Welcome to the forum
@Liz Gale
Sorry to hear your well-established diabetes management system isn’t working as you expect at the moment.
Sounds like you are being methodical, and doing all the right things. If those haven’t worked, and if this has been going on for long enough that it seems unlikely to be illness / increased stress etc then I can see that it would be very frustrating.
Do you have any leftover needles at the previous length? What did you use previously? On injections I never wen’t shorter than 8mm (I’m also fairly slim), but I know many these days get on perfectly well with 6’s or 4’s. If that’s a change in insulin delivery… perhaps your body absorbs differently from that depth? (I have no evidence for this, it’s jyst a hunch, and in your shoes I’d fancy going back to the previous length to rule that physical factor out.
Statins have been known to raise BG in some people, but 20mg is still a fairly low dose (it was what I was started on) so I’m not sure how much if any impact another 10mg a day would have.
How low carb is your menu? And have you been reducing carbohydrate intake to try to reduce doses? Below a certain carb intake, some people see a rise in insulin resistance, which resolves when they add more carbs back in. It’s a bit counterintuitive, but we have members here who have resolved their insulin resistance by adding more carbs back in.
Another possibility may simply be age? As we get older our BGs tend to rise, along with HbA1c? So perhaps a small part of the changes you are observing are just a natural part of the aging process?
Hope you are able to find a fix.
Would you experiment with a different rapid insulin in case your body has ‘gone off’ NR? Either Humalog, Apidra, or one of the newer ultra-fast insulins like Lyumjev or Fiasp?