I am not all that dissimilar than you @KimKat - other than the fact that I could not tolerate any of the oral meds my doctor had me try, so I take insulin only. Initially, my BG responded reasonably well to the orals, but other side effects stopped me from taking them. I was not overweight and I was quite active; however, I tested negative for antibodies, so despite a fairly low c-peptide (meaning I make relatively little insulin of my own), I was diagnosed as Type 2. Still, even without orals, I started on fairly low doses of insulin at the beginning. Over the past few years, though, I had to increase the doses to what I’m taking now. If I eat very low carb, I can use less insulin - but ONLY less bolus insulin (pre-meal insulin) – I still need the same basal insulin whether I eat a lot or a little - or nothing at all. The only thing that reduces that need is periods of more intense activity (For example, I’ll halve my basal insulin for an all-day bike ride).
As for why more injected insulin helps – I read about recent research that indicates that apart from “insulin resistance” (as in, cells needing more insulin present to absorb glucose), there’s a factor of “glucose sensitivity” (though I don’t think they called it that). Meaning, that it’s possible that even though your pancreas (and, perhaps, mine) doesn’t make enough insulin to support your basic needs, it can and does produce a lot more insulin when there is a LARGE amount of glucose present. That might explain why many Type 2’s - myself included - clearly need to take insulin for normal daily requirements and meals; however, when those REALLY BAD days happen - days when I go overboard with crab-consumption, like holidays, the highest numbers are still low compared to what a Type 1 might see, I have never seen higher than 340, for example. In part, because I try and avoid high BGs, but I’m not sure that this is the only reason. I haven’t done an experiment in a while, but a couple years ago, I took three days off of taking insulin and the highest my BG went to was 280. I did not low-carb it those days, either (though also didn’t go crazy). Could be that as my BG approach 300, my pancreas finally “notices” and makes more insulin. I suppose I should go get a c-peptide test with my BG high one of these days to see what it shows.
By the way C-peptide is a product of insulin production. The betas cells produce something called 'proinsulin" that splits and becomes insulin and c-peptide. It’s unreliable to test for insulin levels, as insulin tends to get used/depleted very quickly once it enters the blood stream. C-peptide does not get used up the same way and instead gets eliminated eventually from the the blood, so, since it remains a bit longer, it is a more reliable way to test for the level and efficiency of insulin production.
Ask all the questions! We ALL have too many questions