Is it possible to have LADA/1.5 with high C peptide?

[Vectian]

I have recently had tests back, very high reading for GAD antibodies, negative for the other 2 antibodies. However, my C peptide level is high normal (1080) showing strong insulin production. I was put on insulin after the initial high A1C (97) but stopped taking it after 4 weeks, and BG better now than when on insulin, I am keeping it under control now with diet and exercise alone. Surely a strong auto-immune attack as suggested by the GAD result would result in a low or at least reduced insulin output/C peptide? I have read that it's possible to be GAD positive and have type 2, although there seems to be a lot of disagreement amongst researchers and experts.

 

[Lamont D]

I have recently had tests back, very high reading for GAD antibodies, negative for the other 2 antibodies. However, my C peptide level is high normal (1080) showing strong insulin production. I was put on insulin after the initial high A1C (97) but stopped taking it after 4 weeks, and BG better now than when on insulin, I am keeping it under control now with diet and exercise alone. Surely a strong auto-immune attack as suggested by the GAD result would result in a low or at least reduced insulin output/C peptide? I have read that it's possible to be GAD positive and have type 2, although there seems to be a lot of disagreement amongst researchers and experts.

Hi, you certainly seem to be an enigma wrapped in a mystery. Not that I know much about LADA.
But, I know what it's like to have different things not in the norm.
Being told I'm weird, can be a bit disturbing.

Have you a endocrinologist?
Is this why you are getting the tests?
I can't understand why, your c-peptide insulin levels are above normal and still give you insulin to take.
My c-peptide was slightly higher than normal in a fasting blood test but mine was really high during an eOGTT.
Hence my interest.

I wish I had answers, someone who is LADA will be along soon.
Best wishes.

 

[Vectian]

Hi, you certainly seem to be an enigma wrapped in a mystery. Not that I know much about LADA.
But, I know what it's like to have different things not in the norm.
Being told I'm weird, can be a bit disturbing.

Have you a endocrinologist?
Is this why you are getting the tests?
I can't understand why, your c-peptide insulin levels are above normal and still give you insulin to take.
My c-peptide was slightly higher than normal in a fasting blood test but mine was really high during an eOGTT.
Hence my interest.

I wish I had answers, someone who is LADA will be along soon.
Best wishes.

I haven't been allowed to see a consultant, just a nurse who is very unhelpful. I was put on insulin as they didn't know which type it was/is (I don't fit the profile of either) and the test results take 6 weeks, so just in case I was T1. Now the results are back it's still not really conclusive. My C peptide is in the normal non-diabetic range, at the upper of of that. Having a high C peptide above normal is usually seen in T2 I believe, where you are making plenty of insulin but the insulin resistance is preventing your body from using it properly.

 

[searley]

Typically if your insulin production is normal and you have high hba1c then you are insulin resistant so T2…. The problem with LADA is that you can have times when things work ok…. Then times when they don’t.. so imo ladă is possible but so is T2…. Sometimes when you don’t fit the norms it’s a case of waiting and seeing

 

[Lamont D]

I haven't been allowed to see a consultant, just a nurse who is very unhelpful. I was put on insulin as they didn't know which type it was/is (I don't fit the profile of either) and the test results take 6 weeks, so just in case I was T1. Now the results are back it's still not really conclusive. My C peptide is in the normal non-diabetic range, at the upper of of that. Having a high C peptide above normal is usually seen in T2 I believe, where you are making plenty of insulin but the insulin resistance is preventing your body from using it properly.

I would ask for a doctor appointment and insist on a referral where more investigative diagnostic tests can be done by an endocrinologist.
The only other option is to go private or just thought, you can now ask for a second opinion from another doctor.
I wouldn't leave it as it is, no matter what the dsn says.

 

[Vectian]

I would ask for a doctor appointment and insist on a referral where more investigative diagnostic tests can be done by an endocrinologist.
The only other option is to go private or just thought, you can now ask for a second opinion from another doctor.
I wouldn't leave it as it is, no matter what the dsn says.

All the GP can do is refer me back to the diabetes centre at my hospital, where I'm already registered. So I end up with the same nurse, who says that because you are GAD positive you automatically have T1, with no discussion.

