Endocrine Abstracts

Background: Hypothalamus pituitary adrenal axis (HPA) dysfunction is associated with serious morbidity and mortality. Its symptoms can be non-specific. Objective diagnosis depends on clinical suspicion and confirmed on assessment of early morning cortisol or dynamic assessment of cortisol secretion. The cosyntropin or short synacthen test (SST) has emerged as the most common test to assess the HPA. The insulin stimulation test (IST) is the traditional ‘gold standard’ test for this, but is less favored because it is less convenient to perform, and contraindicated in patients with cerebral and cardiac pathologies.

Cases: We report 4 patients who had normal SST results at first, but continued to remain symptomatic. They then had ISTs which demonstrated cortisol deficiency. They were then commenced on replacement hydrocortisone after which their symptoms markedly improved.

Conclusion: The short synacthen test is more practical compared to the insulin stimulation test, and it remains the favored test to assess the HPA axis periodically. However, clinicians should have a high index of suspicion when symptoms suggesting adrenal insufficiency persist despite a normal SST.