Can a glucometer give wrong readings?

Q: I was diagnosed as a diabetic a year ago. My blood sugars peak about 20-30 minutes after I eat. If I consume more than 15 carbs per meal, they will peak to 190-300 and then are in the normal range for 1-2 hours. Post meal sugar levels vary from 70-120. Sometimes after 2 - 2.5 hours, they drop to the lowest point. I have experienced a level of 36 when it was difficult to open the eyes. At 190 and above, I start getting rapid heart beats and experienced shortness of breath. I was on metformin for a short time, which worked initially. Then I was put on Starlix for about a week, but due to very low levels of blood sugar I had to stop it. I was recently given a fasting arm draw and was told to eat a normal diabetic breakfast of about 40 carbs and be drawn again when I felt the symptoms. I had a fasting of 90 (arm draw) a high of 303 (arm) 313 (my meter) 30 min after I ate. I was in the normal range 125 one hour post meal, and at 60 2 hours post. The doctor was able to draw each but the last reading of 60 was at home. They thought that my glucometer gave wrong readings or I am overly anxious because I couldn't possibly have lows in the 40s 50s and the lowest 36. My doctor asked me to see an endocrinologist because he felt that I wasn't going to lay down, pass out and die. I have 3 children and my husband works out of town. I often have these peaks and drops. Are the drastic peaks, normal? Is it typical to have extreme lows when not on medication? Are glucometers accurate with readings of less than 70?

A:Glucometers are the only practical solution for self-monitoring of blood glucose. They are correct; it is the strip (glucostrip), which contains delicate enzymes that can get spoilt and give wrong readings, but glucometers are stable. There is nothing to worry but low sugar episode should be avoided by reducing/adjusting the dose. This can be done by your attending physician/endocrinologist.