January 13, 2006
Hyperglycemia and DKA, Other
Question from Ann Arbor, Michigan, USA:
Two years ago, my now 12 year old daughter was diagnosed with diabetes while she was in the hospital with whooping cough. Her blood sugar was in the 400s mg/dl [over 22.2 mmol/L]. After she was treated for whooping cough and released, her blood sugar went down to a normal level. Her GAD antibody tests were normal. Her Glucose Tolerance Test showed elevated insulin levels around 300 as well as 110 mg/dl [6.1 mmol/L] fasting and a high of 185 mg/dl [10.3 mmol/L] at one hour. I believe she was 136 mg/dl [7.6 mmol/L] at two hours.
From this test, they determined that she had “pre-diabetes” and told us to check her blood glucose levels randomly as well as whenever she is sick, increase her exercise and watch what she eats. She also has kidney disease, so they tested her for MODY diabetes, which is an experimental test (she was in a research project) and it came back as negative, although not conclusive.
Usually, her fasting blood sugars are within normal range. Her postprandial levels are usually a bit high, in the 140 to 180 mg/dl [7.8 to 10.0 mmol/L] range, and her bedtime range is from 110 to 170 mg/dl [6.1 to 9.4 mmol/L]. It seems the closer she is to having had something to eat, the higher her results. Recently, she was 499 mg/dl [27.7 mmol/L] right after a meal, then 329 mg/dl [18.3 mmol/L] 10 minutes later, and 113 mg/dl [6.3 mmol/L] a half hour later.
I realize that we are told to take blood glucose levels an hour after meals as well as two hours after meals. If a level is taken right after a meal, or lets say, 10 to 20 minutes after finishing a meal, is there a “normal range?” I have heard that checking one’s blood sugar that close to eating might cause inaccurate results or a higher than normal level, but it’s okay. Yesterday, my daughter checked her blood sugar 15 minutes after eating and it was 197 mg/dl [10.9 mmol/L], but an hour after the meal, it was 123 mg/dl [6.8 mmol/L]. Is this considered normal, since the one hour level is normal?
I am not sure if it’s okay to check her blood sugar that close to having eaten, but now I am interested in how high it goes. Even when it spikes 300 to 400 mg/dl [16.7 to 22.2 mmol/L] right after a meal, it comes down to normal by the two hour level. Should I only record the fasting and one and two hour post-prandial levels?
Answer:
A couple of things:
Firstly, I am a little surprised that you have been asked to test her glucose both one and two hours AFTER meals. I likely would advise you to test just prior to the meal and then about two hours after (but I do know colleagues who prefer the one hour check).
The rate of digestion and absorption of food is rather variable, depending upon the patient (their age, other medications) but also hinges on the types of foods eaten. Simple sugars in glucose tablets, juices, soft-drinks, cake frosting, etc. are absorbed right away. More starchy foods make take about 30 minutes or so to digest and get absorbed. Protein may not affect the glucose until several hours later as the intestines digest and absorb the protein, and then the liver has to metabolize some of that protein into needed glucose.
Depending upon the complete standardization of the Oral Glucose Tolerance Test (OGTT), and assuming your daughter’s test was done optimally, her results were consistent with an elevation in fasting glucose (but not yet to diabetic ranges) and the two hour value was likewise suspiciously high, but, again, not to diabetes ranges (two hours greater than 200 mg/dl [11.1 mmol/L] equates to diabetes in an OGTT).”Glucose intolerance” has generally given way to a term that I do not really like, yet called “pre-diabetes.” A two hour glucose, after an OGTT, of greater than 140 mg/dl [7.8 mmol/L] defines impaired glucose tolerance. So, your daughter is real close!
Is she distinctly overweight? I would expect so with these numbers. If she is THIN, then other, rather uncommon, conditions come to mind.
Diet and exercise would certainly be the mainstay of intervention. But, I agree that from what you have written, she may have gotten off the “road to diabetes” and is now on the acceleration ramp! I’d ask that you talk to her doctor to have her rechecked. Please measure some fasting, first awakening morning glucose checks. Confirmed fasting serum glucose levels greater than 125 mg/dl [7 mmol/L] are consistent with diabetes, too.
DS
