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Bolus Insulin Units

ImSpiritus

ImSpiritus

Member
Messages
19
Type of diabetes
Type 3c
Treatment type
Insulin
Hi all,

Just though id post a quick question here whilst waiting for an answer from the Diabetic Centre. Newly diagnosed awaiting course.

I am on Novorapid and at present the ratio I am on is 1:10. But seem to have a problem with how I am working out the carbs to units. For example.

BG before lunch 8.3mmol/l
Steak bake = 33carbs
Coffee with Milk & Sweetner = 5 Carbs

For the above I would normally take 4 units of rapid this would bring my BG down to 7.9mmol/l

However yesterday I had
BG before lunch 8.6mmol/l
2 x Steak bakes = 66carb
Coffee with Milk & Sweetner = 5 Carbs

Only took 6 units instead of the 7 I should have of rapid as Im still awaiting the course and still trying to get confidence in taking insulin but my BG went down to 4.1.

I will add im not your typical T1 but T3c treated as T1.

What could have caused the sudden drop as I was expecting it to be roughly around the 7 mark.
 
Hi @ImSpiritus if carbs were the only thing that affected our BG life with type 1 (or type 3) would be easy (or easier).
Unfortunately, what we eat is not the only thing which can affect our BG. For example, exercise can reduce BG for up to 48 hours after and a few drinks the night before can also lead to a drop in BG.
And then there is the fun of "insulin on board". Not only do we have to take into consideration the insulin we are taking now, we also have to consider any insulin we have taken in the last 3 or 4 hours (NovoRapid is at its most active for 4 hours after injecting).
As if that wasn't enough, different carbs are digested at different rates. For example, jelly babies are digested fast which is why they are a common hypo treatment. Whereas, something with fat in it like chocolate or pizza (but probably not at the same time!) are digested much slower ... the carbs from a pizza may still raise my BG 5 hours after eating it unless I consider this with my insulin timing. In an ideal world, we would time our bolus dose so the peak of the insulin activity exactly matches the peak of the carb digestion. If we take our bolus too early, our BG may drop and, if we take it too late, our BG may spike.
Added to all of that, our bodies are not robots. They don't do the same thing again and again and again. It may be stress or it may be a background sniffle or a run to catch the bus or ... as some seem to think ... the colour of your socks.
For this reason, I try not to overreact when my BG does something I don't expect. I make a mental note and see if it does the same thing next time I am in the same scenario whether it is eating the same thing or doing the same exercise.

So, to go back to your question, you may never know.
Or you may have gone to the gym last night or had a few pints of beer or you may have had some insulin on board after your elevenses or the fat in your steak bake may have delayed the carb digestion. Or it could have been those sneeky socks.
 
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Hi @ImSpirtus,
Welcome to the forum and you have posted a corker of a question!!
And your caution may have saved you from a too low blood sugar level (BSL) or hypo.
Hypoglycaemia (hypo- = low, -glyc- = glucose, -aemia = in the blood_ , hypo for short.
As a T1D and not as health professional advice or opinion:
When this has happened to me in the past it sets off a 'flood' of problem-solving or "detective work'.
The question is where to start?
Glucose meters are supposed to be accurate within +/- 15%, but 4.1 mmol/l as a reading might vary
+/- 0 .6 mmol/l which is still 'miles' away from what was expected!
But if I have trouble obtaining the sample of blood taken for that reading and really squeeze the blood out
of my finger I might get sufficient other non-blood fluid from the finger prick that 'waters down' the blood and
causes a falsely low reading.

Repeating the reading on the same finger and making sure the blood drop flows freely
(second ouch)! is my way to double check the unusual result. To be sure, to be sure!!
Sometimes the BSL reading will vary between fingers and hands !
And are the test strips out-of-date and thus may read inaccurately for that reason!!

Timing of testing: I usually test 2 hours after eating - as this is the usual timing recommended (
(at least > 90 minutes) but could there have been a difference in timing of the reading after
one lunch compared to the other?

Meal sizes: I have found that the meal sizes and thus the carb content of some foods vary - so could the
2 Steak bakes have been different sizes and different amount of carbs in them than the food content label
suggests than with the previous lunch? Also some of the protein in the meat will be changed by the liver
into glucose but usually appear in the blood nearer the 3 hour mark so may not be a factor here.

Snacks: sometimes from past habits I might snack on something as the Steak bakes bake and
forget to allow for that in the carb count. Or add in something into the coffee that is sweeter.

Insulin: site: if I accidentally inject some or all of my insulin into a muscle instead of more shallowly
under the skin the insulin absorbs more quicker and lowers my BSL quicker, usually I know because the
injection really stings or it aches over a much larger area of the skin than the usual injection does.

timing:Did I inject my Novorapid on the first occasion and eat within say 20 minutes , but on the second occasions was there a hold up - a phone call, burnt steak !! or other distraction so that the gap between insulin and eating was longer? say 40 to 50 minutes.
The insulin in the second case would have longer to getting working before the glucose from the meal arrived and thus the BSL could have been lower.?