 

[Antje77]

my C peptide level is high normal

High normal is definitely possible in early LADA.
High normal is not high, it falls within the normal parameters.

Early on with LADA during the honeymoon period, the pancreas can produce varying amounts of insulin. Often too little, sometimes just the right amount (some LADA's can go without insulin for months after having needed insulin before), and in some people it can even produce too much insulin occasionally, causing hypos without being on insulin.

As the autoimmune attack goes on, insulin production will decrease in LADA's, and it can take weeks or years before production is close to zero.

C-peptide measures what is happening at the moment of the blood draw, it changes throughout the day. Did you have your glucose level tested at the same time?

At your age (50 if your profile info is correct), it's well possible you have some insulin resistance going on, which means you need a bit more insulin (and thus a higher C-peptide) than average. Pure speculation here, but I think this is what happened to me (overweight, diagnosed at 39).
I had a C-peptide test two years after my initial T2 diagnosis, 4 years after having symptoms in hindsight. Mine was just below the low normal threshold, LADA can be slow. I had been on insulin for 2 years already at this point.

 

[Vectian]

High normal is definitely possible in early LADA.
High normal is not high, it falls within the normal parameters.

Early on with LADA during the honeymoon period, the pancreas can produce varying amounts of insulin. Often too little, sometimes just the right amount (some LADA's can go without insulin for months after having needed insulin before), and in some people it can even produce too much insulin occasionally, causing hypos without being on insulin.

As the autoimmune attack goes on, insulin production will decrease in LADA's, and it can take weeks or years before production is close to zero.

C-peptide measures what is happening at the moment of the blood draw, it changes throughout the day. Did you have your glucose level tested at the same time?

At your age (50 if your profile info is correct), it's well possible you have some insulin resistance going on, which means you need a bit more insulin (and thus a higher C-peptide) than average. Pure speculation here, but I think this is what happened to me (overweight, diagnosed at 39).
I had a C-peptide test two years after my initial T2 diagnosis, 4 years after having symptoms in hindsight. Mine was just below the low normal threshold, LADA can be slow. I had been on insulin for 2 years already at this point.

I had pre-diabetes in 2016, then reversed it with diet (lost 2 stone) and kept in normal range and not overweight since then. I didn't have an A1C at the time of the C-peptide test, but had one about 10 days earlier at 97 and fingerprick on the day was around 12. I hadn't eaten for quite some time so close to fasting level.

I was showing insulin resistance before I stopped the insulin, everything else seems more fitting with T2 apart from the GAD positive test. I have been on no insulin or meds at all for 3 weeks and BG fine. I just don't understand how the cause of the diabetes can be insufficient insulin (as T1/LADA) when the test shows you are producing a strong amount. If you have plenty of insulin but high BG then that would suggest insulin resistance is the issue, as in T2?

 

[Michele01]

I have recently had tests back, very high reading for GAD antibodies, negative for the other 2 antibodies. However, my C peptide level is high normal (1080) showing strong insulin production. I was put on insulin after the initial high A1C (97) but stopped taking it after 4 weeks, and BG better now than when on insulin, I am keeping it under control now with diet and exercise alone. Surely a strong auto-immune attack as suggested by the GAD result would result in a low or at least reduced insulin output/C peptide? I have read that it's possible to be GAD positive and have type 2, although there seems to be a lot of disagreement amongst researchers and experts.

This probably won’t help at all but when I was pre-diabetic they assumed I was T2. I was put on a tablet (Forxiga only for T2) and I ended up in intensive care with severe ketoacidosis. My antibodies were off the chart. So I’m guessing that LADA can be a difficult diagnosis to make. I hope you find a solution. Maybe ask to see an endo at the clinic rather than a nurse?

 

[WarrickN]

LADA is almost normally first diagnosed as T2D. Commonly presents 50+ years, mild overweight. It is also often sometimes called double or T2.5 because it is autoimmune but some features of insulin resistance suggesting T2D. One estimate I've seen is about 20% of T2D diagnoses are probably LADA but never been tested for antibodies. LADA is a form of T1D - latent autoimmune diabetes in adults.
A longish initial period of not requiring insulin is also common - the period varies but often up to about 5 years. It does still seem that doctors are not yet up to speed with this type of diagnosis and it seems diabetes specialists generally assume high antibodies means go on insulin immediately. The honeymoon period of course means that endogenous insulin production (measured either as insulin or C-peptide) is enough to maintain target glucose concentrations with a bit of help. In my case, that was an early realisation that it is eating carbohydrates were the issue, although as an initial T2D diagnosis I started on metformin.

