Hi fairy lights!
The general consensus is that with 1.5 your fasting is ok because ur still producing base insulin but u spike after meals, however, i am and always have been the opposite! My fasting levels are my worst usually and always sit between 7 and 8 mmol whereas my post prandial are usually always under 7.5 mmol. I would assume the difference between LADA and type 1 is the insulin production and so I agree with the others that the only way to test would be another c-peptide... Once you have no more detectable insulin I would assume they would class you as type 1, but, I have read a few medical journals where they have found evidence that there are more differences between type 1 and type 1.5 than that and so they are looking into it further. I would have posted links but I can't find them but one journal I read said that in patients with type 1.5 they found that beta cell regeneration could occur and that the immune system wasn't ALWAYS attacking the cells and so you can be up and down with regard to insulin requirements.... Most of these studies were done in Scandinavian countries, they tend to know and study diabetes a lot more than the UK unfortunately.....
Diagnosed with GD in 2010, Completely disappeared postpartum. Re-diagnosed December 2012 with type 1.5 diabetes, age 26, BMI 23 currently controlled by only Metformin, 500mg twice a day.