Five hour glucose tolerance test question

[Suzy D]

Hi all, I am new. I have unpleasant symptoms of hypoglycaemia. My endocrinologist suspects reactive hypoglycaemia and has referred me for a five hour glucose tolerance test on a day ward in hospital to be clearer about, is it reactive hypoglycaemia or fasting hypoglycaemia. I am to not eat for 5 hours beforehand, then I have my first blood test, then I get glucose, and then blood tests again every 30 minutes until the end of the 5 hours.

I am eager to get greater clarity, but I suspect I will feel very unwell as the test goes on. I have lately got through the days and nights by eating every 2-3 hours, and getting up once in the night to eat, too. I have bought myself a libre link button to help me see what's going on and while that was scary at first, it is helping me learn which eating patterns work (a bit) and which don't.

I suppose I am looking for a bit of reassurance here – presumably many of you had a test like this as well and lived to tell the tale? I would insert a nervous emoji at this point if I could find it! Thanks in advance.

 

[Antje77]

Hi @Suzy D , welcome to the forum.

I'm sure @Lamont D will pop in shortly to tell you everything he knows about this test and more.
I hope the test will give you clarity on what's going on so you can work on managing this.

Good luck!

 

[Lamont D]

Hi all, I am new. I have unpleasant symptoms of hypoglycaemia. My endocrinologist suspects reactive hypoglycaemia and has referred me for a five hour glucose tolerance test on a day ward in hospital to be clearer about, is it reactive hypoglycaemia or fasting hypoglycaemia. I am to not eat for 5 hours beforehand, then I have my first blood test, then I get glucose, and then blood tests again every 30 minutes until the end of the 5 hours.

I am eager to get greater clarity, but I suspect I will feel very uwell as the test goes on. I have lately got through the days and nights by eating every 2-3 hours, and getting up once in the night to eat, too. I have bought myself a libre link button to help me see what's going on and while that was scary at first, it is helping me learn which eating patterns work (a bit) and which don't.

I suppose I am looking for a bit of reassurance here – presumably many of you had a test like this as well and lived to tell the tale? I would insert a nervous emoji at this point if I could find it! Thanks in advance.

Hi @Suzy D and welcome to the forum.
I think I might have had five or six eOGTT tests.
Can I ask, how did you get referred?
I was referred when my GP, couldn't understand why I was going hypo, when, I didn't take diabetic meds and been misdiagnosed as T2.

And yes, you may feel a bit awful if you go hypo during the test, about 3-4 hours into the test after drinking the 75g of glucose solution. That is if it is RH (Reactive Hypoglycaemia) I found that if you fasted a good few hours before. Before going to bed the night before, if your test is usually around 8-9 a.m..
Yo should be supervised by at least a knowledgeable nurse, I had a sister, until the last one, when I was in a group of patients being tested or treated. Which means that more than one nurse, and a group of people to be with. I always took a book and my headphones to listen to music.
The test begins with a reading, from a cannula fitted to your arm, blood is taken, you have a drink of glucose and then you relax. You get a reading taken either every fifteen or thirty minutes.
if and when you may go hypo, the test will stop.
You will be offered a drink and possibly something to eat.
If it is RH, don't have too much carbs or sugar, as there may be a rebound effect of another reaction to the food and drink they give you. You can always eat something later once you have gotten home.
The nurse should test your BG levels again about fifteen minutes after you have eaten to make sure you are not in hypo levels. And they shouldn't let you go home or drive afterwards if you feel unwell or still in hypo or hyper levels.
These hypos are not diabetic hypos and should not be treated as such. The rebound effect of high and low BG levels are not recommended. You are already getting it, the rollercoaster ride of high BG levels, then crashing to a low into hypo, is in my experience, not aware in the majority of health care.
Because it is a relatively rare condition, the nurses probably have never seen anyone with RH.
I started to record my BG levels, just to see what was happening.
Always ask what is going on. Ask the reasoning.
For instance, when the nurses take venal blood from the cannula, it is going to a specialist blood lab, to be tested for many reasons. This will take a couple of weeks.
If you are thirsty, ask for slivers of ice.
After you have slept, you should be ok.

I will let you have the test first before giving you more advice. Just to say that RH is totally food related. The reaction is because of certain foods. Carbs and sugars mainly.
I have had lactose intolerance since young.
I am also intolerant to many carbs. Including wheat, grains and so on.

In the meantime, you could learn a lot more of others in the threads in the reactive hypoglycaemia sub forum.

The test is ok, and nothing in particular that you haven't already been through.
I did learn a lot from my succession of tests, and I kept asking.

Which, I will say to you if it is of isn't RH. There are more hypoglycaemic conditions other than my condition.
Which is a mouthful......
Non diabetic Late Reactive Hypoglycaemia.

