Confused with the bolus calculator

[Jonathan_R]

OK, I tried the bolus calculator, and got different results than when I do it myself. First let me explain what I do and how. We'll take my most current reading as the test.

Before dinner my BG was 226. Now for every 30, I take 1 unit. So I take 226 and divide that by 30, which is 7.5333. So I round up to 8 units. Now we are half way through. For every 15 grams of carbs, I take 1 unit. I typically calculate 60 carbs. Thats easy, that's 4 units. Now add that to the other and we get 12 units.

Here is what the bolus calculator shows. See the attached screenshot.

http://img401.imageshack.us/img401/6995/boluscalculator.jpg

Oh, I also added 3 additional units to compensate for the glycemic load. So for this one, I took 15 units. This is the first time I have attempted to compensate for the glycemic load.

[Subby]

Before dinner my BG was 226. Now for every 30, I take 1 unit. So I take 226 and divide that by 30, which is 7.5333. So I round up to 8 units. Now we are half way through. For every 15 grams of carbs, I take 1 unit. I typically calculate 60 carbs. Thats easy, that's 4 units. Now add that to the other and we get 12 units.

Jonathan, I can't quite work out how this should be working. For the first part, the correction, you are calculating as if you want to end up with a BG of 0. Why?

Unfortunately the bolus calculator picture is a thumbnail, not a link.


Oh, I also added 3 additional units to compensate for the glycemic load. So for this one, I took 15 units. This is the first time I have attempted to compensate for the glycemic load.

How do you see that working?

[Funnygrl]

I'm confused why you're diving your actual glucose by 30. This would have you taking one or two units even if your glucose was 30 or 60. Obviously not good. Most people have a correction factor that they divide the total difference between actual and target bg by. For me, this is (266-100)/50. This is how must bolus calculators will calculate it Obviously if you were to use this method, you're need a higher correction factor.

I can't see your screen shot (too small) but I'd guess this is the issue.

[Jonathan_R]

Try this. http://img514.imageshack.us/img514/6995/boluscalculator.th.jpg (http://img514.imageshack.us/i/boluscalculator.jpg/)

Subby, I know your not supposed to 0 out the BG, but it is working for me, at the moment.

[Subby]

OK, well - I'm all for using what works. What this suggests though, is that your ISF is currently too high. What calculating to 0 is doing, is boosting your correction dosage up "artificially".

Why not tweak your numbers so you are using the calculations logically? That's what they are there for. And going by experience is pretty much the only way that everyone has to do it.

So, in that scenario, if indeed 8 units will work to bring you down 126 mg/dl, you can learn from that and say that your ISF should be about 1:15, not 1:30.

I'm not saying that is your correct ISF. But something like that may well be a lot more ballpark and useful in different situations, and you can aim for a viable target BG and get results, rather than an ISF that you need to calculate back to 0 to get some result out of.

[Jonathan_R]

That math might work with a bit of tweaking.

1 unit for every 15 over, and 1 unit for every 15 grams of carbs. When I test this, it seems to be consistently off. One short. One isn't bad.

Take the above example. 226 is what my BG was. Now subtract 226 from 120, which leaves us with 106. 106 divided by 15 is 7.0666. For 60 carb meal, thats 4 units. 4 + 7 is 11, and I added 3 units to compensate for the gycemic load. The amount I took was 15 units. If you subtract the 3 units, then thats 12 units.

The 3 units turned out to be to much. 4 hours later my BG was 62.

I sure hope to change this by increasing my dosage for the lantus.

[Subby]

1 unit for every 15 over, and 1 unit for every 15 grams of carbs. When I test this, it seems to be consistently off. One short. One isn't bad.

The whole point is to change the variables ISF and I:C, independently, to what works. If it is "one" off (one what? Number? Unit?) then change it accordingly so that it does work. Your basal should not factor into this. Your basal should do one thing and one thing only. Keep your BG on an even keel in the background given the variable of food removed.

Can you explain how you see your GL calculation working?

[Jonathan_R]

I can try. First off, it's off by 1 unit.

As to the GL, as I understand it, the GL is how much it can raise the BG, which I have witnessed. I just don't have a formula for it yet. I have noticed that certain foods raise my BG more than others, and these correspond to higher GL. So counting carbs by themselves doesn't quite get it. It puts me in the ballpark, but thats it.