Stress: If I am stressed on the first occasion - burnt steak, crank phone caller , still got a cold, etc my insulin will not work as effectively. The BSL will reflect that.
If I am served my cooked lunch with no stresses involved, my insulin will work better on that occasion and a lower BSL may result.

Exercise: If I have exercised in the morning or sometimes the evening before that may affect my sensitivity to insulin - it may work better than on a day when there has not been any prior exercise.
So my BSL on the 'exercise before lunch' day might be lower after lunch than on the 'exercise-free' day.

Medications: I have not personally found medications affecting my BSLs much but if there is a new medication taken one day but not on the other that is something I would check with my doctor.

I think I have covered the list as Detective 101. I hope that helps and that you do not get too many surprises!!
Best Wishes and keep posting - after 52 years on this 'insulin stuff' I am still learning -
but you can learn from all the mistakes we make and not have to experience so many yourself !! :):):)
 
Many thanks all,

Compelling reading, especially when at 48 it's like learning a whole new trade. Hardest part is what works today may not work tomorrow therefore whilst the basics will remain its the content keeps changing. Ive quickly realised how some parts affect me differently to others and now tailored it to myself. For e.g no matter what I eat or the amount of carbs my novorapid doesnt kick in till almost 3 hrs. Continuous finger pricking every 30 mins for 4 hrs after shows me that if I take rapid at the recommended times and then test after 2hrs that my readings are high. Whereas if I then test at the 2.5hr point its come down approx 2/3mmol/l then at the 3hr point it really kicks in and can bring me down 4/5mmol/l especially if I got the units correct. I have taken the rapid to 30mins before a meal if i can but not noticed much difference and still kicks in 2.5/3hr after taking the first bite.

To be honest, I petrified of getting it wrong especially the amount of units I take. Therefore try and keep my meals small and low carb/sugar so I don't have to inject so many units. On the occasion I have had a pizza or a takeaway when i know the carbs are higher I've only taken the units I have been comfortable with. I know this is wrong but still learning. For e.g I know by taking something with 35 Carbs I would take 3.5 units or 4 units dependent on BG before a meal. If I test every so often I can see my BG go up to e.g 15 and then come down. However if I have something with 80 carbs (a takeaway) I've only been taking between 4-6 units dependent on prior BG which is too little. Yet when testing as above it still goes up to 15 but come back down to 13 and remains there for longer periods.

I am probably not making much sense but the crux of it is I am probably for the first time since being a teenager absolutely bricking it in case I give myself a severe hypo due to my own stupidity of getting it wrong. So many factors to consider.

Once again though I thank all that replied and have at least given me some questions to ask the Dietitians and more questions when I get onto the course they have told me will be in a few months. I am due to get the Libre next month to be able to give me a better view and for the Diabetic team so hoping it will help me start to get this right.
 
Ni @ImSpiritus, you have learned lots and applied it - well done.
What you are grappling with, I think, is the two sides of the same coin.

One side: You describe eating and using the insulin to control the BSL rise from that food., using carb counting and insulin to carbs ratios.
It is challenging to get the two opposing 'forces' to match in terms of keeping BSLs in range - both within the upper and lower range limits.
And the more insulin used for more carbs eaten the more you are worried about exceeding upper limit of acceptable BSLs or dropping of BSLs too low.
You do have some room to play here if you deliberately delay the time between Novorapid injection and eating the meal, so that the BSL rise is closer to when the Novorapid is at maximal efficacy.

Other side: you can eat food to best match the action of your insulin. So you need to have slower rises in BSLs which ideally peak, but not to a high sharp peak around the 3 hours mark as you have found.
That is where having less carbs and more protein could work. Less carbs means less early rise and some of the protein is converted by the liver to glucose and forms a peak nearer the 3 hour mark and beyond.
And because less insulin is needed the risk of hypos is reported to be less.

You can find out more about the types of diets which are used for each side of the coin on the Home page, under Type I diabetes and also under Type 2 diabetes. There are also diet books if you have a particular preference.

When you discuss your diabetes management further with your health team just be aware that the eating and using insulin to control the BSL is more familiar to dietitians, doctors and nurses.
But there is evidence to quash any issues about reports of more proneness to heart disease and cholesterol problems on the low carb high fat diet. Let me know it it is needed!!

Only you can decide what suits you best and you can change your diet with your health team's assistance if need be.

As before I ask you to consider reading about the DCCT (mentioned above) so that you are full bottle on it for when your health team and you (as part of it) meet to discuss things.
 
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