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Insulin amount calculations

Old_Dave

Old_Dave

Well-Known Member
Messages
52
Location
Stilton, Cambridgeshire
Type of diabetes
Type 2
Treatment type
Insulin
This is not as silly as it sounds - honest.
How do you all calculate the Basal / Bolus quantities based on your current Blood Glucose reading and your predicted next meal (Carbs).
I'm trying to see if I can get an app / spreadsheet / gizmo that will quickly allow me to calculate quantities even allowing for some slight modifications to suit just me.
Thanks
 
Your basal dosage doesn't depend on your current blood glucose reading. So that's a strange question that kind of implies you might not understand what your basal insulin is for or how to work out the dosage. Have a look at basal testing.

There's no point working out a bolus dose for a meal in the future based on blood sugar readings hours in advance. Bolus wizards/calculator use the following information to work out a bolus dosage:
  • The carb content of your meal
  • Your insulin to carb ratio
  • You current blood sugar
  • Your blood sugar target
  • Your correction factor
So it will work out how much insulin you need to cover your meal and then add a bit on or take a bit off dependent on your blood sugar with the aim of keeping you in target.

Lots of blood sugar monitors have bolus calculators in them.
 
Wow thanks for getting back so fast everybody.
I'm Type 2 on Basal/Bolus (NovaRapid/ Levemir) but eminently going for a change/addition in conjunction with my Diabetes Nurse.
I use a spreadsheet at the moment but I can't believe that everybody else does the same so I was wondering how they calculate quantities.
 
Old_Dave said:
Wow thanks for getting back so fast everybody.
I'm Type 2 on Basal/Bolus (NovaRapid/ Levemir) but eminently going for a change/addition in conjunction with my Diabetes Nurse.
I use a spreadsheet at the moment but I can't believe that everybody else does the same so I was wondering how they calculate quantities.
Click to expand...

A basal test will check if your basal is at the right level. That's the place to start as it's the foundation you build on.

Once that's ok, you can look at your insulin to carb ratio for meals.
 
The Basal level I am on came direct from my diabetic nurse (22 in the morning and 30 in the evening) which I feel is too great a quantity and she has said she will look into alternatives. I have started on the Low Carb Diet and am now getting reasonable results its just calculating for each meal/injection seems to be quite a lot. My eyesight isn't good and trying to read all the numbers I'm sure I will be making a mistake soon so was looking for an alternative method.
 
Changes to your diet, loosing weight, increasing exercise can impact upon your insulin requirements. Really whether your basal is too great a quantity depends upon what your blood sugar control looks like and would require some basal testing to assess - https://mysugr.com/basal-rate-testing/

A basal bolus regime and carb counting does require calculating for every meal. As stated above you can get monitors with inbuilt bolus calculators to do the calculating for you.

An alternative to carb counting, to address your concerns about making a mistake with the numbers, would be to switch to fixed doses of bolus with meals. But this would require keeping your meals at fixed carb content values.
 
Thanks Catapillar but you haven't answered my question. Out of all the thousands of people with diabetes what are the most common ways they have to calculate bolus quantities. I know everything in your first sentence is correct but I just feel that I'm filling up on insulin. I have more lumps and bumps under my skin than a really lumpy thing so I was just wondering.
Mahola - its been quite a while since I had a hypo - just the opposite. I think you must be some sort of super hero or have a cast iron bum - ha.
 
Old_Dave said:
Thanks Catapillar but you haven't answered my question. Out of all the thousands of people with diabetes what are the most common ways they have to calculate bolus quantities.
Click to expand...

Usually, a bolus dose is calculated by carb counting. If you know your insulin to carb ratio is 1unit to X grams of carbs you divide the carb content of your meal by X and that gives you your bolus dose.

The bolus dose can be adjusted for circumstance, heat, exercise, illness and to take account over current blood sugar levels. Please see post #3 for a discussion of bolus calculators.
 
Yes, as mentioned above.
Basal should keep your BG flat over time if you're not eating/drinking(alcohol/carbs), or doing unusual amounts of exercise. (Eg your BG shouldn't change much while asleep)

You have to figure this out first, otherwise it interferes with the bolus calculations.

Once you have figured out how much basal you need, then you can figure out your bolus. You do this with an insulin:carb ratio and a correction ratio. I'd recommend keeping a diary (for each meal - carbs eaten, insulin and blood sugar before meals). It's easier if you can skip snacks while trying to collect this info, if you can manage it. They can interfere otherwise.

For insulin:carb ratio, basically, you need a period during which you:
1) eat a meal with a known quantity of carbs.
2) leave enough time after eating and taking your insulin for all carb and bolus insulin effects to wear off (approx 5 hours for novorapid)
3) end up at roughly the same blood glucose as you started at (eg right before meal/insulin, and 5hrs after).

For example, 24u lantus keeps me flat. That's my basal.
One day from my diary, I started at 13.4. I took 6u novorapid and had 65g carbs for breakfast. I ended up at 12.9, 5 hours later.
65g/6u = 11.8g per unit.

Then you need to figure out your correction ratio, which is how much 1u of bolus reduces your blood sugar (with no effects of food interfering).

Eg if my BG was 15, and taking 2u novorapid took me to 5, 2 units dropped it by 10, so 1unit drops me by 5.
 
Old_Dave said:
Thanks Catapillar but you haven't answered my question. Out of all the thousands of people with diabetes what are the most common ways they have to calculate bolus quantities. I know everything in your first sentence is correct but I just feel that I'm filling up on insulin. I have more lumps and bumps under my skin than a really lumpy thing so I was just wondering.
Mahola - its been quite a while since I had a hypo - just the opposite. I think you must be some sort of super hero or have a cast iron bum - ha.
Click to expand...

You calculate your bolus using your insulin to carb ratio basically. Eg if you have a ratio of 1 unit of insulin to 5g of carbs, you count the carbs in your meal then use your ration to calculate your bolus dose. So if your meal contained 30g of carbs, that would mean you needed 6 units of insulin (30g divided by 5g is 6).

Please note - those are example figures only. Your ratio may be very different.

That's a very simple explanation.

@catapillar has given you a link to basal testing above. She's also mentioned fixed doses. These give less flexibility and require more routine, but you may find them less hassle. It's something to think about anyway.
 
I really need to get to grips with this myself I just don't have the time need a week off work week off from life!
 
@Old_Dave have you a copy, or have you ever read, Think Like a Pancreas by Gary Scheiner?
It is very good, very well laid out and I think there's a Kindle version available. It is a popular book amongst Forum members here. He goes through all the necessary calculations in a very easy way. Well recommended.
 
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