There is a clear discrepancy between the results of the two tests at different cortisol cut-off levels. The ACTH stimulation test is not reliable for assessing the HPA axis in patients with pituitary disease and the insulin stress test remains the standard method.

Insulin-induced hypoglycaemia causes similar degrees of significant hypokalaemia in patients with normal pituitary function and in those with GH deficiency, either alone or in combination with other pituitary hormone deficiencies. Therefore, insulin-induced hypoglycaemia does not appear to be associated with any greater risk of hypokalaemia in hypopituitary adults with GHD compared to those with normal anterior pituitary function.