Hi,
Experts here. I got a c-peptide test done. This was done as a fasting test. Following is the result, which is “normal”.
Result: 1.30 (Reference range: 0.9 - 7.1 NG/ML).
So how does one interpret this? Assuming it is normal, it at least would not indicate type 2 diabetes, right? Where insulin resistance is the issue and C-peptide should be high.
But it doesn’t necessarily indicate tendency towards type 1 either, as it is still ‘normal’?
I have not been following a particularly low carb diet (somewehre between 100 - 200 carbs/day) and am taking insulin and still getting some 'high" numbers after eating.
Input greatly appreciated.
I haven’t yet had anti-GAD testing done. Haven’t found out where to do that yet.
My endo recommended I start metformin (I don’t know if instead of insulin, or as well as insulin - am assuming as well as, to hopefully reduce the dose of insulin required and avoid lows… it will be interesting to see if this makes a difference.
Why is it that you’re not cutting back on your carbs? To do so would surely help.
A fasting c-peptide test with blood sugar “anywhere” near normal means “nothing” according to my endo. I suffer from elevated fasting blood sugars (120-140 mg/dl) and my c-peptide has been measured at various levels between 1.8 and 4.5 ng/ml. All basically within reference range. The claim is that if your body does not have a fasting blood sugar which drives an elevated insulin production, then a low c-peptide could be perfectly normal.
So basically, a fasting c-peptide only has a definitive meaning when you have an “elevated” fasting blood sugar, presumably over 200 mg/dl. Why doctors don’t order a stimulated c-peptide is far beyond me. I think the whole diagnostic tests for insulin production and estimated insulin resistance totally s*ck, but that is my opinion.
So anyway, in my case, my c-peptide means nothing, and I am also diagnosed as T2. You are diagnosed as T1 if you are tested properly for antibodies and are positive or you end up in DKA in the ER, otherwise you are T2. That is the basic diagnostic algorithm in the US.
