OK - I did a 12 hour presoak on the sensor I inserted Wednesday. I compared finger stick with G6 for 24 hours. Here are the results.
Elapsed time
Finger Stick
G6
0:00:00
96
105
0:50:00
80
79
1:50:00
80
77
3:27:00
114
110
5:00:00
163
162
6:10:00
129
129
7:02:00
106
102
10:05:00
131
135
17:00:00
110
120
21:52:00
128
121
24:17:00
85
87
For this one sensor, and this one person (me), there was no negative impact from the 12-hour presoak. And I did avoid the wacko day-1 numbers I get if I don’t presoak. For me it’s “full steam ahead” with presoaking.
Wow, that data collection is impressive. Super helpful. You might only be one person, but you have increased the study’s sample size by 1/3. I’ll try it when I get my G6. I hope that get results like this!
I just did one for the first time, gave it just under 12 hrs. The first 2-3 hours after I switched over to the new (pre-soaked) one were still pretty wonky but settled down after that. The really good thing is that I didn’t have false alarms overnight, which has been a problem before. They’ve tended to be much more sensitive to compression lows or whatever in the first 24 hrs, but the pre-soak thing seems to have nixed that.
G6’s tend to be wonky in the first 24 hours, maybe more than the G5s though they all have this tendency. So the idea is that you insert the new sensor ahead of time to let it acclimate to your interstitial fluids while still running the old sensor. Opinions differ on how long to do it (see discussion upthread) but range from 8-24hrs before ending the old session, moving the transmitter, and starting the new one. This is supposed to enable the sensor to stabilize more quickly after the cut-over. I just tried it for the first time with a 12 hr soak, and it really did seem to have that effect. First few hours were erratic, but it settled more quickly than before and has been solid since.
Did you do an overnight soak, or during the day?
I ask because we seem to be more stable for BG (at least I do) at night rather than the days.
Wondering if a stable BG while they are soaking has anything to do with it.
Decided to test it again with the sensor I inserted Saturday night and soaked for 14 hours. Just wanted to confirm the 1st result wasn’t a fluke. The results at 0 min and 15 min were off about 30% so I calibrated at 15 min. From there through the 12 hour test the results were very close.
Thank you for this!! This is very helpful. I found my G6 sensor was off, too, after a 12+ hour soak. I didn’t check it with a fingerstick 'til the next morning though. After calibration, it seems to be stable I think I should have checked it with a fingerstick right away though instead of waiting for a full night of slightly inaccurate readings!
Great data. My G6 (first time I have ever used it) has been more accurate than my G4…similar to your data. Do I need to restart the sensor before it fails? Not sure when that will be since this is my very first one.
Also, I’m not feeling good about the four hour display on the receiver. I’m having trouble evaluating my overnight basals because I can’t see them. Do I have to pull the data onto PC every morning or am I missing something?
Nice table. I liked it so much I just reproduced my G5 Sunday insertion and data differential.
I really dislike the first 15-20 hours after installing a new G5 sensor.
I find that the errors are no where near as large when I restart an existing sensor every 7 days.
I always restart mine before the session ends, but that’s by habit. I don’t know if it’s necessary. Maybe someone else can help?
I’m using my iPhone, not the receiver. I can see up to the past 24 hours without opening Clarity.
How are you downloading your data to a PC? I’d love to do that from time to time so I can look at longer term trends. The Clarity app on my phone can only do so much.
I used to soak my G5 as well. Even a few hours made a difference!
Funny thing, I soaked my G6 starting last night, swapped the transmitter this morning. And I had to calibrate this one, as it was WAY off. It was reading in the 50’s, and fingerstick showed 178!
First time I had one THAT far off.
I will keep an eye on this sensor, might have a bad one, or some other issue to be this far off.
What exactly are ya’ll presoaking?? I’m lost! I use the G6 and have been for the last 9 months. And compared to the finger pokes, it’s NEVER been off more than 5 points! Example: Fingerpoke: 126. G6: 122. EVERY time it’s close to perfect for me! I only fingerpoke now to calibrate the G6 about once a week. AND, I learned how to replace the battery in the thing! Woohooo … now, with extra adhesive from Dexcom (for free) I can use the thing for up to … so far … 30 days!! I learned how to do it on YouTube’s Looping class. I’ve learned how to make my own pump too but I’m not there yet! LOL But watch this to learn how to keep your G6 going LONG past its ‘use by’ date from the manufacturer. ***OUTDATED*** Dexcom G6 Battery Replacement - YouTube
G6 algorithm can be a little flaky the first 12-24 hours of a sensor b/c it tries to take account of “insertion trauma.” How much so varies quite a bit. Pre-soaking refers to inserting a new sensor 12-24 hours before you’re going to move the transmitter, keeping the old sensor going for the duration. Helps avoid this phenomenon.
There’s a big question whether it will work with the latest G6 sensors, because they now view having data that’s too smooth during the “trauma” period suspiciously and may conclude you’re extending an old sensor, not really starting a new one.
I think I should have checked it with a fingerstick right away though instead of waiting for a full night of slightly inaccurate readings!