C Peptide Test worry

[KM1234]

Hi everyone,

I am wondering what people's experience has been with the C peptide test, and if anyone has had their diagnosis changed from Type 1 to Type 2?

I have been Type 1 for 20 years now, I was diagnosed at 14 with the usual symptoms. My type has never been questioned. I took a while to adjust and had lots of successes and failures over the years, but now seem to have cracked it with my latest HBA1C 51 with the help of the Libre which I have on prescription.

At my clinic appointment this week the Doctor said he was sending my blood off for a C peptide test. He thinks it unlikely that I'm anything but type 1, however I have been thrown in to a total panic. He didn't seem to understand why this worried me so much.

I have taken years to get to where I am care wise, I have the Libre now which has been absolutely life changing, a Diagnosis of Type 2 would change everything (and l assume cause my Libre funding to be removed) and as someone with pretty bad health anxiety, this is causing me distress. I have found lots of information on people being diagnosed as Type 2's and this being changed to Type 1 due to a C peptide test, but there seems to be very little the other way around.

I am absolutely terrified, the doctor has said he will contact me in 3 weeks to let me know the results, but 3 weeks is a long time when anxious. And somewhat Ironically, my blood sugars are terrible because I'm so stressed!

Any advice or experience would be appreciated.

Thank you so much

 

[Northerner]

Hi KM1234, welcome to the forum 🙂 Don't worry, after 20 years of presumably needing insulin to manage your diabetes you are not Type 2, even if the C-peptide shows that you are still producing a bit of your own insulin. I seem to recall that a test of 50-year Joslin medallists (living with Type 1 for 50 years or more) showed that quite a few of them were still producing small amounts of insulin, so it really isn't an either/or situation 🙂

In fact, I am a quite extreme example. I was diagnosed with Type 1 after being admitted to hospital with DKA out of the blue (I was due to run a marathon that week, so not really showing any of the major Type 2 factors). I was put on insulin - 20 units of lantus and 45 of novorapid. After a couple of years I started needing to reduce the lantus as I was waking low in the mornings. After 4 years I had reduced the lantus to zero! Still need novorapid although not so much. Clearly my pancreas is still producing insulin, but my consultant has said on many occasions I could not be considered Type 2. I have encountered a few other people here on the forum over the years who have had a similar history with their Type 1.

My point is that even if the test shows some insulin, your Type won't change, nor will your need for the medication you have been using to manage things i.e. insulin 🙂 So, please don't worry 🙂

 

[Sally71]

Why on earth is the doctor doubting your diagnosis? Many people are misdiagnosed type 2 because a lot of GPs are still labouring under the delusion that type 1 only starts in childhood and therefore if you are over the age of about 20 at diagnosis then you must be type 2. This is not always the case, which many people on this forum can attest to, and why some then have to be reclassified as type 1, because they were wrongly classified in the first place.

You were diagnosed T1 as a child, the diagnosis isn't going to change just because you are older now, and if your treatment is working for you then why is your doctor even doing the test? Seems very strange to me. If you have been needing insulin since the age of 14 then you are type 1 and I hope the test comes back quickly and proves it for you!

 

[Northerner]

why is your doctor even doing the test?

Yes - I should add that my consultant was often suggesting a C-peptide test ought to be done for me, but he said it was expensive and there wasn't any point really as my treatment wouldn't change 🙄

 

[KM1234]

Hi Northerner and Sally71, thank you both for your replies, they are both very reassuring. Just for a bit of context, here is a news article on the Western General where I attend in Edinburgh carrying out C peptide tests, the subject of the article seems a bit sensationalist to me, I very much doubt that someone can just wean themselves off insulin. And the headline is a downright disgrace;

https://www.bbc.co.uk/news/uk-scotland-44144678

I asked the consultant what would happen if C peptide came back in the 'Normal' range, and was told they would have to Beta Cell function test to see if I was type 1 or 2, this is at the point I started worrying.

I suppose I'm now questioning everything that I had been fairly secure in up until this point, and actually I feel quite angry with myself that I allowed them to do this test, but they were very blasé and 'sold' it to me as a "really good thing for type 1's". It was only after that I read the info and realised I could have refused it. I did experience quite a long honeymoon period which when combined with some weight loss meant I had to take very little insulin, but to be honest my control suffered because of this as it was so unpredictable. At diagnosis I was not obese, but I was (still am 🙂) a bit chubbier than I would like.

I turned to the forums as I know those of us with lived experience of Diabetes would understand someone being somewhat protective of their diagnosis. It's all I know really, and I'm finally in a good place with it. When I told a friend about it last night she seemed to think being changed to type 2 would be a good thing, because I could 'just lose weight and be cured!' *eye roll*

Thank you both again, this forum has helped me numerous times in the past so I'm now very proud to be a member!

