If it is the C-peptide test it tells you something about how much insulin you produce.
High C-peptide is associated with T2, as T2's may produce lots of insulin.
Very low C-peptide is associated with T1, as in T1 the beta cells that produce insulin die.
Anything in between could be either T2 or early T1.
And then there are some other types of diabetes as well.
But I'm not sure that's the test they did of course.
Good luck, and let us know when you know more!