Type 1.5 or Type 2?

[giorgoXXI]

Hi everyone,

I had a routine blood test last October where my A1C was 57 and fasting glucose was 9. Since then I went in a low carb diet and in February my A1C is now 39 and fasting glucose was 3.9. I was convinced I was Type 2 as I was overweight (BMI 27) and my diet was very poor full of carbs and sugars. However, as part of the latest test I was tested for GAD and C-peptide and these were my results:

GAD - 16.9 u/ml (normal range < 5)
C-peptide - 0.51 ng/ml

I am seeing the endo in a weeks time to be formally diagnosed, but does this point to me being Type 1.5?

For the blood test I did fast almost 16 hours, that's why my fasting glucose was so low. Would that also reflect in a "low-normal" C-peptide?

Also I've read for the GAD test that between 5-30 is considered a "low positive". Does that make a difference in diagnosis?

Any guidance would be appreciated. Thanks.

 

[markpj31]

I was Type 2 on oral meds, now I'm T1 on insulin. I guess that would make me 1.5?

I've never had C-Peptide tested, they just went with the notion that oral meds were no longer working (and to be honest they probably weren't seeing as I was eating less that 15g of carbs per day)

 

[Lamont D]

Hi @giorgoXXI and welcome to the forum.

Hi everyone,

I had a routine blood test last October where my A1C was 57 and fasting glucose was 9. Since then I went in a low carb diet and in February my A1C is now 39 and fasting glucose was 3.9. I was convinced I was Type 2 as I was overweight (BMI 27) and my diet was very poor full of carbs and sugars. However, as part of the latest test I was tested for GAD and C-peptide and these were my results:

GAD - 16.9 u/ml (normal range < 5)
C-peptide - 0.51 ng/ml

I am seeing the endo in a weeks time to be formally diagnosed, but does this point to me being Type 1.5?

For the blood test I did fast almost 16 hours, that's why my fasting glucose was so low. Would that also reflect in a "low-normal" C-peptide?

Also I've read for the GAD test that between 5-30 is considered a "low positive". Does that make a difference in diagnosis?

Any guidance would be appreciated. Thanks.

If you have been referred, it is for a reason, probably for further tests.
There must have been something like your blood test results that have flagged an appointment.

You have done really well to reduce your hba1c and your fasting levels. So whatever you have done it's working!
I would carry on until your appointment and see what happens.
I don't think I would worry about the low normal, normal being the optimum word!


Let us know how you get on.

 

[HSSS]

I was Type 2 on oral meds, now I'm T1 on insulin. I guess that would make me 1.5?

I've never had C-Peptide tested, they just went with the notion that oral meds were no longer working (and to be honest they probably weren't seeing as I was eating less that 15g of carbs per day)

Type is not determined by whether you are on insulin or not (despite even an few old fashioned medics believing so). Simply going onto insulin as a toe 2 does not make you type 1 or lada (A slow onset variant of type1).

Type 1 is characterised by a destruction of the insulin producing cells by the autoimmune system of your own body.
Type 1.5 or LADA is another adult onset version of type 1 that occurs over months or even years rather that the typically expected days or weeks usually seen in children.
Both will have little to no insulin made and may or may not test positive for antibodies. (Another myth that negative antibodies means type 2)

Type 2 invariably begins with insulin resistance and typically normal to very high insulin production in attempts to overcome this resistance. It does sometimes end up with not just a comparative lack of insulin meaning not enough to do the job properly (because we need ever increasing amounts to overcome the ever increasing resistance) but an actual lack of production too but that’s usually after years of decreasing control.

Now I’m not suggesting you are not type 1 (or LADA) but if you are you were never type 2 but always a misdiagnosed type 1. Apparently that’s a fairly significant number of adult type 1’s.

And that is why cpeptide and insulin should be measured not just assumed Imo both at diagnosis and if control deteriorates without explanation

 

[markpj31]

Type is not determined by whether you are on insulin or not (despite even an few old fashioned medics believing so). Simply going onto insulin as a toe 2 does not make you type 1 or lada (A slow onset variant of type1).

Type 1 is characterised by a destruction of the insulin producing cells by the autoimmune system of your own body.
Type 1.5 or LADA is another adult onset version of type 1 that occurs over months or even years rather that the typically expected days or weeks usually seen in children.
Both will have little to no insulin made and may or may not test positive for antibodies. (Another myth that negative antibodies means type 2)

Type 2 invariably begins with insulin resistance and typically normal to very high insulin production in attempts to overcome this resistance. It does sometimes end up with not just a comparative lack of insulin meaning not enough to do the job properly (because we need ever increasing amounts to overcome the ever increasing resistance) but an actual lack of production too but that’s usually after years of decreasing control.

