Table 2 Evaluating the utility of the insulin stress test (ITT), glucagon stimulation test (GST) and the short synacthen (corticotropin) test (SST)

Insulin tolerance test

1. Very high sensitivity

2. Assessment of ACTH and GH axes

1. Requires experience and medical supervision

2. Labour intensive and time consuming

3. Contraindicated in ischemic heart disease and seizure disorders

4. Hypoglycaemia not always achieved

5. Unpleasant for patients

Glucagon stimulation test

1. Assessment of ACTH and GH axes

2. Can be used in cases where ITT is contra-indicated

1. Nausea in up to 30 % cases

2. False positive (fail) rate 8 %

3. Time consuming

Short synacthen (corticotropin) test

1. Simple and well tolerated

2. Can be used in cases where ITT is contraindicated

3. Reliably excludes clinically significant ACTH deficiency

1. Does not assess GH axis

2. Unreliable if recent pituitary insult e.g. surgery, apoplexy

3. Theoretical concerns of false negative (pass) rate (when compared with ITT)