Spiker
Well-Known Member
- Messages
- 4,685
- Type of diabetes
- Type 1
- Treatment type
- Pump
It's tricky to 'tune' these 3 values - basal dose(s), carb ratio, correction ratio. The best procedure is to have a day of fasting to verify that the basal dose is correct, with testing every 2-4 hours while you are awake.
Once you know that that basal rate is correct, it's then easy to verify the correction ratio and carb ratio by a few simple tests. For the correction ratio wait until you have a high reading, take some insulin, see how much it reduces your blood sugar by after 4 hours. For the carb ratio, sort of the reverse, start at a normal blood sugar, eat some carbs with a known value of grams of carbohydrate (gch), check your blood sugar 4 hrs later. Obviously don't eat during either of these tests, apart from the 'known' carbs.
There are lots of inaccuracies in the process because of the smallish BG numbers involved, the accuracy limits of meters, probably smallish insulin doses. BG over 10 is hard to get an accurate ratio from because of kidney dumping effects and increased insulin resistance. So you really only have a short range to play with, between 4-5 mmol/L and 9-10 mmol/L, to do both the carb ratio tests and correction tests accurately.
Nonetheless once you come up with a new set of ratios you can stick with them and keep doing the same tests from time to time to see if they still fit your data (carbs, insulin, BG).
Over time, basal rate and correction dose will vary with insulin resistance and body weight, carb ratio will vary with insulin resistance but not with body weight (except in so far as overweight can increase insulin resistance). Regular exercise is one of the main factors affecting insulin resistance, apart from overweight.
Once you know that that basal rate is correct, it's then easy to verify the correction ratio and carb ratio by a few simple tests. For the correction ratio wait until you have a high reading, take some insulin, see how much it reduces your blood sugar by after 4 hours. For the carb ratio, sort of the reverse, start at a normal blood sugar, eat some carbs with a known value of grams of carbohydrate (gch), check your blood sugar 4 hrs later. Obviously don't eat during either of these tests, apart from the 'known' carbs.
There are lots of inaccuracies in the process because of the smallish BG numbers involved, the accuracy limits of meters, probably smallish insulin doses. BG over 10 is hard to get an accurate ratio from because of kidney dumping effects and increased insulin resistance. So you really only have a short range to play with, between 4-5 mmol/L and 9-10 mmol/L, to do both the carb ratio tests and correction tests accurately.
Nonetheless once you come up with a new set of ratios you can stick with them and keep doing the same tests from time to time to see if they still fit your data (carbs, insulin, BG).
Over time, basal rate and correction dose will vary with insulin resistance and body weight, carb ratio will vary with insulin resistance but not with body weight (except in so far as overweight can increase insulin resistance). Regular exercise is one of the main factors affecting insulin resistance, apart from overweight.