Have I botched up my Glucose Tolerance Test?

[Zebra33]

Hope this is the right place to post.
I had to have a GTT last week and instead of having a slice of toast and tea at 6am (test appointment for 1.30pm) I had toast & tea at about 7.30am. The diabetes nurse called me today to say I have high sugar and need to go see her. Could the fact that I ate later than I should have affected the results of the test?? (I really was expecting a NORMAL glucose level! )

[TheMightyToosh]

Didn't they ask you what you have eaten that day before they did the test? They usually do.

But I doubt this would have made a big difference for a test at 1.30pm. If you didn't have glucose tolerance issues, tea and toast would not raise your blood sugar to abnormal levels.

Plus they take a 'before' sample to check that your levels weren't raised before you took the glucose dose, so I'm afraid it sounds like your test is kosher and you did really have high glucose.

Are you pregnant? WIth any luck, it will only last as long as the pregnancy does

[Flame]

I think they are probably right. They do the before level, and then the after, with skewed results they would still see the lack of level dropping iyswim.

I have it in my head too that 6 hours is all they actually need anyway (from lab working days I seem to recall a 6 hr fasting glucose test)

[theyoungvisiter]

When I had a GTT I was told not to eat anything from midnight the night before - it was utter hell and I nearly passed out.

Did they say it was supposed to be 6am?

You could always just tell the nurse and see what she thinks - if it was borderline and she thinks the toast could have affected it they might offer to do it again. It does sound unlikely though - it's not like you had a mars bar beforehand.

BTW in my case they didn't take a "before" - or at least not that I can remember. I'm pretty sure they took only one set of bloods, and that was 1.5 hours or whatever after drinking the glucose.

[TheMightyToosh]

Fasting glucose is different from GTT though. Fasting glucose test measures the level when you haven't eaten, so yes, eating then would affect the result, but as Flame says, probably not significantly with this length of time in between.

But a glocose tolerance test is measuring your response to a controlled, high dose of glucose, with a before and after test performed, so tea and toast several hours beforehand would be unlikely to affect the result of a GTT.

[Flame]

the before is standard - you get special labels to put on samples one and two

[Zebra33]

Thanks for the quick replies!

I am preggers. And they told me I could have toast and tea at 6am before the test at 1.30pm.

xx

[lambethlil]

I did this and had to be retested over a whole day as an in-patient; I was too embarrassed to admit what I had done and had to be screened for gestational diabetes! prob best to admit and be retested.