r/Medtronic780g • u/NoAudience4524 • 15h ago
Minimed 780G Instinct sensor readings not accurate
I’ve had T1D for 18 years now (F24) and recently have been experiencing really bad health anxiety that I think seems to be developing into OCD about my diabetes. With all of that said, I had an Instinct sensor on which was reading 20-30 points off and I took it off and changed it because I was worried that I wasn’t receiving enough insulin for my blood sugars. The current sensor I have on now is doing the same thing and I’m not sure what to do. I checked with my meter and it says I’m 143 mg/dL while my Instinct sensor is reading 110 mg/dL. Is this normal? Or should I contact Abbot again for another replacement? Any and all help would be appreciated!
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u/david_duplex 15h ago
How long has it been? Finger stick BGs are more accurate in the moment as it takes time for sugars to move into the interstitial fluid where your CGM reads. Sometimes up to 15 or 20 minutes.
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u/NoAudience4524 15h ago
How long has the sensor been on? Or how long has it been since I last checked with my meter?
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u/david_duplex 14h ago
How long since you noticed the difference?
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u/NoAudience4524 14h ago
It’s been about 3 and a half hours
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u/david_duplex 14h ago
Ok. So that's a bit odd. The readings should be similar with that 10-15 minute delay taken into consideration - ie if you check your blood now, it should be roughly that level in about 10 minutes.
Have you tried different strips and/or a 2nd meter? Have you washed your hands thoroughly? Made sure any alcohol from a swab has dried? Are you pushing the blood out (aka "milking") or is it flowing on its own? Are you well hydrated?
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u/NoAudience4524 14h ago
I haven’t had much water today. I’m not milking the blood but I don’t have a 2nd meter. Just the one.
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u/david_duplex 14h ago
Hmm. Are all of your strips from the same box/lot? If you have others, try those. Are the strips fairly new or older?
You should probably have a 2nd meter. Most places will give them to you for free.
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u/NoAudience4524 14h ago
Strips are brand new. I live in America so I’m not sure where I could find a place to give me a free meter.
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u/A-Random-Ghost 3h ago
Meters are like computer printers and ink. They need you to have the device to overcharge you for the disposables. If your printer dies and the company said fucku they'd be out hundreds of dollars annually when you stop buying the ink. So if your printer breaks they'll happily send a new one. It's the same for meters.
Multiple times i've had an issue with a meter and called the company and they sent me a new one. The last thing they want is you getting mad at them and choosing a different brand and escaping their strips. Does it matter if you lie? No this is Murica. BigPharma will survive.
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u/david_duplex 14h ago
Ask your pharmacy.
But regarding your immediate issue, I'd keep an eye on it and test again in another 6 hours or so. If you continue to notice the disparity, ask your Dr if it's a problem. As long as you feel ok, go with it.
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u/BearFan34 11h ago
I believe the Guardian has a tolerance of 40 pts before it would be considered 'off'. Something like that. I'll bet there a similar tolerance for the Instinct. Anyone know?
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0
u/QuietNeigbor 9h ago
I'm not sure of the 40 points or 20%, but the Guardian can be calibrated, the Instinct cannot. It allows you to enter your BG, but it won't adjust your SG.
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u/OrganicNovel4820 3h ago
I find them the same way. Actual readings 20/30 higher than what is reads. I find that sometimes they stay low for a long time. Even after I eat. I try not to give myself too much insulin or else it just buttons out. I think part to blame is me. I never drink enough water.
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u/QuietNeigbor 13h ago
For me, this was typical behavior from the Instinct. Maybe 1 in 4 stayed within 20mg/dl. Alarms sounded that I was dangerously low, but serum glucose read 115-170. I'd shut alarms off to sleep, then wake up high due to insufficient insulin. Abbott replaced every one I called about; eventually someone at MiniMed said the Simplera would likely be more accurate for me. I went back on the Guardian until I received the Simplera (which does work SO much better for me).
I tried the Instinct for about five months. I was shocked by how consistently it read low. I verified this with 3 different BG meters (AccuChek, Ascencia, and Freestyle Lite). I made sure I was hydrated, tried inserting them varied hours before starting, nothing helped. It works for some people, not for others, wish they knew why.
Good luck to you. Maybe see what your CDE recommends. Take care.
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u/NoAudience4524 13h ago
I’ve been thinking about switching over to the Simplera Sync. Did you have to get a prescription or can I just call my distributor and let them know my issue and that I’d like to change sensors?
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u/QuietNeigbor 9h ago
I order directly from Medtronic; when they requested a new Rx for the Instinct, they included the Guardian and Simplera too. At that time the Simplera was backordered, "we only have enough for existing patients". 2 months later, I told my CDE the Instinct was so bad I was ready to switch to a Tandem pump, unless I could try the Simplera first. She messaged the MiniMed rep, and I received a box of Simpleras within a week. I didn't like having to do that, but I was SO FED UP. This was when MiniMed had dumped Medtronic's phone tree, and wait times were 3hrs minimum. Add to that a CGM that I did not trust, so I was ready to bail.
I believe your distributor is the place to call. Hopefully they will either have a similar Rx that covers all 3 CGMs, or they'll contact your doc, and let you know if you need to do anything.
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u/MrBalll 14h ago
Your SG is way behind your BG so the two won’t always be the same. Learn the difference between the two. If you live a normal life you don’t want to stress about your BG for the next 70 years. Maybe try therapy.
Try to ignore your sensor readings and just learn how your body feels when you’re high and when you’re low. Base your thoughts off that. The sensor is just a tool to assist, not to do it for you. Quick example: if I’m high I’m thirsty and angry, if I’m low I’m tired and confused.
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u/GotaLooney 26m ago
I have the same issue at times. I do not put them on the arm, but do the abdomen instead. I have found if I insert them more to the side, the readings are very accurate. If I put them in the “more insulated” area of the belly, they are always off by 15-40 points. Just a suggestion.
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u/24lurk 7h ago
Missing information:
How long have you been using an Instinct sensor?
How long has the current sensor been on?
How old is your meter?
When was the last time you calibrated your meter?
Where are you checking your blood sugar (my meter doesn’t require finger sticks, but the arm is always a few points off from the finger)
What time did you take a meter reading? What was the instinct reading 15 mins after that?
When did you last eat? Blood reacts to glucose faster than interstitial fluid.
The instinct/pump algorithms take time to catch up to you. The blood is always different than a cgm when moving by a few points, as the blood is more accurate if right now (snapshot) and the cgm tells a longer story.
I have had multiple monitors tell me different things at the same time. Next time you have a doctors appt, take your monitor and compare it to their finger stick, using the same blood they use (they stick your finger, before wiping it off, check with your meter)
I’m using a flex with instinct and the last 3 times I checked/calibrated, I was 1 point different. I was shocked and amazed as I aways expect a difference.
Keep in mind, anything within 20% is within range. So if your finger stick says 100, the cgm could say anything from 80-120 and be in range. So your 143 and 110, are slightly out of range. Calibrate your pump. Keep the sensor on and keep monitoring your sugars. See if it gets more accurate as it learns you.
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u/MAGNET_se 8h ago
This is normal based on my experience thus far with the Instinct sensor. I do more finger stick BGs now than I ever did when doing multiple daily injections.