Unanticipated low yesterday

Type 2, Humalog plus Levemir

My protocol as ordered is to measure my blood glucose before meals then administer a variable amount of Humalog just before eating. So yesterday afternoon, did my finger stick which returned a reading of 148… low end of normal for me. So I took 16 units of humalog.

Made myself a lunch consisting of two small chicken salad sandwiches (small hamburger buns with chicken salad from the grocery store refrigerated section) and about 8oz of whole milk. Ate that at my desk and after I finished I left the computer to adjourn to my easy chair to read for a while. About a minute after hitting the chair, I started to feel those symptoms of a hypoglycemic episode… starting to sweat, feeling chilly.

I recognized what was going on and prepped for dealing with it. I live alone so there’s nobody to baby sit me when these things happen. I got up and unlocked the back door then went and got my meter and measured my blood glucose once again. 69. I immediately called my buddy, told him what was going on, and asked him to come over just in case I needed help. He’s done that for me a couple other times so he knows what’s going on.

I keep cans of sliced fruit in heavy syrup in the refrigerator for just this situation. So I grabbed one, tore the top off and started drinking the heavy syrup. After drinking most of it, I started eating the sliced pears and right about then my buddy arrived. Fortunately, I caught it before it became too dangerous. We talked for a while and I started in on a second can. After a while, I could feel that my blood glucose had returned to normal and the ordeal was over.

So, I’m positive I didn’t accidentally double-dose myself, thus I can’t see any reason for this event to have happened. However, a little while ago, it occurred to me that even though I’m using the very short pen needles, maybe the needle just happened to stick into a vein near the surface and the insulin went directly into my blood system. So I decided to wander in here and see if that’s possible and if anyone else has had something like that happen. Thoughts?

This sounds like you are dosing insulin using a sliding scale. Sliding scales can be at best unreliable. I wish doctors would stop inflicting it on T2 patients.

For me a better system is to count the carbs I plan to eat and incorporate that into my decisions. There is still a correction factor based on what you BG is at the moment, plus a calculation to cover the carbs in your foods. This is a simplistic explanation of how it works. There are several good books explaining the process, there are two that come to mind, “Think Like a Pancreas” and “Using Insulin

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Hi Gary,

Thanks for your response. Yes, I am using a sliding scale. However, I’ve been using that sliding scale for two years now and maintaining fairly good A1C numbers with it (~6.8). I’ll check out those two books but all things considered I trust my primary care physician completely. He’s not an endocrinologist but he’s acknowledged within the local medical community to be expert-level with respect to treating diabetes.He’s also not shy about referring patients to specialists when appropriate and there’s a top-notch endocrinologist associated with the clinic where he practices.

However, my post wasn’t to question my dosing system… it was to ask about my theory that the low blood glucose event I had the other night might have been caused by inadvertently injecting my insulin directly into a vein.

I am not trying to Diss your PCP, but I am 100% with Gary about sliding scales. They are unreliable at best as you are always chasing after less than ideal BG numbers and at worst giving yourself insulin at a dose that is totally inappropriate to cover the carbs you are eating. Talk to your PCP about learning to carb-count. If he is an “expert” he will be delighted.

I also would not be over-concerned about a BG level of 69. Even the better modern meters have an error of plus/minus 10%, so a reading of 69 means you have a 95% chance of being between 76 and 62. Even if correct it is only technically low. .The rule for corrections is 15/15. Take 15 g of fast acting carbohydrates (e.g. glucose tablets), wait 15 mins and test again. You probably over-corrected with all that syrup.

Remember, insulin dosing is a bit of an inexact science.



Thanks for your response. I am confident that I have the requisite skills for carb counting. That’s been my primary focus for the last two years. For this particular instance, I’ve had similar pre-meal BG readings, gave myself an identical dose, and had an identical meal. I am completely sure that the insulin dose was appropriate. I’m not saying I had a low BG incident based on the reading. That reading of 69 was a confirmation that the symptoms I was feeling were indeed a low BG incident.When I find myself sweating, feeling extremely chilly, unsteady on my feet and having difficulty communicating, I take immediate action. For ME, 69 is confirmation of a low BG incident.

My question was not about my meal, my ability to count carbs, the accuracy of my meter, or how good my PCP is. I wanted responses to my question about whether injecting insulin could inadvertently go directly into a vein and thus be the cause of the low BG incident that I EXPERIENCED.