Katie

 

[Northerner]

I can see why the article might have caused you concern Katie, but these reports rarely contain much accuracy about the actual situation As far as I'm aware, all diabetes is 'genetic' - it's a nonsensical statement 🙄 And of course there are many variations - diabetes is not one or two conditions never has been, it is more of a 'spectrum', not least because human beings are complex and different from each other in a multitude of ways! 🙂

Interesting also that they say C-peptide tests cost only £6 - if that's true then my consultant fibbed to me about it being expensive! 🙄

 

[KM1234]

I can see why the article might have caused you concern Katie, but these reports rarely contain much accuracy about the actual situation As far as I'm aware, all diabetes is 'genetic' - it's a nonsensical statement 🙄 And of course there are many variations - diabetes is not one or two conditions never has been, it is more of a 'spectrum', not least because human beings are complex and different from each other in a multitude of ways! 🙂

Interesting also that they say C-peptide tests cost only £6 - if that's true then my consultant fibbed to me about it being expensive! 🙄

£6 seems obscenely cheap doesn't?! But like you say, accuracy is not always a strongpoint with these stories! Thank you again for your reassurance 🙂

 

[DaveB]

Doing the test seems pointless and a waste of NHS funds. If you are actually T2 then you shouldn't need to use insulin. If your insulin is working then there is no need to change and no need for the test?

 

[silentsquirrel]

. If you are actually T2 then you shouldn't need to use insulin.

That's a very sweeping statement, @DaveB. Plenty of Type 2s like me on insulin, and I know I would not manage at all well without. Are you really saying all T2s on insulin are misdiagnosed T1s {or T1.5s)?

 

[Matt Cycle]

Hi Katie. I had a C-peptide done last year after over 30 years of T1. I was going through the process for getting a pump and the consultant said it was a CCG requirement in my area. Like you I was a bit confused and wondering in my mind what would happen depending on the results with a load of what ifs. I'd been settled with my diagnosis for all that time, I was diagnosed at 18, also had the classic symptoms and had been injecting insulin ever since. Having to have this test started to make me question it even though the consultant said it would be fine. The consultant didn't seem bothered by it and just said it wouldn't affect getting the pump.

As it turned out the C-peptide test came back as not detectable and I could then forget about it. I'm not a doctor but with you being diagnosed at 14 with the classic symptoms and of course being on insulin all that time I can't imagine it would be anything other than Type 1. I would have thought those with T1 diagnosed later in life and/or on very small doses of insulin would be more likely to give questionable C-peptide results regarding type.

 

[Northerner]

That's a very sweeping statement, @DaveB. Plenty of Type 2s like me on insulin, and I know I would not manage at all well without. Are you really saying all T2s on insulin are misdiagnosed T1s {or T1.5s)?

Type 2s on insulin actually outnumber Type 1s in the UK - about 400k T1 and about 900k Type 2s. The distinguishing factor is often (but not always) much higher doses for T2 (I have seen members here speak of doses of 200 units or more) due to insulin resistance, which is a characteristic of T2. Some T1s can also exhibit insulin resistance and require higher doses and/or supplementary metformin. As I said earlier, diabetes is complex! 😱 🙂

What I don't really understand is that the C-peptide test has been around for donkey's years, so why is it being seen as some sort of 'breakthrough'? Or is that just the journalists spinning it that way (more than likely! 🙄)

 

[KM1234]

Hi Katie. I had a C-peptide done last year after over 30 years of T1. I was going through the process for getting a pump and the consultant said it was a CCG requirement in my area. Like you I was a bit confused and wondering in my mind what would happen depending on the results with a load of what ifs. I'd been settled with my diagnosis for all that time, I was diagnosed at 18, also had the classic symptoms and had been injecting insulin ever since. Having to have this test started to make me question it even though the consultant said it would be fine. The consultant didn't seem bothered by it and just said it wouldn't affect getting the pump.

As it turned out the C-peptide test came back as not detectable and I could then forget about it. I'm not a doctor but with you being diagnosed at 14 with the classic symptoms and of course being on insulin all that time I can't imagine it would be anything other than Type 1. I would have thought those with T1 diagnosed later in life and/or on very small doses of insulin would be more likely to give questionable C-peptide results regarding type.

Thank you, it’s good to know I’m not the only one who has been unsettled by this. Logic tells me that I’m type 1, having been diagnosed at 14, it came on very quickly, I had all the classic symptoms etc, but I can’t help but think about all the what ifs. I think it’s compounded by having the Libre, as I know how life changing it is and how lucky I am to have it funded, I would now really struggle without it!

 

[m1dnc]

Hi Katie. I had a C-peptide done last year after over 30 years of T1. I was going through the process for getting a pump and the consultant said it was a CCG requirement in my area. Like you I was a bit confused and wondering in my mind what would happen depending on the results with a load of what ifs. I'd been settled with my diagnosis for all that time, I was diagnosed at 18, also had the classic symptoms and had been injecting insulin ever since. Having to have this test started to make me question it even though the consultant said it would be fine. The consultant didn't seem bothered by it and just said it wouldn't affect getting the pump.

As it turned out the C-peptide test came back as not detectable and I could then forget about it. I'm not a doctor but with you being diagnosed at 14 with the classic symptoms and of course being on insulin all that time I can't imagine it would be anything other than Type 1. I would have thought those with T1 diagnosed later in life and/or on very small doses of insulin would be more likely to give questionable C-peptide results regarding type.

Me too. I had the C-peptide test as a prelude to getting the pump. The consultant at the time said that it was really just a formality as she was convinced that I was T1 as my diagnosis followed the classic pattern even though I was not a youngster at the time.