telling them about their blood sugar and adjust their food intake and insulin levels accordingly, he said.
"These tools do take diabetes management to a higher level and can lower risk of long-term complications, but it's still just a tool," Wolpert said. "It's really the patient who is motivated and gets the proper guidance who can use this technology most effectively."
Short- and long-term blood sugar trends and patterns can also be downloaded from the device for viewing by the patient and doctors, Bergenstal noted.
Though often lumped together, type 1 and type 2 diabetes are in many ways different diseases. In type 1 diabetes, formerly called juvenile diabetes, the pancreas stops producing insulin, the hormone that enables the body to convert sugar and starches found in foods into energy.
About 5 percent to 10 percent of people with diabetes have type 1, according to the American Diabetes Association. Tight blood sugar control can minimize the risk of long-term complications, including kidney failure, blindness and nerve damage.
"It's important for people to realize there is a real change in the long-term outlook for the health of people with type 1 diabetes, and that's what this new technology represents," Wolpert said.
The Joslin Diabetes Center has more on type 1 diabetes, and the pros and cons of using an insulin pump.
Posted: June 2010
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