It is unlikely that you would inject directly into a vein. However there are significant variations in the rate of absorption of insulin from the site of injection that are dependent on the exact location of the insulin depot, the tissue surrounding it, the distance to the nearest capillaries etc. Also, hormonal and other physiological factors impinge on the insulin signalling pathways, leading to variations in insulin sensitivity. That is why insulin dosing is an inexact science.

The set point at which you start to feel symptoms of hypoglycaemia is very dependent on BG average levels and also variability. You can acclimate your body to low BGs and lose hypo-awareness. Similarly if you have been running average levels that are higher than normal, you may feel symptoms of hypoglycaemia at levels that would be considered physiologically normal.

My best guess, based on nearly 40 years experience of using insulin, is that your BG dropped a bit more than expected as a result of the unavoidable variability of insulin dosing. You experienced a mild-hypo and felt the symptoms appropriately.

Bear in mind also that the “normal” range is defined as 70-120 is to some extent a convention. For example pregnant T1 women are encouraged to set their range limits significantly lower.

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Jim’s points are excellent so I won’t waste time or space repeating them. A couple of add-ons, however.

Diabetes is a moving target, always. Different people feel low blood sugar in different ways and at different BG levels, and the same person will often experience these things differently at different times. I have had BG readings of 50 that felt utterly normal (no symptoms whatever), and I have had BG readings of 50 that felt far worse. As Jim inferred, physiology is staggeringly complex and things do vary, constantly. We have an acronym for it: YDMV (“Your Diabetes May Vary”, a sendup of the old EPA mileage trope).

It sounds as though you and your doctor are really on top of this, and I don’t doubt that you are. It will surprise you anyway—as it just did.

A dear friend of mine was once told the following by her endo: “If you can figure out why your BG is wrong in 10 seconds or less, great. Otherwise, just correct it and move on.” Words to live by for any PWD.

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I think she said 17 seconds :slightly_smiling: The only thing consistent about diabetes is that it ISN’T consistent. One definition of insanity is doing the same thing repeat4edly and expecting different results – that happens to also be a good definition of diabetes… Hm…

LOL. She said 10 seconds when she told me. Perhaps she tailored the story to the audience. :laughing:

I don’t think its likely to inject into a vein especially with a pen, assuming you are injecting into stomach, back of the arm, thigh etc. and pinching up. My first thought was whether you were on a down slope when you injected. You usually take 16 units to cover that meal with no lows so perhaps you had additional active insulin remaining from breakfast? I would look back to what you injected earlier versus what you ate earlier. IDK about the actions of Levemir; but humalog peaks at approx 3 hours and is active for 5. The difficulty with this disease is a reading of 148 tells you where you are at that precise moment, but not whether you are rising, dropping or stable. If you were on a down slope and then injected you might have been much lower before you even started eating. My second thought is new bottle of insulin? I find a new bottle can be more potent. I would keep an eye on what’s going on after meals as if you continue to have lows I would think decreased insulin needs, due to weight loss, exercise, new meds or just because.

Thanks to all of you for your responses. However, only one person has addressed my original question. Just for grins, I did some analysis on the spreadsheet that I use to track my blood glucose measurements. Each day, I record the three pre-meal measurements. The each days measurements are averaged in a separate column. Then once a month, I calculate the average of the month’s worth of daily averages. So, just now, I calculated the average of all monthly averages since June of 2013. That value, the average of approximately 3,300 measurements, was 183.7. So yes, I know that the global “normal” values are below 100 but almost three years of BG measurements in my case indicate that below 100 is a major low BG event for me. In spite of that “high” average BG, I’ve been maintaining my A1C below 7.0 as a result of closely watching my carbohydrate intake.

Well, then, you probably know this already too . . . but an individual’s “normal” is at least partly relative. In other words, if you normally hover around 100, 60 can feel terribly low. If you normally are at a higher number, say 180 for the sake of discussion, a quick excursion down to 110 or 120 can feel the same way. And all of that can change over time, of course. YDMV, again.

Depending on how long after I had taken the dose and how familiar I was with that dose/ meal combination, I likely wouldn’t have even treated a 69. I consider that level to be normal and non hypoglycemic for me… I am perfectly comfortable at 69 but if I was 69 with a lot of bolus on board and no food digesting I’d be worried.

I’ve read that the speed of change of your blood glucose level also has an effect on how well you feel lows.