Secondly, I have noticed I have quite the spike when I eat. My blood sugar will jump by over 200 points. I'd like to narrow this gap. Right now, I take 41 units of lantus.

Glycemic load - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Glycemic_load)

[fenagle]

I just have to through my 2 cents worth in here. There is a book by John Walsh titled Pumping Insulin. This covers everything pumping from soup to nuts. The best parts for me were the chapters on dosing. The basal testing sounds like something you may be interested in. It will also tell you how to test for sensitivity. I have found this to be a tool that I reference constantly.

[Jonathan_R]

Sounds good. As you can tell, I'm winging it. My initial ratio was for every 50 over take 1 unit and for every 30 carbs I consume, take 1 unit. Man, was my BG's way out of whack then.

I have no idea how to test for sensitivity. I'm going off of my logs, and adjusting the ratio accordingly.

If you can reference any sites that would explain this, that'd be great.

[Jonathan_R]

A side note here, a little over a year ago, they tried to get me on a pump. The insurance denied it.

[Funnygrl]

A side note here, a little over a year ago, they tried to get me on a pump. The insurance denied it.
On what grounds? I'm not sure where you are, but in the US, almost every denial just means "try harder." You can get your insurance to pay for almost any medical need if you appeal.

[Jonathan_R]

They wanted me testing at least 4 times a day, which I was doing then, just as I am now. My insurance is the state medicaid; AHCCCS.

[genie86333]

They wanted me testing at least 4 times a day, which I was doing then, just as I am now. My insurance is the state medicaid; AHCCCS.

Ah, an Arizonan! I'm in CA myself now, but consider AZ home. ;) So, if you're testing 4 times a day & that's what they wanted, what's their problem?

[Jonathan_R]

Ah, an Arizonan! I'm in CA myself now, but consider AZ home. ;) So, if you're testing 4 times a day & that's what they wanted, what's their problem?

Ya got me. I honestly don't know.

[Subby]

I can try. First off, it's off by 1 unit.

You mean one unit out in that particular scenario? What do you mean by that, how do you know?

I know I keep asking questions, but that's the way to make progress with this. If you get working ISFs and I:C ratio based on a good BG target, not aiming for 0 BG, you will be making progress and you can tweak with the right goal in mind.


As to the GL, as I understand it, the GL is how much it can raise the BG, which I have witnessed. I just don't have a formula for it yet. I have noticed that certain foods raise my BG more than others, and these correspond to higher GL. So counting carbs by themselves doesn't quite get it. It puts me in the ballpark, but thats it.


The problem is, that while the GL does indeed suggest that some foods spike faster than others (And the GI/GL is NOT universal - everyone will have variation on the official rankings) this spike isn't something a type 1 can necessarily deal with by pushing the dose up.

There are some probable issues with trying to dose to GL.

GL is an issue of timing, not overall energy. So if you have 20g carbs that act fast, and 20g carbs that act slow, they both need (around about) the same amount of insulin in the end.

If you put your dose up to deal with a high GL, 1) it's unlikely to deal with the initial spike (injected insulin is a lot slower than non-diabetic's insulin response) and 2) you're likely to take too much insulin overall.

Furthermore with GL, it's an attempt to comment only on "typical serving sizes" which may or may not be something your habits reflect. Is that issue firmly covered in each and every case?

I suggest you need to make more observations as to the viability of having high GI/GL foods in your diet at all. Add one hour testing to your testing habits for a while, when you have those high GL foods, to see if you ever deal with big spikes even if you pump up your insulin.

What the limitations dictate for some, like me, is the high GI/GL food needs to a) be tested thoroughly individually on self, as people can vary wildly from these rankings and b) be discarded if an unreasonable spike is seen given the action of insulin doses "in the ball park".

In that process of troubleshooting, there are a few ways to try and get insulin to deal with spikes a little better, but they are limited. On is prebolusing - taking your insulin some time before eating, commonly 10 to 20 minutes. This mean the insulin action is "ramping up" more when you eat your food, and you are a little less likely to see an initial spike, the profiles may match better.

Different injection sites around the body might also give you faster or slower action.


Secondly, I have noticed I have quite the spike when I eat. My blood sugar will jump by over 200 points. I'd like to narrow this gap. Right now, I take 41 units of lantus.


The spikes will likely keep occurring if you eat high GI high GL / spiking carbs.

