Why Use CGM (Continuous Glucose Monitoring)

Why use CGM (Continous Glucose Monitoring)?

The field of Diabetes is rapidly evolving, with newer technologies emerging as we speak. Gone are the days, where single point testing like GRBS or Fasting/post lunch blood sugars were the only means of glucose testing. Enter CGM (Continuous Glucose Monitoring). This technology has been available to us for the last 10 years and many new aspects of the behaviour of the glucose patterns in various types of Diabetic patients are now available to us. Every Diabetic is different, some have a high fasting levels, some have high post meals, some have a night time rise in glucose and some just do not have a pattern, The only way to exactly know this pattern was previously, multiple daily finger prick testing which was painful and cumbersome.

CGM which uses glucose sensors are inserted into the subcutaneous tissue, virtually painless. The tiny filament which is inserted starts to check interstitial fluid glucose, which correlates well with the plasma glucose. Real time sensors are now available, which check the glucose levels every 1 min! The data is stored in a chip for about 1-2 weeks which is then transferred onto a reader upon scanning the sensor, via bluetooth. This data can be collated by a software into a graphical pattern which is easy for the patient and the doctor to analyse. The patient can immediately know what diet has changed his/her glucose levels and the doctor will know how effective the treatment strategy has been.

In patients on insulin who have used CGM, it becomes very clear, very early, as to which type of insulin is more suitable in their case. Also, what dose of insulin suits apatient, at what particular time, also surfaces clearly. For example, patients mostly require very less insulin before lunch and much higher doses after breakfast.

Nighttime low sugars are much more common than what the patient perceives. This is important to diagnose, as hypoglycemia unawareness can lead to coma and seizures.

Certain mild medications work very well for certain subset of patients, and it is very satisfying to see the immediate effect on the glucose levels.

On the other hand, CGM also exposes high glucose levels on patients using strong oral agents, despite the apparent control as shown in routine blood tests. These patients do very well when started on insulin.

On the whole, CGM data can bring a sense of clarity into the understanding of one's glucose patterns. It is also a strong mode of communication, which acts as a common platform between the patient and the doctor. Their whole illness surfaces onto the screen and any action taken by the doctor completely makes sense. I am certain that most CGM patients develop a bond with their doctor, because of this abridging technology.