I’ve had T1 for over 10 years and I just had some bloodwork done. My endo did an anti-gad test and it came back negative. This means that I don’t have the enzyme present that destroys beta cells. He also tested my C-peptide and it was low (0.5). The strange thing is, I don’t take much insulin at all…around 14 humalog units total through a pump.
I’m wicked confused…any insight? Also Mody is often genetic and no diabetes is present in my family at all.
It is my understanding that once you have had diabetes for awhile, the gad tests can come back negative. Had you been tested 10 years ago, you may have had a different result.
I was told I may be MODY as well - but not confirmed. I also have negative GAD antibodies but + IAA antibodies. I also am pumping with a TDD of 15-20 u depending on how many carbs I eat. My last c-pep was 1.3 so low end of normal (but original c-pep when first diagnosed was like 4 but I was put on insulin right away). So, I also make some insulin. My endo won’t commit to a LADA or MODY diagnosis, so I still officially have a T2 dx on her books. Tere are newer tests to conform MODY diagnosis.
The GAD test is by no means a definitive test for type 1. In fact, there are four antibody tests, and only something like 85-90% of type 1 diabetics are positive for any antibodies in those four tests. A low c-peptide (with an elevated blood sugar) is an indication of insulin deficiency.
MODY is a genetic disorder, generally not presenting as insulin deficiency, rather it affects the mechanisms of secretion. Your beta cells are fine, they just don’t get the messages right to squirt the insulin. The worlds best center for MODY is DiabetesGenes. Each form of MODY presents in different ways, most forms have glucose intolerance, but MODY 2 presents with elevated fasting. MODY genetic testing can be expensive, in the US it will run $1000s. You can read up and see if you present with any of the suspect glucose management issues. You do need to perform “all” the antibody tests to do more diagnostics. In either case, measuring as insulin deficient is likely a big indicator you are not MODY.
MODY is strongly genetic, and if neither of your parents has it, it is unlikely you have it, unless you have a spontaneous mutation. Which is not impossible.
On the other hand, you may just be extremely insulin-sensitive. It’s a bell-shaped curve from those who are extremely sensitive on one end, and those who are very resistant on the other end. This has nothing to do with which type of diabetes you have – it applies to everyone. Most people fall under the hump of the bell, but you may be one of the outliers.
Interesting info on Mody. My new endocrinologist is convinced I am a MODY rather than a type 2. He did a complete history on me and spent 2 hours in conversation. When I was diagnosed 4 years ago I took it seriously, dropped weight and changed my diet. I was never obese and I exercised regularly throughout my entire life. After making the changes and it only took 6 months for the weight loss my numbers got better but I still couldn't get off the oral meds. I know many Type 2's are able to when they have made the positive changes. My doctor tried a medication that works well for MODY's (glimiperide) and that has made a difference in my blood sugars. He says he rarely gives his patients this medication but in MODY's it works well. For me, this has been a very helpful diagnosis as I was frustrated that my low-carb diet and exercise couldn't totally keep my numbers in check. I kept trying by lowing my carbs but as a very, very active person, I needed some additional good carbs. Now I can eat a few more carbs and don't feel like I am starving. I guess the point of this conversation is that it does matter what type you are so you can get the proper treatment and see positive results. I was really beating myself up for not being able to get off meds. Now I know that it most likely won't be possible but knowing I did everything I could to try to. Diabetes does not run in my family but auto-immune does. Everyone in my family, (everyone) has thyroid (hypo-hyper) but I got the diabetes instead. Also, defining this disease is important as I have 2 children and at some point, when I have an extra $500 (haha) I will get the genetic test. I appreciate the info on this site. Most helpful.
Dear Whitney, Spirit7, and anyone else reading this who wants to know more about MODY.
Just in case you haven't seen it, bsc started a MODY group here at TuDiabetes that is very useful and has a lot of links to further information about it.
Best wishes,
marty1492
If you are positive for any one antibody, and you are IAA positive, you have confirmed Type 1 autoimmune diabetes. Very strange that your endo has not changed your diagnosis.