If you are under good control and your GP/practice nurse are well up on diabetes, then a hospital appointment may be unnecessary. But if you have other medical conditions too especially ones which necessitate steroids, or you struggle to get control (or if your practice nurse is as hopeless as mine!) then a specialist consultation is wise. You may just a need one or two appointments to get things stabilised and then return to your GP's care. Your GP can always phone a consultant for advice if s/he's stumped, though often I think the problem is they blame the patient rather than admit they don't have the answer. You can insist on a specialist referral if not happy with your GP's care.