February 1, 2003
Diagnosis and Symptoms
Question from New Hampshire, USA:
Shortly after eating an unusually large amount of carbs (soda, candy, etc.), my 14 year old son did a random glucose test using his grandmother's meter which was 222 mg/dl [12.2 mmol/L]. I then tested it two hours later, and it was 98 mg/dl [5.4 mmol/L]. The next morning his fasting blood sugar was 48 mg/dl [2.7 mmol/L], so I gave him a carb rich breakfast (waffles, jam, orange juice). Two hours later it was 111 mg/dl [6.2 mmol/L], and every subsequent test has been normal. Urine test was normal. Is it worrisome for a kid to spike like that?
You probably should not draw any conclusions from a single reading on a blood sugar meter. If you have concerns about diabetes, I would recommend checking with your pediatrician who can arrange testing if necessary.
[Editor’s comment: Testing for diabetes should include blood sugar levels performed by a medical laboratory. The timing of the sample (fasting, random, or postprandial) would influence how high a level is considered abnormal. See Classification and Diagnosis of Diabetes Guidelines for further information.
Occasionally, lab blood sugar testing might be normal in an early case of diabetes, repeat blood sugar testing at the same or a different time, or performing a glucose tolerance test, might be appropriate if there is a high suspicion of diabetes despite normal initial testing. Another test, the glycosylated hemoglobin, might be used to help confirm a suspected diagnosis of diabetes, but the GHB (also called HbA1c or A1c) is not usually considered as appropriate to make an initial diagnosis. Antibody testing is occasionally done as a screening test in high-risk situations, or as confirmatory of type type�1A (autoimmune) diabetes, but is not part of routine testing.
Urine sugar tests or home glucose testing, if done, might be positive, which would make the situation more urgent to get lab testing done to confirm the abnormal results.