June 10, 2013
Daily Care, Insulin
Question from Tabriz, Iran:
The doctor has just decreased my daughter's insulin from 18 to 11 units a day. Before all three meals, she is now to get two units of NovoRapid, via pen, if her blood glucose is 80 to 230 mg/dl [4.5 to 12.8 mmol/L], three units if her blood glucose is higher than 230 mg/dl [12.8 mmol/L]. If she is less than 80 mg/dl [4.5 mmol/L], she is not to get any insulin. In general, my six-year-old daughter's blood sugars have been less than 100 mg/dl [5.6 mmol/L] before meals and less than 150 mg/dl [8.3 mmol/L] after eating. Sometimes, her blood sugar is less than 80 mg/dl [4.5 mmol/L] in the morning. Based on her after meal levels, could she really have type 2? Anyhow, considering her after meal levels, would you please forward us your comments and responses for our following questions? How we can find out if our daughter's pancreas is producing any natural insulin? Are there any medical tests? What is the natural blood glucose level for our daughter? Can we stop insulin injections for 24 hours in order to find out her real blood glucose level? Is this dangerous for her health or not? Is our program of daily insulin injections correct?
As best I understood, your fundamental questions are:
Does your daughter really have type 1? Could it be type 2?
Given her age and what you describe, this is almost certainly type 1 diabetes. A very helpful test would be if there could be measurement of certain immune protein antibody markers that are very often present in classic, autoimmune type 1 diabetes. They are not ALWAYS present, but some parts of the literature suggest these antibody markers are present >90% of the time. Many medical centers and/or reference laboratories can measure them. They include: “GAD antibodies” (glutamic acid decarboxylase antibodies), ICA antibodies (islet cell antibodies; these sometimes are referred to as ICA-512 or IA2 or tyrosine kinase antibodies), insulin autoantibodies, and ZnT8 antibodies.
But type 1 diabetes was diagnosable in children long before we could measure these antibodies, based simply on clinical grounds based on the clinical scenario when the child presented, including the presence of ketones and acids.
It would be highly unlikely for your six year old daughter to have type 2 diabetes. There are RARE inherited forms of diabetes that could present this way and mimic type 1 diabetes. These are referred to as “MODY” diabetes and I would expect that either of her parents and grandparents to have had diabetes to make me more suspicious of MODY.
How do we know if her pancreas is still producing insulin?
I’m sure she still is making “some insulin.” It actually is not too important. She is not making “enough.” If you wanted to challenge and “stress” the pancreas more, your doctors could give her a specific challenge of a mixed meal standard material and measure the insulin “C-peptide” in her blood. I would not advise this outside of specific research settings.
What happens if we stop injections for 24 hours? Is this safe or dangerous?
Please do not stop insulin and challenge her. Her own pancreas might “use up” any insulin secreting capacity reserves. Right now, she is making some insulin to complement the insulin you are giving her. This is referred to as the “Diabetes Honeymoon” and makes management that much more easy. If you stop insulin and she cannot make enough, she can get very ill over the next hours to days and evolve into a serious and potentially fatal metabolic state called “diabetes ketoacidosis” with vomiting and coma.
What is your opinion on the current dosing we are using?
It is hard to judge based on the information you are giving. I prefer patients with diabetes be on what is called a “basal-bolus” insulin plan. This typically uses two distinct insulin types that each have distinct onset and durations of action. Your NovoRapid is a very fast-acting insulin that begins to work within about 15 minutes of injection, has a peak effect about 90 minutes later, and then is quickly much less active shortly after that. This is good insulin to take with meals and to give to correct high glucose readings. But, also, there would ideally be a background, basal, long-lasting insulin as a foundation. These types of insulin include insulin detemir, insulin glargine, or even an older, less basal-acting insulin marketed often as “NPH” insulin.