January 4, 2005
Blood Tests and Insulin Injections, Insulin
Question from Ontario, Canada:
My son takes NovoRapid with each meal using the total carbohydrates divided by 10 method (98g carbohydrates divided by 10 = 10 units NovoRapid). The meal times are 7:30 a.m., 12:30 p.m. and 5:30 p.m. For these three meals, this method works great. But, at 9 p.m., he takes NPH to carry him through the night. When testing between meals, every five hours, he runs between 6 and 8 mmol/L [108 and 144 mg/dl]. However, when testing three and a half hours after supper, before his NPH injection, he runs high 9.5 to 12.5 mmol/L [171 to 225 mg/dl]. Are we testing too soon or is this expected? Does this timing difference play out, because he has a 25g carbohydrate snack at 11 p.m. before bed? He takes nine units of NPH at 21:00.
Answer:
The observed rising of his blood sugar level three and a half hours after dinner is highly expected, if you consider both the short half-life of the NovoRapid (aspart) and the waning of NPH injected the previous night. One possibility might be to substitute the aspart at dinner with the same amount of Regular insulin that has a longer duration or, and I’d be much more in favor of this latter choice, switch to glargine (Lantus) instead of NPH. This new basal insulin is much more stable and effective than NPH covering insulin basal needs up to 24 hours. Nowadays, it is our best choice for patients with type 1 diabetes on intensive treatment. Ask your doctor for further advice.
MS
