Date Published | Dec. 20, 2007 

BY NORM TOLLINSKY

Medical science is still no match for the human body, but it’s getting close.

The newest Medtronic insulin pump and continuous glucose monitoring system come closer than ever to mimicking the human pancreas. The glucose monitoring system wirelessly transmits glucose readings to an insulin pump, alerting the wearer to blood glucose levels that fall above or below preset parameters.

Diabetics using the continuous monitoring device can manage their glucose levels more accurately and adjust insulin delivery to keep their blood sugar levels within a healthy range. A tiny sensor picks up glucose readings from an electrode inserted just below the skin and transmits average readings over a five-minute time span 288 times per day for display on the pump’s LCD screen.

When readings fall outside the preset parameters, the pump vibrates or beeps to warn the patient, who can then administer an extra dose of insulin at the press of a button.
The LCD screen also displays graphs for either three-hour or 24-hour time spans and arrows indicating how fast and in what direction the glucose level is trending.

The integrated monitoring and insulin delivery system empowers diabetics to “make the changes necessary to optimize their control,” said Karen Lyn, a clinical diabetes nurse specialist and Medtronic territory manager for Northern Ontario.

“People relying on fingerstick measurements get four or five readings a day. That’s all they’re seeing. But the day lasts 24 hours, so there are huge gaps. You could go two or three hours not knowing (about a high or low reading). With a continuous monitoring system, it’s just a press of a button to see if you’re on target and need to make changes.”

The continuous monitoring system still requires the use of fingerstick blood glucose monitoring twice a day for calibration purposes, but “the rest of the day it’s just a press of a button to find out what your blood sugar is,” said Lyn.

At the end of the day, patients can connect their pump to their computer via a USB cable and upload the readings to a secure website. The readings are displayed in graphs and accessible to health-care providers or family members regardless of where they’re located.

A 12-week randomized clinical outcome trial conducted to evaluate the use of continuous glucose monitoring found that patients using the Medtronic system experienced a one per cent reduction in HbA1c levels, versus a 0.4 per cent reduction in the control group using traditional intermittent blood glucose testing.

Clinical trials demonstrate that for every one per cent reduction in HbA1c levels (a measurement reflecting a patient’s average blood glucose control over a two to three-month period), there is a 35 per cent reduction in diabetes-related complications and a corresponding decrease in health-care costs, claims Medtonic.

Maintaining near-normal blood glucose control can reduce kidney complications by up to 56 per cent, nerve disease by up to 60 per cent, eye disease by up to 76 per cent and cardiovascular damage by up to 42 per cent, according to the company.

Continuous monitoring systems and insulin pumps aren’t suitable for everyone, but “if you can work a remote control for a television, you can learn how to use the pump,” said Lyn.

Cost is another factor. At $6,800, the device is expensive, although coverage is provided for children under the province’s Assisted Devices Program and by third-party insurance plans. Medtronic also offers payment option plans.

Diabetics interested in considering the use of continuous monitoring and insulin pump technology are advised to discuss the matter with their family physician and diabetes centre staff to find out about their options. Once they make a decision and acquire a device, they can schedule an appointment with a certified pump trainer at their closest diabetes centre to learn how to use it.

Pump technology has come a long way since the 1980s when it was first introduced, said Lyn. “It started off with a pump the size of a Kleenex box. Now it’s shrunk to the size of a pager.”

Pumps deliver fast-acting insulin via a tiny continuous drip, eliminating the pooling and irregular delivery of insulin resulting from the use of traditional delivery systems.

Using a pump, diabetics dramatically reduce the frequency of injections, from 1,440 per year (assuming four injections per day) to 144 infusion set changes per year (based on an infusion set change every two or three days).

Pumps can be purchased with or without the continuous glucose monitoring device.
A standalone continuous monitoring system recently introduced by Medtronic “is great for Type 2 diabetics who are on oral agents,” said Lyn. “It doesn’t deliver insulin but it gives people an opportunity to see if their current regime is working for them.”