Best wishes.

 

[Suzy D]

Hi @Suzy D , welcome to the forum.

I'm sure @Lamont D will pop in shortly to tell you everything he knows about this test and more.
I hope the test will give you clarity on what's going on so you can work on managing this.

Good luck!

Thank you!

 

[Suzy D]

Hi @Suzy D and welcome to the forum.
I think I might have had five or six eOGTT tests.
Can I ask, how did you get referred?
I was referred when my GP, couldn't understand why I was going hypo, when, I didn't take diabetic meds and been misdiagnosed as T2.

And yes, you may feel a bit awful if you go hypo during the test, about 3-4 hours into the test after drinking the 75g of glucose solution. That is if it is RH (Reactive Hypoglycaemia) I found that if you fasted a good few hours before. Before going to bed the night before, if your test is usually around 8-9 a.m..
Yo should be supervised by at least a knowledgeable nurse, I had a sister, until the last one, when I was in a group of patients being tested or treated. Which means that more than one nurse, and a group of people to be with. I always took a book and my headphones to listen to music.
The test begins with a reading, from a cannula fitted to your arm, blood is taken, you have a drink of glucose and then you relax. You get a reading taken either every fifteen or thirty minutes.
if and when you may go hypo, the test will stop.
You will be offered a drink and possibly something to eat.
If it is RH, don't have too much carbs or sugar, as there may be a rebound effect of another reaction to the food and drink they give you. You can always eat something later once you have gotten home.
The nurse should test your BG levels again about fifteen minutes after you have eaten to make sure you are not in hypo levels. And they shouldn't let you go home or drive afterwards if you feel unwell or still in hypo or hyper levels.
These hypos are not diabetic hypos and should not be treated as such. The rebound effect of high and low BG levels are not recommended. You are already getting it, the rollercoaster ride of high BG levels, then crashing to a low into hypo, is in my experience, not aware in the majority of health care.
Because it is a relatively rare condition, the nurses probably have never seen anyone with RH.
I started to record my BG levels, just to see what was happening.
Always ask what is going on. Ask the reasoning.
For instance, when the nurses take venal blood from the cannula, it is going to a specialist blood lab, to be tested for many reasons. This will take a couple of weeks.
If you are thirsty, ask for slivers of ice.
After you have slept, you should be ok.

I will let you have the test first before giving you more advice. Just to say that RH is totally food related. The reaction is because of certain foods. Carbs and sugars mainly.
I have had lactose intolerance since young.
I am also intolerant to many carbs. Including wheat, grains and so on.

In the meantime, you could learn a lot more of others in the threads in the reactive hypoglycaemia sub forum.

The test is ok, and nothing in particular that you haven't already been through.
I did learn a lot from my succession of tests, and I kept asking.

Which, I will say to you if it is of isn't RH. There are more hypoglycaemic conditions other than my condition.
Which is a mouthful......
Non diabetic Late Reactive Hypoglycaemia.

Best wishes.

Hi Lamont,

This is all of interest, thank you! I am especially glad to learn that the test ends once a hypo has been established. Though I sometimes come out of mild hypos without waking up if they catch me out at night. But pure glucose, I shudder to think how spiky that will look in my monitor app! As you say, the nurse may not have come across reactive hypoglycaemia before, unless specially instructed I suppose, so it makes sense to share my concern with him/her.

I am intolerant to gluten and dairy so will bring my own hamper for the meal at the end: a hearty stew is likely to work best. And I won't shy away from saying to the nurse that I am think a hypo may well occur. I have my libre link so am able to keep a bit of an eye on it myself if I want to, even though I know they can be 15% off and also 15 minutes behind actual BS level. I thought I might keep Wednesday's episode of Shetland on BB1 to watch during my test on Thursday, that will keep me distracted for an hour!

I was referred for the glucose tolerance test because I was able to present lots of data to the endocrinologist: libre link data with lots of peaks and troughs, blood test results of lots other stuff done by my GP surgery, a list of unpleasant symptoms, and what I knew from doing the Zoe programme two years ago: my blood sugar control is poor. It was also the Zoe programme that alerted me to the existence of libre link, how handy is that when you want to have a rough idea what's going on! My friend got a monitor for a fortnight as well but she is completely different: her blood sugar goes up and stays up and she is close to prediabetes. Which always seems like a luxury to me now: oh to have a slot and steady insulin response! : /

 

[Lamont D]

Hi Lamont,

This is all of interest, thank you! I am especially glad to learn that the test ends once a hypo has been established. Though I sometimes come out of mild hypos without waking up if they catch me out at night. But pure glucose, I shudder to think how spiky that will look in my monitor app! As you say, the nurse may not have come across reactive hypoglycaemia before, unless specially instructed I suppose, so it makes sense to share my concern with him/her.

