C-Peptide test

The more I learn about Diabetes the more confused I feel. My C-Peptide test was over 3.5, Yet I am wearing an insulin pump. I went from starting insulin in Sept 08 using Lantus 5units/day and Lispro max amt 4units a day. Then I started on the insulin pump about a month ago, My blood sugars are higher than they have ever been, Is my honeymoon phase over?? Am I doing it wrong?? Was I in a progression of worsening diabetic condition?? I am currently using up to 13 or 15 units a day and still high blood sugars!! Sometimes I feel that my body is saying What the Heck!! and responding by spitting out glucose. But what do I know?? My Endo looks at me weird when I tell her this and my symptoms. Can anyone give any advice of their story relating to this?? And yes my C-Peptide test was done the correct way, with a high BS at 203! Thanks for any info. Denise

Hi Denise, wow I am sorry to hear about your troubles. C-Peptide can only clarify your body’s own insulin production. Yours is higher than “normal” (if fasting) of 0.78–1.89 nanograms per milliliter (ng/mL).

Things that can make C-peptide higher then normal: Taking medicines, such as sulfonylurea medicines for type 2 diabetes, corticosteroids, diuretics, or birth control pills, use of alcohol, or kidney failure. You can also be insulin resistant. Your doctor should be able to explain why he did the C-peptide test and what your results mean to you.

You can still make insulin if you are a Type 1, though usually a lot less that you are making. You can also be insulin resistant, which typically describes a Type 2 diabetic… it’s possible to have both.

Honeymoon is usually a description of a Type 1 still making insulin, which can last for months. Taking insulin doesn’t make you a T1, a lot of T2’s take insulin to help offset their body’s resistance.

So sorry to hear about your confusion, I hope you and your endo can work together to get through this tough spot. The fact is that an exact diagnosis of T1, T2 or both, is tricky. The goal, however is the same: diet, exercise, and control of your blood sugar which sometimes includes meds that help lower your resistance, sometimes insulin, sometimes both. Whether you are taking oral or injections – getting the right amount of meds to balance your diet and exercise it the hardest part of diabetes.

hang in there =)

Dear Joe and Denise.

Now I am really confused about the classification of type I or Type II. Or is this just a clumsy attempt by the medical people to classify things as would be if physicists classified things as hot or cold when there in reality a continuum of temperature.

I thought you were type I when the pancreas had totally kicked the bucket and and you were not insulin resistant.

Type II you were insulin resistant with a .still functioning pancreas.

Would not a better classification be diabetic: mild, medium and severe (or some more positive label). Depending upon the measures needed to bring your blood sugar back to normal.

.Or you could classify the diabetes as to the degree of insulin resistance and to the degree that your pancreas was working. and have several (6 to 8) boxes from : non-insulin resistant and pancreas working … to insulin resistant and pancreas not working. This would give the neophyte doctors something to base treatment alternatives instead of starting everyone on metformin then adding sulfonyureas and then if all fails to go to insulin. What if like me you started on a diet and lost 85 pounds back to you high school sports weight and you still could not get your sugar in the normal range would it not be reasonable to add insulin at an early stage to avoid killing the pancreas completely.

there is a lot of debate regarding the actual classification and I am absolutely sure I don’t have the answers :slight_smile: I read (sorry no reference) about sparce beta cell activity from time to time in T1. Over my 30 years with this, I think I noticed a few subtle changes in my basal insulin requirements which I can’t explain. It’s plausible, I suppose that a T1 can make some insulin from time to time. A T1 could also become insulin resistant, and might benefit from some of the T2 meds out there but I would rather just take more insulin. Our resistance varies anyway… take a look at some of the threads here regarding “how much insulin per day” - it’s a good taste for the variablility of this disease.

The take-away is that it is very hard to do an exact diagnosis, espically in LADA/MODY types… and really who cares, because the treatments are similar. The only real disaster is when the insurance companies screw thigs up (oh you are T2 and don’t NEED a pump) or if the patient thinks “oh okay, these are my meds and they are never going to change”.

also, I believe you’re right about eventually abandoning the “Typeing” of diabetes and making more of a continuum.

