***Advertising. I received the FreeStyle Libre 2 free of charge from Abbott for testing purposes. My post reflects my own experience, is true and is in no way influenced by Abbott.***
I have been using the Freestyle Libre 1 since it was launched in Germany in November 2015 and it was the impetus for me to start Zuckerschmuck. I only switched to the Dexcom G5 during my pregnancy because it didn't have an alarm function. However, as I always felt the Dexcom G5 on my body and found it quite bulky, I went back to the Libre afterwards. It is more comfortable to wear and I just like it. The only thing I missed a little compared to the Dexcom was the alarm function at night.
That's why I was really pleased that Abbott equipped the Freestyle Libre 2 with alarm functions and that I was allowed to test it. What interested me most was whether it was true that the Libre 2 measures "better" than the Libre 1. That's why I wore the Libre 1 and 2 in parallel and measured my blood sugar levels at the same time. Here are my results (pink = Freestyle Libre 1, blue = Freestyle Libre 2, with the finger blood sugar measurement in between):
The first three images show good agreement between Libre 1, Libre 2 and blood glucose measurement. Unfortunately, there were also other results:
Of course, I measured more comparative values than those shown here, and this is just an example extract, but the results are representative.
My conclusion:
Personally, I have always had sensors that were closer to the measured blood sugar levels and sensors that had a (regular!) deviation. In the first 24 hours, sensors usually measure less accurately than in the following period. I have always done a comparison blood test with baseline values (stable values without prior carbohydrate or insulin administration) to the Libre sensor at least once a day to get feedback on whether I can rely on the Libre quite accurately or whether I have to calculate a certain difference in my head. I have found that sensors with a deviation from the blood sugar level almost always deviate in the same direction, up or down, and the deviation remains very similar regardless of the level of the glucose/blood sugar levels (e.g. always +approx. 30 mg/dl to the actual value or approx. -20 mg/dl to the actual value). That is why I was able to make good treatment decisions even with a different sensor and always felt very safe with the Libre. My HbA1c values were also in the good 6 HbA1c range with Libre and only very few comparison blood sugar measurements.
Deviations become critical when you rely on alarm signals. And annoying when you are woken up in the night for no reason because of a supposed hypo. That was the case for me once: Libre gave an alarm for <60 mg/dl and my measured blood sugar level was a safe 92 mg/dl and not falling. That makes you irritated and a little unsure and you no longer trust the Libre values and alarms completely. Maybe that's because I'm one of the small number of Libre users whose sensors have inexplicable deviations according to my diabetologist. There's nothing that can be done about it.
But I have a solution, because I think the Libre is so great in terms of handling and size that no other CGM can keep up: I hope there will soon be a "Freestyle Libre 3" with the option of calibration. Then I could "calibrate away" my deviations and trust the measurement results and alarms more. Because I am and will remain a Libre fan :-)
Your Sonja
Founder of sugar jewelry and type 1 for 30 years
