Really stubborn lows with incredible and unusual (for me) insulin sensitivity

Type 1, pumper here,

as I get older I've experienced nothing but greater insulin resistance if anything, yet today saw me experiencing continuous lows almost all day.

I've had no increased exercise or change in my routine, yet I've ingested something like 120 carbs for virtually no insulin intake, seen rapid glucose increases (eventually) only to then see them fall off very very quickly, causing nausea and lethargy.

What on earth can cause this? I'm a little worried about attempting sleep at this point.

I did change my infusion set earlier today after the previous one was being laggy, but that was over 12 hours ago. Is it possible to have found an incredibly receptive site?

Thank you.

120g without insulin is very unusual. Just some brainstorming:

-accidentally you may have switched to an older pump profile.

-something has changed dramatically (temperature, air pressure)

-your digestive tract did not process the carbs. Thus it will just pass through. This effect has been reported by some oils (I not not remember the name but read some discussions here).

-(unlikely) you have caught some sort of stomach bug that attacks your gut and gut flora. You would sit on the toilet right now.

-(unlikely) your kidneys might filter less insulin out than usual. Thus it stays longer potent than usual. It is unlikely and I do not intend to scare you - just brainstorming.

-(unlikely) some of your residual beta cells have managed to grow additional beta cell mass.

Some stomach bugs can cause subclinical symptoms before you get sick. Or it could just be a subclinical virus--it happens.

Also, the liver filters insulin, not the kidneys. I agree that this is highly unlikely.

My guess is that the site is unusually receptive.

If you usually follow very low carb and tight control you may still have some residual beta cell function. And you might trigger a phase 1 insulin response which would do as you describe. Basically, you built up store of insulin over time and eating 120g triggered their release. Your normal eating and bolus patterns may have just let you rest. If you ate another 120g you probably would not see this happen again.

Hmm, to my knowledge the insulin is cleared by the kidneys (renal insulin clearance). Quote from "The renal metabolism of insulin":

The kidney plays a pivotal role in the clearance and degradation of circulating insulin and is also an important site of insulin action. The kidney clears insulin via two distinct routes...

I always become more insulin sensitive with heat. So in the summer, I tend to be able to lower my basal rates and carb ratios a bit. I also tend to have more lows in the summer because of the heat. Even without increased exercise. Maybe that's what's going on? Hope you can get things figured out. But, if you can't, just chalk it up to the fact that diabetes can be totally fickle sometimes. :)

I was forced to eat 120 due to the lows, not the other way around.

The night and my CGM showed a similar happening.
It was 2am, and I was still stuck in the same situation. I'd eaten yet more carbs and was utterly unable to dose for them due to what had been happening, so I thought, well it's only around 35-40 more carbs. i'll goto bed.

In the AM my CGM had showed me steadily flatline with these new carbs until 4am at which point I shot up to 360. At 6am my blood sugar plummeted down to 90 and then slowly conmtinued to rise again.
(I work nights and so continued my nights sleep).
After this near low (compararably) my glucose started to creep up again and by 8am I was back in the 300's.
I woke up to find all of this and bolus wizarded the high and it injected 4 units, and I'm currently experiencing exactly the same effect. Near immediate (less than 5 minute) insulin reaction that is now plummeting down again.
About 30 points every 5 minutes that are near accurate and in correlation to physical finger tests.

To answer the other questions. I have been a type 1 for 28 years. the likelihood of producing any insulin seems very remote to me.

I actually have an endo appointment tomorrow, so I'll fire some questions at him. He isn't the greatest so I'm not sure I'll get any words of wisdom.

I think I may have to try moving the site even though it's less than a day old.


Can you trust the numbers of the CGM? Perhaps the sensor is giving you false highs and lows? While testing the CGM I had one sensor that reported flat numbers although my meter showed a difference of +/-50. If the CGM is not the root of the problem I would recommend to call your pump manufacturer.

Yeah I've been finger testing along with it.

I have a very good low awareness, so they're accurate. The highs while asleep may be open to interpretation, but I've been pretty pleased with this glucose set. it's been on the nail for it's life so far.

It's carried through today as well. I've set a new 'pattern A' basal with considerably lower amounts and spent most of the day with my pump turned off.

This is very strange indeed.

I know already that this is what I'll have to do :D

Thanks, Eric.
Refreshingly realistic.


I am very reactive to higher temperatures ...more lows are the results . I read today on FaceBook a posting by a type 1 , who also besides higher temps seems to be affected by high humidity ..I will need to check if that is so for me too ! Our weather has been up and down like a toilet seat at a mixed party best bet is to do a temp basal , for instance 80 percent for 8 hours rather than using my summer basal schedule ...and I still get caught :(

It's an interesting thought. If this is indeed the cause, it's something that hasn't to my knowledge ever effected me before. I've lived in hotter places than Washington before too. :)

Does anyone know what is it about high temperatures that causes this to happen?

I mean physically and chemically.

If it's hotter, your blood circulates a little faster. It therefore delivers insulin faster, causing better absorption and having it hit before you expect it to.

Oversimplified, but that's the general idea.

Umm. Sorry, my response is not relevant.

Is it possible that with your site the cannula might have entered a vein? If that is the case you would not get normal absorption and instead the insulin would act even more effectively and rapidly. And you body might have tried to react to the injury by clotting, causing variability and possible sudden releases, hence the hypos. Did you try to change sites? Did you have a gusher? Did it fix it?

Although it is unlikely that you magically produced enough insulin to cover 120 grams of carbs, it is actually likely that you might still produce some insulin.

The Joslin Medalist study have been studying people who have survived for 50 years or more with Type 1. They have found that 67% of the people in the study have measurable c-peptide levels. Also, studies on 28 pancreases donated by deceased Medalists have shown that 100% of the pancreases had insulin-positive cells.

Although what you experienced is unusual, there are occasionally posts by people here saying the same thing. So you’re not alone. Weird but not alone…

My appointment with my endo was as expected. Honestly I don't know why I bothered mentioning it :D

Earlier that day (going back to the night in question) I had performed a number of small adjustment boluses to bring down my glucose before deciding my other infusion set was kaput and changed to a new one.
I wonder if it's possible to have, literally a reservoir of insulin just sitting in a bad site somehow blocked from absorption that could be triggered by agitating the site and therefore restoring it's absorbing potential as you remove the old set?

While this wouldn't explain how this situation lasted all day and then into the night with almost no manually given insulin present in my system at that point, it might at least explain why it triggered such a reaction to begin with.

Not to go on a Doctor bash and change the direction of the thread, but my endo seemed fixated on the CGM readings only, and trying to explain to him that although the CGM read only as low as 68, I was in the 40's with my fingerprick test and also how I was feeling (basically sweating and shaking and clearly enormously low) was ignored by him and he became fixated that I could have been feeling false low symptoms due to the rate my levels were changing, and while I know and agree with this as being possible, I wasn't given much of an opportunity to speak to even tell him I was finger testing as well, and a different of 20 on the CGM isn't all that unusual. It became yet another "I'm the Doctor, listen to me" situation where I was no longer needed.

It also, as I mentioned, couldn't possibly explain how the insulin continued to work on and on and on. Eventually he ended up saying he didn't really know why it happened. Hrmph.

Oh well. Onward...

re your GCMS reading 68 ...finger poke in the 40's takes about 15-20 min for the CGM to catch up ( correct ?) ...above all you may have had a very fast drop and you had all the symptoms of a low ( sweating , shaking etc. ) ...MHO had a low (I am speaking as another person with diabetes , who knows about lows :) ) ..I am sure you taught him about your diabetes ! ..hang in .