My gad and c peptide tests came back last week, after being on insulin treatment as they assumed I was type 1. Turns out I'm type 2 and I'm currently being weened off of the insulin.
I would be dubious as to whether a negative gad test and a positive cpeptide test mean you are type 2.
A positive GAD test confirms type 1. But a negative GAD test doesn't confirm anything. About 25% of type 1 diabetics are GAD negative.
A recently diagnosed type 1 diabetic will be honeymooning and producing their own insulin. In a type 1 autoimmune attack on the insulin producing beta cells they don't all die off in one shot - it can take a while for the immune system to kill off all the beta cells. Especially with type 1 diabetics diagnosed later in life then the honeymoon period can be longer and can occasionally be strong enough to cease insulin for a short time.
Unless there's other clinical things going on it might be a little early to count on definitely not being insulin dependant.
@pearceam /
@minx27 of course it's possible to be misdiagnosed type 1 when you are actually type 2. But there aren't any certain tests that can confirm one way or another. As above, a positive GAD test will confirm you are definitely type 1, but a negative GAD test doesn't meant you aren't type 1. If you clinical presentation on diagnosis was sudden onset, weight loss, blood sugar very high (30+) and ketones, that point to type 1. In addition, there is a genetic component to type 1, if you have daughter with type 1 that increases your risk of type 1. I know trial net will test anyone under 40 with first degree relatives with type 1 for the antibodies - so if a child is diagnosed they will test the siblings and the parents, like a strange looking backwards kind of testing. That's because we don't know what triggers the autoimmune disease to be active, but we do know the trigger can happen at any age.
So I guess if you end up with a negative GAD test you will, unfortunately, be left kind of uncertain to the diabetic type. But if you need insulin, you need insulin regardless of type so you would have to keep a close eye on blood sugar and keep in contact with your DSN and consultant to check your response to insulin and you insulin requirements seem to be as expected.