Glucose Tolerance Test

Why the sudden need for Metformin? Did your A1C rise from 2 years ago?

A one-time hit isn't going to ruin you or cause you to quit producing insulin...if you aren't (or if your cells are not sensitive to the insulin you are producing) It is the sustained high BS's that cause damage.

You are going to feel terrible, though. I had to do a GTT with my pregnancies and I felt nauseated afterwards.

I have had a few OGGTs.

It is principally used to monitor how your blood glucose levels respond to the glucose.
Your bloods will be taken from fasting, then usually every half hour to see your spike, then to see your curve back to normal.
Your veinous blood will be taken for the likes of c peptide.
It is a useful diagnosis tool that endocrinologist use. It gives them the understanding of what happens to you and why the type of diabetes.

Let us know how you do.

Is it a 2 hours test or prolonged test?

Hi there. I'm pre diabetes and my GP wants me to do glucose tolerance. Is that usual? I'm not quite sure why I'm having it if all other tests are pre-diabetes. Can any one shine any light on this?

Sally66 said:

Hi there. I'm pre diabetes and my GP wants me to do glucose tolerance. Is that usual? I'm not quite sure why I'm having it if all other tests are pre-diabetes. Can any one shine any light on this?

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It's to see what is going on in your blood to discover the effects of a high glycaemic load.
They want to see how quickly you spike and take bloods in lab conditions.
Is it a 2hour test or prolonged?

Yep getting it done during the half term break (would not go down well taking a morning off school to do it as I've just been off for 3 months recovering from major surgery!!). Hope I don't need to get it done too
often.

Sally66 said:

Yep getting it done during the half term break (would not go down well taking a morning off school to do it as I've just been off for 3 months recovering from major surgery!!). Hope I don't need to get it done too
often.

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If you've had major surgery, then this will be a breeze.
Just take a book and clothes that you can relax and sit for a while.
Once the needles in, you can relax, the time away.
I've had quite a few and it's helped my diagnosis and understanding my condition.

Anyone who is following a low carb diet is advised to "carb up" for at least 3 days before an OGTT to ensure accurate results. You should try for 150g carbs per day for the 2 or 3 days before the test:

From Dr Michael R Eades:

"Following a low-carb diet makes one a little glucose intolerant, which is the reason that the instructions for a glucose tolerance test always include the admonition to eat plenty of carbs in the week before the test. Why? Because all the macronutrients–glucose, fat and protein–are broken down by enzymes during the metabolic process. And all the enzymes necessary for the metabolism of the various macronutrients are made on demand but not immediately.

If you are on a high carbohydrate diet, then you will have plenty of enzymes on hand to deal with the carbohydrates you consume. If you switch to a low-carbohydrate diet, it takes a while to manufacture the enzymes in the quantities needed to deal with the extra fat and protein that your metabolic system hadn't been exposed to. This deficiency of protein/fat metabolizing enzymes is the reason people starting a low-carb diet become so easily fatigued–they've got plenty of enzymes on hand to break down carbs, they just don't have the carbs to metabolize. Once they produce the enzymes necessary to deal with the load of protein and fat, which takes a few days, they become low-carb adapted and no longer feel fatigued.

Once people become low-carb adapted then the same thing happens if they go face down in the donuts. They don't have the enzymes on board to deal with the sudden influx of glucose, and, as a consequence, their blood sugar spikes higher than it would on a person eating the same amount of carbohydrate who is already carb adapted."

I don't know but I

Sally66 said:

Hi there. I'm pre diabetes and my GP wants me to do glucose tolerance. Is that usual? I'm not quite sure why I'm having it if all other tests are pre-diabetes. Can any one shine any light on this?

Click to expand...

GTT is far more reliable than both fasting BG and HbA1c. My HbA1c was 46 at diagnosis but my GTT was 20.6 at one hour and 13.8 at two so definitely diabetic. And my fasting never went above 6.

Surgery advise taking usual meds prior to test. Would this include vitamin supplements I wonder?

A couple of things I did find when I went for an OGTT were:
1) Having to do a 3 bus journey to hosp, i had liver dumped which put my "fasting" level up!
2) Having had more carbs than my normal days worth the up-down of BG made me feel "funny" and the "nurse" kept mithering me to have a carby snack!