Testing for Adrenal Insufficiency


Question

I am a first year Internal Medicine Resident at Rio de Janeiro, Brazil. In my ward there is a patient with Paracoccidioidomycosis which is a deep mycosis present predominantly in South American countries (around 80% of the cases report described in Brazil). Current recommendations support the screening for adrenal insuficciency in all patients since the adrenal gland is the third organ most involved in this disease. Our patient has severe symptomatic disease in the lungs, oral cavity and larynx but has no symptoms/signs or laboratory evidence of Addison's Disease (electrolyte disturbances, etc). Unfortunately our poor public resources do not allow us to use the high-dose short synacthen test (SST). My question is: in the absence of the SST what is the applicability of the Insulin Tolerance Test in diagnosing subclinical primary adrenal insufficiency or even manifest disease? Is it a valid test? And the other question is: is the low-dose SST a reliable test for the diagnosis of primary adrenal insufficiency or should it be reserved only for diagnosing secondary and tertiary adrenal failure? I have read this topic in a few places and I have not things clear in my mind yet. Andre Faria, MD

Response

The standard ACTH test is the best. The low dose ACTH would not be helpful. It should be used in research studies looking for subtle changes in adrenal function. The ITT is as good as the standard test but has risks. You might also contact Prof. Ayrton Moreira, University of Riberao Preto, on this topic. Best regards!

Dr George Chrousos