Insulin Absorption

I had such a long post yesterday which wandered from my experience of waking up with a 34 to being stuck in the 300s, and I appreciate each of you who responded - so nice always to know you are all here.

I started a new (less desperate) thread because I think I've been spiking much higher than usual, and then finally staying higher yet, for about a week and pretty much concluded it was an absorption problem. I have used my hips for awhile because it's my favorite site, but now switched to my stomach and finally have normal numbers again.

So I'm interested in hearing experiences or ideas about absorption. I think a problem with absorption isn't as simple as just "no insulin gets through" or even as "only some of the insulin gets through". Is it possible that a bolus can be absorbed unevenly or over time? That would explain my otherwise odd experience Sunday night of going to bed at 73, five hours after my last bolus, taking 2 glucose tabs (my normal dose unless I'm much lower), and waking up four hours later at 34. Maybe the insulin didn't all get absorbed until much later? Or the fact that I kept ping-ponging between the 200s and 300s with no rhyme or reason.

If absorption (or lack of good absorption) is complex like that it explains things and also is a darn good reason to make sure you rotate sites and have good absorption! I don't like being 34 or 355 (!). The only numbers I like with "3's" are 83....well, ok, 93, 113 and 123!

Hope everyone is having a good blood sugar day!

Generally the absorption of SQ injections can vary based on amount of fat and blood supply in the area.. would think if you hit a blood vessel or damaged one going in, the insulin would go systemic more quickly than normal..

One thing that makes me feel panicked about using these insulin pens is that if I did hit a blood vessel, I don't find out until after I've pulled the pen out and I'm bleeding. If I had just a regular syringe, I could aspirate before injecting to be sure. I'm convinced if I hit a vessel my blood glucose is going to drop to 20 in five seconds flat. LOL. Even though it probably doesn't matter..

OK so bottom line I have nothing helpful to say, lol. :)

I think the small blood vessels in adipose tissue won't cause such a precipitous drop. You would probably need to inject into a major artery or vein to see such a drop :-)

I think you are correct Zoe. It is not just a simple matter of it did or did not get in. I think the other factor when absorption is off is that the blood sugar gets so much higher than usual that all bets are off. There is an incredible difference in my insulin use and the way my blood sugars respond to insulin when I am high all day vs flatlining. So absorption issues along with elevated blood sugar above the norm can lead to a situation in which you have no idea what you are going to get. It could also be the SIZE of the bolus after the absorption issue was fixed since your blood sugar was high. Oy the possibilities are endless..........

I've hit a blood vessel a few times with pens, palomino, and had "gushers" with my infusion set. I never experienced the predicted severe blood sugar drop. I think maybe that is only with a vein?

What I'm talking about is the variation of absorption that many of us get with infusion sets, more than pens.

I'm just used to working with big animals and aspirating every time before I inject because getting something into an artery even if it's not a big one could be bad. It just makes me overly cautious and tend to freak out a bit more than I should.

If you've used your hips a lot, could there not be build up of scar tissue? Possibly a longer cannula would help?

Makes sense, MD. What was strange is that I'd been correcting and correcting and I just kept getting down into the 200s then popping back into the 300s (it's crazy when 200s sound good!). I actually didn't bolus after I changed the set to my stomach as it was 2AM and I was leery of nightime lows. But amazingly it just zipped on down to 122 within an hour. Do you think my idea of the insulin being absorbed once the old site had been released make any sense at all? Changing sites shouldn't have any kind of immediate effect especially if you don't then bolus!

One time, my silohette site started wiggling out at work and my bloodsugar would not stay up for hours, I was scared because I couldn't eat anymore food, when I pulled the site, it started bleeding a lot. My conclusion from that was yes, small vessels can drop your sugar fast if you are infusing directly into them. FYI :)

I use the Inset 30 with my Ping, which is 13mm long. I haven't used my hips for a really long time compared to many as I've only been on a pump for a year. I think that sites just have issues if they are overused and then you need to rotate and when you come back it's ok.

When I was first diagnosed in 1981, after putting a syringe through the skin, we were taught to "draw back for blood" (pull back a unit or two to see if we hit a vessel or not). That advice was quickly scrapped, as it damaged the body tissue quite badly. Today's pens and infusion sets don't even give that option.

But now I understand why they said to do it.

I used to shoot IV R shots pretty regularly and they worked a lot faster. This is probably really dangerous and you shouldn’t do it. I also tried it w/ Novolog when my pump blew up. I think it was about 1/2 way through a 14 mile run so maybe 1.5 hours of no bolus, along w/ the 20 minute ride home. I didn’t want to wait any longer than I had to.

You give new meaning to the title "IV drug user", AR!

Not really, I think that most IV drug users are looking for some sort of economies of scale? More bang for the buck, etc.?

True, a good tool but....then there are the needle freaks who actually get off on the needle itself - somehow I can't see a Diabetic falling into that category!


I have also found that the stomach generally is a better place for absorption if I am still, but in general what helps my absorption best is some physical activity (e.g. a short run/ 15 min intensive exercise) to get my blood circulation going . Yesterday I decided to have breakfast in bed. I took my Levemir and Novo Rapid and was going to take my breakfast, but started writing an e-mail. After 1/2 hr I realized I have not eaten after the injection and I thought I must be low. However, my test showed that my blood sugar had not moved from what it was before the insulin.
This morning my result was 6,8. I took insulin, ate muesli and again stayed in front of the computer. After 2 hrs my bg was 21! I took only 1 unit Novo Rapid and went for a run. After the run it was 5,8.
It seems to me that my insulin gets absorbed only if I have enough physical activity and in my case this is the main factor for absorption.

Yes but if you are hitting a major artery or vein it is quite quick but only lasts for a very small amount of time. The half-life of IV Regular insulin is only 15 minutes which would be similar for fast acting insulin. I suppose it could be possible that the previous basal (before a bloody set) acted for it's normal 3-4 hours and everything getting into fresh blood supply acted very quickly with both combined leading to a long period of lows???? Sometimes I really think there is no answer besides It's Diabetes.

I do think it makes sense. I have a feeling that alot of the time the sets go bad from extreme inflammatory responses that then make the insulin much slower to be absorbed into the system. Taking the infusion set out creates more surface area of the absorption to take place and thus the fairly quick reaction. Theory only........

I have has similar situations to what you describe but I have also had the oppisite where it takes a whole day to bring it down. Hard part is to know which situation you are going to get.....

You have a much stronger constitution than I do my friend...........

A good theory - each time the only thing I could see through the Inset 30 plastic was that the skin did indeed look somewhat inflamed. Thanks for your input; I really was curious about that whole new set/quick response thing.

But on the "there's no answer besides it's Diabetes" I once had a MH client that I had a good playful relationship with. In response to something he said I responded, "life just isn't fair sometimes" or maybe "life sucks sometimes, doesn't it?" He with a smile on his face said, "this is what we pay you the big bucks for?"

Not that I've ever actually made big bucks...but sometimes just accepting that "It's just diabetes" or "life sucks sometimes" is the hardest thing to do.

(I, for one, would usually rather convince myself of some convoluted explanation even if it has little basis in fact!)