A thought on ratios and injections

[DeusXM]

Recently I've come to realise something that seems to be true for me an I'm wondering if it might be the case for others.

Broadly, my insulin ratio is about 1:10 - it varies throughout the day depending on time and also a variety of other things. However, I've noticed something in particular that has got me thinking.

This ratio seems to hold true provided I'm eating less than 50g of carbs. If I eat more than 50g, my ratio seems to shift towards 1:5. Broadly speaking, it's like there is some sort of metabolic limit to my ratio which means I need to bring out the big guns for a carby meal. I'm not just talking about injecting more insulin according to ratio, I'm saying that a 30g carb meal will usually need 3u of insulin but a 60g meal could need nearer 10-12u for me to cover it adequately. Has anyone else found something similar.

Secondly, has anyone noticed if splitting up their bolus injection changes the ratio? I've found that if I'm injecting 12u to cover something, my control is better if I take 6u in each leg at the same time, rather than the full 12 in one go. In fact, it can be to the point that I can actually take what should be a 12u meal, inject 4u in each leg (total 8u) and have the same overall control. Anyone else experienced this at all?

 

[bennyg70]

On the first point, I think I might be the other way round. I dont need much insulin, 25 units roughly TDD.

However when I was keeping record of my breakfast ratios to determine a more precise ratio for mornings, I found that under 30g carbs I would need a certain ratio. But over that 30g I was needing a lesser ratio - Hence less insulin. It was like when my body had a threshold for insulin and the more on board no matter that there were more carb, the harder it worked, and I found that even though it worked fine for the under 30g of carb the days before, over I would go low..

However when Ive had a really big carby meal... like the other week i had a fish & chipshop takeawy and I worked this out to around 100g carbs, a lot for me in one go. And i took an extra 10- 20 % ontop of my usual ratio. and it worked well. There have beena couple of times this has happened. However I couldnt say it was concrete as my carb counting may have been out or light on such a meal in the first place anyway...!

 

[trophywench]

Yes it's true (usually LOL)

Usually you do need more insulin the higher the carb load. It's a bit the same as Sick Day rules, the higher your BG is, the more insulin you will need comparatively to bring it down to a decent number. So if 1u reduces by 2.5 and you are 10, 2u = 5. However if it's 30 when you start, you will probably need more than 10u to get to 5.

A Scottish GP, Katharine Morrison, who had (dunno if she still does) a website/course she wrote for diabetics (can't recall the name) reckons 7u is the limit for one jab, for it to be absorbed reliably. She has a T1 son and that is what they discovered worked well for him anyway and she's suggested it to her own patients and it seems to work.

I have to say, 70g carb doesn't very often happen chez moi, so I can't say if it does or doesn't work like that for me. I mean fish n chips I'd split the bolus anyway cos of the fat, so you can't really count the times when you do that, can you cos it's because of something else and anyway, there's a time-lag? You'd need say S&K pudding, mash & mushy peas to have a LOT upfront, and that meal's never gonna happen for me either !

Some of the T2's would be having 43 jabs for a rich tea biscuit ......

 

[fencesitter]

Interesting. Yes, my son experiences the same thing with a heavy load of carbs. Anything above 60g and he injects a third as much again on top of usual ratio. Seems to work. This idea was first put into our heads by Every Day Ups And Downs 🙂

 

[everydayupsanddowns]

Yep. Guilty as charged - I've observed this as well, though I got the 'add a third' tip from someone else here! (when I was moaning about the problem).

Someone (not Walsh I don't think, Barnard maybe?) suggests a rule of thumb for the tipping point which is 'half your weight in pounds as grams of carbs' eg if 150-200lb then 75-100g.

Obviously this will vary from person to person and yours seems to kick in fairly low - perhaps because you generally seem to moderate your carb intake?

 

[trophywench]

Oh Mike, that means 60g for me. I don't think I need any extra at that?

But still I do tend to bolus twice for a dinner and a pudding, I have a pudding (it could be fruit or ice cream or actually a pud) only about twice a week. Cos I won't usually have anything more at all if I've already had as much as 60g.

 

[FM001]

It makes no difference if my meal has 30g or 80g my ratio is just the same, I suppose splitting insulin doses makes sense though injecting twice isn't going to help with injection site problems

 

[sdean]

I find I definitely need more than my ratio says I should for big carby meals. Eg a roast dinner and pudding (crumble etc.) I would end up at 14/15 if I only did what I 'should' do according to my dose.

 

[everydayupsanddowns]

It makes perfect physiological sense that larger meals are digested more slowly... After all there's more stuff there to chug through.

I guess, like everything it's all going to vary person-to-person though TW. Toby it makes less difference for me at 80g too, but 90g/100g and up seem to be more problematic timing-wise.

Even way back in my diabetic dark days I worked out a vague split dose system for chippy blowouts and while I recognise that fat plays a role there also seemed to be a general slow down for any large meal. Otherwise the fattier ones had the double whammy of a dip into lows after an hour or two with the full dose overreaching the food, followed by a massive high later when the dose had run out, but the food hadn't. Fun fun fun!

 

[everydayupsanddowns]

Secondly, has anyone noticed if splitting up their bolus injection changes the ratio? I've found that if I'm injecting 12u to cover something, my control is better if I take 6u in each leg at the same time, rather than the full 12 in one go. In fact, it can be to the point that I can actually take what should be a 12u meal, inject 4u in each leg (total 8u) and have the same overall control. Anyone else experienced this at all?

