Validating Continuous Glucose Sensor Technology

Investigators:

• Tim Wysocki, PhD (PI)
• Nelly Mauras, MD
• Larry A. Fox, MD

Background:

Keeping blood glucose levels as close to normal as possible is one of the key goals of the management of type 1 diabetes mellitus. For roughly the past 25 years, conventional self-monitoring of blood glucose (SMBG) has been a main tool in helping patients to do this. SMBG involves pricking ones finger with a sharp lancet device. A small drop of blood is then placed on a test strip that is inserted into a glucose meter. The meter provides a reading of the blood glucose level and then stores it in memory for later computer download. SMBG is usually done about 4 to 6 times daily or whenever symptoms of high or low blood sugar are evident. Patients can use the blood glucose information to help them adjust their insulin doses, eating habits and physical activity to achieve good blood glucose control.

Within the past 5 years, new devices have been developed that provide almost continuous measurement of blood glucose levels. So, compared with SMBG that provides 4 to 6 "snapshots" of blood glucose level, these "continuous glucose sensors" provide readings that give a more complete picture of blood glucose changes, more like a movie, rather than a snapshot. The research team at Nemours has been involved in studying these devices since 2001. The technology behind these devices has improved to the point that continuous glucose sensors may soon become a key part of diabetes management, possibly even replacing SMBG some day. But, research is needed to determine the best way to use continuous glucose sensors in the treatment of diabetes.

What We're Doing:

Recently, Nemours received a 2-year grant from the Juvenile Diabetes Research Foundation International to be part of a 9-center study of continuous glucose sensors. This study will enroll 450 to 600 patients with type 1 diabetes ranging in age from 3 year-olds to adults. They will each be assigned by change to either continue using SMBG alone for checking their glucose levels (Standard Care) or to use a Continuous Glucose Sensor in addition to daily SMBG. Patients may use any of three continuous glucose sensors during the study. After 6 months in the randomly assigned groups, all patients in the study will be able to use a continuous glucose sensor for the following 6 months. The study will track patients diabetes outcomes, health care costs, quality of life, and treatment satisfaction and evaluate how patients and their families make sure of the sensor data for treatment adjustments. The primary goal of the study is to provide the data needed to prove to third party payers and health care policy makers that use of continuous glucose sensors in diabetes treatment is cost effective in promoting better metabolic control and lower health care costs.

Some of What We've Found:

Enrollment of patients and families into this study began in January, 2007 and is expected to continue for about 8-9 months until the full sample has entered the study. Each family will remain in the study for 1 year, and so the project will be continuing until about September, 2008.