I would request that the endo order some autoimmunity antibody tests. There are several autoimmune antibodies that can be tested. One of our members, @Melitta, has written extensively on this topic and you can discover her writing by using the TuD search tool.
Here’s one of her topics.
Your c-peptide test could very well mean early stage LADA, so getting the autoimmunity tests are important to confirm. I think you’re smart to implement a low carb way of eating. That takes pressure off of your pancreas. But a lowish c-peptide and an A1c on the low border of “pre-diabetes” are significant. Low c-peptide is not related to low carb eating. It is a measurement of how much insulin your body currently produces.
I am not a doctor but I think you deserve a credible explanation as to why these two tests are at these levels. Unfortunately, doctors often miss this diagnosis.
Congrats on proactively getting and using a blood glucose meter. Writing down some of your results and providing context (B4 breakfast, after exercise, after a meal, before bed) will give the endo more data to consider.
Good luck with your endo appointment. Please share what you learn at that visit.