Question from St. Louis, Missouri, USA:

My four year old son has type 1, diagnosed a year ago. He apparently is still in his honeymoon stage. His control is better than average, last HbA1c was 7.3%. He’ll go in cycles where he will consistently be within 80 – 200 mg/dl [4.4-11.1 mmol/L] for days, then go off on a tangent where he will, against all logic and reason, plummet to 39 mg/dl [2.2 mmol/L] or rocket up to 380 mg/dl 21.1 mmol/L]. All this happens without any change in diet or amount of insulin injected. I don’t believe these sudden lows are caused by the exogenous insulin. If this can be attributed to honeymoon, and a “sputtering out” of his remaining islet cells, how come these remaining islet cells can’t “read” the level of insulin already in his system (from the injections) and recognize that they should not excrete any more, lest they send the body into a hypo? Isn’t this the way they are supposed to work in a normal pancreas? Do “distressed” islets lose their ability to compute?