The distinction between T1 and T2 makes sense, because one is an autoimmune disease and one is a metabolic disorder. If the immune system attacks the insulin producing cells in the pancreas, they are slowly destroyed, but insulin production does not cease immediately. So T1s still can have some insulin production left, especially at the beginning in the honeymoon phase. This phase can last years before the insulin production stops entirely. I think what really needs to change is not the classification, but the education of doctors about diabetes T1 and T2. For some reason many doctors consider insulin a last measure for T2s and would rather watch someone have horrible control for months than simply start them on insulin early, like you said.

Dear Kat. No just months but years if I had not demanded insulin.

First of all, you need to know your lab’s reference ranges for your test. My lab’s normal is 1.1 - 5 (ng/ml). Was it fasting or after eating?

If it was fasting (or even if it isn’t) what you know now is that you are producing your own insulin and could still be going through a honeymoon period. I’ve read that the pump better preserves beta cell function. Did you have antibodies?

I think the distinction between type 1 and 2 is more of a continuum. You have some type 1’s with no antibodies and some type 2’s with antibodies. Some type 1s are insulin resistant as well. Who’s to say at what point someone draws a cutoff line between someone who is slightly insulin resistant, overweight, has antibodies but has a c-peptide that is .8 and someone who is exactly the same with a c-peptide of .9. Drawing a line doesn’t help either of their treatments. The point at which your body cannot compensate for your insulin needs is when we all develop diabetes, and treatment should really be geared to the individual’s primary defect first. As they say (whoever “they” are). Your Diabetes May Vary.

Hey Denise, I just joined tudiabetes and saw your blog. I developed type 1 diabetes 18 years ago during my first pregnancy. At first they thought it was gestational eventhough my one hr glucose tolerance test was 450. After my daughter was born my blood sugars went back to normal until I started taking birth control pills when she was 3 months old. My sugars went up to 500, and I went back on insulin and my doctor gave me a c-peptide at that time. The doctor told me that the birth control shouldn’t affect my sugars, but I went off B.C. and my sugars came down again and I went off insulin Then I got pregnant with my son and my sugars went up before I even missed my period which put me back on insulin and I have been on ever since. I had a second c-peptide run after being diabetic about 6 years and I was still producing some insulin but I am not insulin resistent. In the beginning my insulin needs were low (13-15 u is not much) like yours, so one doctor wanted me to try oral meds, which I did and they didn’t do anything at all. To sum it up. There are so many factors that affect your blood sugars levels, like hormones: my sugars would go low just before my period, stress: I started a new teaching job and my sugar went up to 420 just from walking into the classroom, I had to double my insulin, and illness: I increase my basil rate to about 115% when I am sick, and simply the time of day. There are many things to learn, and everyone is different. I know how overwhelming this can me, but you are not alone. Good luck!

C-peptide is a useful test, but the definitive test for Type 1 autoimmune diabetes (at any age of onset) is antibody testing (glutamic acid decarboxylase antibodies (GADA), islet cell antibodies (ICA), and insulinoma-associated (IA-2) autoantibodies). If the person is antibody-positive, he/she has Type 1 diabetes (someone in this thread mentioned antibody positive Type 2’s, but that is just misdiagnosis–according to the Expert Committee, antibodies are not present in Type 2 diabetes). Antibody testing of newly diagnosed diabetics is the only way to reliably determine if the person has immune-mediated diabetes or not. Often, doctors claim that antibody testing is too expensive—but the out-of-pocket expense to a patient is $479! Any diabetic complication is far more costly than that trivial amount. Type 1 diabetes and Type 2 diabetes are two completely different diseases with different causes, genetics, treatments, and cures. Exogenous insulin is the appropriate treatment for Type 1, and the faster a person gets on exogenous insulin the longer the honeymoon period, which can last many years.