Weird results of OGTT

[kalabati]

Hi everyone!
Please help me understand what is going on with me.
Had pregnancy with gestational diabetes. After delivery in 3 month I had OGTT and I was wearing libre 2 during this test. Here is my lab results: fasting 5.2, after 2 hours 5.7. Both times libre was incredibly close to lab measurements, so I trust this particular sensor. Sounds great, but the problem is that they measured second time right on the lowest point (I circled this on the graph) and after that my libre showed that blood sugar started to climb again until it reached 9.6 mmol/l and it came back to normal only in few hours leading low BG like about 3.2. Doctor isn't going to do or explain anything as technically I passed the test, but this is definitely not normal, I just don't understand what is happening with my pancreas and what type of diabetes/prediabetes I have? How to even "work" with this? Please share what you think as I have no idea what to do with these results.
P.S. Before pregnancy I checked my C-peptide level was 1.3 (ref range 0.9-7.1) and GAD antibodies negative. This was my 2nd gdm pregnancy. I am not obese BMI 21, active, eat mostly healthy, sleep deprived though.
Thank you.

 

[Melgar]

Hi there @kalabati , firstly, and this is a general answer. In a healthy person one has two insulin phases. The first phase release happens very quickly after food. This first phase comes from stored insulin in the pancreas. It’s only a small reservoir and is released fairly quickly. If this release fails to bring down blood sugars into the ‘normal’ range then a second phase of insulin is released. This second phase has to be produced and released by the pancreas. This second phase of insulin production and release will continue until the blood sugars are back in the normal range. The process is called biphasic . Looking at your graph you then went low as you can see from the red. This is common if you have a lot of carbs. The insulin release sometimes overshoots. This is called a reactive low. The liver will then do its thing and release glucose to bring those blood sugars back up into the normal range. From your graph your blood sugars remained pretty stable. So to me, this looks like what has gone on here.

Not wishing complicate this, but CGM devices are less accurate once they go out of the normal range. So what look like high spikes may not be quite that high in reality.

This was a bit of a general answer, but this biphasic process in the pancreas is how the body controls blood sugars.

Edited to add link.

https://www.sciencedirect.com/topics/medicine-and-dentistry/insulin-release

 

[kalabati]

Hi there @kalabati , firstly, and this is a general answer. In a healthy person one has two insulin phases. The first phase release happens very quickly after food. This first phase comes from stored insulin in the pancreas. It’s only a small reservoir and is released fairly quickly. If this release fails to bring down blood sugars into the ‘normal’ range then a second phase of insulin is released. This second phase has to be produced and released by the pancreas. This second phase of insulin production and release will continue until the blood sugars are back in the normal range. The process is called biphasic . Looking at your graph you then went low as you can see from the red. This is common if you have a lot of carbs. The insulin release sometimes overshoots. This is called a reactive low. The liver will then do its thing and release glucose to bring those blood sugars back up into the normal range. From your graph your blood sugars remained pretty stable. So to me, this looks like what has gone on here.

Not wishing complicate this, but CGM devices are less accurate once they go out of the normal range. So what look like high spikes may not be quite that high in reality.

This was a bit of a general answer, but this biphasic process in the pancreas is how the body controls blood sugars.

Edited to add link.

https://www.sciencedirect.com/topics/medicine-and-dentistry/insulin-release

Hi @Melgar ! Thank you so much for your answer. It means, as far as I understand, that my results are normal and expected to be like this?

 

[Melgar]

@kalabati , to be honest I am not knowledgeable on OGTT tests and how that relates to blood sugars, whether your graph is normal or not. In general with everyday meals you would be looking for a graph that starts to rise soon after eating, peaks and returns to within 2 mmol/ls from the reading before your meal. With the OGTT test they may have different requirements.

I think they may also be looking at how strong your first phase insulin response is and if it is intact. Many prediabetic and diabetics lose this first phase insulin release. Mine is very weak to none existent.

One if our members @Lamont D may have more of an incite into these OGTT results so I have tagged him.

As a matter of interest what unit of measurements are they using for your C-Peptide test ? I was thinking pmol/ls , but I would think that would make the lab reference range too high Unless those result refer to a stimulated test, not a fasting test.
ed to add a sentence.

 

[Lamont D]

Hi everyone!
Please help me understand what is going on with me.
Had pregnancy with gestational diabetes. After delivery in 3 month I had OGTT and I was wearing libre 2 during this test. Here is my lab results: fasting 5.2, after 2 hours 5.7. Both times libre was incredibly close to lab measurements, so I trust this particular sensor. Sounds great, but the problem is that they measured second time right on the lowest point (I circled this on the graph) and after that my libre showed that blood sugar started to climb again until it reached 9.6 mmol/l and it came back to normal only in few hours leading low BG like about 3.2. Doctor isn't going to do or explain anything as technically I passed the test, but this is definitely not normal, I just don't understand what is happening with my pancreas and what type of diabetes/prediabetes I have? How to even "work" with this? Please share what you think as I have no idea what to do with these results.
P.S. Before pregnancy I checked my C-peptide level was 1.3 (ref range 0.9-7.1) and GAD antibodies negative. This was my 2nd gdm pregnancy. I am not obese BMI 21, active, eat mostly healthy, sleep deprived though.
Thank you.

