Thread by @DUK_research

This was always going to be a packed out session (even at 5pm!): how we can use c-peptide measurements to improve the diagnosis of #diabetes
#DUKPC

What's c-peptide? It's a molecule we make during the process of producing insulin. So it can be used to look at how much insulin you produce: people with #Type1diabetes have very very low c-peptide levels, while people with #Type2diabetes have higher levels.
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This means a c-peptide measurement can differentiate between #Type1diabetes & #Type2diabetes. But how? In the past, tests were expensive & inaccurate. The #ExeterDiabetes team changed this...
#DUKPC

First, they developed a test using urine samples: it's stable at room temp for a few days, painless and easy to collect.

Then, they turned to a blood sample that could also be made stable. Patients didn't need to fast beforehand and you could do it in the clinic.
#DUKPC

And now, they're looking at a finger prick blood test. It's stable for 10 days at room temp, but it's not as sensitive.

But that's ok, because they now have a fancy machine that can measure at the FEMTOMOLAR range (yup that's a thing, 1000x more sensitive).
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Prof @athattersley gets a chuckle from the audience when he summarises with "things have changed and nobody told us".

And acknowledges this amazing work has been done by @Mcdtj who can't be here as he's been nominated for the NHS Healthcare Scientist of the year award 👍
#dukpc

Next up, @angusgjones moves us on to diagnosis. C-peptide tests can differentiate between Type 1, Type 2 & MODY.

*But* close to diagnosis, people with Type 1 still produce some insulin. So it's not a great test right at the start - that's why we need antibody tests.
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Dr Jones suggests that HCPs use the c-peptide test if their patients diagnosed with #Type2diabetes go onto insulin within 3 years.

It's cheap, easy to measure and can confirm the right diagnosis.
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And finally, Prof Mark Strachan, who tells us he's a c-peptide convert.

It started with a patient who he was convinced had Type 1, but she had real trouble managing her blood sugars. It turned out she had monogenic diabetes & Prof Strachan wishes they'd spotted it sooner
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So they set out to run c-peptide tests with all of their patients with Type 1. So far, they have tested 757 people. Based on their c-peptide levels, 13 have been re-diagnosed as having Type 2 and 7 have been taken off insulin.
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Then there were even more cases of monogenic diabetes - Prof Strachan jokes that he started getting heart palpitations every time an #ExeterDiabetes email came back from the monogenic lab!

Essentially, he was surprised by just how many of his patients didn't have Type 1.
#dukpc

Bottom line, HCPs are definitely misdiagnosing some people. But it's really important that we think about this possibility of reclassifying someone's diabetes - it needs to be discussed in a sensitive, supportive way.
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