Possible LADA or MODY. Maybe resistance from high IAA? Everything's confusing

Type 1 and LADA
1

Hi,

I tried looking for a “diagnosis” type of category but couldn’t find it. I think I’m closest to T1/1.5 so posting here, but please let me know if this is not the right place.

I’m struggling to get a diagnosis. This certainly seems to be a common problem for folks with LADA… I recognize that the most important question is treatment, but it’s hard to let go of a crap-load of conflicting/confusing test results. I’m especially concerned about a possible genetic mechanism. I’m hoping someone here might have some insight.

I am lean (110lb, 5’4”) and very physically active (competitive athlete). To the best of my knowledge, I’ve had blood sugar problems my whole life… reactive hypoglycemia since I can remember, plus mild postprandial hyperglycemia (150-180) with low fasting (60s) when I started testing at age 25. Based on symptoms I feel sure that I’ve had the mild hyperglycemia for a long time. I was completely anovulatory as a teenager (literally not even a single ovulation that I can tell) and put on BCP for PCOS; had to do IVF for my first pregnancy at age 25. Was diagnosed GD through routine screening and then realized it didn’t go away after birth. My blood sugar was always very good in the morning and would go to the upper 100s by the end of the day. Once I got my blood sugar under control (low carb diet, exercise), I suddenly began ovulating and regained fertility (two natural pregnancies followed). Everything has blown up during and after my last pregnancy. I can’t control by diet anymore and I’m starting to see some scary numbers. Here’s what I know.

  • Excellent fasting (60s) that only recently began rising a bit (85-95)
  • Negative GAD, negative ICA
  • Crazy high IAA (145)
  • Low-normal fasting c-peptide (1.5 for ref range of 1.1-4.4, @86)
  • Normal-seeming postprandial c-peptide (3.9 for ref range of 1.1-4.4, mixed meal, @161 for test but rose to 250 and stayed there for hours after; it was quite a glucose challenge and I do know I tend to dump insulin in response to rapid rises)
  • Seem to be insulin sensitive, or at least not extremely resistant (1:10 I:C controls breakfast perfectly; 1:20-1:30 I:C for dinner; I don’t know my correction factor for sure, but 1U brought me from 250 to 75 in 2 hours while eating about 40g carbs)
  • Low total daily insulin needs (no insulin, I’ll be 150-250 for much of the day; 2U for breakfast and it’s all under 130)
  •   My blood sugar rises or stays steady when I exercise (which to me suggests insufficient insulin rather than resistance)

My c peptide would suggest I’m producing insulin, right? But the I:C ratio/low insulin needs would suggest I’m insulin sensitive, right? The IAA seems crazy high. It’s not clear if that’s an autoantibody or a result of previous injection of exogenous insulin. Could I be one of those people where insulin antibodies are causing a kind of resistance by sequestering endogenous insulin? Should I pursue possible LADA and request repeat antibody testing?

I’ve tested my family members to pursue a possible MODY mechanism. My dad has some evidence for mild insulin resistance. My mom’s side (multiple generations) have high postprandial responses with excellent fasting. My brother (who is overweight and sedentary) is definitely pre-diabetic based on my spot check.

Any thoughts? Would you pursue any additional bloodwork?

My endo insists I am insulin resistant and wants me on metformin. I prefer MDI insulin (and I’m on a dexcom). I’m mostly scared for my kiddos, wondering whether this is autoimmune versus genetic.

I don’t know how to go forward.

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You certainly have been very aware of your glucose metabolism. I can’t begin to offer any insight but @Melitta is our resident expert on auto-antibody tests and diabetes. She’ll often respond when she’s mentioned.

Good luck with sorting this out!

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hey Ada, welcome to our community! First, let me just say, don’t worry about posting in the wrong category. It’s not a big deal, and if we think your topic is in the wrong category, we move it…

WOW, you seem to already know a lot, but you still don’t have a definite dx! We have some very smart people here who I hope will comment, some of them are in this conversation

feel free to join any conversations here & welcome again!

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Thank you, Terry4 and MarieB, for your replies! I should add that I am a biomedical research scientist and have been puzzling over this for years. Everything compounded through a very rough pregnancy and postpartum period, and so I’ve been learning as much as I can.

I can’t find an endo to help; the last one I saw insisted it was insulin resistance based on seemingly high insulin levels (but my insulin antibodies were also high so it’s not possible to interpret that, especially considering how sensitively I’m responding to injected insulin) and resolutely refused to engage in further discussion. The nurse practitioner who managed my pregnancy is extremely knowledgeable and helping me get blood work done in the meantime. She is also trying to find an endo that will consider my atypical profile.

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Welcome! With a CGM and your level of knowledge, you’ll get it all figured out (eventually) and do well. I don’t think that MDI and metformin have to be mutually exclusive. Whatever works, right?

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Hi AdaTwist: Regarding the autoantibody testing, here is a blog that I wrote that may be useful. IAA is only relevant if a person has never used exogenous insulin. You did not get the full suite of autoantibody tests, so it might be useful to be tested for IA-2 and ZnT8. Your c-peptide is low, which is very common in early LADA, and you are very insulin-sensitive, quite the opposite of insulin resistant. Over the years, I have heard and read so many stories like yours, from people who have adult-onset Type 1 diabetes but have been misdiagnosed. Many people with LADA started out as having reactive hypoglycemia. And for many, many women, pregnancy is the “straw that broke the camel’s back” and pushes a woman over into overt Type 1 diabetes (1 in 10 women with GDM will be autoantibody positive, and have autoimmune gestational diabetes–I write about autoimmune GDM in this blog. Finally, well known endo (and editor of The Type 1 Diabetes Sourcebook (ADA/JDRF 2013) Dr. Anne Peters treats her lean patients with new-onset diabetes as if they have Type 1 even if they are not autoantibody positive (keep in mind that there may be autoantibodies that have not yet been discovered). Dr. Peters’ Medscape article and video may be useful (Lean Adults With New Diabetes: Treatment Pearls). I hope this information is helpful!

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