# Insulin question

Discussion in 'Type 1 Diabetes' started by Mad76, Jan 23, 2020.

1. ### Mad76 Type 1 · Well-Known Member

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Hi all.
I posted this earlier. But when I tried to edit I managed to delete the whole thread !!!
So, forgive me for repeating myself.

I've been looking at my bg trends.

1 unit of novorapid drops my bg 3mmol
14 grams of carbs increases by 2 mmol
So
I'm thinking my ratio is 1 unit insulin per 19g carbs.

Seems logical ?
My basal is ok. I've tested
But so far been guestimating bolus.
So thinking I might get less ups and downs using the above. My daphne course isnt until June!

Thanks

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2. ### EllieM Type 1 · Well-Known Member

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No

So 21g increases by 3 mmol/L , therefore 21g for 1 unit of novorapid (call it 20g if you like).

Dosing consists of
1) units for the carb you are about to eat - so try 1 unit per 20g
2) correction dose - if your blood sugar is say 9mmol/L pre meal and you want it to be 5mmol/L you'd take (9-5)/3 = 1.3 units as a correction.

Obviously you have to round to nearest whole number.

Good luck.

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3. ### Antje77 LADA · Moderator Staff Member

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Annoying, but it happens. (especially with computers involved if you're in any way like me )

Anyway, here's a copy of my original answer:
What about taking 19 grams of carbs with your calculated insulin dose and see what happens in the following hours?
The calculation looks fine to me, but real life has a tendency to not play according to the rules. If you keep a diary of time, carbs, insulin (and exercise) you should be able to find out if that ratio works for you.

Good luck!

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4. ### miahara Type 2 · Well-Known Member

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As @Antje77 has suggested keeping a diary is a very useful way of assessing the impact of insulin and carbs, the time of day and of exercise.
Here's a link to some diaries you might want to print and use. I've been using one for the past few months and have found it really very useful.
https://integrateddiabetes.com/diabetic-logsheets/

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5. ### Mad76 Type 1 · Well-Known Member

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Thanks guys

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6. ### Hertfordshiremum · Well-Known Member

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Hi

I am Type 1 LADA, I take 0.5 units Novorapid per 10 g of carbs, but I strongly suggest a diary as for me it depends on what the carbs are. For example I can eat 100g of Kefir yogurt which is 10g of carbs and half a unit of Novorapid would cover this perfectly. However if I tried to eat 10g carbs of wheat bread my BG goes sky high, if I take extra insulin to cover my reaction I still spike and then have a hypo later, So I have cut out wheat bread. But have found I can eat pure Rye bread without a problem using my current ratio. Everyone is different so if you are new to this definitely keep a food and insulin diary and you will get to know what works for you. If anyone has any suggestions for me they will be gratefully received as I have quite a list of foods that I have cut out.

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7. ### Mad76 Type 1 · Well-Known Member

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That's great advise. As a relative newbie I didn't even think to check with different foods

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8. ### Shannon27 Type 1 · Well-Known Member

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Maths wise, i would say 1u per 21g carbs if 14g carbs raises by 2mmol, then 7g carbs raises by 1mmol. If 1u drops by 3mmol, then 3 x 7 = 21g. Not far off!
There's also correction dose to figure out

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9. ### Antje77 LADA · Moderator Staff Member

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And then there's different times of day. I need way more insulin for the same food earlier in the day than later in the day...

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10. ### Mad76 Type 1 · Well-Known Member

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Correction dose ?
I just assumed that's the 1 unit of insulin that reduces my bg by 3mmol. Or is it something else??

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11. ### Mad76 Type 1 · Well-Known Member

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It gets more and more complicated the more I learn !

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12. ### Antje77 LADA · Moderator Staff Member

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Yup. But the good thing is you can start working with the knowledge you already have, and just add more things as you go!
Keeping a diary with food, carbs, insulin dose and exercise may show you very useful patterns, please try!

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13. ### Mad76 Type 1 · Well-Known Member

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I will do
But when I do this does it mean I need to eat without taking my novorapid ? To see how much bg levels increase by? And then write this down.
If so, when should I take the novorapid ? After the bg peaks? Obviously i normally take it before i eat

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14. ### Antje77 LADA · Moderator Staff Member

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You can simply do as you usually do, please don't omit insulin for the sake of record keeping! You don't need to know how much you go up without insulin, you need to find out how much insulin to use for what foods!

So test bg and write down, inject as usual (and note amount of insulin), eat (note what you've eaten or amount of carbs), test again some 2 hours after starting eating, (note).
After a couple of days, if you see you're ending up too high or too low after, say lunch, every day, you'll know something's off with the dose for that meal. So X insulin with Y carbs is too much (or too little) insulin.
If you find you have meals where the amount of insulin is exactly right you only have to work out the carbs in that meal to know how much insulin per how much carbs did the trick. But don't expect it to work out exactly as you predicted every time, it won't!

Good luck!

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15. ### EllieM Type 1 · Well-Known Member

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Yes, that's correct. (Though you may find that this varies with exercise and time of day and even your initial blood sugar - some people need more insulin if their blood sugar is particularly high.)

But honestly, don't worry if you don't get things precisely right. In my opinion, insulin dosing is more of a best guess than anything else. The math guides you to make it an educated guess rather than a wild one.

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