 

[Vectian]

LADA is almost normally first diagnosed as T2D. Commonly presents 50+ years, mild overweight. It is also often sometimes called double or T2.5 because it is autoimmune but some features of insulin resistance suggesting T2D. One estimate I've seen is about 20% of T2D diagnoses are probably LADA but never been tested for antibodies. LADA is a form of T1D - latent autoimmune diabetes in adults.
A longish initial period of not requiring insulin is also common - the period varies but often up to about 5 years. It does still seem that doctors are not yet up to speed with this type of diagnosis and it seems diabetes specialists generally assume high antibodies means go on insulin immediately. The honeymoon period of course means that endogenous insulin production (measured either as insulin or C-peptide) is enough to maintain target glucose concentrations with a bit of help. In my case, that was an early realisation that it is eating carbohydrates were the issue, although as an initial T2D diagnosis I started on metformin.

I just don't understand how insulin production can be strong (high normal C Peptide) yet the problem maintaining proper blood sugar is down to insufficient insulin if it's LADA. I think I am the same keeping it under control by limiting carbs at the moment, I'm sure if I started eating pasta, white bread and sweets etc. it would be out of range. I was doing the low carb because if it is T2 that's obviously how you put it in remission, I have read it is possible to have T2 and be GAD positive which is what makes all of this so confusing.

What effect did the metformin have and what was your C peptide at diagnosis?

 

[Melgar]

I'm just wondering why do you think that 1080 pmol\l is high normal? Was it fasting and what was your blood sugar at the time the test was taken? If your blood sugars were very high at the time then 1080 maybe viewed differently. If fasting, I believe that figure falls under 'normal', optimal even. My understanding is that high C-peptides due to IR can go very high, limited only by your pancreas' inability to produce enough insulin to bring your blood sugars down. The upper range can exceed 1700 pmol/l. As for your GAD antibodies, the fact that you are producing them should mean further tests. That said a surprising number of people produce GAD antibodies and don't even develop raised blood sugars. Please don't hesitate to correct me on these stats.

 

[Vectian]

I'm just wondering why do you think that 1080 pmol\l is high normal? Was it fasting and what was your blood sugar at the time the test was taken? If your blood sugars were very high at the time then 1080 maybe viewed differently. If fasting, I believe that figure falls under 'normal', optimal even. My understanding is that high C-peptides due to IR can go very high, limited only by your pancreas' inability to produce enough insulin to bring your blood sugars down. The upper range can exceed 1700 pmol/l. As for your GAD antibodies, the fact that you are producing them should mean further tests. That said a surprising number of people produce GAD antibodies and don't even develop raised blood sugars. Please don't hesitate to correct me on these stats.

High normal as in the upper range of normal, some scales say normal is up to 1200 so not far off that. Pretty much fasting I hadn't eaten for quite a while. This was before any treatment so blood sugar was highish around 12, what difference does that make to the C peptide reading though? I don't get how your pancreas can be compromised by autoimmune attack yet producing an as you say optimal amount of insulin. Surely if the insulin production was insufficient it wouldn't be 1080?

 

[Melgar]

It is difficult to measure insulin production as insulin only has a very short shelf life and becomes unstable, so they measure C-peptides. C-peptides are far more stable and there is a direct correlation between insulin production and C-peptides. I have read that normal production of C-peptides are between 800 - 1200 after fasting.

If your blood sugars were at 12 mmol/ls after fasting and your C-peptides are at 1080 pmol\l then, in my humble opinion, your insulin production is not as high as you think it is. In a non diabetic person who produces healthy amounts of insulin the corresponding C-peptide numbers, with blood sugars that high, C-peptides would be much higher until the pancreas has brought their blood sugars right down through raised insulin production. The fact non diabetics' pancreas' can produce lots of insulin to counter high blood sugars, I'm thinking post prandial, means their pancreas are working well. It seems to me that your pancreas is unable to bring your blood sugars down because it simply cannot produce enough insulin whether or not you have IR. I hope that makes sense.

