[Ronin]

Fellow Pre-D's, et al.,

In all the reading and research I've been doing I've learned that the C-Peptide test is a key indicator of pancreatic function and can tell if you are "normal," heading towards Type-2, or heading towards Type-1.5. So, I asked for the fasting C-Peptide as part of my semi-annual testing.

And the results are (drumroll please):

C-Peptide: 1.3 ng/mL (Normal range = 1.1 - 5.0)
BG: 100 mg/dL
A1c: 5.3%

A lengthly discussion of what this all means followed with my Nurse-Practitioner. The upshot is that I'm doing okay and that there is no clear indication that I am actually a Pre-D. On the caution side is the fact that I've done a lot of basic good stuff with my eating so I should not go wild, while not completley deny myself eitehr -- moderation being the key.

FWIW: the other numbers were
BP: 108/53
Total Cholesterol: 198
HDL Cholesterol: 88
LDL Calculation: 92
Triglicerides: 87

[BlueSky]

Originally Posted by Ronin

.... C-Peptide: 1.3 ng/mL (Normal range = 1.1 - 5.0) ....

That is interesting. With such a low c-peptide, there can't be any insulin resistance. If, in the absence of insulin resistance, BG only starts going up when 60%-80% of the beta cells have been lost, where does this leave you? Does it mean you could be T1.5? Are they going to follow this up with anti-body tests?

[dgrilli]

I was told anything below a 5 and high BG's indicate trouble.

I was also told that type 2's will have high numbers sometimes in the double digits especially type 2's with insulin rsistance and still have very high BG's even with high numbers in the C-Peptide.

Also told that in combo with being positive with GAD antibody you are in the type 1 relm.

1.3 doesn't seem to me like enough to keep your BG's in check not unless your extremely insulin sensitive. But what do I know.

Anyone know how the C-Peptide numbers get skewered either higher or lower?

[Cyborg]

If type 1.5, wouldn't the C-Peptide be lower due to loss of beta cells? The numbers are great and it seems that the routine is working well to control the pre-diabetes. I think the large amounts of exercise have overcome any insulin resistance that otherwise would have been present. Exercise combined with eating well seemed to have produced great results.

Great numbers!

[BlueSky]

Originally Posted by Cyborg

If type 1.5, wouldn't the C-Peptide be lower due to loss of beta cells? ...

Just because c-peptide is in the normal range doesn't necessarily mean that there hasn't been beta cell loss. Insulin levels are low-normal, but a reduced number of beta cells could working overtime to keep keep them that way. This would explain why eating carbo increases blood glucose. The remaining beta cells are not able to cope with the extra load.

That is my take on it. I am interested to hear what the medical experts had to say.

[lilituc]

I agree, that sounds more like LADA to me. I actually had a high normal C-peptide at diagnosis. You should probably have them do a GAD test to see if you have antibodies. MODY is also a possibility if you only have impaired insulin response when you eat.

[Dan Gato]

BlueSky, et al,

My C-peptide was 3.6, but on the day of the test I took a 5mg
Glipizide, before testing. I think that the Glip affected the result. my BG that morning was 80.

I've been type 2 for over a year, & need Metforfim & Glip to control my BG's. I also do mid-carbing, fewer than 100 a day.
My A1C was 5.6 I want to lower it even more.

Have you had a c-peptide test?

[Ronin]

Hi Everyone!

Thanks for the responses. There were various reason for requesting the C-Peptide test. The first was to confirm or dismiss the idea that a person as active as I am could be Insulin Resistant. The second was to see if my Fasting values were below normal which might indicate the impending demise of my pancreas/pancreatic function.

On the day of the lab work, my FBG at 0530 when I got up was 101 per my meter. I had no food since about 6 PM the night before and only a cup of water to make sure that I'd have something to "fill the cup." The lab test, done around 0830, came back at 100 so there was no increase in my BG from my liver.

Considering the 5.3% HbA1c and it being consistent with the A1c's done in previous months (see signature block for details), is 1.3 mg/dL really low, or just representative that my pancreas had probably not been very active for over 12 hours?

I can also attest to the fact that my BG levels have never gone above the 140's at the two-hour-post-prandial mark and are generally in the 120's to 130 in that time frame even when I ingest carbs at the meal. What I find most indicative that my pancreas is working is my FBG and one-hour post-breakfast readings. Every day the same meal (140 g fruit with 70 g youghrt - one hour later three-egg-white omlette with fat free cheese, turkey ham, one slice toast [5 g carbs] 1/4 cup OJ and coffee with Equal). One hour after the omlette, et cetera my BG levels are either the same as or lower than my FBG levels. So, it would apear that my pancreas is working .

Of course doing C-Peptide tests along with an OGTT would tell the whole story. However, given my HbA1c readings I doubt that the VA would authorize an OGTT with C-Peptide readings as I do not clearly fall into the Pre-D or Diabetic category.

I will look into the antibody tests at my next six-month testing period. Until then I'm going to limit my conumption of test strips to FBG and Post-Breakfast testing as the rest of the daily tests are holding quite steady. I'll also continue with a monthly A1c (I've got a half-dozzen kits remaining in stock). If the A1c's start to go up or the FBG and Post Breakfast start to go wacky then more testing.

Question for the 1.5's: what did your BG do as your pancreas was failing and how long did that process take? Is is prudent to wait six-months for the antibody testing, or should I go for that right away?

[BlueSky]

Originally Posted by Ronin

... what did your BG do as your pancreas was failing and how long did that process take? Is is prudent to wait six-months for the antibody testing, or should I go for that right away?

The BG level doesn't affect the antibodies. Once the auto-immune response has been triggered, it doesn't matter when you test for them. As long as there are still functioning beta cells, there will be antibodies. The only problem is that they don't always show up in the test ... . I would suggest doing the antibody test right away.