Help understanding these blood sugar test results?

November 14, 2010 9:07 AM

Help interpreting this oral glucose challenge blood sugar test? (To preface, I have an appointment with an endocrinologist; just looking for background.)

Fasting level was 108; 30 minutes after taking the glucose it spiked to around 190; then by two hours had dropped to a healthy 96. I know the fasting level is somewhat too high, but is the spike after 30 minutes also cause for concern? I can't find anything about this online -- the focus of everything I've read focuses on the fasting level and the level you're at after 2 hrs.

posted by anonymous to health & fitness (4 answers total)

Hi, I'm a Type II diabetic, but am not a doctor.

You're looking at a single number, which is meaningless. It literally doesn't matter, what does matter is the trend of your glucose level.

It short, it's hard to say. I'm guessing that a 190 could be seen as high and a vague sign of a problem, but that's a total guess on my part. The important part is that it was 96 after two hours.

Don't worry about it for now, just be sure and ask the endocrinologist about it and listen to what they say.
posted by nomadicink at 10:03 AM on November 14, 2010

Here's what Wikipedia says a normal blood sugar levels ought to look like across a normal day.

From this, it seems like a spike 30 minutes after the intake of sugars is to be expected. This is because the mechanisms that drive sugar conversion react to blood sugar level and start gearing up when sugar levels start to go up. The crash after the high sugar lunch (the two dotted lines) is a result of the body overshooting - producing conversion enzymes longer than it needs to and, as a result, pulling the blood sugar level down below what you want it to be before equilibrium is reestablished.

Your numbers seem a bit higher than the number in the graph I link to, but that might be very dependent on the measuring technique used so I wouldn't sweat it too much.

And if you ever REALLY curious about differences between measuring techniques or have trouble sleeping call me and ask me to tell you about the Einstein Stokes equation and how diluent viscosity effects the performance of immunoassays.
posted by Kid Charlemagne at 11:13 AM on November 14, 2010

These are not random numbers, they are part of a controlled test: Fast for x hours, drink y amount of straight glucose, measure levels at set points.

OP: Here is the wikipedia explanation of the test and result interpretation.
posted by SLC Mom at 1:28 PM on November 14, 2010

This page suggests a normal peak of 160-180 following an oral glucose tolerance test. A 1 hr glucose of >190 is one (you need two) of four criteria for the diagnosis of gestational diabetes.

I don't consider the fasting level too high. 110 fasting glucose is the cutoff for a diagnosis of pre-diabetes, and pre-diabetes is essentially a risk for being at risk-- don't think of yourself as pre-pre-diabetic, that doesn't make any sense.

I don't know why your 30 minute glucose was slightly high. Are you small? Were you dehydrated? But I wouldn't worry about it in your shoes.

Some context could matter. Are you pregnant? Why are you seeing an endocrinologist? Was this test administered in a doctors office? Was this administered to rule out type II diabetes?

There's no complicated math, no waiting on lab results to evaluate an OGTT. If this was administered in a doctor's office, and the doctor didn't go over the results with you, it suggests either that the doctor was inconsiderate enough to let you wait anxiously, or that there are complicating details that the doctor wanted the endocrinologist to evaluate.
posted by nathan v at 3:53 PM on November 14, 2010