Patients unable to undergo insulin hypoglycaemia tests (for example, those with a history of epilepsy or ischaemic heart disease) can instead be given 1mg glucagon, subcutaneously. This causes a transient rise in blood glucose and, during the subsequent fall, ACTH and GH are released. Glucagon is a less-reliable stimulus than insulin, and in approximately ten per cent of patients, there is no rise in ACTH or GH levels, even in the presence of normal reserves of these hormones. Arginine infusion stimulates GH secretion and may be used to assess GH reserves in some cases.
