The way you assess your bolus ratio for carbohydrates is to eat your usual meal and give the calculated dose of insulin. Then check your blood glucose after the meal and find out how high it goes—you are trying to keep it below 180 mg/dl. Check three times, and if the glucose goes much higher than 180 consistently, you need to increase the ratio. For example, if you gave 1 unit for 15 grams carbohydrate at breakfast, try using 1 unit per 12 grams of carbohydrate, and check again. Sometimes, if you change the ratio, you find that your peak after the meal is below 180 mg/dl, but then you go low later on. If this happens, you have a number of options:
• You can try giving your bolus a little earlier: say, fifteen minutes before eating, rather than immediately before eating.
• You might decide to have a snack to prevent the low glucose level.
• If you are on a pump, you could reduce your basal temporarily at the time when you predict you will go low.
• A newer solution to this problem is to use pramlintide (Symlin)—this drug is injected before the meal, and it lowers postmeal glucose levels by suppressing glucagon levels after the meal and by delaying stomach emptying. The starting dose is 2.5 units of pramlintide, and it is incrementally increased by 2.5 units every few days to a maximum of 10 units before each meal. Pramlintide can cause nausea, and some people can only tolerate lower doses. If you are prescribed pramlintide, you will need to back off on your meal bolus ratio. How much you back off is variable: you may need to change the bolus from 1 unit for 15 grams carbohydrate to 1 unit for 20 to 30 grams carbohydrate.
Why do you have a correction insulin bolus? The correction insulin is to correct the drift upward in your glucose levels because the basal insulin is not perfect. The other reason for having a correction insulin bolus is if you underestimated the effect of the carbohydrate in a meal, and so underdosed your meal insulin, causing the glucose levels to run high. To figure out your correction ratio, look at your insulin bolus for carbohydrates:
• If you need 1 unit of insulin for 15 grams carbohydrate, 1 unit will lower your blood glucose by 50 mg/dl.
• If you need 1.5 units of insulin for 15 grams carbohydrate (that is 1 per 10 grams carbohydrate), then 1.5 units will lower your blood glucose by 50 mg/dl—or 1 unit will lower your blood glucose by 33 mg/dl (50 1.5 =
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WHAT IT IS A three-phase plan that has been likened to the low-carbohydrate Atkins program because during the first two weeks, South Beach eliminates most carbs, including bread, pasta, potatoes, fruit and most dairy products. In PHASE 2, healthy carbs, including most fruits, whole grains and dairy products are gradually reintroduced, but processed carbs such as bagels, cookies, cornflakes, regular pasta and rice cakes remain on the list of foods to avoid or eat rarely.