Re: doses - have you read the 'law of small numbers' stuff. I'm not 100% with Bernstein, but this is a very interesting read. http://www.diabetes-book.com/book/chapter7.shtml

 

[DeusXM]

Yeah, I'm familiar with Bernstein's approach. Like you, I'm a bit mix and match with him. For instance, I will cut down on carbs where possible but I'm not going to become all militant about never eating a slice of bread. My issue is I see diabetes treatment as minimising the effect of diabetes on my life - completely swearing off any food group might be good for the blood sugar but would still affect my life. There's more to life than good BGs, although that isn't a bad place to start.

 

[everydayupsanddowns]

This felt it might have relevance to your OP though:

A number of years ago, researchers at the University of Minnesota demonstrated that if you inject about 20 units of insulin into your arm, you?ll get on average a 39 percent variation in the amount that makes it into the bloodstream from one day to the next. They found that abdominal injections had only a 29 percent average variation, and so recommended that we use only abdominal injections. On paper that seems fine, but in practice the effects on blood sugar are still intolerable. Say you do inject 20 units of insulin at one time. Each unit lowers the blood sugar of a typical 150-pound adult by 40 mg/dl. A 29 percent variability will create a 7-unit discrepancy in your 20-unit injection, which means a 280 mg/dl blood sugar uncertainty (40 mg/dl x 7 units). The result is totally haphazard blood sugars and complete unpredictability, just by virtue of the varying amounts of insulin absorbed. Research and my own experience demonstrate that the smaller your dose of insulin, the less variability you get. For type 1 diabetics who are not obese, we?d ideally like to see doses anywhere from ? unit to 6 units or at the most 7. Typically, you might take 3?5 units in a shot. At these lower doses, the uncertainty of absorption approaches zero, so that there is no need to worry about whether you should inject in your arm or abdomen or elsewhere.

 

[DeusXM]

Ah, I missed that bit. That's interesting. I wonder though, does it apply to absolute amounts of insulin injected, or if doing lots of small injections at the same time reduces the variability? It's not clear, all we know is the larger the total volume of insulin injected, the more variability.

 

[everydayupsanddowns]

I took it that it was connected to the volume of fluid under the skin. A consultant I spoke to recently said she could see how that might happen.

I *think* Barnard might suggest to do exactly as you say elsewhere - ie to split larger doses into several smaller jabs in diff locations (but at the same time).

Mike

 

[everydayupsanddowns]

Just went back to the article and found this by way of his explanation for the variability:

When you inject insulin, you?re putting beneath your skin a substance that isn?t, according to your immune system?s way of seeing things, supposed to be there. So a portion of it will be destroyed as a foreign substance before it can reach the bloodstream. The amount that the body can destroy depends on several factors. First is how big a dose you inject. The bigger the dose, the more inflammation and irritation you cause, and the more of a ?red flag? you send up to your immune system. Other factors include the depth, speed, and location of your injection.

 

[PattiEvans]

A Scottish GP, Katharine Morrison, who had (dunno if she still does) a website/course she wrote for diabetics (can't recall the name) reckons 7u is the limit for one jab, for it to be absorbed reliably. She has a T1 son and that is what they discovered worked well for him anyway and she's suggested it to her own patients and it seems to work.

The website is www.dsolve.com and it's worth a look. Some while ago I read (mostly all of) it and have since split any dose over 7u simultaneously into units of 7u - in reality infrequently over 2 shots since my total carb intake most days is around 70 - 90g but there are occasions, eating out or entertaining, when it can exceed that. It DOES work better than injecting large amounts at once in one go.

 

[Abi]

I certainly find that higher carb meals need more insulin than estimated per insulin carb ratio, as well as split dose ( split in time not site) to account for slower digestion of large meals. Even on a pump I often failed to get good control if I went into a pub and had a main meal say followed by a fruit crumble and custard- I'd spike into the teens and need several corrections. I had success with this type of meal if I'd been on a long strenuous walk earlier- could calculate dose as per usual ratio but still needing a dual wave bolus over several hours on the pump- so I imagine at least 2 doses at least 2 hours apart on injections- not so much fun if you want to stagger home from the pub after said indulgent meal, several glasses of wine, following long walk- and fall straight into bed!
I think 60 -70 g carb is about the limit for me without things getting very complicated- and I weight 60 kg
Regarding 2 smaller doses simultaneously- more reliable absorption would certainly be beneficial but the slower uptake of larger doses would work better for me as explained above, due to prolonged digestion

On a slightly different note I wonder if those people who need to split their basal insulin are generally on smaller doses per kg body weight.
I know that novonordisk maintain that levemir should last 24 hours id a dose of 0.4 u per kg is given. Also seem to recall on googling info re lantus that most studies were done with a dosage of at least 0.3 u/ kg. It makes sense that a smaller dose would have a greater surface area to volume ratio and may get dispersed more rapidly although I am aware that these insulins have been modified to give more prolonged action

 

[trophywench]

No wonder Lantus didn't work for me and Levemir CERTAINLY didn't last 24 hours. In any case even if it did, unless it actually matched my basal pattern (ie that which I actually require as opposed to the inbuilt pattern of the insulin) it was still only ever gonna be somewhat right some of the time.

Now 55kgs and 9.6u TDD basal .......