The way many of us deal with this, is eating carbs we know for a fact do not spike us as much, and moderating carb serves both overall and per meal.

Try eating meals with carbs you know do not spike you extremely, and only 30g carbs a few times, bolusing for the 30g. Just see if that helps with reducing this spike you are talking about. I'm not pushing a low carb diet on you, but there is a relationship between carb types and carb amounts and spiking you really need to explore, rather than just trying to cater for all scenarios.

Here's one way to think of the conundrum:

At one end of the scale you have too much spiking (too many carbs, too fast for the insulin to deal with, too tricky to get the dose right for) You are here.
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----------- you want something in the middle that you find acceptable ----------
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On the other extreme you have no spiking (eating no spiking food/carbs)

[Subby]

I just have to through my 2 cents worth in here. There is a book by John Walsh titled Pumping Insulin. This covers everything pumping from soup to nuts. The best parts for me were the chapters on dosing. The basal testing sounds like something you may be interested in. It will also tell you how to test for sensitivity. I have found this to be a tool that I reference constantly.

Excellent suggestion, although if not likely to pump (I hope you can come back to that and get a pump!) Using Insulin is a similar book but for injections.

There are no websites I know of that will give you the whole picture like these books. Get one. It will be the best bit of cash or so you will spend in a long, long time. Can order from Amazon or John Walshes website, The Diabetes Mall (http://www.diabetesnet.com/) (You'll find bits and pieces of great there here, too)

[Jonathan_R]

Subby, I don't mind your questions at all. I am learning more here on this forum, than the entire time I have been diagnosed. And when I was diagnosed, the diabetic educator didn't do much with me cause she determined that I already knew most of it. Apparently, she was wrong. I don't mind learning. Now to try and answer your questions.

While I have given you one scenario, I have about 17 days worth of scenarios, with tests 3 to 4 times per day. So I went back and tested against those, (not all, just 2 or 3). BG-120/15 + Carb/15 = Bolus. I suppose I could take it down to BG-105/15 + Carb/15 = Bolus. Then that would match up.

As to the GL, I am not referring to the GI. The GI is how fast the BG spikes. The GI is a ratio from 0% to 100%. The GL is supposed to tell us how much the BG will go up. Take both in account and you have a complete picture. This is why my log includes not just the amount of carbs, but also the GI and the GL. I've been tracking this for a couple weeks now, and I am just beginning to see how much. As I test against my observations and theories, we shall find out.

I do realize that if I have two servings, then I need to double the GL.

I think part of my prob is guessing at the amount of carbs. I just picked up the calorie king, so hopefully, that will help.

I am especially reluctant to try a low carb diet, and here is why. A couple months ago I was in ICU for DKA. My BG wasn't all that high, by my standards (350). While in the hospital I talked with their diabetic educator (different from the last one), and we went over the meals I eat, and the carbs. She said I was being to strict and needed more carbs. She said I needed 180 carbs per day. So for me eating only a triple angry whopper :D , which is 50 carbs, she said was not enough. She said to have a small fry with it. :eek: Yeah, I was surprised.

The spike, however, have not changed, before my admission into ICU or since. So there has to be more to the puzzle.

She did tell me the fat was bad. However, in light of recent events, the ketogenic diet suggests a high fat diet, so I might have unknowingly been doing the right thing.

[Subby]

Subby, I don't mind your questions at all. I am learning more here on this forum, than the entire time I have been diagnosed. And when I was diagnosed, the diabetic educator didn't do much with me cause she determined that I already knew most of it. Apparently, she was wrong. I don't mind learning. Now to try and answer your questions.

While I have given you one scenario, I have about 17 days worth of scenarios, with tests 3 to 4 times per day. So I went back and tested against those, (not all, just 2 or 3). BG-120/15 + Carb/15 = Bolus. I suppose I could take it down to BG-105/15 + Carb/15 = Bolus. Then that would match up.


Not sure why you are modifying the spike: it is these numbers you should be changing:


BG-120/15 + Carb/15 = Bolus. I suppose I could take it down to BG-105/15 + Carb/15 = Bolus. Then that would match up.


If you need an I:C of 1:16, use it. If you need an ISF of 1:14, or 1:13.5, use it.

