I'm another one who suspects you might be a slow onset Type 1 or LADA (Latent Automimmune Diabetes in Adults).
Just to clarify the diabetes diagnosis situation..... An HbA1c result of 48 or more gets you a diagnosis of diabetes. After that clinical signs such as age, BMI (Body Mass Index) poor diet, disordered eating may point towards Type 2 but there is no specific test done and it is an assumption based on how you present. Many HCPS (Health Care Professionals) are under the misunderstanding that Type 1 only exhibits in children and young adults, so if you are over 20 you must be Type 2 in their eyes, so they treat you with Type 2 medication. This is further complicated by the fact that Type 1 diabetes in later life often has a slower onset, so it may appear to respond to Type 2 meds and/or lifestyle changes but gradually needs stronger medication. I am quite sure there are a good number of Type 2 diabetics on insulin who are actually Type 1 but have never been properly tested.
As stated above, the tests which should indicate if you are Type 1 are C-peptide (which measures the amount of insulin you are producing) and GAD antibody test which looks for the antibodies produced by the immune system which attack the insulin producing beta cells in the pancreas and kill them which is the cause of Type 1 diabetes.
As
@leonS says, put them o the spot and ask them why they think you are Type 2 when you are not particularly overweight and relatively young and not responding to the routine Type 2 medication. Personally, I don't think they should be considering Trulicity before they have ruled out Type 1. You might have to push for a referral to a specialist diabetes clinic to get the appropriate testing done. Most diabetes nurses at GP practices have very limited training or knowledge of Type 1 diabetes and many GP are even less well informed, so you might need to be quite firm about asking for the tests and a referral. The tests mentioned can sometimes have results which are difficult to interpret which is why a consultant at a hospital clinic should be overseeing them and as stated one of them needs frozen within a very short space of time before being sent off to the lab in that state so most GP practices do not have the facilities for that or the onward transport of a frozen sample to an appropriate lab for testing and there are only a few in the country which do that testing, so again it needs to be handled by a department which have logistics in place for such sample storage and dispatch.
Sorry if that all sounds complicated but unfortunately with diabetes, you have to be your own expert and particularly with staff at GP practices, who often don't have enough knowledge, you have to do your homework and be prepared to fight your corner. Having the correct diagnosis is really important so that you get appropriate treatment, rather than them trying all sorts of drugs on you just in case they might work, because they have a blinkered approach to your diagnosis and haven't actually considered that you might be Type 1.
