Wondering what usual C peptide levels are like in people diagnosed with LADA? At diagnosis and how has it changed over time? I just found out my results, with normal C Peptide (1082, higher end of normal) but also very high GAD antibodies, which doesn't seem to make sense.
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What are C peptide levels like in LADA/ adult T1?
- Thread starter Vectian
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Did you have the "honeymoon period"?
Robin
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Probably a short one, I wasn’t very proactive about going to the doctor, because I put my symptoms down to the menopause to start with, so between October and February, I wasn’t feeling great, but I was following a low carb diet to lose a bit of weight, so probably mitigated the worst of the symptoms, then I realised I was actually losing weight without trying and went to the doctor. So from February to about July, I was being treated as Type 2, on Metformin and Gliclazide, then basal insulin was added in and was given the GAD test, because the hospital consultant suspected Type 1. I didn’t get a full basal/bolus regime until a full year after diagnosis, but my HbA1c had been elevated all that time..16.1% in the old system, think that equates to over 150, until the July when I got basal insulin. Then I managed to get it to around 80 until I got bolus insulin added in, and managed to reduce it to 48, not much of a honeymoon, I don’t think.
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I remember my insulin needs gradually creeping up (well… in fits and starts!) over the first couple of years, before settling(ish) into more of an annual cycle up and down through seasons of needing a bit more, then a bit less as the months turn warmer and colder.
Wow 150 for a year, I thought my 97 was high! The honeymoon period is when your pancreas is still making some insulin and you need less medications (or in my case, none) for a while. I just don't understand how it's possible to have t1 with high-normal insulin production.
Did you have a period of time when you needed not much or none at the start?
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I didn’t personally. My T1 was fairly classic onset, so a period of months of feeling increasingly rough (but putting off doing anything about it), and then being hurried into hospital with BG in the 30s-40s and ++++ ketones (top marks all round!). I needed exogenous insulin from the start, and if I’d stopped it, my levels would have leapt right back up again.
There are some on the forum with LADA (a slower onset form of T1) whose flagging beta cells seemed to get a bit of a second wind after getting the support of some injected insulin for a while. Or others who initially responded to oral meds while their immune system continued to destroy beta cells, until they reached a tipping point of insulin insufficiency when only adding injected insulin would do.
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Has MODY been considered for you? That’s a collection of monogenic forms of diabetes that can sometimes be mistaken for T1, and can be treated without insulin.
There are genetic checks which can identify the single faulty gene involved.
I'm 50 so it's a long time since I was young! Nurse said I am adult onset t1, but that is purely down to a positive gad antibody result, everything else seems more like t2 and I previously had prediabetes in 2016 which I reversed at the time. I have taken no insulin at all for 2 and a half weeks, and BG is better than when I was on it, 100% in range. And found out today C peptide was at the higher end of normal, if you aren't producing enough insulin it should be low. Doctors are confused as well..
Interesting. From posts over the years from some T1s I wonder whether just having a positive GAD result implies damaged beta cells but in practice those posters may show good BS control and ability to have fairly high carbs in the diet so perhaps some beta cell activity may remain longterm. I feel that both a positive GAD test and a low C-Peptide test are needed to confirm T1. Where there is a negative GAD but low C-Peptide then that implies damaged beta cells from whatever cause.
Lucyr
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Yeah I always use the Exeter site. Was the cpeptide fasting or stimulated (after a meal without insulin when bg is high)? If fasting then over 250 is high insulin production and more indicative of T2, or if stimulated over 600 is high insulin production and more indicative of t2.
C-Peptide Exeter Clinical Laboratory International
www.exeterlaboratory.com
Do you know how positive your GAD antibodies were too? My GAD antibodies were slightly positive, and cpeptide was something like 265 stimulated with bg around 18, so I didn’t get a t1 diagnosis since 265 stimulated is low normal and too high for t1 after 15 years.
1082 is pretty high and suggests significant insulin production and insulin resistance. I’d expect cpeptide to be retested in a few years time if you’re fairly newly diagnosed now, to decide type at that point. It is possible to have a reading that high during the honeymoon period if you’re obese, but if you’re still producing high levels of insulin in a few years then you’re very unlikely to be type 1
C-Peptide Exeter Clinical Laboratory International
www.exeterlaboratory.com
Hi yes it is mysterious. The GAD value was very high, above 2000 (which is the max so could be any point above that) but C peptide in the middle of normal range. It was not fasting, but quite a few hours aftervlast meal. I have been on no insulin at all for 2 and a half weeks and had better control than when I was on insulin, 100% in range and daily average 6.1. I was becoming pretty insulin resistant before stopping insulin, needing about 1unit per 5g carbs. Plus I have been prediabetic in the past, everything suggests t2 more apart from the GAD result. I am not overweight but didn't lose weight before diagnosis either.Yeah I always use the Exeter site. Was the cpeptide fasting or stimulated (after a meal without insulin when bg is high)? If fasting then over 250 is high insulin production and more indicative of T2, or if stimulated over 600 is high insulin production and more indicative of t2.
C-Peptide Exeter Clinical Laboratory International
Do you know how positive your GAD antibodies were too? My GAD antibodies were slightly positive, and cpeptide was something like 265 stimulated with bg around 18, so I didn’t get a t1 diagnosis since 265 stimulated is low normal and too high for t1 after 15 years.