The other thing central to this I think is, learn something, discard data and move on. So you think an I:C of 1:16 might work better? Start using an I:C of 16, and judge those results - don't go back and revise previous results, it's not reflecting real results.


As to the GL, I am not referring to the GI. The GI is how fast the BG spikes.The GI is a ratio from 0% to 100%. The GL is supposed to tell us how much the BG will go up. Take both in account and you have a complete picture. This is why my log includes not just the amount of carbs, but also the GI and the GL. I've been tracking this for a couple weeks now, and I am just beginning to see how much. As I test against my observations and theories, we shall find out.


You're talking about it like it's physics or engineering with definitive rules. You do know that both GI and GL (which is completely dependent on GI) may be completely different for different people? Have you looked at the actual testing variance for each "result"? It can be quite large. The resulting single ranking could reflect you, or it may not at all.

In my limited experience and opinion, GI and GL are just guidelines of more or less general guidance to different people, that in no way are likely to be able to be incorporated into definitive insulin dosage for IDDMs. I guess I've said that in a few ways, a few times, so I'll cease and desist now. You keep saying it's all working for you - and I think that's great if something works for you, good luck with it.


I am especially reluctant to try a low carb diet, and here is why. A couple months ago I was in ICU for DKA. My BG wasn't all that high, by my standards (350). While in the hospital I talked with their diabetic educator (different from the last one), and we went over the meals I eat, and the carbs. She said I was being to strict and needed more carbs. She said I needed 180 carbs per day. So for me eating only a triple angry whopper :D , which is 50 carbs, she said was not enough. She said to have a small fry with it. :eek: Yeah, I was surprised.


I'm surprised too, that's absolutely shocking advice and you should see some quality medical help. She should be teaching you how to judge how individual foods react with your body, not handing down very dubious food recommendations.

The thing is, she doesn't need to deal with a spike you might or might not be getting from various foods if "general advice" happens not to apply to you. You need to care more than her.


The spike, however, have not changed, before my admission into ICU or since. So there has to be more to the puzzle.


Yes, there likely is, but you can't "slip away" from the fact that what predominantly spikes you is carbs. Here is what I think might have been happening:

Before ICU, you were relatively low carbing but still not adequately covering your carbs with insulin, ergo, you were getting high BGS. You may not have have adequate basal coverage either, which would contribute to skidding high.

After, you've been having high carb meals and found that they have been spiking you. You are trying to get the dosage right and I think you'll get it a bit better, but possibly not much better if you are one of us that spike easily with many carbs. Ergo, you are getting high BGs.

What my suggestions are based around, which started off because you were asking why your calculations were so far off the bolus calculators, is to get on the level with your calculations so you can use them effectively, and to try removing more troublesome carbs (hard to suggest that when the dietician is suggesting extremely carby junk food, eh?) focus on reducing your doses, and see if you make progress that way. So as such, I'll leave it at that, and say good luck!

[Jonathan_R]

To bad you don't live near me. :( I am learning more from you and this forum, than I have from all medical professionals, regarding diabetes, combined.

I do know that the GI and GL is dependent on the individual person. I should still be able to come up with a formula. If I work it right, I might even be able to come up with a formula that works for everyone. We'll see.

I do agree that my basal dose is to low, which is contributing to the high spikes, so I am working on that angle first. Can't change to many things at once, or you won't know what works and what doesn't.

Agreed, the carbs make me spike. Do I misunderstand that the basal insulin should work in the background and help keep things in balance, and then all I should have to do is take my bolus to match for the food. That's ideal right.

Once I get my basal right, then I'll start messing with the carb intake.

When I was first diagnosed, they had me on 60 something units of lantus. I crashed in January. I had a blood sugar of 30 something. My daughter still has a hard time with that, cause the blessed paramedics told my wife and daughter that I would go into a diabetic comma and die. I had another seizure on Easter, and my blood sugar was 99. That one hurt me more than anything else. They had to give me morphine for the pain.

I can remember being at work (in a call center) and my chest would feel weird, like palpitations. So I'd check myself, and found more than one I was again in the 30's. I'd hit the mute button and scream; "somebody get me some sugar"! So I cut my lantus dose in half. I have been slowly increasing it. One unit every other day. Today was my 2nd day at 41 units. Tomorrow, I go to 42.

[butterflykisses]

something I do for those foods I know is going to cause a sharp spike is to bolus early, like 15 minutes before eating. Works for me!