,Hi, @kalabati welcome back.
I will try and interpret the graph from my experience with glucose tolerance tests. However, wether there is something happening that I'm not aware of, that might effect the results.

I'm a fella, so not had GD, but because of my endocrinologist insisting on my first and second to confirm the first. They both were similar to yours but not exactly, for some reasons.
The very high rapid spike going up to around 12 from a pre test reading of normal is classic RH or symptoms of RH, which my endocrinologist told me can be a part of GD. The reason behind the cause of the high spike could be insulin resistance or a weak first phase hormonal/insulin response. As I do. Or a combination of the two, or some other imbalance related to hormones.
As I said, this is a experience of what happened to me.
A normal would not have such as spike, and it would be more of a curve returning to normal levels around from two to three hours.
As with RH, there is a double spike, but you're is still quite high. And as you say, they stopped the test, which is usually two hours. And if they had continued the test, they would have seen the below hypo levels after the second spike and obviously the overshoot of excess insulin in your blood to drive your BG levels into hypo levels.
Did you have anything to eat or drink during the twenty minutes of your hypo, to get you back into normal levels?
If not, your body, liver response for glucagon or liver dump, that would be the little bumps in normalising BG levels, because of the insulin. Hyperinsulinaemia is quite common in metabolic conditions.

You must show your doctors, is one an endocrinologist?
Have you had other episodes, recorded on you CGM?
You must have some symptoms, other than the sleepless nights?
Again, I am only speculating, but I hope this helps.


If it is hypoglycaemia or some type akin to RH.
It is a food intolerance issue.
Or you have the reaction because you have an intolerance to glucose as the test shows. Foods which are made of sugars, or carbs, can cause the high spike, just like the glucose did.
I would advise using your CGM to test your foods that you have. Your favourite food, or lower your carb intake to get better results and try and lower the spikes and control and manage your BG levels better, of course depending on what you have.
I would ask for more tests, in case it's not RH.
A two hour test is not diagnostic of RH. It is for insulin resistance or glucose tolerance. Which is either or both to the interpretation of the doctor.
There could be other reasons for going hypo.

I eat very little carbs, more protein and natural saturated fats. But I also use fasting and intermittent fasting, so I can be in normal BG levels more of the time. It works for me. But you might be different.

Keep asking.
Best wishes.

 

[Melgar]

Thanks @Lamont D for explaining the graph as you see it. I’ve never had an OGTT test, but thought of you.

 

[Lamont D]

I've been trying to find my results from the tests I did.
Titled.....
Simila similibus chestnut, using
DPP-IV inhibitor to treat reactive hypoglycaemia.
It is online.
It I have photos, which are poor, but if you download it, it can be read.

 

[Lamont D]

Sorry, upside down and blurred.

 

[kalabati]

@kalabati , to be honest I am not knowledgeable on OGTT tests and how that relates to blood sugars, whether your graph is normal or not. In general with everyday meals you would be looking for a graph that starts to rise soon after eating, peaks and returns to within 2 mmol/ls from the reading before your meal. With the OGTT test they may have different requirements.

I think they may also be looking at how strong your first phase insulin response is and if it is intact. Many prediabetic and diabetics lose this first phase insulin release. Mine is very weak to none existent.

One if our members @Lamont D may have more of an incite into these OGTT results so I have tagged him.

As a matter of interest what unit of measurements are they using for your C-Peptide test ? I was thinking pmol/ls , but I would think that would make the lab reference range too high Unless those result refer to a stimulated test, not a fasting test.
ed to add a sentence.

Hi @Melgar ! Thank you! They are using ng/ml for C-Peptide test, it was fasting test and as far as I understand my c-peptide is quite low for fasting, but because it's still within normal range, doctors don't worry about this and I still quite lost in everything related to diabetes

 

[kalabati]

,Hi, @kalabati welcome back.
I will try and interpret the graph from my experience with glucose tolerance tests. However, wether there is something happening that I'm not aware of, that might effect the results.

