September 13, 2000
Question from Newtown, Pennsylvania, USA:
My daughter is seven and was diagnosed with type 1 diabetes three years ago. Her first course of therapy was using Regular and NPH mixed, twice a day, before breakfast and dinner. She was switched to Humalog about three months ago, in place of Regular. Her HbA1c was 9.2% and came down to 8.2% after three months of using the Humalog. Is there a rule of thumb to follow when administering the Humalog with regard to how much one unit will lower her blood sugar? For instance if her blood glucose reads 150 mg/dl [8.3 mmol/L], is it safe to assume that one unit will lower her by 50 mg/dl [2.8 mmol/L] and reduce her to 100 mg/dl [5.6 mmol/L] prior to her meal. How much Humalog is necessary to cover a certain amount of consumed carbohydrates? I’ve read as much about the insulin as I could and have not found specifics related to this.
I know when you are on pump therapy this is the method of thinking used. That is our goal to get our daughter ready for pump therapy. Having her think about what she’s eating related to how much insulin she takes and what her blood sugar is prior to, is a good stepping stone.
Your questions are very good ones and should be referred to your diabetes team so they can tailor their answers to your daughter. Many people working the diabetes field use a general rule of thumb that 1 unit of Humalog will lower the blood glucose by a certain amount, but the amount can vary from person to person. Your diabetes team can help you determine your daughter’s response to Humalog by incorporating in other factors such as carbs consumed, next meal time, time of day, and exercise (either just finished or upcoming). When starting pump therapy an insulin to carb ratio is determined by the team and adjusted as necessary.
It sounds like the change to Humalog has been to your daughter’s advantage. Keep up the good work.