UGH. Medtronic Guardian Enlite vs. Dexcom

Growl. I started the Medtronic 630G last month, and just recently added their CGM to the mix (I was told the only way to get the free upgrade this summer was to purchase the whole system together…). The first day was actually pretty decent as far as accuracy goes. I like the Guardian because it’s flatter and doesn’t catch on things as much as the Dexcom. But, alas, that’s not really the important thing, is it?

It’s been 3 days and the accuracy SUCKS. I’ve followed all the rules exactly as far as when and how and what to calibrate. I’m still using the Dexcom at the same time for comparison and…I thought maybe the Guardian would impress me and be better. Yesterday, Mr. Pump said 89 flat - cool, I like that number. Mr. Dex was howling at me saying 54 and trending down. I don’t feel low. I check anyway. Yup - 51.

Honestly, if it would have been the highs that were a little off, I can deal with that. If I’m high, I’m high :laughing:. As long as it’s not like super high. But this low? Mr. Pump should have buzzed and went crazy and maybe even suspended if I agreed to that.

I’ll keep going. I’ll keep using both until I run out of Dexcom life. But I’m scared to just have this Guardian guy by itself. I could pretty much trust Mr. Dex. I have zero faith in the Guardian. And, jeepers - the time it takes to calibrate this sucker. What the heck. If it’s gonna take up to 15 minutes to calibrate, I think it should maybe be a little more accurate.

I’m hoping with the new pump, they’ve obviously made some adjustments. Does anyone have any experience with insurance covering the pump (I would not order any more supplies for the CGM part) plus the Dexcom separately? I’ll contact them today about it, but I’m interested to hear anyone else’s thoughts.



I understand how you feel because I have this issue with the Dexcom all time. Thankfully when it switched to the G4/G5 it did get better. But it still can be up to 80%+/- off from my meter. It doesn’t matter if it’s the Dexcom receiver or my T:Slim. I don’t have a smartphone so obviously I don’t have the G5. I can’t get the upgraded version of the T:Slim because the insurance won’t cover it and my husband says no go since this pump is still good.

What is the Medtronic policy for for the initial “money back no-questions-asked” return? If I were that dissatisfied with the CGM now, I would be worried that it might not get any better but then I’d be stuck with a 4-year commitment. Now is the time to ask questions.

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True. I suppose I’ve had the same issues with Dexcom in the past. It just seems so crazy to me to have both on at the same time and to just see it be so wrong in real time :confused: I hope you get more options available soon!!

True. I’ve been hesitant to ask again because I had asked initially, and they said 30 days from the purchase. I purchased it back at the end of Jan - but my docs couldn’t do the training until mid Feb (just for the Pump) and were just able to do the training for the CGM last Friday. So, I’m sort of out of the window…but maybe they’ll work with me since the timeline of trying everything out together was out of my control? We’ll see :slight_smile:

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Just looking at making this leap to 670G by way of 630G myself. Currently use Dexcom (with my old pager-style Medt pump, now out of warranty), so this concerns me a lot.

Question though: I thought the 670G rollout was to be accompanied by rollout of Guardian 3 sensors, which are supposed to be 20% better than the Enlites and within a whisker of the G5’s accuracy, but I wasn’t clear that they’re out yet. Are those new ones the ones you’re using?

This snippet is taken from Dexcom presenting at the

Raymond James Institutional Investors Conference.

So, in our industry, you’re going to hear about MARD. And what you’re going to hear is that you’re going to hear competitors or would-be competitors make all sorts of claims, and everybody always wants to claim that they’re as good as DexCom. And what I will caution you, as you do research on continuous glucose monitoring, our industry and our competition, is be careful because you can’t believe everything you read. And what we find in clinical trials is that companies do all sorts of things. They exclude data points for whatever reason, they don’t explain why the data points were excluded, but they exclude data points they don’t like. They cherry pick sensors. It’s very, very common for companies to build a number of different lots of sensors, cherry pick which ones seem to perform the best, use those in their clinical trial, and achieve a decent MARD for clinical trial purposes.

