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Insulin to Carbs ratio

M

mbudzi

Well-Known Member
Messages
92
Hi - need some general advice about how to create a ratio of insulin to carbs. I know this should be done with GP/Nurse etc, but their advice has been of limited use - "try injecting 4 units of rapid acting and see how it goes".

First the goal. Am I right in assuming the aim is to get my post eating blood glucose reading back to below 8 after 2 hours. Is this the same for those chasing the low carb plan - I'm still developing my understanding of what HIGH sugars are, when they start doing damage, but I have read enough to know that NICE guidance isnt necessarily best guidance. So any ideas other logic would be great to help me shape my way forward.

Second, the ratio of insulin to carbs. I know I can learn this on DAFNE, but I'm not allowed to go until I have been diabetic for a year. I don't want to run high and make mistakes for a year until they educate me. So any guidance I can get to build on the random approach recommended by my GP would be great. I think others on the forum have said 10g of carbs = 1 unit of rapid acting. Is this a sensible kick off point if I am not taking background insulin. I don't need background. If I eat low carb, I don't need insulin at all at this stage.

To put peoples minds at rest and in the hope of getting some advice, I am monitoring regularly - hourly and 2 hoursly after meals. Always before I drive (3 - 4 times a day) and before I go to bed.

HELP - please. I really want to get this on track and I'm getting readings in the 10+ and hypos when I follow the expert advice.
 
It is a bit of trial and error but just for example my son is 1:10 for Breakfast, 1:17 for lunch and 1:15 for dinner. I think DAFNE start at 1:10 but someone will be along to help with that. If you are in the honeymoon period you might need very small amounts of insulin now and in a years time that might be much different. You also need to know that your basal is about right as any changes to that can sometimes affect your ratios. Next issue is food like pizza and pasta. For fatty meals you might need to split your short acting insulin or take it later. If you keep good records you will be able to follow trends and see places where you might be high or low and go about preventing some of those levels. It is one big balancing act and don't expect that you can stay 'in range' every minute of every day. Keep track of when you do a lot of exercies also and if you are sick levels need to be carefully monitored and treated. Try and relax and don't let it get you down as it takes a long time and experimentation to find the best way to keep levels stable .
 
Yes, DAFNE will start you out on 1 unit per 10g of carb. But DAFNE is very much about a basal/bolus regime (ie background insulin is involved too) and you say you're not using background insulin yet? - so I'm not sure if it will work for you.
DAFNE also will counsel you to check bg before meals, ie not to worry aboaut the 2-hours-after-eating bg. So this may not suit you, if you feel ill when you get post-meal spikes.

The DAFNE blood sugar targets are as follows:
before breakfast: 5.5 - 7.5
before other meals: 4.5-7.5
before bed: 6.5-8.0

They also say, as a rough guide, that 1 unit of quick acting can lower your bg by 2-3 mmols, and 10g of carbohydrate can raise it by 2-3 mmols. I would add though that this is just a starting point; you need to work out what actually happens in your body. We are all different.

Although they start you off on 1:10g, I know of people who have had to go down to 0.5:10g, and also people who may need to be on as much as 3:10g, especially in the morning. So it's a very individual thing. Write out your blood sugars and compare them with the DAFNE targets, and see if you can see a pattern. Don't change your ratio immediately you have a high bg, keep things as constant as possible and watch it for a couple of days before adjusting the ratio. And if you can, try to avoid chasing those post-meal bg spikes, at least until you have your overall ratios right. Getting the meal time bgs in target is kind of the first step. Worry about the rest later.

There you go - DAFNE in a nutshell - let us know if it helps at all!
 


Snodger has explained it all fairly well but in addition I would recommend that you get a half unit insulin pen for both the background and bolus insulins. Also in figuring out the correct ratio do test mid morning and mid afternoon to see if your ratio is correct. If you don't test you might find that you start to go hypo with 2-3.5hrs after the main bolus if youve injected too much bolus, in which case you will need to eat a small snack or use some glucose.

The other way to calculate ratios is by keeping the 1u the same but adjust the carb in the ratio. As long as you know your tables it can be easier to work out in your head. If you have a good bg level before you eat and you eat for example 30g carb you just divide the amount of bolus you have injected into the 30g carb and that will be your ratio for that time of the day. You will probably need to round up your injection to the nearest half unit and then that will give you better control than using a 1u pen.
 
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