Question from Carbondale, Pennsylvania, USA:

My daughter has type 1 diabetes. Recently, my 14 year old nephew asked me to test his blood sugar with her meter. He had eaten about 10 Oreo cookies 20 minutes before his test. The first reading came up as 202 mg/dl [11.2 mmol/L]. I had him wash his hands and retest; he was then 171 mg/dl [9.5 mmol/L]. I was a little concerned so I retested him the next morning, fasting, and his blood sugar was 96 mg/dl [5.3 mmol/L]. He’s very physically fit, normal weight and height, has no other symptoms of diabetes, and was not on any medication. He had a bruised kidney about four months ago while skiing, but no other medical history. My advice to his mother was that you do have to allow for a margin of error with home blood glucose meters, but to mention the high numbers to his doctor during his next visit and request a glucose tolerance test, which she did. She was told that those readings are in the normal range for a non-diabetic after eating such a high carbohydrate snack and that type 1 never presents with only high blood sugar and no other symptoms so his doctor didn’t feel any further testing was necessary. If that were your child, would you be comfortable with that answer, which includes no further follow-up? Just how high do you believe a non-diabetic person’s blood sugar can go after eating and still be considered normal? Also, what other factors, besides diabetes, might cause that high of a reading?