After the assessment of basal hormone levels, dynamic tests are used to assess hormonal reserves. GH and ACTH secretion in most cases can be tested using the insulin hypoglycaemia test (Fig. 2.22), where insulin is given intravenously. Hypoglycaemia causes symptoms of neuroglycopenia, such as sweating and tachycardia, with concomitant ACTH and GH release. Provided that adequate hypoglycaemia is induced (blood glucose ┬▓2.2mmol/l), cortisol levels should rise to 580nmol/l (21┬╡g/100ml) or above, and GH levels to above 20mu/l (10ng/ml). If these levels are not achieved, the patient is deficient in either ACTH or GH.
