BG numbers have gotten much higher than normal

Have had Type 2 for many years and has been under control with oral meds - Januvia, Metformin, Glimepiride. Now out of the blue my levels went 250-325 most of the time. Started on pre-meal insulin but does not seem to be helping. Today BG was higher after pre-meal insulin and lunch.

How do you determine the amount of insulin to use? Do you count carbs?

My PA told first told me to take 3 units before biggest meal (dinner) if I tested over 200. When that didn’t do much he told me to do it before lunch and dinner and if over 200 take 5 units. Today before dinner I tested 335, so I took 6 units of pre meal insulin. I did not have much in carbs… hamburger patty and a half a slice of toasted white bread, small amount of cheese on top and some coleslaw. 90 minutes later (60 after eating) my BG was higher…355.

I suspected something like that. That method of dosing insulin is called a “sliding scale” and it’s as obsolete as the dinosaurs.

The purpose of insulin is to counteract the carbohydrate you consume. More carbs require more insulin, fewer carbs require less. Furthermore, each person responds individually to a given type and amount of insulin. For me, one unit of fast-acting insulin will handle about 16 grams of carbohydrate. For your body, that number is likely to be different—maybe a little, maybe a lot. How can you possibly know how much insulin is the right amount unless you know what that number is for you?

And that’s only part of the story. In order to take the right amount of insulin for a meal you’re about to eat, you need to know what’s in the meal, i.e., how much carbohydrate, and how much those carbohydrates will raise your blood sugar. To take a fixed amount of insulin regardless of the specific meal contents is to assume that a green salad will affect you exactly the same amount as a chocolate cake. If someone can see the logic in that, please explain it to me!

The point of all this is that you need to learn how to count carbohydrates and then adjust your dosage accordingly. That involves a good deal of self-education. It would be wonderful if there were a magic shortcut for that, but I’m sorry to report, there isn’t. There is, however plenty of help available from many sources including books, peer discussions in places like this, Certified Diabetes Educators, etc.

Doing this the way you’ve been told just isn’t going to give you stable, well controlled blood sugars . . . as you’re discovering.

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I understand, just confuses me when I ate what I thought was a meal low in carbs, took 6 unites of pre meal insulin yet my BG went UP by 10%. That and the fact that after 15 years of having it under control, no changes in my lifestyle and practically overnight it’s now out of control.

Sulfonylurea drugs (which glimepiride is) work by stimulating the beta cells to work extra hard and pump out more insulin. There is a theory, unproven and not universally accepted, but subscribed to by many leading experts, that long term usage of sulfonylurea drugs can eventually exhaust beta cells by running them continuously in overdrive. That would go a long way toward explaining why even well-controlled T2s eventually end up needing insulin. Personally I am convinced that I would have a lot more beta cell function left if I had demanded insulin years earlier than I did. (My latest c-peptide came in at 0.1, much lower than which you can’t get.)

Clearly something in your physiology has changed recently, and of course you want to find out what is going on and deal with it. But stay focused on the immediate problem: getting your blood glucose under control. No matter what is causing it, that needs to be the first priority. Using insulin well involves a learning curve and takes time. No one nails it on the first try.


Regardless of how few carbs you ate (and there are quite a few of those pesky carbs in half a slice of white bread and the “sauce” on the coleslaw you ate) 6 units would not be enough for a lot of PWDs to both bring down a high of 335 and cover the carbs you ate. How much insulin you will need to bring a high of 335 down to a “reasonable” BG depends on your individual ISF (insulin sensitivity factor) and how much insulin you will need to cover X amount of carbs depends on your individual I:C (insulin to carb) ratio. Why you are having much higher BGs now when there have not been any big changes in your “lifestyle” is likely due to one or a number of the following: our metabolism changes as we age; treatment with a sulfonylurea med may have led to the death of enough beta cells resulting in a need for more exogenous insulin; perhaps there is another illness occurring in addition to D that is contributing to or causing higher BG’s; or your D is not playing fair because D is a rule-breaker. Regardless of the “why,” I suspect you will experience much better control if you carb count and do what you need to do in order to determine your ISF and I:C ratio. There are quite a few good books out there, but I highly recommend Gary Scheiner’s Think Like a Pancreas. I wish you the best!


You might want to see a CDE, a certified diabetes educator. I’ve had T1D a really long time, and a few years ago I started getting really wacky numbers and I went to one 4 or 5 times until she could figure things out for me. I mean, she really carefully studied my log book and made suggestions for tweaking my insulin to my endo. It made a huge difference - the endos simply don’t have the time to do such careful study.

here’s a link to the professional association for CDEs.

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