I have had type�1 diabetes for 37 years and have recently changed to Humalog insulin before each meal and NPH at bedtime. I do a blood test before each injection as well as other times as I think necessary, and I find I am increasingly ‘feeling down’ if the test is not between 4 and 10 mmol/L [72 and 180 mg/dl] because of the risk of long term side effects. Most are in the realms of normal, but I’ll often have a 12 or 14 mmol/L [216 to 252 mg/dl] every day or so, and I worry. Am I worrying unnecessarily?

Long-term complications of diabetes are mainly determined by the average of blood glucose levels, not by any single reading. This is measured by the hemoglobin A1c reading, a blood test which measures how much glucose is attached to hemoglobin in the blood, and gives an “average” of glucose levels over the previous 2-3 months. This test should be done about every 3 months by your diabetes care team. The American Diabetes Association recommends keeping the HbA1c level below 7%, which indicates an average blood glucose level of about 150 mg/dl (or about 8 mmol/l).

So, while you are right to be concerned about your glucose levels and to be aiming for tight control, in reality it is very difficult to get every reading in the normal range. You do not need to be overly concerned about an occasional high reading, if your HbA1c is at goal.

The insulin regimen you are on is a good one for achieving tight control. If there is a particular time of day that you often get high readings, your diabetes care team should be able to help you adjust your insulin dose and/or your food intake to help avoid this.

ML

[Editor’s comment: You need to find out what the normal range for HBA1c is for the laboratory performing the test. There are several methods used in the testing, so, unfortunately, there is not a single normal range. You should strive to keep your level at less than 1% above the upper limit of normal, making sure you are not having frequent or severe hypoglycemia.

SS]