 

[Vectian]

It is difficult to measure insulin production as insulin only has a very short shelf life and becomes unstable, so they measure C-peptides. C-peptides are far more stable and there is a direct correlation between insulin production and C-peptides. I have read that normal production of C-peptides are between 800 - 1200 after fasting.

If your blood sugars were at 12 mmol/ls after fasting and your C-peptides are at 1080 pmol\l then, in my humble opinion, your insulin production is not as high as you think it is. In a non diabetic person who produces healthy amounts of insulin the corresponding C-peptide numbers, with blood sugars that high, C-peptides would be much higher until the pancreas has brought their blood sugars right down through raised insulin production. The fact non diabetics' pancreas' can produce lots of insulin to counter high blood sugars, I'm thinking post prandial, means their pancreas are working well. It seems to me that your pancreas is unable to bring your blood sugars down because it simply cannot produce enough insulin whether or not you have IR. I hope that makes sense.

Producing a strong amount of insulin as shown by the C peptide almost at the top of normal range but blood sugar not coming down would suggest insulin resistance surely? If the pancreas was not producing enough the C peptide would be lower. Having constantly high BS is not the same as a normal person eating a load of sugar and having an isolated spike of 12. I had insulin for 4 weeks, then in the last 4 weeks I have had zero medications or insulin and my blood sugar has been pretty much in normal range. This is after losing weight (although I wasn't overweight before) and a low carb diet.

 

[Lamont D]

I am aware that I'm theorising.
But one of the many causes of T2, of which insulin resistance is promient, is because the first phase hormonal/insulin response to carbs causes over time the precursor to T2. Because the second phase insulin response called an overshoot in response to the spike and insulin resistance. In turn causes too much insulin production, so you could have T2 because of the imbalance of too much insulin. Not too much glucose.
But would be diagnosed because of higher than normal hba1c.
These patients with this type of T2 are treated with mainly the gliptin group of meds. Which helps correct the first phase imbalance.
There are so many ways to become T2.
Maybe this is an individual variety of such diagnosis, or maybe LADA. Until the tests are done, we won't know!

 

[Melgar]

Producing a strong amount of insulin as shown by the C peptide almost at the top of normal range but blood sugar not coming down would suggest insulin resistance surely? If the pancreas was not producing enough the C peptide would be lower. Having constantly high BS is not the same as a normal person eating a load of sugar and having an isolated spike of 12. I had insulin for 4 weeks, then in the last 4 weeks I have had zero medications or insulin and my blood sugar has been pretty much in normal range. This is after losing weight (although I wasn't overweight before) and a low carb diet.

The only thing you know is your fasting blood sugars are 12 mmol/l when you gave blood. Your body's C-Peptide was 1080pmol in response to that high fasting blood sugar. What I was suggesting is your C-peptides were not that high in response to 12mmol/ls of sugar. I used the non diabetic example, not because I lost my mind and thought they were the same, I was suggesting that a non diabetic's pancreas would respond with a lot more insulin and the corresponding C-peptides, after a spike of 12mmol\ls after a carb laden meal (even if it got that high). I just questioned your C-peptide numbers, given your high fasting blood sugars. That is all. I would also think that with 12mmol/ls of blood sugar and insulin resistance as well your C-peptides would be a lot higher. Just my opinion.

My own pancreas is producing 537pmol/L after a fasting level of 6 mmols. The lab range is 260-1730 pmol/L so half what you are producing, but still within range. My blood sugars can be as high as 10 mmol/ls in the mornings, but on the day I had my bloods taken they were a just 6 mmols after about 15 hours fasting. I do not have insulin resistance and I have a normal insulin sensitivity. My BMI is 19. The Dr's are undecided on the type of diabetes I have and are comfortable waiting to see what happens. In BC, Canada your Ac1's would need to be above 9% to get tested for any of the 4 types of antibodies. Your post pricked my interest because of the LADA aspect.

