February 19, 2005
Insulin Analogs, Meal Planning, Food and Diet
Question from Olathe, Kansas, USA:
The reason I am asking the question is because the diabetic "team" that is treating my child does not seem to understand the material themselves and, thus, cannot explain it. How can I better understand and calculate carbohydrates in order to apply insulin? My child uses R and NPH. The doctor has recommended we change to Lantus and NovoLog. That is fine with me except, if I can't get a clear way to count carbohydrates in order to apply the insulin, then I am better off with what she is using right now. There is probably a simple set of arithmetic formulas to zero in on the relationship of intake of food and application of insulin. The reason I am also seeking help from all I can ask is that my child has Down syndrome and type 1 diabetes. At her age of seven, she can't speak and does not seem to understand how to more less communicate the glucose level of swings and feel when she is high or low. So, most of the time it is a guessing game, that is where the medical team I am dealing with falls short. The obvious would be to look for another, which I am. That is another up hill battle.
Given the town that you wrote us from, I am anticipating that you either see pediatric diabetes team from the regional children’s hospital (most of whom I know personally) or the other state medical school (and I know members of that team as well). These are high-quality folks so I am surprised that you are not getting the answers to what you are looking for.
Your child’s current insulin plan of NPH and Regular is such that, for the most part, you must anticipate that insulin, meals, and activities are relatively fixed, recurrent and predictable, and routine. Your team has probably asked you to “count carbohydrates” to this point, but perhaps has not required you to dose insulin differently day-to-day, based on that carbohydrate intake.
Switching to an insulin plan using glargine (Lantus) and aspart (NovoLog) insulins uses a different strategy that tries to better mimic the normal insulin secretion that occurs in non-diabetics. The Lantus provides a relatively constant amount of “background” (basal) insulin at a lower, prolonged dosage and the NovoLog provides the “spike” of insulin needed to accommodate after food is consumed. This is called a basal-bolus insulin plan. The key is to provide the bolus insulin based on what you eat. Therefore, if the child eats a little, then less insulin is required when compared to when they eat a lot! So, the key certainly hinges on how well, accurately, and consistently you can count carbohydrates and then “do the math” to figure out how much insulin is required.
The carbohydrate content of foods are on all labels and information is available (probably from your diabetes team) regarding carbohydrate content for portions and other prepared food items. There are little “slide-rule” type charts to keep in a backpack or purse and there are now such programs listing oodles of choices as part of personal digital assistants (such as a PalmPilot type device). Again, your diabetes team, especially the dietician, should be able to aim you to these right away!
As for the amount of insulin per carbohydrate consumed, well, that differs from person to person, based on their activity and medications, overall health and other factors that influence one’s sensitivity to insulin. Commonly, a starting off point would be 1 unit of short-acting insulin (such as NovoLog) for every 15 grams of carbohydrates consumed. [Perhaps you use the conversion of “1CARB = 15 grams”.] Some people require more at various times of the day, such as 1 unit for every 10 grams at breakfast. Some require less.