Dexcom Really Does Track Lows

It’s been mentioned in the forum many times that Dexcom really lags when coming out of a low, like it just stays low far longer than you are really low.

I never really noticed this and thought I’d post how well it tracked my deep low from this morning.

The red dots and squares rimmed by white are the finger sticks taken on my Contour Next One. This actually is xDrip+ and not Dexcom, it’s a different algorithm but very close to what the Dexcom algorithm is.

You can see how well the CGM tracked the low including its duration.

And yes, I had to treat with about 100g carbs (o.j., pastries, bread, breakfast taco—all my favs, nary a G tab crossed my lips :tongue:)

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Was each fingerstick also a calibration?

I don’t know anything about xdrip or how it works with calibrations.

No, only the circles, not the squares.

The Contour Next One connects to xDrip+ via Bluetooth and automatically enters the value, giving the user the opportunity to use it as a calibration or not. Also, if I later decide to use it as a calibration I just tap it and the dialog to use it as a calibration will come up.

I think Dex likely lags for lows similarly as it does for other movement, but when you’re low and it’s screaming at you about it and you feel crappy and like eating ALL THE SUGAR, it’s much harder to be like, oh, I should give it 15 min to catch up because it’s using interstitial fluid not blood and not eat ALL THE THINGS. I do think its accuracy for extreme readings is not quite as good, but the same would likely be true for home meters, so hard to say which is off.

And for what it’s worth, every time I’ve checked my blood sugar when debating eating more when my Dex is still saying I haven’t started to rise, my meter has shown that I am rising.

That’s the point of my post. My tracing absolutely and accurately matched the meter readings for the full course of the hypoglycemic excursion. And that’s what I normally see.

Truly a case of YDMV.

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If this had been my Dexcom trace, the title of my post would have been: “Wow, the CGM actually tracked my low (for a change)!” :smile_cat:


Ok. So I didn’t want to hijack. At least too soon.

But I am curious as to the cause of the low which required 100 g carbs to correct?

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My bet would be that it was insulin.

Sorry, just having fun. :slight_smile:

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I had the temerity to take 10 units of novolog for 26g of carbs when my Bg was 145.

Go figure. Guess I misjudged my C/I this time.

This was after one of my no bolus days on Sunday (this happened Monday). I have these no bolus days every so often, which I have documented here previously. I think my pancreas must be schizophrenic.

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