 

[Vectian]

The only thing you know is your fasting blood sugars are 12 mmol/l when you gave blood. Your body's C-Peptide was 1080pmol in response to that high fasting blood sugar. What I was suggesting is your C-peptides were not that high in response to 12mmol/ls of sugar. I used the non diabetic example, not because I lost my mind and thought they were the same, I was suggesting that a non diabetic's pancreas would respond with a lot more insulin and the corresponding C-peptides, after a spike of 12mmol\ls after a carb laden meal (even if it got that high). I just questioned your C-peptide numbers, given your high fasting blood sugars. That is all. I would also think that with 12mmol/ls of blood sugar and insulin resistance as well your C-peptides would be a lot higher. Just my opinion.

My own pancreas is producing 537pmol/L after a fasting level of 6 mmols. The lab range is 260-1730 pmol/L so half what you are producing, but still within range. My blood sugars can be as high as 10 mmol/ls in the mornings, but on the day I had my bloods taken they were a just 6 mmols after about 15 hours fasting. I do not have insulin resistance and I have a normal insulin sensitivity. My BMI is 19. The Dr's are undecided on the type of diabetes I have and are comfortable waiting to see what happens. In BC, Canada your Ac1's would need to be above 9% to get tested for any of the 4 types of antibodies. Your post pricked my interest because of the LADA aspect.

The normal range for C peptide includes stimulated, so presumably the upper end is as high as a non-diabetic person would go, even with a high carb meal. So I don't think that their number would go a lot higher, just that the body would respond much better to the insulin produced and that would bring it down quickly. I believe that non-diabetics can reach 11 or so, although that would obviously be not often and only after a lot of sugar/carbs.

From what you have described it sounds like your case fits more squarely with LADA, a lower rate of C peptide shows less insulin but not impeded by IR so would suggest insufficient insulin production which is what happens in LADA. Apparently it can progress very slowly, I have heard someone say their "honeymoon period" where the body is still producing some insulin was over 10 years. Others can be much shorter. The antibodies don't 100% confirm LADA (as in my case) but more than one is a much stronger chance and combined with the overall picture would give a good idea. Here in the UK you can have the antibody test done privately, could you do that if doctors not willing? My initial A1C was 97 (11%) so pretty high.

 

[Vectian]

I am aware that I'm theorising.
But one of the many causes of T2, of which insulin resistance is promient, is because the first phase hormonal/insulin response to carbs causes over time the precursor to T2. Because the second phase insulin response called an overshoot in response to the spike and insulin resistance. In turn causes too much insulin production, so you could have T2 because of the imbalance of too much insulin. Not too much glucose.
But would be diagnosed because of higher than normal hba1c.
These patients with this type of T2 are treated with mainly the gliptin group of meds. Which helps correct the first phase imbalance.
There are so many ways to become T2.
Maybe this is an individual variety of such diagnosis, or maybe LADA. Until the tests are done, we won't know!

Thanks. My initial A1C was 97, so pretty high. I have had the antibody tests, but they just confused things, very high GAD antibodies but negative the others. That would suggest LADA, but then I also had quite a bit of IR and C peptide in the upper end of normal range (pretty much fasting) whereas LADA would normally have low normal or low C peptide as they aren't producing enough. I have read that it's possible to be T2 and have GAD antibodies, there is a lot of disagreement amongst researchers and doctors around LADA. I don't know what further tests would confirm one way or another though.

 

[Melgar]

The normal range for C peptide includes stimulated, so presumably the upper end is as high as a non-diabetic person would go, even with a high carb meal. So I don't think that their number would go a lot higher, just that the body would respond much better to the insulin produced and that would bring it down quickly. I believe that non-diabetics can reach 11 or so, although that would obviously be not often and only after a lot of sugar/carbs.

From what you have described it sounds like your case fits more squarely with LADA, a lower rate of C peptide shows less insulin but not impeded by IR so would suggest insufficient insulin production which is what happens in LADA. Apparently it can progress very slowly, I have heard someone say their "honeymoon period" where the body is still producing some insulin was over 10 years. Others can be much shorter. The antibodies don't 100% confirm LADA (as in my case) but more than one is a much stronger chance and combined with the overall picture would give a good idea. Here in the UK you can have the antibody test done privately, could you do that if doctors not willing? My initial A1C was 97 (11%) so pretty high.

We have a 100% social health care in Canada, no private private health like you do in the UK, so unless I go across the boarder into the US I have to wait.