More thoughts on continuous glucose monitoring (CGM) here: Like you, I anxiously await the mainstreaming of this utopia of diabetes management.
It's great to see progress, like European approval of Abbott's much-hailed Navigator system, and FDA approval of a seven-day-wear version for DexCom. (The company will host an open conference call to discuss the new product on Monday, June 11, at 1:30pm Pacific.)
As noted yesterday, however, I believe the benefits of CGM aren't quite outweighing the drawbacks for users just yet.
Dr. Martha Nolte of UC San Francisco summed it all up nicely in a recent presentation at that university's annual Diabetes Patient Symposium:
"CGMS — Does it help?" one of her slides asked, rhetorically, and then:
• Alarms for high and low blood sugars and
trend alarms allow earlier intervention,
prevent more severe highs and lows.
• 24-hour trend data helps fine tune insulin
• Improves HbA1c
All good stuff. BUT... followed by a number of slides outlining the drawbacks, including inconvenience, low accuracy and high cost.
For specifics, check out these comparison charts* she presented:
Start-up time on the newer CGMs is two to ten hours, and the best accuracy for an FDA approved model is just 72%, which means nearly 30% innaccuracy. Ugh.
In addition, Dr. Nolte says "all of the CGMS devices miss low glucoses." Which sucks, considering that detecting lows is (almost) the whole reason we're so hot to use the systems in the first place.
As you all know, I tried the original DexCom for five months and found it to be a great idea whose time hasn't quite come. It requires four or more fingerstick calibrations per day, which are possible using only one specific OneTouch meter model (which I happened to hate -- required too much blood and wasted a lot of test strips). My unit also has extremely loud alarms that cannot be adjusted or disabled, and since the accuracy isn't all that great, the unit would often beep my husband and I awake all night for no good reason. I mostly keep it in my closet now, awaiting obsolence by Version 2.0. CGM made liveable...
Oh, how we pin our faith in a better diabetic existence on this nebulous force. But we are justified in our high hopes, I believe.