Now I’m not suggesting you are not type 1 (or LADA) but if you are you were never type 2 but always a misdiagnosed type 1. Apparently that’s a fairly significant number of adult type 1’s.

And that is why cpeptide and insulin should be measured not just assumed Imo both at diagnosis and if control deteriorates without explanation

I was Type 2 for 10years or so on Metformin and then the other later oral drugs they prescribe. My last Hba1c on Metformin/Sitagliptin etc was 57, but at that stage I went into Ketoacidosis in December 2021, not only that, Metformin was causing me horrific stomach problems (it always did to be fair, but GP said keep taking Imodium) which also caused low levels of sodium. At that point, all oral meds were terminated and I was moved on to insulin, which for me, is far easier to manage.

 

[HSSS]

I was Type 2 for 10years or so on Metformin and then the other later oral drugs they prescribe. My last Hba1c on Metformin/Sitagliptin etc was 57, but at that stage I went into Ketoacidosis in December 2021, not only that, Metformin was causing me horrific stomach problems (it always did to be fair, but GP said keep taking Imodium) which also caused low levels of sodium. At that point, all oral meds were terminated and I was moved on to insulin, which for me, is far easier to manage.

by which measure that sounds like type 2 on insulin as your profile says rather than the type 1 your comment said.

 

[markpj31]

by which measure that sounds like type 2 on insulin as your profile says rather than the type 1 your comment said.

Well, I called it type 1.5 as I thought that was the term used when somebody transitions from type 2 to insulin dependant?

 

[HSSS]

Well, I called it type 1.5 as I thought that was the term used when somebody transitions from type 2 to insulin dependant?

that refers to LADA or a form of type 1. You’re still type 2, just insulin dependent. A lot of people are under similar misunderstanding hence my highlighting it so the myth doesn’t continue.

 

[Deleted member 527103]

Well, I called it type 1.5 as I thought that was the term used when somebody transitions from type 2 to insulin dependant?

Type 1 is not defined by whether you take insulin or not.
There are people with other types of diabetes such as gestational and type 2 diabetes who take insulin.
Our treatment does not define whether we have an automimmune condition (Type 1) or not.

LADA is a term used by some to describe people with Type 1 who were diagnosed as an adult.
The first A stands for Auto-immune ... which is what causes Type 1.

Type 1.5 is just another name for LADA.

Having type 2 and taking insulin is just that - it is not possible to "progress" from type 1 to Type 2. They are completely different conditions.
It is possible to have Type 1 diabetes and insulin resistance (type 2).

Sometimes, I wish they had different names as it can be very confusing at times.

 

[Antje77]

Having type 2 and taking insulin is just that - it is not possible to "progress" from type 1 to Type 2. They are completely different conditions.
It is possible to have Type 1 diabetes and insulin resistance (type 2).

To add to that, I suppose it would be possible to develop T1 even if you already have T2, T2 doesn't in any way protect you from autoimmune diseases.
So that could be a remote possibility as well.

 

[HSSS]

To add to that, I suppose it would be possible to develop T1 even if you already have T2, T2 doesn't in any way protect you from autoimmune diseases.
So that could be a remote possibility as well.

But most drs would just assume your type 2 had got worse and never identify the type 1

 

[Jaylee]

Hi everyone,

I had a routine blood test last October where my A1C was 57 and fasting glucose was 9. Since then I went in a low carb diet and in February my A1C is now 39 and fasting glucose was 3.9. I was convinced I was Type 2 as I was overweight (BMI 27) and my diet was very poor full of carbs and sugars. However, as part of the latest test I was tested for GAD and C-peptide and these were my results:

GAD - 16.9 u/ml (normal range < 5)
C-peptide - 0.51 ng/ml

I am seeing the endo in a weeks time to be formally diagnosed, but does this point to me being Type 1.5?

For the blood test I did fast almost 16 hours, that's why my fasting glucose was so low. Would that also reflect in a "low-normal" C-peptide?

Also I've read for the GAD test that between 5-30 is considered a "low positive". Does that make a difference in diagnosis?

Any guidance would be appreciated. Thanks.

Hi,

Focusing back on your question.

The C pep result. Are you sure that measurement is in “ng/ml?” (And not. nmol/L??)

 

[giorgoXXI]

Hi,

Focusing back on your question.

The C pep result. Are you sure that measurement is in “ng/ml?” (And not. nmol/L??)

It was actually officially 170 pmol/L on the test, which I believe converts to 0.51 ng/mL