I'm a fella, so not had GD, but because of my endocrinologist insisting on my first and second to confirm the first. They both were similar to yours but not exactly, for some reasons.
The very high rapid spike going up to around 12 from a pre test reading of normal is classic RH or symptoms of RH, which my endocrinologist told me can be a part of GD. The reason behind the cause of the high spike could be insulin resistance or a weak first phase hormonal/insulin response. As I do. Or a combination of the two, or some other imbalance related to hormones.
As I said, this is a experience of what happened to me.
A normal would not have such as spike, and it would be more of a curve returning to normal levels around from two to three hours.
As with RH, there is a double spike, but you're is still quite high. And as you say, they stopped the test, which is usually two hours. And if they had continued the test, they would have seen the below hypo levels after the second spike and obviously the overshoot of excess insulin in your blood to drive your BG levels into hypo levels.
Did you have anything to eat or drink during the twenty minutes of your hypo, to get you back into normal levels?
If not, your body, liver response for glucagon or liver dump, that would be the little bumps in normalising BG levels, because of the insulin. Hyperinsulinaemia is quite common in metabolic conditions.

You must show your doctors, is one an endocrinologist?
Have you had other episodes, recorded on you CGM?
You must have some symptoms, other than the sleepless nights?
Again, I am only speculating, but I hope this helps.


If it is hypoglycaemia or some type akin to RH.
It is a food intolerance issue.
Or you have the reaction because you have an intolerance to glucose as the test shows. Foods which are made of sugars, or carbs, can cause the high spike, just like the glucose did.
I would advise using your CGM to test your foods that you have. Your favourite food, or lower your carb intake to get better results and try and lower the spikes and control and manage your BG levels better, of course depending on what you have.
I would ask for more tests, in case it's not RH.
A two hour test is not diagnostic of RH. It is for insulin resistance or glucose tolerance. Which is either or both to the interpretation of the doctor.
There could be other reasons for going hypo.

I eat very little carbs, more protein and natural saturated fats. But I also use fasting and intermittent fasting, so I can be in normal BG levels more of the time. It works for me. But you might be different.

Keep asking.
Best wishes.

Hi @Lamont D , thank you for your reply! I can't see the pictures they are blured for me, but you explained that your problem is reactive hypoglycemia. According to libre I have it as well (but 4-5 hours after drinking sugar and I had lunch to raise sugar again), but my biggest concern is that after they checked my 2 hours blood sugar, it started to spike again until it reached 9.6 mmol/l. I mean if they checked 3 hours mark after drinking sugar I wouldn't pass this test, as my sugar was between 8.4-9.6 at this time, so looks like they missed my second spike. Unfortunately I can be referred to endocrinologist only by my family doctor, but he doesn't see the problem as officially I passed and if I didn't wear libre I wouldn't know about second spike. I just want to do something with this situation, just don't know what as it doesn't look like typical diabetes type 2 or type 1. It also doesn't look like LADA or typical insulin resistance as well as I don't have excessive weight and I'm quite active. My thought is that my pancreas is just "weak" or damaged and can't make enough insulin? Could it be the case?

 

[Lamont D]

Hi @Lamont D , thank you for your reply! I can't see the pictures they are blured for me, but you explained that your problem is reactive hypoglycemia. According to libre I have it as well (but 4-5 hours after drinking sugar and I had lunch to raise sugar again), but my biggest concern is that after they checked my 2 hours blood sugar, it started to spike again until it reached 9.6 mmol/l. I mean if they checked 3 hours mark after drinking sugar I wouldn't pass this test, as my sugar was between 8.4-9.6 at this time, so looks like they missed my second spike. Unfortunately I can be referred to endocrinologist only by my family doctor, but he doesn't see the problem as officially I passed and if I didn't wear libre I wouldn't know about second spike. I just want to do something with this situation, just don't know what as it doesn't look like typical diabetes type 2 or type 1. It also doesn't look like LADA or typical insulin resistance as well as I don't have excessive weight and I'm quite active. My thought is that my pancreas is just "weak" or damaged and can't make enough insulin? Could it be the case?

I will explain why you probably get the high spike. Tho it is not certain.
As you will be probably aware, your body responds to sensing food. And if you have been tested as a fasting test for the blood panel tests you have had, have come back normal. So non diabetic.
You may become T2, without control. But with the c-peptide being normal, highly unlikely to be T1 or any of the others you mentioned.
It is your body's response to food.
When you have the glucose or carbs or sugars relative to the amount of glucose drunk.
The glucose derived will raise your BG levels rapidly because...
1. The first phase hormonal/insulin response cannot cope with the glucose.
2. The insulin response within that, like me, is weak, it might be insulin resistance or the background insulin and the insulin response is not enough.
3. A hormone, pushes the response out of balance, such as thyroid, adrenal, cortisol.
But I suspect it's a weak first phase insulin response., For the simple reason, you have a classic double spike followed by the overshoot of insulin towards driving down your BG levels into hypo levels.

It does in my opinion from the graph probably akin to Hypoglycaemia condition.
Have any similar graphs showing an episode of hypoglycaemia?
I'm not certain whether it is a weak pancreas but you never know without the diagnostic tests.

I hope that helps.
Keep asking.