I am intolerant to gluten and dairy so will bring my own hamper for the meal at the end: a hearty stew is likely to work best. And I won't shy away from saying to the nurse that I am think a hypo may well occur. I have my libre link so am able to keep a bit of an eye on it myself if I want to, even though I know they can be 15% off and also 15 minutes behind actual BS level. I thought I might keep Wednesday's episode of Shetland on BB1 to watch during my test on Thursday, that will keep me distracted for an hour!

I was referred for the glucose tolerance test because I was able to present lots of data to the endocrinologist: libre link data with lots of peaks and troughs, blood test results of lots other stuff done by my GP surgery, a list of unpleasant symptoms, and what I knew from doing the Zoe programme two years ago: my blood sugar control is poor. It was also the Zoe programme that alerted me to the existence of libre link, how handy is that when you want to have a rough idea what's going on! My friend got a monitor for a fortnight as well but she is completely different: her blood sugar goes up and stays up and she is close to prediabetes. Which always seems like a luxury to me now: oh to have a slot and steady insulin response! : /

Hi again,
Funnily enough I'm not gluten intolerant but to the wheat (carbs) itself.
I think we a relative newbie, your understanding of what happens is brilliant.
I can explain further if you wish. It is quite complicated, and the terms used is an adventure in itself.
Having a CGM to back you up when talking to an endocrinologist is very good forward thinking.
And now I understand why you were referred, and I do agree the next stage is the eOGTT.
All the tests do not prove RH, but are elimination tests and only after a couple more tests can the true diagnosis be known.
It is widely known that CGMs get what is known as compression loss whilst sleeping. This is a good reason to have a back up glucometer to finger test the low.
I have never used a CGM, when I was going through it all, I only had a glucometer, CGMs were not about a decade ago. I'm sure my endo would have insisted on one.
But I managed, and as there was only one of two around that had actually been diagnosed, you could say I was thrown into the deep end, but it was a great learning curve. And thanks to my endo, he did save my life.
I was really unhealthy and suffering, cos my GP didn't have a clue, not did another endo, six or seven years earlier.

Forgot to mention, one of the tubes drawn will be for c-peptide and GAD tests for antibodies.
I would be surprised, if that is what they find. And I hope they test insulin levels as well, which is something everyone with a metabolic condition should get.
On my soapbox again!!!

Keep asking, there is so much to learn.
Best wishes.

 

[Suzy D]

Hi again,
Funnily enough I'm not gluten intolerant but to the wheat (carbs) itself.
I think we a relative newbie, your understanding of what happens is brilliant.
I can explain further if you wish. It is quite complicated, and the terms used is an adventure in itself.
Having a CGM to back you up when talking to an endocrinologist is very good forward thinking.
And now I understand why you were referred, and I do agree the next stage is the eOGTT.
All the tests do not prove RH, but are elimination tests and only after a couple more tests can the true diagnosis be known.
It is widely known that CGMs get what is known as compression loss whilst sleeping. This is a good reason to have a back up glucometer to finger test the low.
I have never used a CGM, when I was going through it all, I only had a glucometer, CGMs were not about a decade ago. I'm sure my endo would have insisted on one.
But I managed, and as there was only one of two around that had actually been diagnosed, you could say I was thrown into the deep end, but it was a great learning curve. And thanks to my endo, he did save my life.
I was really unhealthy and suffering, cos my GP didn't have a clue, not did another endo, six or seven years earlier.

Forgot to mention, one of the tubes drawn will be for c-peptide and GAD tests for antibodies.
I would be surprised, if that is what they find. And I hope they test insulin levels as well, which is something everyone with a metabolic condition should get.
On my soapbox again!!!

Keep asking, there is so much to learn.
Best wishes.

Thank you so much for taking the time to explain, it's very kind of you, and I feel for you with your metabolic condition journey. I probably have enough info for now, until after my test anyway. And yes, there will be an insulin test with my GTT as well, but I don't remember seeing anything about c-peptides or antibodies. I am sure I will be back! Best wishes.

 

[Lamont D]

Thank you so much for taking the time to explain, it's very kind of you, and I feel for you with your metabolic condition journey. I probably have enough info for now, until after my test anyway. And yes, there will be an insulin test with my GTT as well, but I don't remember seeing anything about c-peptides or antibodies. I am sure I will be back! Best wishes.

If it is RH, or not, I will explain the science behind it, and how the medical profession have RH all wrong.
I say this from my own experiences and from others that have posted looking for answers.
Hope it goes well for you, and don't be too concerned with the test. It is an adventure.
Best wishes.