Medical Device Daily Executive Editor

SAN DIEGO – The Medtronic Diabetes (Northridge, California) unit of Medtronic (Minneapolis) said participants in a pilot study, whose results were reported over the weekend, used its Guardian RT continuous glucose monitoring system to make therapy decisions for improved diabetes management.

The patients responded to glucose values displayed by the system, along with “high” and “low” alerts, following confirmatory fingerstick measurements.

Dr. Dorothee Deiss, a diabetologist at the Charite Clinic (Berlin, Germany), reported during the American Diabetes Association (ADA; Alexandria, Virginia) meeting that 94% – 15 of 16 – of the patients in the small study used the real-time glucose values and/or high or low glucose alerts to control glucose fluctuations.

Other findings during the 10-day study included 81% of the participants reporting greater satisfaction with their blood glucose control; 75% adjusting their insulin delivery based on Guardian RT data; 63% changing their diet as a result of that data; and 31% making “lifestyle changes” based on the insights they received from real-time continuous monitoring.

No severe hypoglycemic (low blood sugar) or hyperglycemic (high blood sugar) events were reported by those taking part in the pilot study.

Deiss said the findings “suggest that the Guardian RT System has the potential to help diabetes patients make more informed treatment decisions, on a more proactive basis, compared to random fingerstick measurements that patients rely on today.”

She said the clinic “noticed that patients using real-time readings have more confidence in managing their disease, particularly at night, which often is a critical time for patients who struggle from severe hypoglycemia.”

Medtronic said a randomized, controlled study is under way using the Guardian system, involving 162 patients in France, Germany, Israel, Italy, Slovenia, Sweden and the UK. Its goal is to achieve a reduction in A1c levels – A1c being a test that measures average blood sugar levels over a two- to three-month period – of 0.5% or more.

The larger study, whose results are expected to be available later this summer, also will evaluate the number and duration of high and low blood sugar fluctuations, average daily blood glucose, quality of life and the health economic impact associated with improved glycemic control.

Medtronic’s Guardian RT System uses a subcutaneous glucose sensor that records as many as 288 glucose readings a day. The sensor is a small electrode that is inserted under the skin and measures interstitial fluid, which is found between the body’s cells.

Readings are relayed every five minutes to a monitor that displays the glucose value. Alarm thresholds can be pre-set to alert patients when glucose levels become too high or low. The system also allows patients to download information to a computer and print reports on their glucose patterns for discussion with their physicians.

Medtronic’s supplemental premarket approval application for the device is under review by the FDA.

The company also noted that three other studies reported at the ADA demonstrated the value of insulin pump therapy in lowering A1c levels in Type 1 diabetic pediatric patients.

In an international study of 1,041 Medtronic insulin pump users, children with Type 1 diabetes were studied in 30 centers in 17 countries. Children who used their insulin pump to deliver bolus dosages – extra insulin – had “significantly better” A1c levels.

In addition, the A1c levels of those children in the study who had less than half their total daily insulin delivered as a baseline, or basal, rate were significantly better than those with a higher daily basal rate. Medtronic said that indicates that “patients were able to achieve better blood sugar control” by “fine-tuning” bolus and basal insulin delivery with an insulin pump.

A study involving 102 patients with a mean age of 12.4 years showed “sustained significant improvements in A1c levels for up to three years” using insulin pump therapy compared to levels prior to pump use.

“At the final study evaluation,” said Medtronic, “75% of patients had a lower A1c level than they had prior beginning pump therapy.”

Another study followed 27 patients, ages 2 to 7, over a two-year period and found pump therapy a safe and effective alternative to twice-daily insulin injections. When comparing pump therapy to twice-a-day injections, said Medtronic, pump users had fewer sick days and reduced episodes of severe hypoglycemia. A1c levels also were improved after the switch to pump therapy, according to the company.