1082 is pretty high and suggests significant insulin production and insulin resistance. I’d expect cpeptide to be retested in a few years time if you’re fairly newly diagnosed now, to decide type at that point. It is possible to have a reading that high during the honeymoon period if you’re obese, but if you’re still producing high levels of insulin in a few years then you’re very unlikely to be type 1
C-Peptide Exeter Clinical Laboratory International
Very high GAD levels would suggest a strong attack, so you would expect the beta cells to degrade quickly and reduce function, but seems my insulin output is normal. I have read research that says you can be GAD positive but not have autoimmune diabetes, especially at older onset but nothing makes sense.
I have very high GAD result (max they can measure, above 2000) but completely normal C Peptide which doesn't make sense at all. That would suggest that insulin resistance (which I have) is the issue rather than lack of insulin production, and the very high GAD would usually mean a strong attack so quickly declining pancreas function which doesn't seem to have happened.
Robin
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Do you have any other autoimmune conditions? I believe you can produce GAD antibodies with certain other things including rheumatoid arthritis or thyroid issues, and stiff person syndrome.
rebrascora
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What did you have as a meal before the C-peptide test. I am guessing your meal was low carb so your own insulin production was not particularly stimulated and just needing to cover background needs at the time the test was taken.
Following a low carb way of eating when you are LADA can really confuse the diagnostic process. Unfortunately most health care professionals have no real understanding of how powerful a low carb way of eating can be on managing BG levels and sparing the beta cells from significant stress which may well increase the risk of them being killed off. Your brief spell using insulin may also have given your remaining cells a breather and allowed them to function well enough to cover your limited diet for now, but if you are LADA that will change sooner or later.
I was initially assumed to be Type 2. My GAD and C-pep were performed about 10 weeks after diagnosis, but my diabetes had a very sudden onset and I clearly remember the very night it happened, even though I didn't and never have had DKA. It was the sudden unquenchable thirst that happened in the space of an hour and I went from feeling normal to drinking pint after pint of water and resultant toilet visits and nothing would quench it. That went on for 2 weeks until I hed blood tests and was diagnosed during which time I cut my sugar intake right down and then started cutting my total carbs right down after that and started on insulin 6 weeks after diagnosis and tested for Type 1 about 4 weeks after that. My C-pep was normal/borderline low at that time but when GAD came back it was very positive and my diagnosis was confirmed. I have remained low carb, despite being on insulin and encouraged to eat normally, and I most definitely need insulin, so I am confident that mine is Type 1. Not had a further C-pep but pretty sure I have more or less run dry of my own production and that seemed to happen just over 2 years from diagnosis judging by my insulin doses being more or less steady (with tweaks for exercise or illness etc) and I believe 2 years is about the norm for the honeymoon period but as with everything diabetes related it can vary enormously and some people with 5 decades of Type 1 in the US were found to still have some endogenous insulin production, so it is by no means clear cut, which is why some people like @Lucyr are left without a clear diagnosis 15 or more years after onset.
Following a low carb way of eating when you are LADA can really confuse the diagnostic process. Unfortunately most health care professionals have no real understanding of how powerful a low carb way of eating can be on managing BG levels and sparing the beta cells from significant stress which may well increase the risk of them being killed off. Your brief spell using insulin may also have given your remaining cells a breather and allowed them to function well enough to cover your limited diet for now, but if you are LADA that will change sooner or later.
I was initially assumed to be Type 2. My GAD and C-pep were performed about 10 weeks after diagnosis, but my diabetes had a very sudden onset and I clearly remember the very night it happened, even though I didn't and never have had DKA. It was the sudden unquenchable thirst that happened in the space of an hour and I went from feeling normal to drinking pint after pint of water and resultant toilet visits and nothing would quench it. That went on for 2 weeks until I hed blood tests and was diagnosed during which time I cut my sugar intake right down and then started cutting my total carbs right down after that and started on insulin 6 weeks after diagnosis and tested for Type 1 about 4 weeks after that. My C-pep was normal/borderline low at that time but when GAD came back it was very positive and my diagnosis was confirmed. I have remained low carb, despite being on insulin and encouraged to eat normally, and I most definitely need insulin, so I am confident that mine is Type 1. Not had a further C-pep but pretty sure I have more or less run dry of my own production and that seemed to happen just over 2 years from diagnosis judging by my insulin doses being more or less steady (with tweaks for exercise or illness etc) and I believe 2 years is about the norm for the honeymoon period but as with everything diabetes related it can vary enormously and some people with 5 decades of Type 1 in the US were found to still have some endogenous insulin production, so it is by no means clear cut, which is why some people like @Lucyr are left without a clear diagnosis 15 or more years after onset.
Not that I know of, I did look into that but neurological conditions with high GAD are very rare, SPS syndrome one person in a million, and twice as many that get it are women, so would be 0.3 in a million chance! It is apparently possible to be GAD positive and have t2, there seems to be a lot of disagreement amongst researchers.
It was quite a few hours after the last meal. Low carb yes but not very low carb, certainly not keto as I eat lots of vegetables and no meat. Mainly avoiding pasta, white bread, rice, sugar & processed rubbish etc. But most diabetics do that don't they? Anyway not stimulating insulin would mean that my stimulated result would be even higher, it was already 1080 which is in the middle/upper end of normal range. I don't understand how I can have reduced and compromised beta cells and so insulin production with a c peptide like that? That seems to suggest that the problem is insulin resistance rather than lack of insulin production? I was becoming pretty resistant to insulin before I stopped taking it, and needed twice as much as 4 weeks earlier to have the same effect. My BS has been better since I stopped insulin, not worse.
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