Battle of the CGMs...
I was asked by @AbbottGlobal (and lucky to be one of the first in the US!) to try to their new Freestyle Libre System in exchange for my thoughts. After following many diabuddies across the pond, I already knew it was the most instagrammable of all CGMs, but I wasn’t quite sure how the device would compare to my trusty Dexcom. So, here it goes. The battle of the CGMs:
1) Accuracy: I found that both devices were fairly comparable in this category. However, I noticed that the Freestyle Libre System consistently ran higher than both my Dexcom, which is calibrated by my meter, & meter itself (I use the Freestyle Freedom Lite which is top ranked for accuracy). I also make sure to crosscheck my meter against the standard one at my Endo’s lab, so I do trust this number above all others. Since I use my CGM more for trends than actual numbers, this discrepancy didn’t bother me too much, as my actual curves (yup real diababes have curves, not straight lines…) followed the same trends for both devices.
2) Sensitivity to change: I noticed that the FreeStyle Libre System was much faster on picking up changes in BGs than my Dexcom. For example, I find that my Dexcom often lags behind when recovering from a low, which can lead to over-treating hypos. So thanks, FreeStyle Libre System, your short lag time saved me from a lot of Ben & Jerry's. #weddingdiet.
3) Insertion process: The Freestyle Libre System definitely takes the cake here. It’s fast, quick & painless. Basically a one & done deal. Dexcom, on the other hand, still gives me heart palpitations at every new sensor change.
4) Warm-up/Sensor life: Dexcom 2 hours vs. FreeStyle Libre 12 hours (I warmed it up overnight). One thing I experienced on both devices were wonky readings the first day. However, with Dexcom, I have the ability to “cook” the sensor, which is essentially putting in a new sensor before taking out the old one. By inserting the new sensor about 12-24 hours before warm-up, I find that I get perfectly accurate readings my first day. I would think that FreeStyle Libre’s long, bordering-on-forever warm-up period would ameliorate those first day "CGM jitters," but for me this was not the case. On the plus side, the FreeStyle Libre System's sensor lasts 10 days, versus the Dexcom's 7 days (although virtually all T1D's stretch that out...)
5) Aesthetics: The Freestyle Libre is much smaller and far less bulky than Dexcom. It’s about the size of two quarters stacked on top of each other. Although the only approved site is the upper arm, you can barely see it’s there. The FreeStyle Libre System lays flat against clothing, unlike Dexcom, which forms an awkward bump.
6) Invasiveness: The FreeStyle Libre System is more “laissez-faire” in terms of blood sugar monitoring. The Dexcom is definitely more proactive, but it can also feel like a barking dog sometimes. Or, as my mom likes to tell me, Dexcom’s blaring alarms at night are just training me for a baby. The Dexcom continuously gives me BG values, and will send alerts when I am high or low. In contrast, the FreeStyle Libre System is technically a “flash glucose monitor” and acts in a more reactive manner, only telling me my BG’s when I swipe or “flash” the handheld device over the sensor. If I am out of range, it will then alert me, but I must swipe the device first. I think this is an advantage or disadvantage, depending on your needs. If you’re like me, a (semi) functioning adult that can sense their lows, I find the Dexcom alarms invasive and slightly embarrassing in public. Also, Dexcom has an annoying tendency to give inaccurate readings if you fall asleep on the device, leading to false alarms and countless hours of lost sleep. However, if you are a child/T1D parent who relies on Dexcom alarms, or someone who is hypoglycemic unaware, I think the lack of an alert system on the FreeStyle Libre System could be a deal-breaker.
7) Price/Accessibility: The FreeStyle Libre System is significantly less expensive than Dexcom, which is a big win for those who are self-funding. It is also more accessible, as the FreeStyle Libre system will now be available in pharmacies starting this upcoming Monday. As for Dexcom, it must be ordered through Dexcom itself or a third party medical supplier.
8) Application Integration: If the FreeStyle Libre System could be integrated with my other devices, I think it would be my clear champion. I hope that they develop an application soon, as I think this is the biggest downside to their system. My favorite feature of Dexcom is that it's fully compatible with my iphone and Apple watch, allowing me to check my BGs at the flick of a wrist (particularly helpful while working out). Dexcom also generates more detailed reports on my BG trends than the Freestyle Libre System that can be shared with my Endo. I think having that continuous data is especially important for someone looking to gain tight control of those shugs.
Well, is there a clear winner? Honestly, I think there are positives and negatives to both, & just like anything in Diabetes, nothing is perfect. In summary, if you’re someone who is looking for a more proactive monitor, are hypoglycemic unaware, or a TID child/parent, I think Dexcom is the right choice for you. If you want a reliable, affordable, no-fuss device that provides support, but is not overwhelming you with data or beeps, then the FreeStyle Libre System is a better option. Whichever device you prefer, I think using a CGM/FGM is integral for modern diabetes management.