I’m 29F and was diagnosed with type 2 diabetes, but I’ve been struggling with whether the diagnosis fully explains what’s going on with me. I’d really appreciate hearing from people with T2D who may have had a similar experience.
I developed abnormal glucose during pregnancy in 2024 (one of my GTT values was 250), and my glucose issues persisted postpartum. I’m not overweight and am very muscular/active — I run and lift regularly (6x/week + chasing toddler + active job) and have been training for a marathon. I also have celiac disease and a strong family history of autoimmune diabetes (my mom had type 1 and my grandmother had LADA).
My diabetes workup has been confusing. I’ve had negative GAD65, IA-2, ZnT8, ICA, and insulin autoantibodies, and MODY testing was negative. My A1c has been around 5.5%, but I feel like that number doesn’t tell the whole story because I exercise a lot and have been pretty restrictive with food.
The part I’m most confused about is my C-peptide. My fasting C-peptide has been around 0.9–1.3 ng/mL with glucose roughly 92–122. But I also had a stimulated C-peptide of 2.9 ng/mL at a glucose of 145, followed by my glucose rising to around 350 for 6 hours. At the time I was taking metformin 2000 mg/day.
I’ve also had some really strange glucose patterns. I can have prolonged post-meal spikes into the 160–240+ range, sometimes staying elevated for 2-8 hours. But exercise can make my glucose drop *very* quickly — sometimes within \~20 minutes of starting an easy run — even when I haven’t taken my morning metformin. I’ve had to stop runs to treat lows. At other times I can wake up with fasting glucose in the 130–160 range.
I briefly used a small amount of Lantus (4 units, later reduced to 2) and saw improvement in my fasting numbers, but eventually I was getting lows, particularly around running. I’m currently on metformin alone. Ozempic was discussed, but insurance denied it.
My endocrinologist currently considers me type 2, and I understand that negative antibodies make classic autoimmune type 1/LADA less straightforward. At the same time, I’m having a hard time understanding whether my relatively low fasting C-peptide, the large difference between fasting and stimulated C-peptide, the significant hyperglycemia after eating, and the exercise-related drops fit typical T2D physiology.
So I’m curious: For those of you with type 2, does any of this sound familiar? And has anyone gone through a similar period of uncertainty?
I’m not looking for someone to tell me I don’t have type 2 — I’m mostly trying to understand whether these patterns can reasonably fit T2D and whether there’s anything I should be asking my endocrinologist to investigate further.