Continuous glucose monitoring can help patients manage type 1 diabetes

29 June 2005

Minneapolis, USA. Results of a pilot study show participants actively used real-time glucose readings to better control glucose fluctuations. Diabetes patients in the study used Medtronic's Guardian RT Continuous Glucose Monitoring System to monitor glucose levels throughout the day and night. The system is designed to help patients reduce erratic blood sugar (glucose) fluctuations that can result in diabetes-related complications, including coma, blindness, kidney failure, amputation, impotence and heart disease.

During the 10-day pilot study, 16 patients responded to glucose values as well as high and low alerts displayed on the screen of a Guardian RT System to make proactive therapy decisions (following a confirmatory finger stick measurement) for improved diabetes management. Ninety-four percent (n=15) of the study participants actively used the real-time glucose values and/or high or low glucose alerts to control glucose fluctuations; 75 percent (n=12) adjusted their insulin delivery; 63 percent (n=10) changed their diet; and 31 percent (n=5) made lifestyle changes after gleaning insights from real-time continuous glucose monitoring (CGM).

In addition, 81 percent (n=13) of patients reported greater satisfaction with their blood glucose control when using the Guardian RT system. No severe hypoglycemic (low blood sugar) or hyperglycemic (high blood sugar) events were reported.

"These findings suggest that the Guardian RT System has the potential to help diabetes patients make more informed treatment decisions, and on a more proactive basis, compared to random fingerstick measurements that patients rely on today," said Dr. Dorothee Deiss, diabetologist at the Charite clinic in Berlin, Germany. "In addition, our clinic has 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."

The pilot study, entitled "First Experience Using The Guardian RT Continuous Glucose Monitoring With Real-Time Values and Alerts in Type 1 Diabetes Mellitus Patients; Results of a Pilot Study" (Abstract Number: 393-P), was presented at the 65th Annual Scientific Sessions of the American Diabetes Association.

Results of the pilot study are preliminary and no definitive conclusions can be made without confirmation of a larger study. A randomised, controlled, multi-center study is underway using the Guardian RT System in 162 diabetes patients in Germany, France, Sweden, Italy, United Kingdom, Slovenia, and Israel. The goal of the larger study is to achieve a reduction in A1C levels of 0.5 percent or more (an A1C test measures blood sugar control over a three-month period). The study 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. Results of this larger study are expected to be available this summer.

The Guardian RT continuous glucose monitoring system

The Guardian RT System is designed to use a subcutaneous glucose sensor, which records as many as 288 glucose readings per day - providing nearly 100 times more information than three daily fingerstick readings provide. The continuous glucose sensor is a tiny electrode that is inserted under the skin using the Sen-Serter(R), a small device that makes sensor insertion easy for patients or their caregivers. The sensor measures glucose in the interstitial fluid found between the body's cells, and is typically discarded and replaced after three days of use.

Glucose measurements obtained by the sensor are relayed every five minutes from a transmitter to the Guardian RT's monitor, which displays the glucose value on its screen. In addition, alarm thresholds can be preset to alert patients when glucose levels become too high or too low. The alarm feature is designed to provide added assurance to patients for managing erratic glucose patterns.

Medtronic anticipates real-time continuous glucose readings to be a more advanced method for assessing glucose control compared to today's standards of A1C tests and fingerstick measurements. An A1C test is only an average - it does not reveal day-to-day glucose fluctuations that can cause short and long-term health complications.

Similarly, fingerstick measurements are limited since they only reveal a glucose value at a single moment in time. Patients using fingerstick measurements are unable to detect approximately 60 percent of low blood sugar (hypoglycemia) events and have difficulty assessing blood sugar fluctuations while they sleep. In contrast, the Guardian RT system is designed to provide real-time glucose readings throughout the day and night, allowing patients to understand how fast, and in what direction, their glucose levels are heading.

By discovering how diet, exercise, medication and lifestyle affect their glucose levels, patients can make more informed treatment decisions to improve their diabetes management. The Guardian RT System is designed so that patients can also download information to a computer and print reports highlighting their glucose patterns for further analysis and discussion with their healthcare providers. Medtronic's supplemental pre-market approval application is currently under review by the United States Food and Drug Administration (FDA).

Diabetes statistics

Diabetes is reaching epidemic proportions worldwide. According to the International Diabetes Federation's latest figures, approximately 194 million adults have diabetes worldwide, and this number is expected to reach 333 million by the year 2025. More than 18 million Americans are estimated to have diabetes, with an approximately 5.2 million undiagnosed according to the Centers for Disease Control and Prevention. Diabetes is the sixth-leading cause of death in the United States.

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