Unfortunately, when they commercialize those products, they’re not representative of real-world performance. At DexCom, we don’t do that. When we run a clinical trial, our manufacturing operations have been completely built out and qualified. So, when we run a clinical trial and achieve MARD accuracy that I just described, you know that that’s what patients are going to experience in the real world with real commercial product. So just a caution when you hear of would-be competitors talking about their performance and their accuracy as compared to DexCom. Just be careful.

-Steven Robert Pacelli


No kidding. The 670G does have a new sensor - that is supposedly the only sensor FDA approved to be so accurate you can dose from the SG. I’m not using that one - I’m using the…whatever the one is they have at this moment in time :slight_smile: that is supposedly “better” than the first Enlite sensors they had.

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Ah man. I just love Dexcom :frowning:

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I think the dexcom G5 is FDA approved for dosing,.

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Yes it is.

Ah yep. Well the first to control the hybrid loop. I just feel like if they can make such a huge leap to being the first and only to do that…then why can’t the current sensor be accurate at least once in a day :neutral_face: lol. Ah well, I know I shouldn’t complain because at least we have the technology :yum:

I use the 640g with the “enhanced” enlites, I’ve also used Dexcom there is really not alot in it accuracy wise. Calibration has never taken me 15 minutes, longer calibrations occur when ISIG is low and there is a a larger difference between your BG and SG.

I find it best to calibrate when waking, fasting and before meals, 3-4 times a day.

I would say the enlites are more problematic than the Dexom, give them a good whack and move the filament and you’re in trouble.

I don’t know buddy, the G5 is the best CGM available I agree.

But my 640g enhanced enlites are accurate enough for me to bolus from most of the time

  1. You only have a 30-day money back on the pump; should have tried their CGM at the same time. If you are within 30 days, return it ASAP
  2. Is this new CGM the same sensor as the new 670g will use? If so, thanks for steering me clear of Medtronic forever.
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is the 640g and the 670g sensor the same one? I’m dying to know.

I was told that the 670 G sensors will be the new improved sensors. My son just got the 640G in order to get on the expedited upgrade pathway for the 670 G. The Minimed rep told me that the sensors they gave us with his 640 pump are identical to ones I use with my old Minimed pump. But my Enlites work decently well, so long as I avoid calibrating too often or when my sugar is changing rapidly . So I think the new improved ones should be good enough.

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Thanks for posting this.
My endo just told me last week to switch to the 670G (I have a 530 still under warranty for the next 3 years) and I told him “no way… not until it uses a Dexcom” (which I know is never).

He said the Medtronic CGM is supposed to be just as good as the Dexcom, and I laughed!
He told me “that’s what the data shows” and I now I know why the data might not be representative!

Thanks again Anthony… I might just forward this along to him!

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I was using the Dexcom G5 with T:slim X2 pump and loved it however, I was quite interested in the 670G system. So I contacted Medtronic and they offered me he 630G with Guardian sensors in the mean time as priority pathway to the 670G for free. I was also interested in this because of the Smartguard features since I had frequent overnight lows.

Upon receipt, I got started immediately and kept wearing the Dexcom to compare results. The readings were drastically different. The Dexcom was near perfect compared to every finger stick however, the Guardian was between 50-100 points off at any given time. Also, why do calibrations take so long? Dexcom calibrations are immediate; Medtronic, about 15-20 min and so by the time it calibrates, the readings have obviously changed.

To make things worse, the Medtronic kept shutting off my pump at night saying I was as low as 30 but when I woke up and tested, I was at 120. This led to several mornings where I was super high because the pump had shut itself off due to inaccurate lows.

The accuracy is no where near Dexcom and to be honest, I’m not sure how anyone could ever use the Guardian system. One can only HOPE that the Guardian 3 is better. Although this is my personal experience, I no longer use the Guardian system and I am skeptical of the 670G performance. With the Dexcom, you don’t need to calibrate at specific times or more than 2x per day for exceptional accuracy. That’s really how it should be, if not better. The Medtronic pump has a lot more features that are not available on the T:slim but the company is definitely behind in terms of CGM accuracy.

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Looks like I will go hybrid in the November time frame.

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