December 22, 2007
Question from Indianapolis, Indiana, USA:
My daughter has been having unexplained extreme lows for the past five days. Her blood sugar levels have been as low as 18 mg/dl [1.0 mmol/L] to 30 mg/dl [1.7 mmol/L] throughout this period. There has been no change in diet or activity. We have checked her meter to verify proper readings. The lows are random and inconsistent, with no pattern. We have consulted our doctors on this issue and they have no answers. Nine this past July, my daughter takes between 6 and 6.5 units of NPH every morning at 7 a.m. and four units of NPH around 6:45 p.m. In the morning, for a correction, we say that one unit of Humalog brings her number down 50 mg/dl. In the morning, she takes one unit of Humalog per 7 grams of carbohydrates. Her lunch includes about 50 grams of carbohydrates. At dinner, she takes one unit of Humalog for each 13 grams of carbohydrates. Actually, her numbers have been better this week, but not perfect. I started giving her a little less NPH in the morning and a little more lunch. I just can't imagine where those "freak" numbers came from. We have never experienced numbers like that before, for no reason.
Every now and then I see this and really cannot give a good explanation, then it goes away. It almost seems like there is extra insulin, from the pancreas or from some depot of insulin that just gets used. I suppose even a brief change in sensitivity to the insulin can be happening. Sometimes, I blame such drops in blood sugars on a virus, but isn’t that what we doctors do?…everything is a virus.