Thanks for all the additional information on the punch test.

This in the category of "for what it's worth," as I still don't quite know what to make of it, and I won't be discussing it in depth with my doctor for a couple of weeks.

After reading that 50% of all SFN cases are attributed to diabetes or pre-diabetes, and knowing that I have neither, but I do have issues with hypoglycemia, I requested an Oral Glucose Tolerance Test. In this test, they make you fast, drink this really sweet drink, and then test your glucose a 1/2 hour, an hour and two hours later. Oh, and they take a baseline fasting glucose level before you drink the stuff too.

As always, my fasting glucose was well below even pre-diabetic levels, but at the 1/2 mark, I was out of range too high, and then I came back in range at some point afterwards. (I'm still waiting for LabCorp to get their crap together two-weeks post-test and post my full results to my account so I can see them, but that's what the doc told me over the phone.) What the test didn't catch was that I became hypoglycemic at the 3 hour mark, but I expected that.

Anyways, what this test confirmed is that I do have a glucose metabolism issue with high spikes. Whether or not these issues could be responsible for the SFN, I don't know, but I'll be pursuing that. I have a glucose meter and will be experimenting and logging results just to see how prevalent these spikes are. I've not seen an endocrinologist yet, but that may be the next step. And for now, I'm treating myself as if I am diabetic and and am eating accordingly.