What is CGM?

I have been talking about CGM for several weeks, maybe more.  My family and friends may think that I'm speaking another language.  I guess I am...so here's the translation from the language of diabetes for you.  And thank you for wanting to understand our new language!

CGM stands for Continuous Glucose Monitoring.  We currently monitor Ally's blood glucose levels by pricking her fingers a minimum of 8 times per day.  We prick her finger and use her blood glucose meter  to check levels when she wakes up, before each meal or snack, before/after exercise, before bathtime, before bed, in the middle of the night, whenever she looks pale, acts funny, says she's hungry...  Sounds like we should have all the hours in the day covered doesn't it?  Well, believe it or not there is a lot of time in between these checks that we have no idea about.  Glucose levels in the body are constantly changing.  Spot checking (by pricking her finger) only tells us what her blood glucose level is at that moment.  It's the in between stuff that we want to know more about.  Are we missing highs or lows in that time?  I know that her levels are like a roller coaster of ups and downs...as different things affect blood glucose levels - foods and how quickly those carbs are broken down into sugar, exercise, anxiety, excitement, illness...the list goes on.  But our goal is to try to keep those glucose levels within a safe range, safe for the moment and ultimately safe for her lifelong health.

So how does it work...
The Continuous Glucose Monitoring system (also known as MiniLink) includes a sensor and transmitter which can provide continuous glucose measurements to help you control your glucose levels better.  The sensor measures the glucose levels in the fluid under your skin.  (Blood Glucose Meters measure the glucose levels in the blood.)**  The transmitter takes electronic signals generated by the glucose sensor and sends them by radio frequency to the pump.

So, this is what Ally now wears (not her belly in the photo!).  A pump connected to her with a tube and small cannula inserted under the skin for delivering insulin.  Also a sensor inserted under the skin with the MiniLink Transmitter connected to it which sends glucose readings to the pump.  However, Ally's sites are located on her bum, not on her belly as she does not have enough fat there.

We have the Medtronics MiniMed Revel insulin pump.  The wonderful part about the MiniLink is that Medtronic integrates the CGM with the insulin pump.  Some of the other CGM systems require a separate receiver, which we do not need as our pump functions as the receiver.  However, I know several people who really LOVE their Dexcom CGM.  If you do not have a Medtronic pump, you should check out this post at The Princess and The Pump about their experience with Dexcom.

With the CGM, the pump will display a five minute average of Ally's current blood glucose level, updating every 5 minutes.  It will also show a trend arrow, pointing up if blood sugar levels are rising, and pointing down if blood sugar levels are dropping.  Double arrows if it is a rapid rise or fall.  We are hoping to catch lows and highs before they get to a dangerous level.  The CGM will also allow us to view a 3hour, 6hour or 24hour graph of her blood glucose readings right on her pump.   This information will help us to understand how foods, exercise, insulin, etc change her glucose levels.    Again, our goal is to reduce the risk of long-term health complications such as eye, nerve, heart, and kidney disease. 

Ally is all hooked up to her new pump and CGM.  At this moment, we are obsessed with looking at the glucose readings constantly.  Ally is GIDDY!  No matter what the number says, she will call out "Mom, my pump says I'm 197..hee hee...that's so cool!" 

**I do want to note that you cannot rely completely on the glucose level readings from the CGM.  We still will need to do finger pricks and test blood glucose using the glucose meter - maybe a little less often though.  Most of the time, glucose travels to your blood first and then to the fluid surrounding the cells in your tissue.  Therefore, you must use BG meter readings before treating any low or administering any insulin.