Continuous Glucose Monitoring

Continuous glucose monitoring provides maximal information about shifting blood glucose levels throughout the day and facilitates the making of optimal treatment decisions for the diabetic patient. This report discusses continuous glucose monitoring in terms of its purposes, technologies, target populations, accuracy, clinical indications, outcomes, and problems. In this context, the medical literature on continuous glucose monitoring available through the end of 2004 is reviewed. Continuous glucose monitoring provides information about the direction, magnitude, duration, frequency, and causes of fluctuations in blood glucose levels. Compared with conventional intensified glucose monitoring, defined as three to four blood glucose measurements per day, continuous monitoring provides much greater insight into glucose levels throughout the day. Continuous glucose readings that supply trend information can help identify and prevent unwanted periods of hypo- and hyperglycemia. The difference between an intermittent and a continuous monitor for monitoring blood glucose is similar to that between a regular camera and a continuous security camera for monitoring an important situation. A regular camera takes discrete, accurate snapshots; its pictures do not predict the future; it produces a small set of pictures that can all be carefully studied; and effort is required to take each picture. A continuous security camera, on the other hand, takes multiple, poorly focused frames; displays a sequential array of frames whose trend predicts the future; produces too much information for each frame to be studied carefully; and operates automatically after it is turned on. The two types of blood glucose monitors differ in much the same way: 1 ) an intermittent blood glucose monitor measures discrete glucose levels extremely accurately, whereas a continuous monitor provides multiple glucose levels of fair accuracy; 2 ) with an intermittent monitor, current blood glucose levels do not predict future glucose levels, but with a continuous monitor, trends in glucose levels do have …